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ROBERTO RAFFAELI
Professore Associato
Dipartimento di Scienze e Metodi dell'Ingegneria
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Pubblicazioni
2024
- A method for the assessment and compensation of positioning errors in industrial robots
[Articolo su rivista]
Ferrarini, S.; Bilancia, P.; Raffaeli, R.; Peruzzini, M.; Pellicciari, M.
abstract
Industrial Robots (IR) are currently employed in several production areas as they enable flexible automation and high productivity on a wide range of operations. The IR low positioning performance, however, has limited their use in high precision applications, namely where positioning errors assume importance for the process and directly affect the quality of the final products. Common approaches to increase the IR accuracy rely on empirical relations which are valid for a single IR model. Also, existing works show no uniformity regarding the experimental procedures followed during the IR performance assessment and identification phases. With the aim to overcome these restrictions and further extend the IR usability, this paper presents a general method for the evaluation of IR pose and path accuracy, primarily focusing on instrumentation and testing procedures. After a detailed description of the experimental campaign carried out on a KUKA KR210 R2700 Prime robot under different operating conditions (speed, payload and temperature state), a novel online compensation approach is presented and validated. The position corrections are processed with an industrial PC by means of a purposely developed application which receives as input the position feedback from a laser tracker. Experiments conducted on straight paths confirmed the validity of the proposed approach, which allows remarkable reductions (in the order of 90%) of the orthogonal deviations and in-line errors during the robot movements.
2024
- Empirical Characterization of Track Dimensions for CMT-Based WAAM Processes
[Relazione in Atti di Convegno]
Lettori, J.; Raffaeli, R.; Bilancia, P.; Borsato, M.; Peruzzini, M.; Pellicciari, M.
abstract
Wire Arc Additive Manufacturing is based on a welding torch usually attached to a robotic arm with multiple degrees of freedom. Robot-based additive manufacturing allows non-planar and non-uniform thickness layers to be deposited where the slices have non-constant thickness. Thus, in addition to the motion settings, fine regulations of the welding parameters become necessary to obtain variable bead heights in the same slice. This paper aims to evaluate the user-accessible welding parameters’ influence on the deposited material’s dimensions during continuous Cold Metal Transfer (CMT) and its variant named CMT Cycle Step. In particular, the height and width of beads are investigated by varying the travel speed and the wire-feed rate (continuous CMT), as well as the size of the droplets by varying the number of CMT cycles and the wire-feed rate (CMT Cycle Step). In particular, the characterization of the material deposited during the CMT Cycle Step is not deeply studied in the literature. The experimental specimens are measured and the obtained values are numerically processed to yield empirical formulas that link the dimensions of the deposited material with the selected process parameters. The results show that CMT Cycle Step is more stable than continuous CMT, which confirms its higher suitability for accurate manufacturing.
2024
- Implementation and virtual assessment of a non-uniform cylindrical slicing algorithm for robot-based additive manufacturing
[Articolo su rivista]
Lettori, J.; Raffaeli, R.; Borsato, M.; Peruzzini, M.; Pellicciari, M.
abstract
Robot-based additive manufacturing (RBAM) is an additive manufacturing (AM) technology powered by robotic manipulators. The material is deposited from a nozzle onto an initial surface, adding successive layers on top of each other and pouring it along multiple directions (multiaxial deposition) thanks to the dexterity of robots, often of the anthropomorphic type. Furthermore, it is possible to manufacture layers of non-uniform thickness, thus obtaining non-parallel and non-planar layers. In particular, RBAM can be implemented to realize revolved parts with protruding portions. Cylindrical or conical slicing algorithms have been devised to process the sub-volumes, reducing the number of layers and the need for support structures. In this context, the paper presents a novel algorithm for non-uniform cylindrical slicing that processes sub-volumes connected to a cylindrical shape. The specific contribution of the work is an algorithm that moves from a curved slicing to increase the adhesion between the central body and the first layer, and it relaxes the curvature in the subsequent layers, arriving, if possible, at a planar slicing. The algorithm considers robots' intrinsic constraints on movements. Planar paths are better approximated than non-planar ones since they prevent the robot from constantly changing the nozzle angle, thus increasing the overall quality of the printing. The algorithm is applied to four test cases and compared with other slicing approaches using numeric indices, objectivating its strengths and limits.
2024
- Non-Uniform Planar Slicing for Robot-Based Additive Manufacturing
[Articolo su rivista]
Lettori, J.; Raffaeli, R.; Borsato, M.; Pellicciari, M.; Peruzzini, M.
abstract
Planar slicing algorithms with constant layer thickness are widely implemented for geometry processing in Additive Manufacturing (AM). Since the build direction is fixed, a staircase effect is produced, decreasing the final surface finish. Also, support structures are required for overhanging portions. To overcome such limits, AM is combined with manipulators and working tables with multiple degrees of freedom. This is called Robot-Based Additive Manufacturing (RBAM) and it aims to increase the manufacturing flexibility of traditional printers, enabling the deposition of material in multiple directions. In particular, the deposition direction is changed at each layer requiring non-uniform thickness slicing. The total number of layers, as well as the volume of the support structures and the manufacturing time are reduced, while the surface finish and mechanical performance of the final product are increased. This paper presents an algorithm for non-uniform planar slicing developed in Rhinoceros and Grasshopper. It processes the input geometry and uses parameters to capture manufacturing limits. It mostly targets curved geometries to remove the need for support structures, also increasing the part quality.
2024
- Preliminary Design of an Automatic Palletizing System During the Pre-sales Stage
[Relazione in Atti di Convegno]
Guidetti, E.; Bilancia, P.; Raffaeli, R.; Pellicciari, M.
abstract
2023
- Advanced virtual prototyping of robotic cells using physics-based simulation
[Articolo su rivista]
Raffaeli, R.; Neri, F.; Peruzzini, M.; Berselli, G.; Pellicciari, M.
abstract
Robotic cells are complex mechatronic systems whose final performance is determined by the interaction of the control logics with the mechanical behavior of the process. In this context it is fundamental to develop engineering methods and tools for the virtual prototyping of the cells that emulate both contributions. With such mechatronic digital models, it would be possible to replicate the real behavior of the systems and to optimize the cell productivity, up to building complete digital twins. This paper proposes an engineering method to develop realistic Virtual Prototypes of robotic cells including their geometry, operating logic, performance, and physical behavior. A case study on a robotic cell composed of two anthropomorphic robots for the flexible process of automatic assembly of industrial parts is presented to demonstrate the approach.
2023
- An Approach for Volume Decomposition in Robot-Based Additive Manufacturing
[Articolo su rivista]
Lettori, J.; Raffaeli, R.; Borsato, M.; Pellicciari, M.; Peruzzini, M.
abstract
Robot-Based Additive Manufacturing (RBAM) combines material deposition nozzles and robotic manipulators to increase the flexibility of cartesian/delta Additive Manufacturing (AM) systems. RBAM overcomes the traditional limit given by the planarity of the manufacturing layer and allows variable slice thickness to be realized. Also, RBAM enables the deposition of the material in multiple directions. In this context, volume decomposition algorithms are implemented to split a solid into several sub-volumes. Each sub-volume is sliced according to an optimal direction to perform support-free manufacturing and to avoid tool collisions. A novel algorithm for the volume decomposition of a given input geometry is presented. In particular, it allows several planar separation surfaces to be computed that are used to split a general input shape. The surfaces are defined by analyzing overhangs according to an initial slicing direction. The normal of the surfaces identifies the slicing direction of the related sub-volumes. The algorithm steps are iterated to reach the complete removal of overhangs. The approach is tested in some case studies to evaluate its applicability.
2023
- An AR Tool to Support Warehouse Operations in the Context of Industry 4.0
[Relazione in Atti di Convegno]
Casciotta, E.; Khamaisi, R. K.; Raffaeli, R.; Peruzzini, M.
abstract
Augmented Reality (AR) is one of the leading technologies of the Industry 4.0 revolution, offering innovative interfaces to promote the diffusion of digital contents into industrial processes, thanks to flexible and robust solutions and cost-effective devices. In this context, this paper explores the adoption of AR in industrial logistics where several open issues still discourage its effective use in everyday scenarios. After a review of objectives, approaches and technics of AR integration in logistics operations, the paper presents a framework to identify goods in a warehouse, retrieve data relative to the package, display info to the user to drive operations. The approach aims at easing and speeding up the activity of the warehouseman to identify goods, check the relative information and to put each good on the correct shelf. A prototypal application was developed within the Unity platform and integrated with the company ERP system to manage data on the products and retrieve images of the identification labels. A real use case involving a primary company producing agricultural tractors is proposed to test usability of the prototype. Results showed that the developed application allows relevant benefits in terms of process effectiveness, error prevention, aiming at reducing the operator mental workload.
2023
- An Overview of Industrial Robots Control and Programming Approaches
[Articolo su rivista]
Bilancia, Pietro; Schmidt, Juliana; Raffaeli, Roberto; Peruzzini, Margherita; Pellicciari, Marcello
abstract
Nowadays, manufacturing plants are required to be flexible to respond quickly to customer demands, adapting production and processes without affecting their efficiency. In this context, Industrial Robots (IRs) are a primary resource for modern factories due to their versatility which allows the execution of flexible, reconfigurable, and zero-defect manufacturing tasks. Even so, the control and programming of the commercially available IRs are limiting factors for their effective implementation, especially for dynamic production environments or when complex applications are required. These issues have stimulated the development of new technologies that support more efficient methods for robot control and programming. The goal of this research is to identify and evaluate the main approaches proposed in scientific papers and by the robotics industry in the last decades. After a critical review of the standard IR control schematic, the paper discusses the available control alternatives and summarizes their characteristics, range of applications, and remaining limitations.
2023
- Automatic Assembly Precedence Detection in Axisymmetric Products
[Articolo su rivista]
Bonino, B.; Giannini, F.; Monti, M.; Raffaeli, R.
abstract
Assembly sequence planning starting from CAD models turned out to be a relevant task in the industrial manufacturing field. To have a successful assembly sequence, the relations between the assembly's parts and the possible interferences during the assembly operations deserve to be investigated. In particular, the collision analysis is the phase in which the movement of each part along some directions is evaluated to assess if it is obstructed by any of the other parts, and according to which the precedence matrix is computed. A lot of work has been done to address the problem, however, existing algorithms need to be improved yet. Among the open issues, the following three result to be the most challenging: the combinatorial explosion of the problem complexity, the limited choice of the assembly directions, and the engineering meaning of parts that is not taken into account, or it is manually given in input by experts. In this paper, an automatic assembly sequence planning approach is introduced. The focus is on the collision detection and precedence analysis for engineering meaningful subassemblies, namely the axisymmetric. Information automatically extracted relying on geometric processing and engineering knowledge, such as parts features and semantic interpretation of mechanical components, is first exploited to identify the subassemblies and, then, to choose the feasible assembly direction, as well as to treat fasteners and deformable parts in a more realistic way. An industrial CAD model of a gearbox is selected as case study to illustrate the approach, also emphasizing the importance of axisymmetric subassemblies.
2023
- Exploring the Adoption of UX-Driven Approaches to Design Industrial PLC User Interfaces
[Relazione in Atti di Convegno]
Peruzzini, M.; Valentini, L.; Tutarini, A.; Bilancia, P.; Raffaeli, R.
abstract
Modern automated production systems (e.g., automatic machines, assembly lines, robotic cells) are typically governed by dedicated industrial controllers, such as Programmable Logic Controllers (PLCs), which supervise and coordinate the process by exchanging I/O data, sequencing tasks or triggering actions with the involved automation modules. Different solutions have been developed to offer an intuitive Human-Machine Interface (HMI) programming to the user, based on PLC HMI editors, according to vendor-specific programming languages. However, in the current industrial practice, user interfaces (UIs) are usually generated by software specialists and far from adopting any user-centered approach. As a result, the generated UIs are poorly usable and hard to understand for end users (e.g., operators), diverging from Industry 5.0 ideas that put humans at the center of the modern factory design. In this context, the present paper aims at exploring how the adoption of User eXperience (UX) driven approaches can benefit the design of industrial PLC UIs, reflecting on advantages and limits, and transdisciplinary perspectives. A case study utilizing Beckhoff TwinCAT as PLC environment and Adobe XD as UX design tool is examined and discussed.
2023
- Geometric Analysis of Product CAD Models to Support Design for Assembly
[Relazione in Atti di Convegno]
Bonino, B.; Giannini, F.; Monti, M.; Raffaeli, R.; Berselli, G.
abstract
Design For Assembly (DFA) aims at improving product design facilitating assembly phases via the application of evaluation metrics and design guidelines. However, DFA analyses are usually performed manually and the adoption of supporting tool is poor. This paper investigates the application of algorithms allowing to extract from CAD assembly models the required data to perform automated DFA analyses, thus providing a tool to support designers’ everyday works. In particular, attributes from geometric feature recognition algorithms, solids properties and assembly parts’ semantics are leveraged and mapped to the parameters required to accomplish DFA evaluations. The proposed approach is illustrated on a 3D printer for home use. At first, a manual DFA analysis has been performed on the product identifying product BOM, components properties, assembly cycle and times according to models in the literature. Then, the CAD model of the printer has been processed with some geometric algorithms to verify the possibility to extract the required data to be used as input to the DFA analysis. The test case has demonstrated the feasibility of the approach, even if some design considerations and improvement directions still need the critical evaluation of the designer.
2023
- Path Approximation Strategies for Robot Manufacturing: A Preliminary Experimental Evaluation
[Relazione in Atti di Convegno]
Bigliardi, Matteo; Bilancia, Pietro; Raffaeli, Roberto; Peruzzini, Margherita; Berselli, Giovanni; Pellicciari, Marcello
abstract
Industrial Robots (IRs) are increasingly adopted for material subtraction or deposition functions owing to their advantages over machine tools, like cost-effectiveness and versatility. Unfortunately, the development of efficient robot manufacturing processes still faces unsolved issues related to the IRs poor positioning accuracy and to the tool path generation process. Novel engineering methods and tools are needed for CAD based programming of accurate paths and continuous robot motions to obtain the required manufacturing quality and tolerances. Within this context, to achieve smoothness along the tool path formed by linear G-code segments, the IR controllers’ approximation strategies, summarily reported in the manufacturer’s manuals, must be considered. The aim of this paper is to present the preliminary work carried out to identify the approximation algorithms of a Kuka IR when executing linear moves. An experimental study is conducted by varying the controller settings and the maximum translational velocity. The robot behavior has been acquired thanks to the controller tracing function and then processed to yield relations readily employable for the interpretation of G-Code commands and the subsequent generation of proper robot motion instructions. The obtained formulas allow to accurately predict the robot geometric path and kinematics within the corner transition between two linear segments.
2023
- Shape and Context-Based Recognition of Standard Mechanical Parts in CAD Models
[Articolo su rivista]
Bonino, B.; Giannini, F.; Monti, M.; Raffaeli, R.
abstract
The work here presented is part of a wider research project aimed at extracting and using in industrial applications high level semantic information from 3D product models that are described by means of their boundary representation (B-rep). The specific focus of the paper is the recognition among the components of the CAD model of an assembly of those belonging to some categories of standard parts largely employed in mechanical industry. The knowledge of these components is crucial to understand the structure of mechanical products as they have specific meaning and function. Standard parts follow international standard in shape and dimensions, and also typical mounting schemes exist concerning their use in the product assembly. These distinctive features have been exploited as a starting point to develop a multi-step recognition algorithm. It includes a shape-based and a context-based analysis both relying on the geometric and topological analysis of a CAD model. As already anticipated by Voelcker in his visionary ability to anticipate open challenges, the shape of an object alone is not enough to understand its function. Therefore, context assessment becomes crucial to validate the recognition given by the shape-based step. It allows to uniquely recognize components in mechanical CAD models, by confirming correct results, refusing the false positives, as well as choosing the correct one when the assignment is multiple.
2022
- A Framework for Hybrid Manufacturing in Robotic Cells
[Articolo su rivista]
Lettori, Jacopo; Raffaeli, Roberto; Peruzzini, Margherita; Pellicciari, Marcello
abstract
Compared to other additive technologies, Wire and Arc Additive Manufacturing (WAAM) offers high deposition rates, flexibility and a larger build volume as well as reduction of material waste. WAAM can be combined with a subtractive technology in hybrid robotic cells to further increase the application scope, thus producing products with improved surface finish where needed. However, there are some open issues that limit this process. So, the main goal of this paper is to review current research developments and provide a framework aimed at manufacturing parts by hybrid cells. A procedure is defined which moves from the evaluation of the designed shapes, their analysis to identify a proper manufacturing sequence until the elaboration of the instructions for the cell automaton controllers. Main WAAM issues are outlined to identify main research directions, and a test case is presented to highlight the process phases
2022
- A review of geometry representation and processing methods for cartesian and multiaxial robot-based additive manufacturing
[Articolo su rivista]
Lettori, J.; Raffaeli, R.; Bilancia, P.; Peruzzini, M.; Pellicciari, M.
abstract
Nowadays, robot-based additive manufacturing (RBAM) is emerging as a potential solution to increase manufacturing flexibility. Such technology allows to change the orientation of the material deposition unit during printing, making it possible to fabricate complex parts with optimized material distribution. In this context, the representation of parts geometries and their subsequent processing become aspects of primary importance. In particular, part orientation, multiaxial deposition, slicing, and infill strategies must be properly evaluated so as to obtain satisfactory outputs and avoid printing failures. Some advanced features can be found in commercial slicing software (e.g., adaptive slicing, advanced path strategies, and non-planar slicing), although the procedure may result excessively constrained due to the limited number of available options. Several approaches and algorithms have been proposed for each phase and their combination must be determined accurately to achieve the best results. This paper reviews the state-of-the-art works addressing the primary methods for the representation of geometries and the subsequent geometry processing for RBAM. For each category, tools and software found in the literature and commercially available are discussed. Comparison tables are then reported to assist in the selection of the most appropriate approaches. The presented review can be helpful for designers, researchers and practitioners to identify possible future directions and open issues.
2022
- Accurate transmission performance evaluation of servo-mechanisms for robots
[Articolo su rivista]
Bilancia, Pietro; Monari, Luca; Raffaeli, Roberto; Peruzzini, Margherita; Pellicciari, Marcello
abstract
2022
- Engineering Method and Tool for the Complete Virtual Commissioning of Robotic Cells
[Articolo su rivista]
Raffaeli, Roberto; Bilancia, Pietro; Neri, Federico; Peruzzini, Margherita; Pellicciari, Marcello
abstract
Intelligent robotic manufacturing cells must adapt to ever-varying operating conditions, developing autonomously optimal manufacturing strategies to achieve the best quality and overall productivity. Intelligent and cognitive behaviors are realized by using distributed controllers, in which complex control logics must interact and process a wide variety of input/output signals. In particular, programmable logic controllers (PLCs) and robot controllers must be coordinated and integrated. Then, there is the need to simulate the robotic cells’ behavior for performance verification and optimization by evaluating the effects of both PLC and robot control codes. In this context, this work proposes a method, and its implementation into an integrated tool, to exploit the potential of ABB RobotStudio software as a virtual prototyping platform for robotic cells, in which real robots control codes are executed on a virtual controller and integrated with Beckhoff PLC environment. For this purpose, a PLC Smart Component was conceived as an extension of RobotStudio functionalities to exchange signals with a TwinCAT instance. The new module allows the virtual commissioning of a complete robotic cell to be performed, assessing the control logics effects on the overall productivity. The solution is demonstrated on a robotic assembly cell, showing its feasibility and effectiveness in optimizing the final performance.
2022
- Enhancing Product Semantics Understanding Through Automatic Part Type Recognition in CAD Assembly Models
[Articolo su rivista]
Bonino, Brigida; Giannini, Franca; Monti, Marina; Raffaeli, Roberto
abstract
Focus of this work is the recognition of the standard parts contained in a CAD
assembly model, with the aim of enhancing the model semantics. Standard parts are components
typically used in mechanical industry, which have a specic engineering meaning and
follow international standards. In particular eight categories of standard parts are considered,
i.e. screws, nuts, O-ring, washers, circlips,keys, studs and pins. The provided algorithm relies
on the geometric and topological analysis of the CAD model parts. A part is assigned to one
of the categories if it satises the geometric requirements extracted for that specic category,
based on engineering knowledge and design rules. In addition, if a part is recognized
as standard part, besides the class of membership, further information is provided as result,
namely its engineering dimensions.
2022
- Systematic assessment of simulation software for assembly lines in Industry 4.0 context
[Articolo su rivista]
Lettori, Jacopo; Borsato, Milton; Raffaeli, Roberto; Pellicciari, Marcello; Peruzzini, Margherita
abstract
Nowadays, the layout, tasks, and work sequences of assembly lines are designed according to several Design Principles (DPs) related to Industry 4.0 (I4.0). I4.0 is a manufacturing process revolution that includes innovative technologies and new paradigms among systems and operators. A vast collection of simulation software can be used to evaluate I4.0assembly lines. In this context, the paper aims to provide a framework for guiding the assessment of simulation software in the context of I4.0assembly lines. First, process requirements are evaluated and mapped to select DPs, prioritized according to design goals by an analytical hierarchy process. Then, suitable simulation software is selected accordingly, and the virtual model is designed. Finally, the possibility of the software providing meaningful elaborations for the selected DPs is assessed. The framework was applied to a prototypal I4.0assembly line composed of automated logistic systems, cobots, and vision systems to guide the execution of tasks. The assembly line has been modeled in Siemens Process Simulate. The functionalities of this software have been analyzed according to the defined DPs.
2022
- Transdisciplinary Evaluation of Simulation Software for Industry 4.0 Assembly Lines
[Relazione in Atti di Convegno]
Lettori, Jacopo; Borsato, Milton; Raffaeli, Roberto; Pellicciari, Marcello; Grandi, Fabio; Peruzzini, Margherita
abstract
Industry 4.0 is driving the revolution of manufacturing processes by combining innovative technologies and new interaction paradigms among systems and operators. In particular, the layout, tasks and work sequences of assembly lines are designed according to several transdisciplinary Design Principles (DPs), such as process efficiency, product quality, ergonomics, safety and operators’ workload. A large variety of simulation software can be employed for evaluations. However, the related ability to assess multidisciplinary factors must be evaluated. The paper aims to provide a framework for guiding the assessment of simulation software in the context of Industry 4.0 assembly lines. Process requirements are first analyzed and mapped to select DPs, prioritized according to design goals by an analytical hierarchy process. Then, suitable simulation software is determined accordingly, and the virtual model is realized. Finally, the possibility of the software to provide meaningful elaborations for the selected DPs is assessed. The framework has been tested on a prototypal Industry 4.0 assembly line composed of automated logistic systems, cobots and systems to guide the execution of tasks. The line has been modeled in Siemens Process Simulate, analyzing the completeness and appropriateness of the functionalities of this software according to the defined DPs.
2022
- Trends in Human Factors Integration for the Design of Industry 4.0
[Relazione in Atti di Convegno]
Grandi, F.; Peruzzini, M.; Raffaeli, R.; Pellicciari, M.
abstract
The fourth industrial revolution is evolving the machines as well as the abilities of people working in the factories. Human roles and tasks are changing, moving from highly physical tasks to decision-making and high-precision activities, asking for different competencies and creating new types of interactions with machines. This paper reviews the design and engineering methods for the inclusion of human factors in modern companies. Human factor integration (HFI) can play a key role in the design of factories with a great impact on social aspects and global process sustainability. The paper proposes a systematic view of the main tools to design human-centered industrial processes, with a specific focus on manufacturing, and discusses trends to achieve and effective HFI.
2022
- Virtual Prototyping as a Supporting Tool for the Design of Complex Robotic Cells
[Relazione in Atti di Convegno]
Raffaeli, R.; Neri, F.; Peruzzini, M.; Berselli, G.; Pellicciari, M.
abstract
The fourth industrial revolution is characterized by flexible production systems that can respond to the demand for high variability and customization of the product. To maintain the efficiency of the production process, automated and flexible solutions are mandatory. This paper describes an approach to design Virtual Prototypes of robotic cells and support designer in the definition and simulation of the manufacturing system. The identified model is capable of replicating the performance of the cell under different aspects in a holistic manner: geometry, operating logic, performance, and physical behavior. The design approach is demonstrated on a robotic cell composed of two anthropomorphic robots for the flexible process of automatic assembly of mechanical parts. The resulting model proves to be straightforward, accurate and complete.
2021
- A heuristic approach to detect CAD assembly clusters
[Relazione in Atti di Convegno]
Bonino, B.; Raffaeli, R.; Monti, M.; Giannini, F.
abstract
Mechanical assemblies are very complex structures, made of many parts of various shapes and sizes with different usages. Consequently, it is challenging to manage them during all the manufacturing processes, from the design to the assembly and the recycling. Aiming to simplify the assembly structure and reduce the number of parts to deal with simultaneously, in literature many works exist on subassemblies identification starting from the CAD assembly model. However, the methods provided loose sight of many details associated with the parts, as well as the fact that the treated model represents a real mechanical assembly which respects precise engineering rules. At this regard, this work introduces a novel methodology to detect meaningful clusters in CAD assembly models. The logic applied relies on engineering knowledge, both of mechanical assemblies' components and of assembling techniques, and on the leveraging of the semantics of components. In particular, referring to general design rules, we have identified some heuristics to exploit to partition the assembly into different types of clusters, such as the symmetry along an axis and the presence of fasteners or welds. It results that the assembly's parts are meaningfully grouped, considering, at the same time, their shape, functionality, and type of contact.
2021
- A Reference Framework to Combine Model-Based Design and AR to Improve Social Sustainability
[Articolo su rivista]
Grandi, Fabio; Khamaisi, Riccardo Karim; Peruzzini, Margherita; Raffaeli, Roberto; Pellicciari, Marcello
abstract
Product and process digitalization is pervading numerous areas in the industry to improve quality and reduce costs. In particular, digital models enable virtual simulations to predict product and process performances, as well as to generate digital contents to improve the general workflow. Digital models can also contain additional contents (e.g., model-based design (MBD)) to provide online and on-time information about process operations and management, as well as to support operator activities. The recent developments in augmented reality (AR) offer new specific interfaces to promote the great diffusion of digital contents into industrial processes, thanks to flexible and robust applications, as well as cost-effective devices. However, the impact of AR applications on sustainability is still poorly explored in research. In this direction, this paper proposed an innovative approach to exploit MBD and introduce AR interfaces in the industry to support human intensive processes. Indeed, in those processes, the human contribution is still crucial to guaranteeing the expected product quality (e.g., quality inspection). The paper also analyzed how this new concept can benefit sustainability and define a set of metrics to assess the positive impact on sustainability, focusing on social aspects.
2021
- A systematic approach for evaluating the adoption of additive manufacturing in the product design process
[Articolo su rivista]
Raffaeli, R.; Lettori, J.; Schmidt, J.; Peruzzini, M.; Pellicciari, M.
abstract
Additive Manufacturing (AM) technologies have expanded the possibility of producing unconventional geometries, also increasing the freedom of design. However, in the designer’s everyday work, the decision regarding the adoption of AM for the production of a component is not straightforward. In fact, it is necessary to process much information regarding multiple fields to exploit the maximum potential of additive production. For example, there is a need to evaluate the properties of the printable materials, their compatibility with the specific application, redesign shapes accordingly to AM limits, and conceive unique and complex products. Additionally, procurement and logistics evaluations, as well as overall costs possibly extending to the entire life cycle, are necessary to come to a decision for a new and radical solution. In this context, this paper investigates the complex set of information involved in this process. Indeed, it proposes a framework to support and guide a designer by means of a structured and algorithmic procedure to evaluate the opportunity for the adoption of AM and come to an optimal design. A case study related to an ultralight aircraft part is reported to demonstrate the proposed decision process.
2021
- Benchmark on Human Simulation Tools: A Transdisciplinary Approach
[Capitolo/Saggio]
Grandi, Fabio; Cavallaro, Sara; Peruzzini, Margherita; Raffaeli, Roberto; Pellicciari, Marcello
abstract
Nowadays companies have to face a competitive market that requires small volumes with a high level of customisations. In this context, assembly quality and timeliness is crucial. To guarantee flexibility and personalization, manual operations still have a crucial role for a lot of manufacturing sectors, so that workers' conditions and ergonomics are important factors to achieve a better product quality and overall cost reduction. Ergonomics evaluation in manufacturing is a challenging and expensive activity that requires a transdisciplinary approach, to merge technical and social sciences to finally have a consolidated and reliable evaluation. This paper compared two digital human simulations tools offered by Siemens Tecnomatix: Jack and Process Simulate. They were applied on the same industrial case study, concerning the hood assembly of an agricultural machine, comparing results on ergonomics reports and usage time. Results confirmed the advantage of adopting a digital approach to predict the human effort and ergonomic risk related to a series of tasks. At the same time, they showed the major strengths and weaknesses of the two analysed tools and defined how they can be successfully adopted by companies. The paper finally provided guidelines to drive companies in choosing the best tool according to their needs.
2021
- Design for Manufacturing and Assembly: A Method for Rules Classification
[Relazione in Atti di Convegno]
Favi, C.; Mandolini, M.; Campi, F.; Cicconi, P.; Raffaeli, R.; Germani, M.
abstract
The paper provides a method to acquire, process, and represent DfMA rules to help designers and engineers in the development of mechanical products compliant with manufacturing and assembly technology. This research work wants to define a general method able to link DfMA design guidelines (knowledge engineering) with geometrical product features that are available by the investigation of the 3D model. Numerical parameters of design features are related to design guidelines for the identification of manufacturing and assembly issues within the analysis of the 3D model.
2021
- Design of a Test Rig for Tuning and Optimization of High Dynamics Servo-Mechanisms Employed in Manufacturing Automation
[Articolo su rivista]
Belloni, Mattia; Bilancia, Pietro; Raffaeli, Roberto; Peruzzini, Margherita; Pellicciari, Marcello
abstract
The Industry 4.0 framework is pushing the manufacturing systems towards a zero-defect production based on robot technologies. The increasing level of automation in the production lines is raising new challenges for designers that must face the latest requirements in terms of product quality and power consumption. Among the multitude of components of the industrial plants, Servo-Mechanisms (SMs) play a crucial role and govern important performance indices of both robots and automatic machines. During the execution of high dynamics tasks, the SMs performance is influenced by many factors, including motion law, acting load, temperature and degradation. The development of accurate models aiming at predicting and optimizing the SMs behavior may not be practicable without extensive experimental activities. Owing to these considerations, this work introduces a novel test rig for the accurate characterization of industrial SMs. The rig is designed by combining the advantages of the existing prototypes. It is equipped with high precision sensors and an active loading system that enable to test the SM in various working conditions. Also, the rig modularity facilitates the installation of newly commissioned components and the execution of static and dynamic experiments. The paper mainly focuses on the rig mechanical design and components selection criteria.
2021
- Digital twin for smart manufacturing: a review of concepts towards a practical industrial implementation
[Articolo su rivista]
Lattanzi, Luca; Raffaeli, Roberto; Peruzzini, Margherita; Pellicciari, Marcello
abstract
Latest trends and developments in digital technologies have enabled a new manufacturing model. Digital systems can monitor, optimize and control processes by creating a virtual copy of the physical world and making decentralized decisions. This paradigm relies on the development of a digital counterpart, the Digital Twin, for each production resource taking part to the whole manufacturing process. Although real applications of Digital Twin may differ in technical and operational details, in the past years, a huge effort has been done in order to identify and define focal functionalities and properties, as well as main challenges for the practical implementation within real factories. This paper is intended to review and analyse principles, ideas and technological solutions of the Digital Twin vision for production processes focusing on the practical industrial implementation. The purpose of this document is therefore to summarize the current state-of-art on Digital Twin concepts, and to draw their up-to-date state for application and deployment in real industrial processes. Finally, future directions for further research are discussed.
2021
- How to include User eXperience in the design of Human-Robot Interaction
[Articolo su rivista]
Prati, E.; Peruzzini, M.; Pellicciari, M.; Raffaeli, R.
abstract
In recent years Human-Robot Collaboration (HRC) has become a strategic research field, considering the emergent need for common collaborative execution of manufacturing tasks, shared between humans and robots within the modern factories. However, the majority of the research focuses on the technological aspects and enabling technologies, mainly directing to the robotic side, and usually neglecting the human factors. This work deals with including the needs of the humans interacting with robots in the design in human-robot interaction (HRI). In particular, the paper proposes a user experience (UX)-oriented structured method to investigate the human-robot dialogue to map the interaction with robots during the execution of shared tasks, and to finally elicit the requirements for the design of valuable HRI. The research adopted the proposed method to an industrial case focused on assembly operations supported by collaborative robots and AGVs (Automated Guided Vehicles). A multidisciplinary team was created to map the HRI for the specific case with the final aim to define the requirements for the design of the system interfaces. The novelty of the proposed approach is the inclusion of typically interaction design tools focusing in the analysis of the UX into the design of the system components, without merely focusing on the technological issues. Experimental results highlighted the validity of the proposed method to identify the interaction needs and to drive the interface design.
2021
- Parametric Cost Modelling for Investment Casting
[Relazione in Atti di Convegno]
Mandolini, M.; Campi, F.; Favi, C.; Cicconi, P.; Germani, M.; Raffaeli, R.
abstract
This paper presents a parametric cost model for estimating the raw material cost of components realized employing the investment casting process. The model is built using sensitivity analysis and regression methods on data generated by an analytic cost model previously developed and validated by the same authors. This is the first attempt of developing a parametric cost model for investment casting based on activity-based costing. The proposed cost model accounts component volume, material density and material price. The error in estimating the raw material cost for components whose volume is within the common range of investment casting is around 11%.
2021
- Review on the leveraging of design information in 3D CAD models for subassemblies identification
[Articolo su rivista]
Bonino, B.; Giannini, F.; Monti, M.; Raffaeli, R.
abstract
In industrial manufacturing, both in the design and the production phase, the management of modern mechanical assemblies is becoming demanding due to their increasing complexity. The use of stable subassemblies concept constitutes a better alternative, which allows to independently treat smaller groups of the assembly's parts, also to achieve a parallel production. At this regard, several methods for automatic subassemblies identifi-cation, starting from the assembly CAD model, have been provided. However, most of the methodologies proposed rely on human intervention, especially in the model processing to make available essential data, while other details are ignored. After giving the definition of stable subassembly, this paper focuses on the application of stable subassemblies identification to industrial CAD models and highlights the issues arising. With the aim of ensuring a reliable CAD model analysis, starting point of the identification, the possible real engineering situations, both related to assembling methods and modelling techniques, are presented. Ap-proaches to algorithmically address them are then described, with the help of two examples of mechanical assemblies.
2021
- Sustainable strategies: a continuously improving methodology
[Articolo su rivista]
Raffaeli, R.; Rossi, M.; Cappelletti, F.
abstract
The paper presents a methodology partially inspired by Japanese Kaizen concept; its implementation starts when different circumstances arise, e.g. an analysis is carried out and some criticalities emerge. The proposed methodology aims at continuously improving processes under the environmental and economic perspectives. It is made up of eleven steps that leads the group from the issue identification to a new status, improved than the previous one, and improvable than the following. The case study describes an implementation of the methodology in an Italian medium company acting in the clothing sector, demonstrating its validity and efficacy. It was launched in the firm after energetic and environmental analyses outlined material, energy wastes and environmental impacts; they were tackled, and results show the methodology to be successful both from environmental and economic point of view.
2021
- Ux in ar-supported industrial human–robot collaborative tasks: A systematic review
[Articolo su rivista]
Khamaisi, R. K.; Prati, E.; Peruzzini, M.; Raffaeli, R.; Pellicciari, M.
abstract
The fourth industrial revolution is promoting the Operator 4.0 paradigm, originating from a renovated attention towards human factors, growingly involved in the design of modern, human-centered processes. New technologies, such as augmented reality or collaborative robotics are thus increasingly studied and progressively applied to solve the modern operators’ needs. Human-centered design approaches can help to identify user’s needs and functional requirements, solving usability issues, or reducing cognitive or physical stress. The paper reviews the recent literature on augmented reality-supported collaborative robotics from a human-centered perspective. To this end, the study analyzed 21 papers selected after a quality assessment procedure and remarks the poor adoption of user-centered approaches and methodologies to drive the development of human-centered augmented reality applications to promote an efficient collaboration between humans and robots. To remedy this deficiency, the paper ultimately proposes a structured framework driven by User eXperience approaches to design augmented reality interfaces by encompassing previous research works. Future developments are discussed, stimulating fruitful reflections and a decisive standardization process.
2020
- A constraint-based approach for optimizing the design of overhead lines
[Articolo su rivista]
Cicconi, P.; Manieri, S.; Nardelli, M.; Bergantino, N.; Raffaeli, R.; Germani, M.
abstract
The use of computational methods in engineering design is a long-standing issue. Several mathematical approaches have been investigated in the literature to support the design optimization of engineering products. Most of them are focused on the optimization of a single structure, without considering a system of structures. The design of supports for electric lines requires tools for the management and sizing of a system of structures that interacts with each other under specific load conditions. This paper deals with a framework to support the design optimization of an overhead line using methods related to the theory of the Constraint Satisfaction Problem. The object-oriented model of a transmission line has been described and then implemented into a prototypical software platform. The parameters to be considered as variables are defined by the designer at the beginning of the optimization process. These variables are geometrical dimensions, poles locations, cable pre-tension, etc. The set of constraints is related to normative, climate conditions, datasheets, material limits, and expert knowledge. To demonstrate the effectiveness of this approach, a case study has been developed considering a variable number of constraints and parameters. In particular, the case study is focused on the design of a low-voltage sub-network between two distribution substations.
2020
- A design approach for overhead lines considering configurations and simulations
[Articolo su rivista]
Cicconi, P.; Manieri, S.; Bergantino, N.; Raffaeli, R.; Germani, M.
abstract
Nowadays, the contribution of the CAD modeling is not yet well exploited into the design of overhead lines. Even if some commercial tools are available, they are very similar to configuration tools with design rules related to reference normative. Sometimes, if 2D/3D CAD tools are employed, they are viewers or customized versions with specific features for the design of overhead lines. This situation limits the interoperability between the design of overhead lines and traditional software employed in the design of civil structures and infrastructures. Moreover, an information modeling approach is still lacking in current tools for the management of additional data about maintenance, cost, etc. In the context of overhead lines, the paper aims at showing an information modeling approach with a platform software which includes a configuration tool, a CAD module, an analytical-based solver, a costing tool, and a Finite Element Method solver. The CAD module is employed to define a 3D model including, as tag-objects, a set of information regarding the lifecycle design of overhead lines. Finally, a Finite Element Model solver enhances a second level of validation and enables advanced simulations.
2020
- A framework for analytical cost estimation of mechanical components based on manufacturing knowledge representation
[Articolo su rivista]
Mandolini, M.; Campi, F.; Favi, C.; Germani, M.; Raffaeli, R.
abstract
This paper presents a novel framework for manufacturing and cost-related knowledge formalization. This artefact allows industries to capitalize the knowledge of experienced practitioners in the field of manufacturing and assembly, so that it can be used by designers for quickly and analytically estimating the production costs of components during product development. The framework consists of the following: (i) a cost breakdown structure used for splitting out the manufacturing cost, (ii) a data model (cost routing) to collect the knowledge required to define a manufacturing process, (iii) a data model (cost model) for collecting the knowledge required to compute the manufacturing cost of each operation within a manufacturing process, and (iv) a workflow to define the manufacturing process. The proposed framework provides several advantages: (i) knowledge formalization of product manufacturing cost, (ii) knowledge sharing among design/engineering departments, and (iii) knowledge capitalization for decision-making process. The proposed framework is used to formalize the knowledge required for analytically estimating the manufacturing cost of open-die forged components. Results highlight that the framework addresses the most important requirements for a knowledge-based cost estimation system.
2020
- A Knowledge Formalization Approach for Manufacturing Cost Estimation
[Relazione in Atti di Convegno]
Mandolini, Marco; Favi, Claudio; Campi, Federico; Raffaeli, Roberto
abstract
Target pricing is a methodology to develop competitive products by determining the target price from market analyses. To guarantee the right profit margin, target cost is a direct consequence of target price. In this situation, the manufacturing cost estimation at the design phase becomes an essential task.
The paper presents a framework for collecting knowledge required for estimating manufacturing cost of components. The framework consists of: (i) a cost break-down structure used for splitting manufacturing costs, (ii) a data model for col-lecting that knowledge required for defining manufacturing processes, (iii) a data model for the collecting that knowledge required for computing the manufactur-ing cost of each operation within a manufacturing process and (iv) a workflow for analytically estimating cost of components. The framework has been mainly conceived for managing components realized through forming and shaping pro-cesses. The result presented in this paper guarantee the following benefits: (i) knowledge elicitation on product manufacturing cost, (ii) knowledge sharing among design/engineering departments, and (iii) knowledge capitalization for de-cision-making process.
2020
- Additive manufacturing adoption in product design: an overview from literature and industry
[Articolo su rivista]
Lettori, Jacopo; Raffaeli, Roberto; Peruzzini, Margherita; Schmidt, Juliana; Pellicciari, Marcello
abstract
2020
- An industry 4.0 framework for the quality inspection in gearboxes production
[Articolo su rivista]
Cicconi, P.; Raffaeli, R.
abstract
Nowadays, the development of Internet of Things (IoT) technologies have been enhancing the factory digitalization with several advantages in terms of production efficiency, product quality, and cost reduction. This opportunity encourages the implementation of digital twins related to physical systems for controlling the production workflow in real time. Firstly, the paper studies the enabling technologies for supporting the defect analysis in the context of Industry 4.0 for mechanical workpieces. Secondly, the approach aims to study the integration between the CAD geometry and the quality check process for the inspection planning. A Knowledge-Based tool has been proposed to support the configurations of the quality control chain for each CAD geometry. The test case is focused on the fragmented production of customized gearbox parts.
2020
- Analysis of LGV usage for the improvement of a customized production
[Articolo su rivista]
Cicconi, P.; Raffaeli, R.; Postacchini, L.; Monteriù, A.; Pallotta, E.; Prist, M.; Ciarapica, F. E.; Germani, M.
abstract
The paper describes an approach for analyzing the use of a Laser-Guided Vehicle (LGV) in the context of the small and medium-sized enterprise. The use of LGVs is an efficient solution to provide more flexibility in the context of Just-In-Time production; however, the investment cost can limit this application. A methodology has been proposed in this work to analyze the technical feasibility of using an LGV in the manufacturing industry of customized products. The test case focuses on the study of a laser-guided system to optimize the handling of molds for customized production. In this scenario, an LGV is proposed to substitute manual carts used for moving molds from the warehouse to the injection machines. The traditional path included an intermediate station for pre-heating the molds in hot-air ovens. The proposed solution includes the study of an induction heating system on the LGV to optimize time and energy consumption.
2020
- Design Optimization: Tools and Methods for ETO Products
[Relazione in Atti di Convegno]
Cicconi, Paolo; Mandolini, Marco; Nardelli, Miriam; Raffaeli, Roberto
abstract
The design of Engineer-To-Order products needs tools and methods for reducing time and cost during the phase of the quotation preparation. Modularization is one of the more applied design methods for ETO systems; however, it is necessary to integrate traditional tools with practices of design optimization in order to im-prove the development of a proposal. Even if commercial design tools for model-ling specific types of engineering systems are available, the application of design optimization is still based on the use of tools not integrated with each level of the design phases. Moreover, these tools often require a software customization. In fact, the integration of geometrical modelling, simulations, analysis, and optimiza-tion concerns the interaction between different tools. This paper describes an ap-proach to support the Multi-Object Optimization related to the design of complex ETO systems with focus on the oil & gas context. In this context, Genetic Algo-rithms and Constraint Satisfaction Problems are introduced as tools to support the design optimization of steel structures. The approach includes the employment of different and integrated tools throughout the design phases. This paper also shows a collection of tools to support the different levels for the design of differ-ent ETO products during the preparation of an offer related to a proposal submis-sion
2020
- Integrating a constraint-based optimization approach into the design of oil & gas structures
[Articolo su rivista]
Cicconi, P.; Nardelli, M.; Raffaeli, R.; Germani, M.
abstract
Currently, design optimization is widely applied in civil and mechanical engineering. Optimization strategies are used to enhance the product performance and reduce the cost, lead time and environmental impacts related to the product lifecycle. In this context, evolutionary algorithms are used for determining the optimum solution in engineering problems. The design of complex products, such as those that are engineered to order, often requires the study of subproblems. Modularization is a common practice to reduce the complexity; however, the configuration practices are difficult to be applied in engineered to order products. As a solution, the integration of the optimization tools and model-based simulations is proposed to manage the complexity. However, even when a commercial software is available to support the parameter optimization, there may exist a lack of design tools that can be integrated with the product structure of an engineered to order product. This paper describes a design optimization approach that integrates a Constraint Satisfaction Problem (CSP) tool with model-based simulations in a collaborative design context. A platform tool is developed using the. NET and MiniZinc languages. The case study is focused on the design optimization of a 700-ton steel structure. In particular, the optimization analysis considers the mechanical behavior, weight, and cost reduction.
2020
- Novel Robotic Cell Architecture for Zero Defect Intelligent Deburring
[Articolo su rivista]
Schmidt, Juliana; Grandi, Fabio; Peruzzini, Margherita; Raffaeli, Roberto; Pellicciari, Marcello
abstract
2020
- Transdisciplinary Assessment Matrix to Design Human-Machine Interaction
[Capitolo/Saggio]
Grandi, Fabio; Peruzzini, Margherita; Raffaeli, Roberto; Pellicciari, Marcello
abstract
Designing highly usable and ergonomic control dashboards is fundamental to support the user in managing and properly setting complex machines, like trains, airplanes, trucks and tractors. Contrarily, control dashboards are usually big, intrusive, full of controls and not really usable for different users. This paper focuses on the re-design of an ergonomic and compact dashboard for tractor control, proposing an innovative methodology in line with human-centered design and ergonomics principles. The study started by shifting the focus from how a machine works to how a task has to be performed and how the user interacts with the machine. It uses virtual simulations and human performance analysis tools to support the concept generation and the detailed design, and to test the new idea with users in the virtual lab. Indeed, within the virtual environment, different configurations of controls can be tested, checking which controls are mostly used and measuring human performance indexes (i.e., postural comfort and mental workload) for each configuration. Virtual mannequins can be used to as “digital twins” to interact with virtual items and to calculate robust comfort indicators during task execution. The study adopted the proposed methodology to an industrial use case to develop a usable and compact armrest for a new tractor platform. The new armrest is smaller than the previous one (-30% in dimensions), more usable (keeping on board only frequent controls, better positioned), and more comfortable (it satisfies 95% of the population size). This new approach could be used also for the design of new products.
2019
- A Comparative Assessment of Learning Outcomes in Online vs Traditional Teaching of Engineering Drawing
[Relazione in Atti di Convegno]
Raffaeli, R.; Cicconi, P.; Mandorli, F.
abstract
In recent years, long distance learning has become more and more popular. Web based technologies, that allow the sharing of information in real time, as well as the development of Learning Management Systems, provide the required technological support to implement long distance courses. However, long distance learning is characterized by a completely different relationship between teacher and student, in respect to the traditional teaching approach. It is then important to understand if this difference can affect the students learning outcomes. In this paper the comparison is presented between the summative assessment of two separated groups of students, attending an engineering drawing course, that is part of the curriculum for the bachelor degree in mechanical engineering. One group attended the course in a traditional form, while the second group attended the course in remote. The aim of the study is to verify if significant differences exist between the two groups of students, in terms of learning outcome. The identification of such differences is the premise to develop appropriated teaching strategies, aimed to overcome possible deficiencies related to the teaching approach.
2019
- A decision theory approach to support action plans in cooker hoods manufacturing
[Articolo su rivista]
Cicconi, P.; Postacchini, L.; Bergantino, N.; Capuzzi, G.; Russo, A. C.; Raffaeli, R.; Germani, M.
abstract
Nowadays, Knowledge-Based systems are widespread decision-making tools applied in product design and manufacturing planning. The series production requires agile and rapid decision-making methods to support actions in manufacturing lines. Therefore, agent-based tools are necessary to support the detection, diagnosis, and correction of accidental production faults. The context of Industry 4.0 has been enhancing the integration of sensors in manufacturing lines to monitor production and analyze failures. The motivation of the proposed research is to study and validate decision theory methods to be applied in smart manufacturing. This paper shows a Knowledge-Based approach to support action decision-making processes by a Bayesian network model. The proposed method aims at solving production problems detected in the manufacturing process. In particular, the focus is on the automatic production of cooker hoods. A case study describes how the approach can be applied in the real-time control actions, after a problem in quality is detected.
2019
- A design approach to support BIM for existing structures
[Relazione in Atti di Convegno]
Cicconi, Paolo; Raffaeli, Roberto; Borghi, Alessandra
abstract
2019
- A Digitally-enabled Integrated Approach to Design and Manufacture Shoe Lasts
[Articolo su rivista]
Marconi, Marco; Manieri, Steve; Germani, Michele; Raffaeli, Roberto
abstract
In the era of the fourth industrial revolution the efficient sharing and exploitation of information are key success factors for companies. In order to maintain competitiveness and to answer to the requests for highly customized products, shoe last producers need to innovate their processes, by adopting digital technologies. The present paper proposes an innovative integrated approach for shoe last design and manufacturing. The process is enabled by CAD/CAM technologies, which allow to integrate the design and manufacturing phases, and by haptic technologies, which allow to interact with the virtual models to simplify the successive planning and manufacturing operations. The final aim is to support traditional companies in the implementation of the Industry 4.0 paradigm. The test case about marking operation confirms that the adoption of the proposed approach leads to a sensible improvement in the company operational efficiency, thanks to the reduction in the number of repetitive tasks.
2019
- A knowledge based approach to support the conceptual design of ETO products
[Relazione in Atti di Convegno]
Nardelli, M.; Cicconi, P.; Savoretti, A.; Raffaeli, R.; Germani, M.
abstract
The ever-increasing competitiveness, due to the market globalization, has forced the industries to modify their design and production strategies. A key point is the development of products that fulfil the individual customer needs as close as possible. ETO companies manufacture new products according to the customer technical requirements given in the request for proposal. Computational Design Synthesis is the research area focused on activities to automate the design phase in the production of products such ETO structures. In this context, Knowledge Based Engineering applications are usually applied to automate design routines and to implement a multidisciplinary product design. Knowledge should be elicited and formalized, so that it can allow the past cases retrieval and the connection between customer specifications and the product configuration tasks. This paper proposes an approach for the rapid definition of the product structure related to a ETO product, including the early cost evaluation in configurations. The research scope aims at defining a framework to support the knowledge repository, which is the Knowledge Based used to design new products and estimate their costs.
2019
- A model-based approach to support the design of mold heating for composites
[Relazione in Atti di Convegno]
Cicconi, Paolo; Pallotta, E.; Russo Anna, Costanza; Raffaeli, Roberto; Prist, Mario; Monteriù, A.; Longhi, Sauro; Germani, Michele
abstract
2019
- An analytical cost estimation approach for generic sheet metal 3D models
[Articolo su rivista]
Mandolini, M.; Favi, C.; Germani, M.; Marconi, M.; Raffaeli, R.
abstract
This paper defines a systematic workflow for production cost estimation of sheet metal stamped components. The approach represents a solution toward the adoption of Design to Cost methods during early product design. It consists in a sequence of steps that, starting from a 3D CAD model with annotations (material, roughness and tolerances) and production information (batch and production volume) leads to the manufacturing cost through an analytic cost breakdown (raw material, stamping and accessory processes, setup and tooling). The calculation process mainly consists in a first step where geometric algorithms calculate the sheet metal blank (dimensions, shape, thickness) and specific product features (e.g. flanges, louvers, embossing, etc.). The following steps allow to calculate the raw material, the stamping process and the process-related parameters, which are the manufacturing cost drivers (e.g. press, stamping rate/sequence/force and die dimensions/weight). The manufacturing cost is the sum of the previous calculated items. Testing the approach for three different components, the average absolute deviation measured between the estimated and actual cost was less than 10% and such a result looks promising for adopting this method for evaluating alternative design solutions.
2018
- A CSP-based design framework for appliances under energy labelling
[Articolo su rivista]
Cicconi, Paolo; Landi, Daniele; Russo Anna, Costanza; Nardelli, Miriam; Raffaeli, Roberto; Germani, Michele
abstract
Nowadays, several consumer goods are sold with an energy label which provides energy information about consumption,
efficiency, noise, and performance. These labels are regulated by local energy policy and governments. Because of this,
customers are becoming increasingly aware about the energy efficiency and consumption of products such as household
appliances. In Europe, several household appliances are involved in the European Energy Labelling Directive. Therefore,
the manufacturers are paying attention to Ecodesign tools and methods to support the development of eco-innovation and
sustainable products. In this context, the paper proposes a design methodology to support the development of efficient cooker
hoods using an approach based on a constraints satisfaction problem model. The scope of the proposed research is to reduce
the time-to-market of household appliances considering the energy efficiency optimization from the early design phases to
the embodiment design. A Case Based Reasoning is also implemented to define a pre-configured model of product before the
CSP optimization. The CSP model has been developed as an analytical system, which can predict the energy label achieved
by a final prototype of a cooker hood. The interaction of such tools can fill the gap between traditional design methods and
eco-innovation approaches, in order to support the designer in the decision-making activity. The test case shows a cooker
hoods optimization based on a CSP tool, developed using a programming framework based on Gecode platform.
2018
- A decision theory approach to support action plans in cooker hoods manufacturing
[Relazione in Atti di Convegno]
Cicconi, P.; Postacchini, L.; Bergantino, N.; Capuzzi, G.; Russo, A. C.; Raffaeli, R.; Germani,
abstract
2018
- A dependencies satisfaction tool to support the cost oriented configuration of industrial products in the conceptual design stage
[Articolo su rivista]
Peruzzini, Margherita; Pistacchi, Mauro; Savoretti, Andrea; Mandolini, Marco; Raffaeli, Roberto
abstract
Sustainability and cost optimization are actually the main drivers of product and system design in modern companies. However, cost assessments are usually carried out at the end of the design process to check the validity of the decisions already taken. Therefore, when targets are not achieved, numerous time-consuming iteration loops are necessary to optimize the initial solution. The paper situates in a research aimed at merging functional-based and design-to-cost approaches to propose a CAD-based platform able to assess new product variants from the earliest stages by configuring and assessing feasible design solutions. In particular, an approach is proposed for dealing with dependencies among design parameters in order to support the designer in a rapid definition of valid solutions and optimise them. The approach is described and then applied on an industrial test case, a bridge-crane design process.
2018
- A Design Methodology for a CSP-Based Optimization Approach
[Relazione in Atti di Convegno]
Cicconi, Paolo; Nardelli, Miriam; Raffaeli, Roberto; Germani, Michele
abstract
Design optimization is a common practice in industry. Different
mathematical algorithms have been developing to support the optimization in
engineering design. The integration between optimization methods and simulations
is an interesting issue in engineering design. A typical optimization workflow can
include simulation steps; however, the Virtual Prototyping analysis is more timeconsuming
than analytical calculations. The study of Constraints Satisfaction
Problems is a mathematical topic which can be applied for solving engineering
issues in design. The strength of this approach is the velocity on searching the
satisfied solutions. This paper proposes a design methodology which considers the
use of CSP models and calculation tools to optimize the sizing of columns and
beams in the design of a steel structure. The calculation tools regard analytical
models and numerical analysis. While the analytical approach regards the
computing of cost and weight, the numerical analysis is used to verify and check
the engineering performance in terms of deformation and stress state. A
customized application, based on MiniZinc platform, has been developed and
proposed to solve the CSP model for a test case steel structure. The CSP problem
has been limited to the calculation of analytical constraints such as cost and weight.
Finally, the resultant set of solutions has been evaluated using numerical solution
to complete the optimization analysis.
2018
- A model-based simulation approach to support the product configuration and optimization of gas turbine ducts
[Articolo su rivista]
Cicconi, Paolo; Raffaeli, Roberto; Marchionne, Matteo; Germani, Michele
abstract
Nowadays, product configuration and optimization are very important topics in several industrial
applications such as the manufacturing of Engineered-to-order (ETO) products, where there is a
fierce increase in market competition. The product configuration allows past design solutions to be
reused and new product variants to be defined and pre-designed. However, the delivery of new configurations
of products requires a technical feasibility analysis before closing the contract of the order
with the customer. There is a lack of commercial tools which can support the designer from the early
configuration phase to the product optimization with the automatic generation of geometric models
and simulations. While traditional software tools can be used for the product configuration, with
automation in the CAD modeling, other ones can combine optimization algorithms with numerical
simulations. However, the combination of all these design levels requires the development of a dedicated
platform tools. The research aims to reduce time and cost related to the early design phase of
an oil & gas system, focusing on gas turbine ducts. The paper proposes a methodological approach
to integrate the design optimization with the product configuration using Model-Based simulations
to verify the technical feasibility and to optimize the product design. As a test case, the early design
of a gas turbine chimney is proposed.
2018
- An extended B-Rep solid modeling kernel integrating mesh and NURBS faces
[Articolo su rivista]
Ferrari, Giacomo; Raffaeli, Roberto; Casciola, Giulio; Morigi, Serena
abstract
In several application contexts, virtual solid models require to integrate portions of polygonal meshes with synthetic models, designed by traditional parametric/analytical multipatches systems. The paper reports the research aiming at covering the theoretical and numerical aspects connected with an extended geometric solid modeling system, focusing on the B-Rep models and introducing the new paradigm of Extended B-Rep (EB-Rep), which is able to integrate mesh-faces as part of a B-rep model. This paradigm introduces a notion of continuity between parametric and discrete representations, regularized Boolean Operations, a join operator and an approach to represent a valence semi-regular mesh as an EB-Rep structure. A prototype of the geometric solid modeling kernel has been realized and tested in the OpenCascade library environment.
2018
- CAD feature recognition as a means to prevent ergonomics issues during manual assembly tasks
[Articolo su rivista]
Marconi, Marco; Germani, Michele; Favi, Claudio; Raffaeli, Roberto
abstract
Feature-based modeling and feature recognition algorithm are state of the art technologies, mainly
used to favor the integration and exchange of data between design and manufacturing phases. This
paper aims to investigate the possibility to extend the use of the feature recognition as a means
for the prevention of ergonomics issues during the manual assembly phase, such as Work-related
Musculo-Skeletal Disorders (WMSDs). Starting from the features analysis of a 3D product model, the
proposed five steps method allows preventively identifying potential ergonomics issues. The main
novelty of this study is related to the correlation between design tools, product virtual representations
(e.g. 3D models), assembly and ergonomics aspects. Results obtained with two case studies, a
cooker hood and a tool-holder carousel, confirm the usefulness of the proposed method in helping
designers to prevent potential ergonomics issues for operators involved in the assembly phase.
2018
- Supporting design tasks through constraint satisfaction tools
[Relazione in Atti di Convegno]
Nardelli, Miriam; Cicconi, Paolo; Raffaeli, Roberto; Germani, Michele
abstract
Nowadays, different commercial tools are available to support engineers during optimization tasks in
engineering design; however, many researches have been still studying tools and methods to improve
the design process and overcome some limits related to configuration and design optimization. This
paper proposes a methodological approach to highlight how a CSP analysis can support the first phase
of an optimization analysis, to reduce the design space of solutions to be investigated and subsequently
optimized. A test case shows a CSP study applied to steel structures for oil & gas applications.
2017
- A life cycle model to assess costs and environmental impacts of different maritime vessel typologies
[Relazione in Atti di Convegno]
Favi, Claudio; Raffaeli, Roberto; Germani, Michele; Gregori, Fabio; Manieri, Steve; Vita, Alessio
abstract
Maritime vessels have long service life and great costs of building, manning, operating, maintaining and repairing. Making a consistent lifecycle model among the different vessel typologies, repeatable with the same level of detail and comparable for the implementation of decision-making strategies, remains an open question. This paper aims to define a suitable lifecycle model in the context of maritime vessels to cope with the current limitations of ad-hoc and fragmented methods. The model considers the main aspects involved in the vessel lifecycle such as building materials, manufacturing and assembly, maintenance/service, operational activities, use, etc. The model provides a common structure for the lifecycle assessment (LCA) and lifecycle cost analysis (LCCA) including the way to retrieve and to collect the data necessary for the analysis starting from the available project documentation and the design models. The method is flexible and it is able to cover a large variety of maritime vessel typologies. As example, a luxury yacht has been analysed using the developed method, demonstrating the applicability of the proposed model in one of the most critical vessel typology.
2017
- An approach to support model based definition by PMI annotations
[Articolo su rivista]
Cicconi, Paolo; Raffaeli, Roberto; Germani, Michele
abstract
PMI annotations are widely used to support the Model Based Design within modern companies. In
particular, the introduction of digital annotations marks the transition from the 2D drawings to the
3D representation in many manufacturing and design companies. However, today the implementation
of the PMI technology presents some limits, such as the lack of functions to generate structure
templates to be applied to similar CAD models. The proposed approach aims to overcome the limits
of traditional tools which are not able to add a PMI annotation’s structure from one model to
another one. The paper describes a method to reuse digital PMI annotations in a new model during
the design phase, where the annotations are inherited from similar CAD documents. The proposed
approach is based on two levels of geometric analysis: the searching of similar template models
from an XML database, and the identification of the related geometric entities, which are used as
associated objects for the definition of 3D annotations. The test case is focused on the automatic
generation of PMI annotations for exhaust duct items used in oil & gas applications. The proposed
tool has been developed within a software program called Duct Designer, which is used for the
CAD automation of duct items. Particularly, the test case enhances the retrieval and reuse of sizing
schemes from previous 3D models in order to obtain an automatic rebuilding of the geometric
annotations.
2017
- Analysis of the requirements of an early life-cycle cost estimation tool: an industrial survey
[Relazione in Atti di Convegno]
Savoretti, Andrea; Mandolini, Marco; Raffaeli, Roberto; Germani, Michele
abstract
Cost estimation is a critical issue for many companies concerning both offers generation and company strategic evaluations. In
this paper, a framework for early cost estimation has been proposed to some firms for an assessment of its main features. The aim
of the industrial survey is to promote a discussion on the needs and the expectations regarding cost estimation in order to obtain
feedbacks to be addresses in the implementation of a software tool. Gather data has led to a ranking of the main characteristics
the tool should have.
2017
- Design knowledge formalization to shorten the time to generate offers for Engineer To Order products
[Relazione in Atti di Convegno]
Raffaeli, Roberto; Savoretti, Andrea; Germani, Michele
abstract
Cost Estimation for offer generation in ETO companies is a critical and time-consuming activity that involves technical expertise and a knowledge base. This paper provides an approach to acquire and formalize the design and manufac-turing knowledge of a company. The method has been described as a sequence of steps, which moves from the data acquisition of the past projects to the definition of a cost function based on dimensioning parameters. This approach has been ex-perimented on a family of cranes for plants in collaboration with an industrial partner.
2017
- Reverse Engineering and Scanning Electron Microscopy Applied to the Characterization of Tool Wear in Dry Milling Processes
[Relazione in Atti di Convegno]
Cabibbo, Marcello; Forcellese, Archimede; Raffaeli, Roberto; Simoncini, Michela
abstract
An innovative method of tool wear assessment, based on the digitization of the cutting tool performed by a piezoelectric 3D scanner and on the analysis of the surfaces of a 3D model generated using the Reverse Engineering technique, has been developed. To this purpose, face milling experiments were carried out under dry cutting condition on AISI 420 B stainless steel using inserts in cemented carbide, with a two-layers coating (TiN and TiAlN). The time dependence of the insert wear was analysed by interrupting milling at predetermined time values. The proposed approach has been validated by comparing the output provided by the reverse engineering method to that measured experimentally by analysing the worn insert images obtained using a stereo microscope. An excellent agreement between the results given by the two different methodologies has been found. The worn tools have also been analysed using the scanning electron microscopy technique in order to understand the wear mechanisms operating during dry milling.
2017
- Toward a function-based IT platform for variants redesign of household appliances
[Articolo su rivista]
Peruzzini, Margherita; Raffaeli, Roberto; Malatesta, Marco; Germani, Michele
abstract
Modular product design is an efficient strategy to let manufacturing companies meet the customers' requirements by offering a wide variety and customization of products and significantly saving time and cost during engineering and production (Fei et al., 2011). Despite numerous approaches for function modeling and modular product design (Srinivasan et al., 2012; Eckert, 2013; Vermaas, 2013) that have been developed in the last decades, carrying out an efficient product variants' design process is still an open issue for many manufacturing companies. The proposed approaches offer numerous ways to model information about product functionality, but each approach is useful and particularly well suited for different applications and domains (Summers et al., 2013). The present research compares the existing approaches for product variants design and defines a function-based model to support product design and redesign according to a modular framework, merging qualitative technical issues with business-oriented evaluation. Such a framework has been used to develop a multiuser IT platform, composed of a knowledge-based engine and four different tools to support designers and engineers in product variants creation, management, and configuration, from product functional modeling to cost estimation and life cycle assessment. The proposed model has been tested on industrial cases in the context of household appliances. Experimental results demonstrates that, after a preliminary context analysis and a proper knowledge base creation, such a model supports a more conscious decision-making and promote collaboration within an interdisciplinary design team. Finally, the case study shows the necessity, but in the meanwhile the insufficiency, of a functional decomposition as the only representation viewpoint.
2017
- Towards a design-to-sustainability platform based on functional representations and simplified geometric layouts
[Articolo su rivista]
Peruzzini, Margherita; Roberto, Raffaeli; Marco, Mandolini; Raffaeli, Roberto
abstract
Sustainability is becoming one of the main drivers of the modern product and system design. However, sustainability assessments are usually carried out at the end of the design process to check the validity of the decisions already taken. As a consequence, when targets are not achieved, numerous time-consuming iteration loops are necessary to optimize the initial solution. The paper merges functional-based and design-to-cost approaches to propose a CAD-based platform able to assess product lifecycle costs and impacts from the earliest design stages by configuring and assessing feasible design solutions. It considers both economic expenses and environmental impacts during all phases of product lifecycle on the basis of the company knowledge.
2016
- Automation of drafting execution by schemes definitions and feature recognition
[Articolo su rivista]
Raffaeli, Roberto; Cicconi, Paolo; Germani, Michele
abstract
Despite of the widespread of annotated 3D virtual models, it is still important to produce engineering drawings for a correct communication among the people of the design and manufacturing chain. Automatic drafting through meta drawing definitions, called Drafting Schemes, is proposed in this paper to save time when drawing becomes a repetitive task. The approach produces drafts with a predetermined content in terms of views arrangement and dimensioning strategy, and guarantees robust results to the variations of the input geometry. In fact, the geometrical entities referenced by the generated dimensions are retrieved through dedicated search algorithms based on recognition of geometric features of the input model.
The approach has been implemented and tested on a family of gear motors showing feasibility and good results in terms of drafting time savings.
2016
- Explicit 3D Functional Dimensioning to Support Design Intent Representation and Robust Model Alteration
[Articolo su rivista]
Mandorli, Ferruccio; Otto, E. Harald.; Raffaeli, Roberto
abstract
Design intent representation is a well-known issue in the MCAD domain, and is related to the readability, alterability, and usability of CAD models. The recent widespread introduction of functionality and commands in modern CAD systems, aimed at facilitating explicit modeling, introduces not only a new modeling paradigm supplementary to the feature-based approach, but also a new perspective on how the design intent can be captured and represented. Taking into account the traditional method of communicating design intent with functional dimensioning in mechanical drawings, in this paper a novel approach is presented, aimed at translating this traditional design intent representation from 2D into 3D. Objectives are directed towards the specification and implementation of dimensioning correspondence mapping and the identification as well as examination of shortcomings in current systems. This should help direct future improvements aimed at supporting 3D dimensioning within 3D explicit modeling systems.
2015
- A CAD Tool to Design Bespoke Insoles for Severe Orthopaedic Treatments
[Articolo su rivista]
Mandolini, Marco; Carloni Vitali, Massimiliano; Macchione, Alessandro; Raffaeli, Roberto; Germani, Michele
abstract
Patients affected by serious foot pathologies often require special orthotics to stand and walk correctly. Skilled operators obtain such insoles on the basis of manual procedures and following the prescriptions of orthopaedic technicians. The process is handicraft and time consuming. The paper presents a virtual prototyping approach which is based on dedicated foot scanners, CAD-based design tool and milling machines to obtain the bespoke footwear orthotics. The major contribution is a geometric procedure to design complex insole shapes starting from the foot scan and highly customized shoe lasts which are required in case of important deformities.
The approach has been tested on several patients thanks to the collaboration with a partner insole producer and some orthopaedic centres. Patients have generally reported positive feedbacks on the comfort and functionality of the insoles.
2015
- A Web-enabled Configuration System for Interior Design
[Articolo su rivista]
Mengoni, Maura; Raponi, Damiano; Raffaeli, Roberto
abstract
Web-enabling technologies represent the next generation of design environments to design and manufacture complex systems, such as them characterizing contract furniture. In the context of web applications to facilitate and support teamwork in collaborative product development, the paper presents a CAD-based infrastructure for the 3D visualization of co-designed solutions, the on-line customization of furniture items and the creation of a shared relational database of products, architectural scenes and knowledge-based rules guiding configuration. A double-level geometry is presented to manage 3D web representation and product structure. A use case is adopted to show main platform functionalities and possible advantages for the extensible contract furniture cluster.
2015
- Supporting the Configuration of New Product Variants by Reusing the Implicit Knowledge of Past Solutions
[Relazione in Atti di Convegno]
Malatesta, Marco; Cicconi, Paolo; Raffaeli, Roberto; Germani, Michele
abstract
The market globalization pushes for ever new products in order to reach new niches. In the household appliances field, the marketing specialists daily configure new combinations of numerous functional and product requirements seeking new product definitions. Each novel combination requires an assessment of technical and economic feasibility by the design departments.
This paper proposes a method for a preliminary validation of new configurations at the marketing stage. Indeed a tentative Bill of Materials (BOM) and a cost of the product are obtained. A knowledge base is derived by eliciting the requirement compatibilities from existing products. The approach is matrix based and it analyzes recurrent dependencies between requirements and components variants to determine which parts are most likely to appear in the BOM. Then, the knowledge base is integrated with rules that are input by experienced designers through a simple syntax.
The approach has been tested moving from the requirements of some instances of a family of cookers, and comparing the results obtained from the application of the method with the actual product BOM.
2015
- Virtual prototyping in the design process of optimized mould gating system for high pressure die casting
[Articolo su rivista]
Raffaeli, R; Favi, C; Mandorli, F
abstract
Purpose – High Pressure Die Casting is a widely used industrial process to manufacture complex-shaped products in light alloys. Virtual prototyping techniques, especially numeric based simulations of the casting process, allow the die filling process to be evaluated and help faster optimization of the gating system, which is the most critical element of the mould. This paper presents a four step approach to design optimal moulds taking advantage of the simulation tools.
Design/methodology/approach - No formalized method to design an optimal gating system is available yet and the majority of the studies aim to optimize existing geometries or to choose from alternative solutions. Rather than optimizing the geometries of predefined designs by running attempt trials, the proposed approach defines a procedure to position cavities, gating systems and, finally, to determine the whole mould geometry.
Findings - The approach is demonstrated through three different industrial applications. The design of a 6-cavity mould for gas cooking burners is reported at first. Then, two test cases, a cup and a radiator, are reported for showing different arrangements of the gating system. The reached quality of the mould design has been assessed using metallographic analyses of the casts.
Originality/value – The design of a mould is strictly correlated to its product and mainly based on a trial-and-error approach. Numerical simulations offer a powerful and not expensive way to study the effectiveness of different die designs and filling processes. The paper proposes a structured approach for the definition of the gating system. It ultimately leads to improvements in both product quality and process productivity, including more effective control of the die filling and die thermal performance.
2014
- A CAD Tool to Design Bespoke Insoles for Severe Orthopedic Treatments
[Abstract in Atti di Convegno]
Mandolini, M.; Carloni Vitali, M.; Macchione, A.; Raffaeli, R.; Germani, M.
abstract
2014
- A new business model for the orthopaedic and customized footwear sector
[Relazione in Atti di Convegno]
Vitali Massimiliano, Carloni; Germani, Michele; Mandolini, Marco; Raffaeli, Roberto
abstract
This research work aims to develop and demonstrate a new business model for the orthopaedic and customized footwear sector, called “Orthopaedic Footwear Cluster”. The peculiarity of this idea consists in splitting the shoe, and related accessories, design and manufacturing processes, between the hub (big industry) and the nodes (small orthopaedic shops), in order to joint the benefits of each subject of the cluster, without loosing the customization required by the customers. It is expected to reduce the time to market (50%), costs (30%) and environmental impacts.
2014
- A web-based platform to support contract furniture design
[Articolo su rivista]
Mengoni, M.; Peruzzini, Margherita; Raffaeli, R.; Raponi, D.
abstract
Contract furniture design is the process of creating finished commodities for hospitality, retail, store, office, restaurants, etc. According to the process stage, numerous stakeholders with different skills, abilities, background and interests are involved in the development of products and services. The management of these temporary networks is complex and requires proper computer-supported cooperative work platforms able to achieve coherent design solutions. The paper explores contract furniture design challenges and requirements to define a technological platform to support compa- nies in market analysis and penetration, product configuration and team working. System architecture and its main software modules are described in detail and preliminary implementation results shown.
2014
- A Web-enabled Configuration System for Interior Design
[Abstract in Atti di Convegno]
Mengoni, Maura; Raponi, Damiano; Raffaeli, Roberto
abstract
2014
- Comportamento all'usura degli utensili da taglio in lavorazioni di fresatura a secco mediante l'uso di strumenti di misura innovativi
[Relazione in Atti di Convegno]
Forcellese, Archimede; Pieralisi, Massimiliano; Raffaeli, Roberto; Simoncini, Michela
abstract
Il presente lavoro si propone di sviluppare un metodo innovativo di valutazione dell'usura basato sulla digitalizzazione degli utensili da taglio con scanner a contatto e sull'analisi delle superfici acquisite attraverso tecniche di Reverse Engineering. A tal proposito, sono state condotte prove di fresatura a secco su blocchi di acciaio AISI 420B mediante inserti in Cermet con rivestimento PVD. L'analisi dell'usura degli inserti è stata effettuata interrompendo, ad intervalli di tempo prefissati, il processo di fresatura. Il metodo proposto è stata validato confrontando i risultati ottenuti attraverso tecniche di Reverse Engineering a quelli misurati sperimentalmente dall'analisi delle immagini degli inserti usurati ottenute mediante stereomicroscopio. In particolare, l'andamento dell'altezza della parte usurata sulla superficie scansionata in funzione del tempo, previsto attraverso la tecnica proposta, è analogo a quello ottenuto mediante microscopia e i valori sono pressoché coincidenti.
2014
- Identification of Weld Beads in Assemblies of B-Rep Models
[Articolo su rivista]
Raffaeli, R; Mandolini, M; Germani, M
abstract
Current CAD systems have dedicated functionalities to model weld beads, but it is often cumbersome to use these systems. This study presents a method to analyze the geometry of assemblies of B-Rep models to automatically identify possible welds among the parts using prediction rules. Adjacent faces are detected, and Boolean operators on planar loops are used to identify bead paths. Beads are then split in homogeneous portions based on the topology of the connected parts.
The main goals of this study are to increase the speed of the welding definition process and to benefit applications such as the cost estimation of steelwork products. Cost estimates are based on the shape, the length and the dimension of each weld bead. Some industrial examples are presented to show the benefits in terms of time savings and accuracy to the estimation process.
2014
- Improving the modular structure of a product to facilitate the redesign process: an example for eco-design
[Relazione in Atti di Convegno]
Malatesta, Marco; Germani, Michele; Gregori, Fabio; Raffaeli, Roberto
abstract
Products are continuously redesigned to offer new variants and penetrate new market niches. Changes are often dictated by improvements which are necessary in specific Design Contexts (DC), such as performance, eco-sustainability, assembling, cost, usability. Modularity is a well consolidated approach toward the rapid product reconfiguration and is beneficial to limit the scope of changes to product subsets. However, this consideration needs to be included in the design of the modular structure of a product.
The paper introduces the concept of Design Context Module (DCM), as a module implemented in components that will strongly affect a certain DC, letting the designer to restrict the number of the parts to be modified. The approach moves from the traditional modularization based on the functional decomposition and introduces an iterative procedure to refine the DCMs structure. The optimization is driven by the maximization of similarities and dependencies among components of the same module and by indexes expressing the impact of the components on specific DCs.
The approach has been tested in the field of the household appliances. The modular structure of a freestanding cooker has been redefined in consideration of redesign activities aiming to improve the eco-sustainability of the product. The application of the approach has led to the identification of few modules characterized by high impacts on the environment.
2013
- A Finite Element Method to support the materials selection phase during the insole design process
[Relazione in Atti di Convegno]
Mandolini, M; Germani, M; Raffaeli, R
abstract
Purpose: The paper aims to define a method to support the materials selection phase during the insole design process. The proposed scientific approach is pursued adopting a finite element method to simulate the mechanical behaviour for combinations of materials to create customized insoles. The paper presents also two processes, one to design the custom made insole and the other to select the insole materials combinations with the aim to uniform the foot plantar pressure.
Method: The insole design and the materials selection processes are based on the use of software tools to manage the materials properties, in order to make them as scientific as possible. A Finite Element Method is used to calculate the stress-strain relationships of a custom combination of multiple layers of materials. The contextualization of this method into the insole design process allows the proposed idea to be successfully implemented.
Result: The error committed by the Materials Combinations Simulator has been verified with a large set of materials (EVA, PU and rubber). Experimental tests have been performed to evaluate the deviation with the results of the simulation model, highlighting an error less than 10%.
Discussion & Conclusion: This work is a step toward a more scientific design process for custom made insoles. The possibility to simulate the mechanical behaviour of a combination of multiple materials lead to the elimination of the physical tests. The integration of the proposed Materials Combinations Simulator system with an Insole Design software tool will represents a further innovation respect the state of the art
2013
- An approach for managing engineering changes in product families
[Relazione in Atti di Convegno]
Raffaeli, R; Malatesta, M; Marilungo, E; Germani, M
abstract
Product development is characterized by continuous updating of existing solutions in order to cope with new market requirements. Families of product variants are used to satisfy the needs of new potential customers and penetrate new market niches. New requirements impact on the structure of a product to be changed and also on the other instances of the family which share common parts. Several change management approaches have been proposed in the literature but they are limited to analysis of a single product instance. This paper proposes a dependency-based change propagation approach which is able to cope with engineering changes extended to product families. The proposed tool is based on a multilevel representation of the product structure, where functions, modules and physical parts are defined and interrelated. This system allows evaluating the consequences of engineering changes introduced in the family structure and computing indices of the impact on several design for X contexts. The tool was tested within the R&D department of a large sized company producing household appliances. Gather data are presented and analyzed to identify potentialities and shortcomings of the approach.
2013
- An integrated methodology for the functional design of dental prosthesis
[Articolo su rivista]
Meneghello, R; Savio, G; Raffaeli, R; Cerardi, A; Turchetto, M; Planchenstainer, L
abstract
In this work it is proposed an integrated methodology for the functional design and simulation of removable complete dentures. This methodology develops in four phases: virtual and physical prototyping, contact forces and areas analysis and functional optimization of teeth and arches geometry. A virtual environment for the modeling of the prosthesis (NM-Tooth) was developed: it includes a database of 3D CAD models of artificial teeth and allows to simulate the fabrication techniques used in dentistry. In particular, it is possible to create a full denture virtual model by a semi-automatic procedure, where a preliminary occlusal configuration is set up. By using rapid-prototyping techniques, a physical model of the prosthesis is manufactured which is utilized for the experimental, in vitro, analysis. The analysis phase includes the study of the occlusion forces in relation to the identification of contact areas; a multi-axial force measuring system allows the detection of forces acting on the physical model. Simultaneously, with a reverse engineering procedure, the relevant contact areas in the virtual model are related with the load configuration. According to the experimental output, it is possible to modify the preliminary geometry both of the arches and of the individual tooth. This integrated methodology is an original instrument to study the dental prosthesis and acquire information for its functional improvement.
2013
- Automated inspection of mechanical components by optical systems
[Relazione in Atti di Convegno]
Raffaeli, R; Germani, M
abstract
In the mechanical field agile production requires rapid and flexible shop-floor control techniques in order to verify the manufacturing operations effectiveness. To accomplish this goal, 3D scanning systems are evermore used for quality control purposes. Generally, 3D CAD (Computer Aided Design) product models can be used as reference in order to manage the verification process. The geometrical information represented in the 3D CAD model can be used in order to virtually plan, simulate and pilot the inspection process.
The present work targets the development of view planning algorithms in order to support the automatic inspection of 3D shapes, including dimensional and geometrical tolerances. Algorithms have been implemented in a prototypal software system that has been experimented as off-line application to provide inputs to a multi-axis Degree of Freedom (DoF) robot arm mounting an optical 3D scanner.
Two test cases from automotive and die casting fields are presented. They show the computation of acquisition poses in a suitable sequence and correspondence to the experimental data.
2013
- CAD tools for designing shoe lasts for people with diabetes
[Articolo su rivista]
Bernabéu, J A; Germani, M; Mandolini, M; Mengoni, M; Nester, C; Preece, S; Raffaeli, R
abstract
In the context of a research program aiming at defining a framework to acquire patient data and support the whole shoe design and manufacturing process, this paper presents new CAD tools to design and validate lasts for shoes designed specifically for people with diabetes. Shoe last custom-izing systems have already been proposed in literature. However, tools for designing shoes for peo-ple with diabetes do not currently have the capacity to modify the last in order to reduce the risk of foot ulceration whilst at the same time preserving the style of the shoe. The main contributions of the work are given by a method to identify the required design features to guarantee the footwear preventive function, the determination of a systematic protocol for orienting, and measuring the virtual models of the feet and the lasts, and the definition of geometrical operators to modify the last shape according to its original aesthetic and the required footwear parameters. Such variables are computed by a knowledge based system on the basis of the patient’s pathology. The paper presents the implementation of two CAD tools and describes the procedures and the geometrical algorithms to handle the last geometry. Finally a case study is reported to show the advantages provided by the proposed approach in terms of achieved quality of the design process and expected footwear performance.
2013
- Context dependent automatic view planning: the inspection of mechanical components
[Articolo su rivista]
Raffaeli, R; Mengoni, M; Germani, M
abstract
Literature shows how 3D CAD product models can be used as reference in order to manage the verification process by 3D optical scanning systems and the computation of the optimal viewpoints. However, in the mechanical field, a variety of inspection tasks is experienced by engineers involved in the quality control process: GD&T verification, production phases control such as sheet metal cutting, evaluation of aesthetic appearance of parts, global shape deformation measurement and specific point deviations assessment. This leads to the necessity of flexible view planning approaches which adapt to the specificity of the required inspection task. The present work targets the development of a comprehensive view planning approach in which several algorithmic options are triggered by the product features to be inspected. Algorithms have been implemented in a prototypal software system which has been experimented as an off-line application to provide inputs to a multi-axis Degree of Freedom (DoF) robot arm mounting an optical 3D scanner. Two test cases from die casting and automotive fields are presented. They show the computation of acquisition poses in a suitable sequence and efficiency in the obtained results.
2013
- Elicitazione ed Uso della Negative Knowledge nell'Apprendimento del Disegno Meccanico
[Relazione in Atti di Convegno]
Mandorli, F; Raffaeli, R
abstract
Questo articolo propone un approccio sistematico per la definizione della negative knowledge relativa all???apprendimento del disegno meccanico e descrive le procedure utilizzate per la sua elicitazione ed il suo impiego, che hanno potuto essere adeguatamente sviluppate anche grazie all???ausilio fornito della piattaforma eLearning di Ateneo, basata su Moodle. L???insegnamento delle regole per la corretta realizzazione e la giusta interpretazione dei disegni meccanici sono ancora oggi un elemento essenziale nella formazione di un ingegnere meccanico. Anche nell???insegnamento del disegno meccanico, come avviene per molte altre discipline, l???aspetto più problematico riguarda l???individuazione delle metodologie più adatte per trasmettere e facilitare l???apprendimento, non solo della conoscenza dichiarativa, che in questo caso è rappresentata dalle norme nazionali ed internazionali, quanto piuttosto della conoscenza procedurale, ossia dell???insieme delle strategie di applicazione ed interpretazione delle norme, che permettono di arrivare alla definizione/interpretazione semanticamente corretta del disegno. Da questo punto di vista, l???apprendimento della capacità di evitare errori gravi è importante quanto l???apprendimento della capacità di fare ciò che è corretto. Questa conoscenza, relativa alla capacità di sapere cosa non fare, viene spesso indicata in letteratura come negative knowledge e rappresenta una parte significativa del bagaglio di conoscenze di un esperto.
2013
- Improving the link between computer assisted design and configuration tools for the design of mechanical products
[Articolo su rivista]
Raffaeli, R; Mengoni, M; Germani, M
abstract
The competitive market forces companies to offer tailored products to meet specific customer needs. To avoid wasting time, design efforts generally address the configuration of existing solutions, without producing substantial design modifications. Configuration tools are used to achieve customized products starting from a common platform.
Many approaches have been successfully proposed in literature to configure products. However, in the mechanical field they need further investigation in order to be efficiently linked to Computer-Aided Design technologies. Research is focused on tools and methods to automatically produce geometrical models and improve the flexibility of the continuous product updating process.
In this context, this paper aims to combine product configuration approaches with design automation techniques in order to support design activities of products to fulfil specific requirements. The approach is based on entities called Configurable Virtual Prototypes (CVP). Three different domains are managed and connected via CVP: Product Specifications, Geometrical Data and Product Knowledge. In particular, geometry recognition rules are used to identify the parameterization of parts and the assembly mating constraints.
The approach is exemplified through an industrial case study where a tool has been developed on the basis of the described method. Advantages of the system are shown in terms of achieved product configuration efficiency.
2013
- Off-line view planning for the inspection of mechanical parts
[Articolo su rivista]
Raffaeli, R; Mengoni, M; Germani, M; Mandorli, F
abstract
3D optical scanning systems are used more and more for quality control purposes. The effective utilization of such systems needs an efficient virtual planning of the product acquisition viewpoints. Literature shows how 3D CAD product models can be used as reference in order to manage the verification process and as a basis for the computation of the optimal viewpoints.
However, in the mechanical field, a variety of inspection tasks is experienced by engineers involved in the quality control process: GD&T verification, production phases control such as sheet metal cutting, evaluation of aesthetic appearance of parts, global shape deformation measurement and specific point deviations assessment. This leads to the necessity of flexible view planning approaches which adapt to the specificity of the required inspection task.
The present work targets the development of a comprehensive view planning approach in which several algorithmic options are triggered by the product features to be inspected. Algorithms have been implemented in a prototypal software system which has been experimented as an off-line application to provide inputs to a multi-axis Degree of Freedom (DoF) robot arm mounting an optical 3D scanner.
Two test cases from die casting and automotive fields are presented. They show the computation of acquisition poses in a suitable sequence and efficiency in the obtained results.
2013
- Supporting teamwork in contract furniture design
[Relazione in Atti di Convegno]
Mengoni, M; Peruzzini, Margherita; Raffaeli, M.; Raffaeli, Roberto
abstract
Contract furniture design is oriented to develop customized products for the creation of a finished commodity for hospitality, offices, retails, restaurants, stores. It is assuming a growing importance all over the Europe and represents a preferred channel for promoting Made in Italy offer. Numerous competences with different skill, abilities and background are necessary to fulfill market requirements. Stakeholders are arranged into complex inter and intra temporary networks where sometimes- conflicting interests and purposes need to converge into a single and integrated design solution. Contract furniture combines product design with interior and architectural design requests to provide coherent furniture by assembling custom high-quality items from different firms. As a consequence, the design process is complex and collaboration is imperative to achieve the expected goals. This paper explores contract furniture design and defines a technological platform to support team working. The proposed methodology is applied to an industrial case study in the hospitality and retail sectors. Method application brings to define the system platform architecture and its main software modules.
2013
- Supporting the modification process of products through a change management tool
[Relazione in Atti di Convegno]
Malatesta, M; Raffaeli, R; Mengoni, M; Germani, M
abstract
Updating products requires design activities, virtual and physical prototyping of new solutions, test and validation steps. If problems are detected at any of these stages, they cause iterations, waste of time and resources. A change propagation method is initially described as a way to facilitate the introduction of product changes. The approach relies on a multilevel product representation, the modelling of the component dependencies, algorithms to compute the propagation of some desired changes. Outputs are represented by the list of the affected components and indices indicating the impact on the product requirements. The method has been applied in the whole redesign process of a standard product like the fridge. Modifications must be usually released under time constraints. In this context, the outputs of the proposed method are an useful support to reduce iterations and resources waste. The experimentation has been based on case studies assigned to two groups of designers working with and without the tool. It has resulted that designers become more aware of the implications of the engineering changes, they are allowed of better decisions and the whole process becomes shorter.
2012
- A Framework to Link Product Configuration and CAD Automation
[Relazione in Atti di Convegno]
Raffaeli, R; Mengoni, M; Germani, M
abstract
The competitive market forces companies to offer tailored products to meet specific customer needs. To avoid wasting time, design efforts generally address the configuration of existing solutions, without producing substantial design modifications. Configuration tools are used to achieve customized products starting from a common platform. Many approaches have been successfully proposed in literature to automate most design activities when configuring products. In the mechanical filed, research is focused on tools and methods to automatically produce geometrical models and improve the flexibility of the continuous product updating process.
In this context, this paper aims to combine product configuration approaches with design automation techniques in order to support redesign activities of products to fulfil specific requirements. The approach is based on entities called Configurable Virtual Prototypes (CVP). Three different domains are managed and connected via CVP: Product Specifications, Geometrical Data and Product Knowledge. In particular, geometry recognition rules are used to identify the parameterization of parts and the assembly mating constraints.
The approach is exemplified through an industrial case study where a tool has been developed on the basis of the described method. Advantages of the system are shown in terms of achieved product flexibility.
2012
- A Knowledge-Based Design Process For Diabetic Shoe Lasts
[Relazione in Atti di Convegno]
Germani, M; Bernabeu, J A; Mandolini, M; Mengoni, M; Raffaeli, R
abstract
2012
- Automatic geometric recognition of weld beads for supporting virtual prototyping and cost estimation of welding
[Relazione in Atti di Convegno]
Raffaeli, R; Malatesta, M; Mandolini, M; Germani, M
abstract
Welding is widely used in industry for products made of joined sheet metal parts and beams. The virtual prototyping process of welds in standard CAD systems relies on functionalities to manually add weld beads to the assembly models. Weld beads can be in the form of symbolic annotations or 3D solid representations. The size of products in terms of number of parts and required weld beads makes this process cumbersome and time consuming. This paper presents a method to analyze CAD models of product assemblies in order to automatically identify possible welds among the parts using geometric recognition rules. Adjacent faces are detected and Boolean operators on planar loops are used to identify bead paths. Beads are then split in homogeneous portions based on the topology of the connected parts. The geometrical analysis of the connected parts also allows a bead to be characterized in terms of thickness, type, length and accessibility. Finally, the user is provided with functionalities to edit manufacturing properties or exclude unwanted welds. The approach is applied at the design stage to rapidly come to the definition of the welds. If integrated with a CAD tool, this can be used as input for an efficient detailing phase. Moreover, the paper presents an application for the cost estimation of the designed welded product. Weld beads are given a realization time, and hence a cost, based on their geometric size and employed welding technology. Some examples from the industry are presented to show benefits in terms of time savings and accuracy of the cost estimation process. Copyright ?????? 2012 by ASME.
2012
- Mould Design Process in High Pressure Die Casting Supported by Virtual Prototyping
[Relazione in Atti di Convegno]
Raffaeli, R; Favi, C; Mandorli, F
abstract
High Pressure Die Casting is a widely used industrial process to manufacture complex-shaped product in light alloys. Virtual prototyping techniques, especially numeric based simulations of the casting process, evaluates the die filling process and helps faster optimization of the gating system. However, no formalised method to design an optimal gating system using virtual prototype tools is available yet and the majority of the studies aim to optimise existing geometries. The purpose of this work is focused on new approach to easily define the entire geometry of the mould without starting from an existing solution. The paper presents a four step approach which allows optimal mould and gating system to be designed taking advantage of simulation tools. Rather than optimizing the geometries of predefined designs by running attempt trials, the approach defines a procedure to position cavities, gating systems and determine the whole mould geometry. The design of a 6-cavity mould for gas cooking burners is reported as a test case for the validation of the method. The reached quality of the mould design has been assessed using metallographic analyses of the cast products.
2012
- Tools for design and validation of shoe lasts for diabetic patients
[Articolo su rivista]
Germani, M; Mandolini, M; Mengoni, M; Nester, C; Raffaeli, R
abstract
Background: It is common practice to prescribe customised footwear to people with diabetes to reduce the risk of foot ulceration. Although shoe customising systems have been proposed, effective tools for designing shoe lasts for diabetic patients are lacking. The shape of the lasts must meet certain biomechanical objectives, while maintaining the style of the shoe.
Method: The main contributions of this work are as follows: the creation of an artificial-neural-network-based framework to correlate foot measurements and medical data to required footwear features; the definition of repeatable geometrical procedures to measure foot and last scans; and the definition of geometrical operators to modify the last shape according to its original aesthetic and specific footwear parameters. These parameters are computed by a knowledge-based system on the basis of the patient's pathology and best practices of experienced technicians.
Results: Dedicated software systems integrated in a common platform are implemented to support the last design process. Test case studies and a survey show the advantages provided by the proposed approach in terms of achieved quality and shoe developing time (72% time savings).
Conclusions: A design framework with dedicated tools is proposed for the customisation of shoe lasts for diabetic patients. Further research should be focused on tools to design the insole, outsole and other shoe components.
2012
- Virtual planning for autonomous inspection of electromechanical products
[Articolo su rivista]
Raffaeli, R; Cesetti, A; Angione, G; Lattanzi, L; Longhi, S
abstract
High quality electromechanical products require sophisticated and costly diagnostic tools to ensure the absence of defects in the final artefacts. The main requirements for reliability tests are flexibility, sensor sharing and early defect detection. The aim is the substitution of the current practice based on manual checking of few samples with standardized and repeatable quality control carried out by autonomous mobile platforms.
Virtual planning of the inspection tasks, the simulation of the navigation in a poorly structured environment as well as the interaction with the product, are crucial aspects which have been faced through a dedicated system framework. The paper proposes a solution composed of a software for the virtual planning and simulation of inspection tasks, hardware setup composed of an autonomous platform with sensors and actuators, and a service oriented software infrastructure for navigation and perception. Consistent paths to be followed by the robot are elaborated in a graphical environment on the basis of inspected product locations and measuring tasks.
The system has been implemented for household appliance inspection in reliability laboratories where life tests are carried out under real operation conditions. The results in terms of inspection mission planning capabilities and localization performances are presented.
2011
- Advanced Computer Aided Technologies for Design Automation in Footwear Industry
[Articolo su rivista]
Raffaeli, R; Germani, M
abstract
In the footwear industry there is growing methodological research linking advanced computer-based technologies to the traditional manufacturing process. This paper deals with the automation of shoe design phases and describes a computer aided design system that brings together theories and tools from geometric modeling, image processing, and reverse engineering. At first, the paper reviews the current technologies used for creating new shoe models. Then the paper presents an approach based on shoe 3D virtual modeling in order to overcome the traditional time-consuming manual operations. The approach is concretized into dedicated tools able to automatically perform design of the last shape model and flattening of the shoe styling curves represented in the virtual prototype. The modeling tool uses 3D geometric rules derived from the analysis of strategies adopted by skilled manual operators, while the styling curves recognition and flattening are based on specific image processing algorithms and geometrical deformation rules. Experimental results show a good compromise between quality results and modeling time.
2011
- An Early-Stage Tool to Evaluate the Product Redesign Impact
[Relazione in Atti di Convegno]
Raffaeli, R; Mengoni, M; Germani, M
abstract
In order to face the rapid changing market requirements, companies need methods and tools in order to implement flexibility over the whole product development process, from ideation to manufacturing. The proposed approach targets the development of a method to support decision making in product redesign activities. Design alternatives and product modifications can be rapidly evaluated in terms of feasibility, cost and time. The approach is based on a product structure multilevel representation, where functions, modules, assemblies and components are strictly interrelated. The representation allows criteria and rules in order to efficiently connect the elements within the same level and among levels. Such connections will contain the values to estimate the impact of analyzed product changes. In this way the structure will serve as evaluation tool in the early redesign phases. In order to manage and interact with the structure a software tool has been developed, called Modulor. This system allows modeling the product representation and rapidly evaluating the consequences in terms of change propagation. The tool was tested within the R&D department of a large sized company producing household appliances. Pilot studies have revealed shorter redesign cycles thanks to a broader understanding of implications while deciding among several implementation solutions.
2011
- An integrated methodology for functional simulation of dental prosthesis
[Relazione in Atti di Convegno]
Meneghello, R; Turchetto, M; Savio, G; Cerardi, A; Raffaeli, R; Planchenstainer, L
abstract
Studies and implementations of virtual and physical prototyping on dental prosthesis can be found in literature, together with experimental studies on forces generated during chewing due to occlusal geometry.
In this work it is proposed an integrated methodology for the functional design and simulation of dental prosthesis. This methodology develops in four phases: virtual and physical prototyping, contact forces and areas analysis and functional optimization of teeth and arches geometry.
A virtual environment for the modeling of the prosthesis (NM - Tooth) was developed: it includes a database of 3D CAD models of artificial teeth and allows to simulate the fabrication techniques used in dentistry. In particular, it is possible to create a full denture virtual model by a semi - automatic procedure, where a preliminary occlusal configuration is set up. By using rapid-prototyping techniques, a physical model of the prosthesis is manufactured which is utilized for the experimental analysis.
The analysis phase includes the study of the occlusion forces in relation to the identification of contact areas. A multi - axial force measuring system allows the detection of forces acting on the physical model. Simultaneously with a reverse engineering procedure the relevant contact areas in the virtual model are related with the load configuration.
According to the experimental output, it is possible to modify the preliminary geometry both of the arches and of the individual tooth.
This integrated methodology is an original instrument to study the dental prosthesis and acquire information for its functional improvement.
2011
- Computation of optimal acquisition viewpoints for the 3D optical inspection of mechanical components
[Relazione in Atti di Convegno]
Raffaeli, R; Germani, M; Mandorli, F; Mengoni, M
abstract
Purpose:
In the mechanical field agile production requires rapid and flexible shop-floor control techniques in order to verify the manufacturing operations effectiveness. To accomplish this goal, 3D scanning systems are evermore used for quality control purposes. Generally, 3D CAD (Computer Aided Design) product models can be used as reference in order to manage the verification process. The geometrical information represented in the 3D CAD model can be used in order to virtually plan, simulate and pilot the inspection process. Even if many methods have been developed to support view planning from known 3D CAD models, it is still necessary to study strategies and tools to improve the verification process performance.
Method:
The present work targets the development of view planning algorithms in order to support the automatic inspection of 3D shapes, including dimensional and geometrical tolerances.
Result:
Algorithms have been implemented in a prototypal software system that has been experimented as off-line application to provide inputs to a multi-axis Degree of Freedom (DoF) robot arm mounting an optical 3D scanner.
Discussion & Conclusion:
Two test cases from automotive and die casting fields are presented. They show the computation of acquisition poses in a suitable sequence and correspondence to the experimental data.
2011
- Knowledge Based Plants Layout Configuration and Piping Routing
[Relazione in Atti di Convegno]
Cicconi, P; Raffaeli, R
abstract
The design of industrial plants requires managing many geometrical and non geometrical data to reach a satisfactory solution in terms of costs, performance and quality. An approach is presented to support designers in the elicitation and formalization phase of the required knowledge. Then an integral prototypal software application accomplishes layout configuration tasks through a customized graphic wizard. A routing algorithm is presented to automate calculation and modelling of piping and electrical cables respecting design constraints. Cogeneration plant powered by micro gas-turbines has been chosen as test case to evaluate the proposed design method and tool.
2011
- Methods and Tools Dedicated to Shoes Customization for People with Diabetes
[Relazione in Atti di Convegno]
Germani, M; Mandolini, M; Mengoni, M; Raffaeli, R; Montiel, E; Davia, M
abstract
Purpose: Study and development of innovative tools in order to support the design and manufacturing of customised shoes for people with diabetes.
Method: The approach is based on the identification of main critical stages of footwear customisation when patient parameters have to be properly used; medical knowledge formalisation is translated in new software design tools that interest the footwear shape and the suitable materials.
Result: Rapid customisation of preventive shoes for people with diabetes
Discussion & Conclusion: ???Diabetic foot??? in one the main effects of diabetes; it is important to develop shoes able to prevent this kind of complication. This paper reports an approach and related design tools that allow customising shoes on the basis of patient features. Rapid manufacturing technologies have to be still analysed in order to complete the whole process.
2011
- Shoes Customization Design Tools for the “Diabetic Foot”
[Articolo su rivista]
Davia, M; Germani, M; Mandolini, M; Mengoni, M; Montiel, E; Raffaeli, R
abstract
Diabetes is one of the main causes that generate foot health related diseases. It impacts on a large percentage of world population and is expected to grow in next 20 years. Good footwear is fundamental for influencing foot health status in particular when foot can be subjected to many serious problems as in case of diabetic patients. This research work faces this problem by defining an approach and related computeraided echnologies in order to properly design customized shoes for people suffering from diabetes. Design rules have been fixed by formalizing knowledge that expert podiatrists use to prevent foot diseases. Studied and implemented technologiesinterest the whole footwear design process: foot scanning, foot dynamic pressure measurement, design of last, insole and outsole. This paper is focused on the description of design software system structure and related tools, and, then, it reports preliminary experimental results on 20 case studies.
2010
- A Framework for Flexible and Autonomous Reliability Tests of Household Appliances Supported by Virtual Planning
[Relazione in Atti di Convegno]
Raffaeli, R; Cesetti, A; Angione, G; Lattanzi, L; Longhi, S
abstract
The development of a framework for diagnosis and testing in reliability laboratories (life test labs) of household appliances is addressed. The proposed system targets the repetitive task of gathering numerous measurements on products in order to guarantee a standardized and repeatable quality control. The proposed innovation considers the diagnosis and testing station not as a fixed system but as a flexible one, based on mobile robot with sensory and diagnostic skills.
The developed framework mainly consists of a service oriented software infrastructure for virtual planning and simulation of inspection tasks, hardware setup composed of an autonomous platform with sensors and actuators, a control system dedicated to navigation and perception.
The paper mainly presents the inspection virtual planning system. Some details are then provided on the implementation of a prototypal system for household appliances inspection. Some result in terms of performances of system components are presented in the last part of the paper.
2010
- A Knowledge Based Approach to Flexible Part Design
[Articolo su rivista]
Germani, M; Raffaeli, R
abstract
Virtual prototyping (VP) of complex machines requires the realistic representation of components to perform robust analyses and simulations. In many cases, machines are an assembly of rigid and flexible components. Although modern three-dimensional CAD systems can be considered powerful tools for modelling solids or surfaces representing rigid bodies, they are not adequate to model soft material components, especially a realistic visualisation of physical behaviour. This drawback motivated the present research work. In particular, this paper describes an approach and the related knowledge-based software system (FlexSim) developed to create virtual prototypes facilitating product development in cases of flexible parts like cables, pipes and wires. The resulting VP tool integrates the CAD technology and the dedicated structural simulation methods to automatically model and validate three-dimensional functional sub-groups having flexible parts. The system application is shown on metallic reinforced elastomer hoses used for hydraulic power transmissions. For this purpose, a finite-element approach has been implemented to find hose configurations for given boundary conditions determined by mounting positions. Pipe fittings are selected and automatically assembled and the optimal hose length and its ideal spatial disposition are calculated. Simulations of behaviour allow the rapid optimisation of a solution. The system has been tested on agricultural harvest machines and mining equipment, which widely employ hydraulic transmissions for moving groups of components. As a result, the number of physical prototypes, the lead-time due to the trial-and-error activities and the product development costs can be significantly reduced.
2010
- A method for performance evaluation of RE/RP systems in dentistry
[Articolo su rivista]
Germani, M; Raffaeli, R; Mazzoli, A
abstract
Purpose - The purpose of this paper is to investigate a method for comparing the scanning and reproducing accuracy of highly shaped objects like plaster casts used in dentistry. Design/methodology/approach - Theoretical considerations on errors introduced by the scanning systems and subsequent point clouds data elaboration have led to a method to estimate the accuracy of the whole process. Suitable indices have been chosen and computed at each stage. As a final result, the overall chain, scanning and reproducing systems can be assessed. In order to validate the proposed method casts have been scanned by means of commercial systems and then reproduced by using different rapid prototyping technologies, materials and parameters. Error indices have been computed and reported. Findings - Since it is not possible to define reliable and meaningful reference models for non-standard shapes, an absolute accuracy value for the scanning process cannot be stated. Anyway the proposed method, thanks to relative performance indices, allows the comparison of different acquisition systems and the evaluation of the most performing manufacturing chain. Practical implications - The study provides a method to assess the relative performance between commercial systems both in scanning and reproducing stage. Originality/value - In literature, some studies on the accuracy of scanning devices have been found but they are based on standard geometrical features. In this paper, the problem of complex shapes in absence of reference model is addressed instead.
2010
- A software system for “Design for X” impact evaluations in redesign processes
[Articolo su rivista]
Raffaeli, R; Mengoni, M; Germani, M
abstract
Market always asks for new products in short time. It requires an introduction of new tools and methods for managing continuous product changes while evaluating their impact in terms of design efforts, manufacturing costs, time to market, etc in real time. The present research work aims at developing a design platform to support the creation, visualization and navigation of a multilevel product representation where functions, modules, assemblies and components are strictly interrelated. The introduction of "Design for X" principles as rules to relate all aspects contributing to product design, allows evaluating the impact of changes at three levels. The approach and the proposed platform have been applied in the field of refrigerators in order to support both designers and engineers in rapidly configuring the optimal design solution in respect of the company's requirements formalized by the implemented "Design for X" rules.
2010
- An Approach to Support the Implementation of Product Configuration Tools
[Relazione in Atti di Convegno]
Raffaeli, R; Mengoni, M; Germani, M; Mandorli, M
abstract
Companies applying mass customization paradigm regard the design process as a configuration task where the solution is achieved through the extraction of a new instance from a modular product structure. In this context product configuration management tools are evermore important. Although tools have been already proposed, they fail in real industrial contexts. Main causes are recognizable in high efforts in systems implementation and lack of flexibility in products updating. This research aims to develop an approach to overcome drawbacks and simplify the implementation and the use of product configuration systems also in redesign activities. The paper initially reviews existing systems in terms of design knowledge representation methods and product structure formalization techniques. Then, an approach based on Configuration Virtual Prototypes which store and manage different levels of knowledge, is presented. In particular, a framework is outlined in order to represent design data and its formalization in configuration tools. Three different domains are managed and connected via Configuration Virtual Prototypes: Product Specifications, Geometrical Data and Product Knowledge. Specifically, geometrical data aspects are analyzed in detail providing approaches for eliciting knowledge introduced by parametric template CAD models. The approach will be exemplified through a real application example where an original tool has been developed on the based of the described method. Benefits of the system will be shown and briefly discussed, in particular in terms of reachable flexibility in solutions.
2010
- Approach for Intelligent Design and Manufacturing of Footwear for Diabetic Persons
[Relazione in Atti di Convegno]
Germani, M; Mengoni, M; Montiel, E; Raffaeli, R
abstract
Diabetes and arthritis are major foot health related diseases, impact on a large percentage of European and world population, and are set to grow in next 30 years. Footwear is fundamental to influencing foot health status not only because good footwear can be beneficial, but also because poor footwear can cause so many serious problems. There is thus an increasing health care need driving the research into improved “intelligent” design and manufacturing technologies. This paper faces this problem by studying a new approach to develop proper shoes for people with diabetes able to reduce foot problems by implementing the following key issues: customization, rapidity and comfort. Main research goals can be achieved by basing the whole footwear product development process on the integration of innovative technologies and techniques to support shoes customization for diabetic persons such as new biomechanical CAD systems, new foot scanning devices, new manufacturing methods and new comfort measurement tools. The paper is focused on the description of the adopted approach and some preliminary results about the innovative supporting systems.
2010
- Automation of flexible components virtual prototyping: methodology, tools and validation
[Articolo su rivista]
Raffaeli, R; Mandolini, M; Germani, M
abstract
3D CAD systems are powerful tools for modelling rigid bodies but they are not adequate in order to model flexible material components, especially if a realistic simulation of physical behaviour is required as in virtual prototyping. This paper describes the methodology used to develop a knowledge-based system in order to automatically create virtual prototypes of uniaxial flexible components like cables, pipes and wires. The method has been translated in an operative design software system for metallic-reinforced elastomer hoses. The resulting VP tool integrates the 3D CAD technology and suitable structural simulation methods. The robustness of software system has been verified and errors are assessed. A dedicated experimental set-up has been realised in order to compare the virtual results with the real component behaviour. The system has been applied in the design of multifunctional agricultural machines showing reduction of physical prototypes and the lead-time due.
2010
- CAD-Based Environment to Bridge the Gap between Product Design and Tolerance Control
[Articolo su rivista]
Germani, M; Mandorli, F; Mengoni, M; Raffaeli, R
abstract
Mechanical product quality is strongly influenced by the respect of Geometrical Tolerances (GT). On the other hand, competitiveness forces companies to improve their productivity making the tolerance verification process faster and faster and more flexible. Component control by 3D full field optical digitizing systems and specific CAD-based (Computer Aided Design) inspection software tools are important steps forward for the achievement of the above-mentioned goals. However, the adoption of these solutions in industry is minimal. This may be due both to technological factors, i.e. poor systems usability, and organizing factors, i.e. clear separation between design department and quality control department. In this context, our research aims at developing a new easy to use CAD-based tool for simulating, driving and optimizing the GT inspection process. Once a component has been digitized, the developed software system automatically realizes the tolerances virtual control. Hence, the designer can prescribe tolerances, pilot the measurement system and verify the component conformity. The implemented tool is based on Full of Information (FoI) CAD models, which contain tolerance data, linked to a knowledge database, where measurement strategies and verification rules are stored. A computation engine calculates the measurement paths and performs the tolerances verification. The prototypal system has been tested on different real cases. Experimental results showed high performances in terms of timesaving and robustness.
2010
- Change Management, Modularity and Design for X: A Design Supporting Tool Based on an Integrated Approach
[Relazione in Atti di Convegno]
Raffaeli, R; Mengoni, M; Germani, M
abstract
Flexibility has become imperative to face the increasing market demands. Its implementation across the whole product development process is not a trivial task. It requires the introduction of new tools and methods for managing continuous product changes while evaluating in real time their impact in terms of design efforts, manufacturing costs, time to market, etc. The present research work aims at developing a design platform to support the creation, visualization and navigation of a multilevel product representation where functions, modules, assemblies and components are strictly interrelated. The introduction of “Design for X” principles as rules to relate all aspects contributing to product design, allows the evaluation of changes impact at the three levels. The approach and the proposed platform have been applied in the field of refrigerators in order to support both designers and engineers to rapidly configure the optimal design solution in respect with the company requirements formalized by the implemented Design for X rules.
2010
- Modelling Product Structure in Order to Support “Design For X” Evaluations
[Relazione in Atti di Convegno]
Germani, M; Mengoni, M; Raffaeli, R
abstract
2010
- Modular Product Configuration: an Automatic Tool for Eliciting Design Knowledge from Parametric CAD Models
[Relazione in Atti di Convegno]
Raffaeli, Roberto; Cicconi, Paolo; Mengoni, Maura; Germani, Michele
abstract
The offer of tailored products is a key factor to satisfy specific customer needs in the current competitive market. Modular products can easily support customization in a short time. Design process, in this case, can be regarded as a configuration task where solution is achieved through the combination of modules in overall product architecture. In this scenario efficient configuration design tools are evermore important. Although many tools have been already proposed in literature, they need further investigation to be applicable in real industrial practice, because of the high efforts required to implement system and the lack of flexibility in products updating. This work describes an approach to overcome drawbacks and to introduce a product independent configuration system which can be useful in designing recurrent product modules. To manage configuration from the designer perspective, the approach is based on Configurable Virtual Prototypes (CVP). In particular, the definition of geometrical models is analyzed providing a tool for eliciting and reusing knowledge introduced by parametric template CAD models. Semantic rules are used to recognize parts parameterization and assembly mating constraints. The approach is exemplified through a case study.
2010
- Palatal Volume Following Rapid Maxillary Expansion in Mixed Dentition
[Articolo su rivista]
Gracco, A; Malaguti, A; Lombardo, L; Mazzoli, A; Raffaeli, R
abstract
Objective: To evaluate volumetric variations in the palate following rapid expansion, both immediately after treatment and over time. Materials and Methods: The sample was composed of 30 patients in early mixed dentition treated with a Haas-type device cemented onto the primary second molars. The mean age of the patients upon commencement of expansion was 7 years and 6 months (standard deviation [SD], 12 months). Measurement of palatal volume was conducted via 3D acquisition of plaster models using laser scanning before treatment (T1), upon device removal (T2), and 2.6 years afterward (T3). Results: The volume of the palate increased in a statistically significant fashion from T1 to T2 and from T1 to T3, and it decreased in a nonsignificant fashion from T2 to T3. Conclusions: Palatal volume significantly increases with rapid maxillary expansion (RME) treatment with insignificant relapse. The use of virtual 3D models with the aid of Apposite software permits evaluation of the morphologic and volumetric changes induced by orthodontic treatment.
2010
- Three-dimensional diagnosis and visualization supports in orthodontics based on Reverse Engineering and Solid Free-form Fabrication techniques
[Capitolo/Saggio]
Mazzoli, A; Germani, M; Raffaeli, R; Gracco, A
abstract
2009
- A Knowledge Based Approach for Affordable Virtual Prototyping: The Drip Emitters Test Case
[Relazione in Atti di Convegno]
Cicconi, P; Raffaeli, R
abstract
Virtual prototyping lacks of application in SME due to the costs of software systems and the necessity of skilled operators. The aim is to improve dripper emitters design process reducing costs. A knowledge base is presented to gather data on products behaviour in terms of experimental data and simulation results for a set of meaningful test cases. Input design parameters were linked to performance indices on the base of the correlations emerged in the analysis. Specifications for a new product can be used to extract similar cases and to define a possible solution in terms of a combination of them.
2009
- Approach for Integrating Tolerance Control into Product Design Stage
[Relazione in Atti di Convegno]
Germani, M; Mengoni, M; Raffaeli, R
abstract
Ever-increasing competition in global markets forces companies to manufacture higher-quality products faster than their competitors. In this context it is imperative taking in account all manufacturing and quality control aspects in the early design phase. The right prescription of the GD&T tolerances has a meaningful impact on the whole product development process. The designer has to be able to take rapid decisions in order to minimize cost and maximize quality. The decision-making process has to be supported by proper data usually generated in the design department. The aim of this research work is the centralization of product development phases into design stage. In particular an approach is proposed in order to transfer the tolerancing activities from the manufacturing shop floor to the product design department. The approach is concretized in a set of software and hardware tools able to: simulate and plan the GD&T quality control, manage the measurement system, analyze the acquired data and improve the tolerance prescriptions. A set of metrics has been identified in order to evaluate advantages and limitations of the proposed approach.
2009
- Approach for Managing Lean Product Design
[Relazione in Atti di Convegno]
Germani, M; Graziosi, S; Mengoni, M; Raffaeli, R
abstract
Flexibility is the main keyword in order to face the rapid changing market requirements. Companies need methods and tools in order to implement flexibility over the whole product development process, from ideation to manufacturing. The proposed approach goes towards the concretization of the lean product design concept. It can be achieved if design alternatives and product modifications can be rapidly evaluated in terms of feasibility. resources. cost and time. The approach is based on a multilevel representation of the product structure. where functions. modules. assemblies and components are strictly interrelated. The complex representation requires suitable software tools in order to model and visualize the entire structure and support the easy user navigation. On the other hand it is necessary to define rules and operators to interact with the structure in order to make product changes and evaluate the possible impact. Finally. this system has to be integrated within the product development flow for exchanging data and information with CAD, PLM and ERP tools. In this paper the general approach is defined and the preliminary software solution is described.
2009
- Automation of 3D View Acquisition for Geometric Tolerances Verification
[Relazione in Atti di Convegno]
Germani, M; Mengoni, M; Raffaeli, Roberto
abstract
Geometrical tolerances control of mechanical components requires methods and tools in order to improve the efficiency of process in terms of time. Dedicated software systems in order to plan and simulate the control and hardware tools in order to rapidly acquire the needed 3D information can support the process improvement. In this context it is important to use the 3D CAD (Computer Aided Design) model, as base to plan and pilot the whole process. The aim of present work is to describe an automatic geometrical tolerances measurement system usable during the design stage. It is based on three main tools: a CAD-based modular software tool, in order to plan, simulate, and pilot the whole verification process, a 3D optical digitizer, as shape acquisition system, and a multi-axis Degree of Freedom (DoF) robot arm in order to move the digitizer. This paper is focused on the developed algorithms to optimize the 3D views acquisition planning. Surface Normal Method and Visibility Map concepts have been reworked for range scanner positions determination and the optimal path is computed by a graph of alignable simulated scans. Experimental test cases are reported in order to show the system performance.
2009
- How Product Designer Can Manage the Quality Control Process
[Relazione in Atti di Convegno]
Germani, M; Mengoni, M; Raffaeli, R
abstract
The right prescription of the GD&T tolerances has a meaningful impact on the whole product development process. The designer has to be able to take rapid decisions in order to minimize cost and maximize quality. The decision-making process has to be supported by proper data usually generated by the design department. The aim of this research work is the centralization of product development phases into design stage. In particular an approach is proposed in order to transfer the whole tolerancing activities from manufacturing shop floor to product design department. The approach is concretized in a set of software and hardware tools able to: simulate and plan the GD&T quality control, manage the measurement systems, analyze the acquired data and improve the tolerance prescriptions. A set of metrics has been identified in order to evaluate advantages and limitations of proposed approach.
2009
- Sviluppo di un Sistema di Prototipazione Virtuale per Protesi Odontoiatriche
[Relazione in Atti di Convegno]
Raffaeli, R; Savio, G; Germani, M; Meneghello, R
abstract
Nella realizzazione di protesi totali removibili risulta assente una fase di progettazione che preveda la definizione di specifiche tecniche in grado di consentire la verifica funzionale sulla protesi realizzata. In questo articolo si presenta uno studio finalizzato allo sviluppo di un sistema di prototipazione virtuale di protesi dentarie totali removibili. Tale sistema costituisce il nucleo di un ambiente integrato per la progettazione e la simulazione funzionale dei singoli denti e della protesi con particolare riferimento alla loro configurazione cinematica e strutturale.
Il prototipo virtuale ottenuto può essere sottoposto ad indagine per la verifica della qualità funzionale dello schema di occlusione realizzato in termini di distribuzione dei contatti nella massima intercuspidazione e negli eventuali movimenti protrusivi e di lateralità, mediante algoritmi basati sull’analisi di interferenza.
Il sistema è stato validato mediante confronto tra protesi virtuale e protesi reale, sottoposta a scansione ottica. Tale confronto è basato sull’analisi delle posizioni e degli angoli di orientamento dei singoli denti e sull’identificazione dei punti di contatto, cardine della prestazione funzionale del dispositivo protesico.
2009
- Validation of a Virtual Prototyping Tool for Uniaxial Flexible Parts
[Relazione in Atti di Convegno]
Raffaeli, R; Mandolini, M; Graziosi, S
abstract
Modern 3D CAD systems piping modules are powerful tools for modeling solids as rigid bodies but neglect their physical behavior. On the contrary, Virtual Prototyping requires the realistic representation of components especially for flexible parts. A finite element based system is presented to model flexible uniaxial components like hoses, wires and cables on the base of mounting and loading conditions. It interacts with a 3D CAD system in order to generate geometries and assess optimal solutions, interferences and overall stress condition.
The proposed system requires an adequate validation in order to be efficiently integrated in the design workflow. The first investigated aspect was material characterization. Since metallic reinforced elastomeric hoses show non linear behavior, a simplified model based on mean section characteristics was drawn from numeric models and experimental measurements. Then, some significant configurations have been physically reproduced on a test bed, acquired through a Reverse Engineering system and compared with simulation outputs of identical setups.
The approach, the validation activity, results and some meaningful application examples are presented in the paper.
2008
- Agile design approach for managing change propagation in modular products assembly
[Relazione in Atti di Convegno]
Graziosi, S; Germani, M; Mengoni, M; Raffaeli, R
abstract
Implementing mass customization manufacturing implies frequent design changes and recurrent process variations. Decisions taken during product development can have consequences on the functional, physical and process structures, which either enhance or reduce product manufacturability. This paper proposes a methodology to help designers on considering both design and production process aspects in order to assist them on finding best solutions. In particular, we deal with the integration of design and assembly planning aspects in software tools conceived to achieve a more cost-effective realization of modular product variety.
2008
- Direct fabrication through electron beam melting technology of custom cranial implants designed in a phantom based haptic
[Articolo su rivista]
MAZZOLI, A; GERMANI, M; RAFFAELI, R
abstract
Repairing critical human skull injuries requires the production and use of customized cranial implants and involves the integration of computer aided design and manufacturing (CAD and CAM). The main causes for large cranial defects are trauma, cranial tumors, infected craniotomy bone flaps and external neurosurgical decompression. The success of reconstructive cranial surgery depends upon: the preoperative evaluation of the defect, the design and manufacturing of the implant, and the skill of the operating surgeon. Cranial implant design is usually carried out manually using CAD although this process is very time-consuming and the quality of the end product depends wholly upon the skill of the operator. This paper presents an alternative automated method for the design of custom-made cranial plates in a PHANToM ®-based haptic environment, and their direct fabrication in biocompatible metal using electron beam melting (EBM) technology.
2008
- Evaluation of 3D Technologies In Dentistry
[Articolo su rivista]
Gracco, A; Mazzoli, A; Raffaeli, R; Germani, M
abstract
Quality of service, in terms of improvement in patient satisfaction, is an increasingly important objective in all medical fields, and is especially imperative in orthodontics due to the high numbers of patients treated. Information technology can provide a meaningful contribution to bettering treatment processes, and we maintain that systems such as CAD, CAM and CAE, although initially conceived for industrial purposes, should be evaluated, studied and customized with a view to use in medicine. The present study aims to evaluate Reverse Engineering (RE) and Rapid Prototyping (RP) in order to define an ideal chain of advanced technological solutions to support the critical processes of orthodontic activity.
2008
- Integration of a Flexible Pipes Simulation Tool in a CAD System
[Relazione in Atti di Convegno]
Raffaeli, R; Mandolini, M; Germani, M
abstract
3D CAD systems are powerful tools in modelling solids or surfaces representing rigid bodies. For a comprehensive virtual prototype of devices and machines also flexible parts like cables, pipes and wires must taken into account. In this paper, we present a software system developed for simulating one-dimensional flexible parts, especially metallic-reinforced elastomers hoses, used for hydraulic power transmissions. For this purpose a finite element approach has been followed to find hose configurations for given boundary conditions determined by assembly positions. The model considers large displacements, as well as gravity and inner pressure effects. The tool has been implemented to interact as a knowledge-based system with a parametric 3D CAD modeller in order to allow real time definition of the design solution. Pipe fittings are selected and interactively assembled, the hose is chosen out of working parameters with the optimum length, and the simulation engine calculates the configuration and its deformation level. The system has been tested on mining equipment, which widely employs hydraulic transmissions for moving groups of components.
2008
- Object-oriented framework for managing modular product configuration
[Relazione in Atti di Convegno]
Raffaeli, R; Germani, M
abstract
Companies applying mass customization paradigm regard the design process as a configuration task where the solution is achieved through the extraction of a new instance from a modular product structure. In this context product configuration management tools are evermore important. Circumscribing the application to the design phase their main objective is to automate the activities such as: components arrangement and dimensioning, 3D geometry modelling, 2D drawings execution, multi-view BOM compiling, costs estimation.
Our research aims to develop an approach to simplify the implementation of product configuration systems.
This paper, after a review of current available configuration systems in terms of design knowledge representation methods and product structure formalisation techniques, presents an object-oriented approach that is adopted as base for rationalising the design knowledge capture and structuring the product platform. The result is a framework able to manage the product configuration task.
The approach will be exemplified through a real application example and benefits as well as limitations of the proposed approach will be discussed, in particular in terms of usability.
2008
- Reverse Engineering Techniques to Evaluate Palatal Morphologic and Volumetric Changes After the Use of a Rapid Expander
[Relazione in Atti di Convegno]
Mazzoli, A; Germani, M; Raffaeli, R
abstract
The rapid palatal expander (RPE) is an orthopaedic appliance that widens the upper jaw by separating the midpalatal suture. This procedure also allows for the creation of more space for the eruption of the permanent teeth. The procedure for RPE is still controversial and many different methods have been described since the time of Angell, when he presented the first case of correction of maxillary transverse discrepancy in 1860. A permanent increase in maxillary transverse width is attained routinely in children and adolescents using orthodontic expansion appliances and retention, and this treatment does not normally cause any problem. In this work is presented a preliminary study, based on a reverse engineering measurement approach, to evaluate the palatal morphologic and volumetric changes after the use of a RPE appliance in four children patients (aged 7-8 years) in mixed dentition with a posterior crossbite, a skeletal Class II malocclusion and with narrow maxillary arches. The patients were treated using the Haas RPE in order to solve the maxillary contraction. For each patient three measurements were done: pretreatment (T1), after expansion therapy (T2), and six months after the removal of the expander (T3).
2008
- Sketches to Support Automatic Product Configuration
[Working paper]
Germani, M; Raffaeli, Roberto
abstract
2007
- Application of reverse engineering and rapid prototyping in orthodontics
[Relazione in Atti di Convegno]
Lombardo, L; Gracco, A; Mazzoli, A; Raffaeli, R; Germani, M
abstract
2007
- Caratterizzazione di sistemi RE/RP per il settore odontoiatrico
[Relazione in Atti di Convegno]
Mazzoli, A; Raffaeli, R; Germani, M
abstract
The quality of the service, in terms of patient satisfaction improvement, is an evermore important objective to be achieved in all sectors of the medicine, and it is more evident in the orthodontic field, due to the high percentage of interested people. The information technologies can give a meaningful contribution to the processes improvement. However, CAD, CAM, CAE systems have been conceived and developed to be used in the industrial fields. On the other hand, in our opinion, they have to be evaluated, studied and customized to be usable in medicine.
In this context the present research aims to define an ideal chain of advanced technological solutions, considering Reverse Engineering (RE) and Rapid Prototyping (RP), for supporting the critical processes of the orthodontist activity.
2007
- Development of a Multilayer Change Propagation Tool for Modular Products
[Relazione in Atti di Convegno]
Raffaeli, R; Germani, M; Graziosi, S; Mandorli, F
abstract
In this work we focus our research on the product design related aspects; currently we deal with modularity, product architecture and change propagation issues along the design process. In order to apply abstract concepts to design practise different approaches and tools have been proposed; anyway presently concrete software solutions and applications examples are still lacking. Companies modify their products for a number of reasons and rarely start from new ideas when designing. Due to the lack of suitable tools and methodologies designers are not aware of modifications impacts and propagations when trying to change or update a product. In this paper we present our research efforts in developing a methodology and the related software tool to support change management during the product redesign. It is conceived as guiding tool based on a product multilevel representation: from functional contents to implementation design; currently the designer can obtain a complete presentation of the product parts characteristics and their relations. In this way the resulting graphical model becomes a company tacit knowledge repository about the product. Operational functionalities are provided to support the designer during his activities. This work has been carried out and tested on the redesign process of a washing machine in collaboration with an Italian company, leader in house working appliances.
2007
- Multi-Level Representation for Supporting the Conceptual Design Phase of Modular Products
[Relazione in Atti di Convegno]
Germani, M; Mengoni, M; Raffaeli, R
abstract
Designing a new product, in most cases, means a modification of an existing one. Both adopting known solutions in different products, that inserting new technological processes into a consolidated context, the most design effort must be dedicated to the early evaluation of the impact of needed engineering changes to achieve the final result, in terms of cost, quality and time. Such activity is particularly strategic in the modular product development. The aim of our research work is to develop a method and the related tools that enable designers to easily represent the product platform, to structure the relations between modules defined at different levels of detail and, hence, to simulate, analyze and evaluate the modifications impact during the new product variant definition phase. A multi-level product structure able to represent the product informative content at different levels of detail is presented.
2007
- Progettazione di Placche Craniche Personalizzate usando Tecnologie SFF e Sistemi di Modellazione Haptic
[Relazione in Atti di Convegno]
Raffaeli, R; Germani, M; Mazzoli, A
abstract
Repairing severe human skull injuries requires customized cranial implants. Trauma and cranial tumors are the main causes for large cranial defects. The success of the reconstructive cranial surgery depends on diverse aspects regarding the preoperative evaluation of the defect, the design and manufacturing of the implant and the execution of the operation. Currently, the design of membranes is mainly a manual work, even with the use of CAD facilities, and results in a time-consuming and user-dependent skull reconstruction.
This paper presents a critical review of a design methodology for custom-made cranioplasty plates in a PHANToM®-based haptic environment and the possibility to manufacture the same using Solid Freeform Fabrication technologies.
2007
- Solid Freeform Fabrication of Custom Cranial Implants Designed in a Phantom-based Haptic Environment
[Relazione in Atti di Convegno]
Mazzoli, A; Germani, M; Raffaeli, R
abstract
Repairing severe human skull injuries requires customized cranial implants. Trauma, cranial tumors, infected craniotomy bone flaps and neurosurgical external decompression are the main causes for large cranial defects. The success of the reconstructive cranial surgery depends on diverse aspects regarding the preoperative evaluation of the defect, the design and manufacturing of the implant and the execution of the operation. Currently, the design of membranes is mainly a manual work, even with the use of CAD facilities, and results in a time-consuming and user-dependent skull reconstruction. This paper presents an automated design methodology for custom-made cranioplasty plates in a PHANToM®-based haptic environment and the possibility to manufacture the same using Solid Freeform Fabrication technologies.
2007
- 3D Simulation System for GD&T Inspection Process Planning and Optimisation
[Relazione in Atti di Convegno]
Germani, M; Mandorli, F; Mengoni, M; Raffaeli, R
abstract
The last generation of CAD software systems allows the creation of models that consider the whole product lifecycle. Along the product development phase important activities are related to the geometrical tolerances prescription and their control planning. However, the Geometrical and Dimensional Tolerances (GD&T) representation, analysis and verification processes are still rarely taken into account in CAD systems. Such a bottleneck implies a “over the wall” communication between design and quality control departments. On the other hand, the tolerances verification process needs an high level of automation in order to extend the number of inspected products and to shorten the time from control strategy definition to the measurement process. Our research work is focused on the development of an approach for the automatic inspection planning, simulation and optimisation of geometrical tolerances. The approach is based on the integration of three technologies: the augmented CAD models, the 3D optical digitizing systems and the articulated robot systems. In this paper the methodology is presented both for specific geometrical tolerances verification and for the global shape control.
2006
- Design Structure Matrix used as Knowledge Capture Method for Product Configuration
[Relazione in Atti di Convegno]
Germani, M; Mengoni, M; Raffaeli, R
abstract
The present work focuses on the study of a method to acquire and formalise the design knowledge in a way usable for implementing a knowledge-based software system to support the NPC. The approach is based on the representation of corporate knowledge within a structured framework where market requirements, product specifications and functional aspects are interrelated. A hierarchical multi-level DSM structure allows representing such knowledge in a rationale manner. This paper presents the methodology to formalize the product knowledge, the used structure to define the specifications for implementing the knowledge-based product configuration system and, finally, a practical example to illustrate our proposed framework.
2006
- Innovative Design Automation Technologies for Corrective Shoes Development
[Relazione in Atti di Convegno]
Raffaeli, R; Alfaro, D; Germani, M; Mandorli, F; Montiel, E
abstract
The paradigm of Mass Customisation (MC) is today fundamental for the European fashion industry. Footwear industry is still labour intensive and companies need solution to reduce costs and remain competitive in the global market. In particular, specialized companies that produce customized medical shoes prescribed for people with feet malformations deal with small batches or unique pairs. This work presents some approaches and low-cost solutions related to foot measurement and CAD data elaboration for facilitating the diffusion of "made-to-measure" products. An integrated process made of hardware devices and customized software is explored and described aiming to increase production efficiency and reduce costs.
2005
- A product model architecture to support the configuration of solution phase in gas turbine plants design
[Relazione in Atti di Convegno]
Raffaeli, R; Germani, M; Mandorli, F
abstract
Gli impianti turbogas per la produzione industriale di energia stanno assumendo un ruolo importante negli ultimi tempi. Il processo di progettazione dell’impianto è dato da un insieme di attività decisionali complesse ed iterative che coinvolgono tecnici con competenze diverse. La soluzione raggiunta sotto forma di layout di impianto e geometrie delle sezioni deve essere verificata dal punto di vista strutturale, acustico, fluidodinamico e dipende anche dalle esigenze di ingegnerizzazione. Se sono necessarie modifiche le analisi precedenti devono essere ripetute.
Risulta quindi evidente che dalle primissime fasi di definizione dell’impianto il team di sviluppo dovrebbe essere supportato da strumenti collaborativi e coordinati in modo da sviluppare contemporaneamente il prodotto, ognuno dal suo punto di vista tecnico.
In questo contesto questo articolo si pone due obiettivi principali: 1) lo studio e lo sviluppo di uno strumento di progettazione per la configurazione automatica di un impianto turbogas, 2) lo studio di un sistema di progettazione capace di creare selettivamente l’informazione indispensabile alle diverse attività di analisi e di rigenerare la configurazione dell’impianto in base ai risultati delle analisi stesse.
2005
- Development of a Collaborative Product Development Tool for Plants Design
[Relazione in Atti di Convegno]
Germani, M; Bonaventura, L; Mandorli, F; Raffaeli, R
abstract
2005
- Innovative Technologies to Support Positioning of Corrective Appliances in Orthodontic Treatments
[Relazione in Atti di Convegno]
Raffaeli, R; Germani, M; Mandorli, F
abstract
Time Compression Technologies (TCT) are strongly widening their application fields, particularly in not traditional sectors, such as archaeology, jewellery, architecture and so on. The biomedical domain, especially orthodontics, is one of the most interesting. The design and positioning processes of corrective dental appliances consist of phases which can strongly benefit from Reverse Engineering (RE) and Rapid Prototyping (RP) techniques in terms of quality and time reduction. In these last years new systems have been developed to support the operator work but, unfortunately these technologies are still not largely used in orthodontic laboratories. In this context, the present paper, facing the problem of critical activities identification in corrective treatments orthodontic practice, proposes a low cost and easy to use technical solution in order to support orthodontists for a rapid and accurate positioning of vestibular and lingual brackets. In particular a new CAD (Computer Aided Design) software system to support the dental appliances design process has been implemented.
2005
- Modelli 3D digitali ed ortodonzia assistita da computer
[Articolo su rivista]
Mandolesi, F; Duranti, G; Raffaeli, R
abstract