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Francesco GHERARDINI

Ricercatore t.d. art. 24 c. 3 lett. B presso: Dipartimento di Ingegneria "Enzo Ferrari"


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Pubblicazioni

2020 - A methodological approach for the design of inclusive assistive devices by integrating co-design and additive manufacturing technologies [Relazione in Atti di Convegno]
Gherardini, Francesco; Petruccioli, Andrea; Dalpadulo, Enrico; Bettelli, Valentina; MASCIA, Maria Teresa; Leali, Francesco
abstract

Additive Manufacturing is a widespread technology that may enhance product customization based on specific users’ needs, as in the case of assistive devices. Many chronic physical progressively disabling diseases, but also ageing, may cause severe limitations in daily life, which can be overcome by highly customized aids. Literature shows that the active involvement of the patient in the development of assistive devices through co-design allows for their greater therapeutic effectiveness and acceptance. Therefore, this paper proposes a methodological approach for the development of inclusive assistive devices to support daily activities in persons with disabling diseases of the upper-limb. The approach integrates co-design, standardized tools, and low- and high-tech prototyping techniques and tools, which lead to significant feedbacks from patients. The patients are encouraged to interact with conceptual prototypes through direct 3D CAD modelling and touch screen devices. Assessment tests highlight the suitability of the method to achieve the expected goals.


2020 - Design for Visual Quality Enhancement of Artificial Infrastructure Facilities: An Application to Electricity Pylons [Articolo su rivista]
Di Angelo, Luca; Gherardini, Francesco; Di Stefano, Paolo; Leali, Francesco
abstract

(1) Background: The visual impact of artificial infrastructures on natural landscapes generates a common negative perception in public opinion. However, as in the case of electrical energy, the increasing demand for power supply and its need for capillary distribution require the installation of new lines, commonly overhead lines with tall tower-like pylons. In most countries, this situation is faced with many attempts of solutions, as participatory workshops and design contests. Nevertheless, the solutions are usually not further developed into real structures due to many limitations (e.g., regulatory, safety, lack of feasibility). (2) Methods: This paper presents a systematic method for the design of tower-like pylons (e.g., electric ones) able to improve the visual quality on the landscape areas in which they will be installed. The method identifies a design strategy that advantageously exploits the inevitable visual impact of pylons on the landscape by integrating the symbolic morphology and the topologically optimized pylon structure from the earliest design phases. (3) Results: The resulting structure is designed in three steps. First, a concept is morphologically developed by integrating symbolic references to the landscape, environment, or cultural society. Second, the concept is topologically optimized, by reducing the structural weight and its visual impact, and respecting regulatory requirements. Third, the resulting structure is engineered and embodied into an industrially feasible layout. (4) Conclusions: The method is able to develop an original, brand new tower-like pylon integrating all the types of requirements, such as regulatory, industrial feasibility, and social components' needs. The resulting electricity pylon presents an enhanced visual quality according to the citizens' feedback.


2020 - Design Tools and Methods in Industrial Engineering, Proceedings of the International Conference on Design Tools and Methods in Industrial Engineering, ADM 2019 [Curatela]
Rizzi, Caterina; Andrisano, Angelo Oreste; Leali, Francesco; Gherardini, Francesco; Pini, Fabio; Vergnano, Alberto
abstract

This book collects the proceedings of the ADM 2019 International Conference, entitled “Design Tools and Methods in Industrial Engineering”, held in Modena, Italy, on 9–10 September 2019. This is not the first time that an event organized by ADM (formerly known as Italian Association of Machines Design, today renamed the Italian Association of Design Methods for Industrial Engineering) or by our scientific sector (ING-IND/15) takes place in Modena. I am pleased to remember the “ADM day” held at the Military Academy of Modena in 2008, as well as the ING-IND/15 workshop organized in 2009 in the hills of Bologna, not far from Modena. However, this conference is particularly significant, for the reasons I wish to summarize here. Firstly, the ADM Conference constitutes a new international, permanent event held in Italy, aimed at disseminating cutting-edge research to a national and international audience. For several years, our association has had a collaborative relationship with the Spanish members of INGEGRAF and the French members of Smart (formerly AIP-PRIMECA), with whom we organize the International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing (JCM) every two years. This event is hosted alternately by one of our three countries. Therefore, the ADM International Conference was born from the need for an event “in the middle”, to strengthen the international research network and to meet our colleagues in Italy. As a matter of fact, the ADM 2019 scientific committee was joined by Spanish and French colleagues, as well as German, Swedish, Norwegian and American ones, thanks to partnerships created by our “Enzo Ferrari” Department of Engineering (Modena) over the years. Secondly, I am honoured to play the role of conference chair, a position that has led me to be one of the editors of this book. In more than 45 years of experience in this sector, I have seen many developments and evolutions. From the first use of CAD in the industrial sector, today we have reached a high multidisciplinary level and integration with information technology and electronics. The integration of novel tools and approaches in the industrial world is also due to the activity of our scientific sector, capable of developing and integrating innovative tools and methodologies with the traditional themes of industrial engineering. Finally, this conference is held in 2019, an important year for me, marking the conclusion of my mandate as Rector of the University of Modena and Reggio Emilia, as well as that of Full Professor for our scientific sector. As the Dean of the ADM association and the scientific sector, I enthusiastically accepted the proposal of Francesco Leali, my collaborator for years and now my colleague, to nominate the University of Modena and Reggio Emilia, and in particular our “Enzo Ferrari” Department of Engineering, as the location for the ADM 2019 International Conference. I would like to thank both him and my departmental colleagues, in particular the researchers of my lab, LaPIS lab, for organizing this event at the “Enzo Ferrari” Department of Engineering, so dear to me, having been one of its first promoters and founders. Equally, I would like to thank the ADM President Prof. Vincenzo Nigrelli, and Prof. Caterina Rizzi, Coordinator of the ADM Scientific Council, whose members, in turn, I gratefully thank. Further thanks go to the publisher, Springer, who honoured us by publishing the proceedings of this first ADM International Conference in the series “Lecture Notes in Mechanical Engineering”. Therefore, as editor of this first book, I hope that it will be the first of a new series of international conference proceedings underlining the leading role of our scientific sector in the international scene. The colleagues who will be hosting the next ADM conferences will have the burden, but above all the honour, of continuing this project that today we have


2020 - Effective integration of Cobots and additive manufacturing for reconfigurable assembly solutions of biomedical products [Articolo su rivista]
Rossi, F.; Pini, F.; Carlesimo, A.; Dalpadulo, E.; Blumetti, F.; Gherardini, F.; Leali, F.
abstract

Collaborative robotics and additive manufacturing are two enabling technologies of the Industry 4.0 manufacturing paradigm. Their synergic integration requires novel and effective design approaches, aiming to the development of new reconfigurable solutions for customised processes and products. This work presents an integrated approach that exploits the capabilities of Cobots to mimic the repetitive and exhausting operator’s movements as well as the competitive advantages offered by additive manufacturing to realize tailored equipment. In particular, the case study shows the development of a customised device for the manipulation of biomedical components by means of a Cobot, which is introduced in a workstation to replace manual operations. Moreover, the flexibility and the effectiveness of a Cobot can be improved thanks to customised devices for gripping and pick-and-place operations based on a specific application. During the development phase, we simulated the assembly process, and tested different options. The final configuration, with conformal circuits and suction cups, can pick, manipulate and assembly the biomedical components, and thanks to a Fused Filament Fabrication technology is additively manufactured. In conclusion, this developed prototypal solution proves the real capabilities offered by integrating Cobots and additive manufacturing for the lean automation of a biomedical workstation.


2020 - Implementation of a quality framework on the launch phase of an automated assembly line for top class automotive chassis [Relazione in Atti di Convegno]
Bertoldi, A.; Gherardini, F.; Leali, F.
abstract

Today the assembly lines of cars chassis are highly automated by robotic operations. Even in the top class automotive sector, the production of aluminium chassis involves numerous automated operations, such as TIG and MIG welding, riveting and gluing. This practice allows, on the one hand, to reduce time and costs, improve process repeatability and quality standards. On the other hand, it requires the quality improvement of the whole process (from supplied parts approval to welding reworks minimization). The industrialization phase of a new car chassis and the launch of its automated assembly line are particularly critical, even more if the line has already been designed and only minimally modifiable. Therefore, this paper proposes the implementation of a quality framework to manage the launch of an automated assembly line of a new aluminium chassis of top class cars, selected as a case study. The framework was implemented, aiming at improving the entire process quality, and finally validated by critically comparing the results obtained with those relating to models currently in production. Due to their importance to the final quality, we focused on the welding operations, which require actions both on process parameters and supplied parts approval (e.g. tolerances on parts end cuts). The new line shows a clear improvement compared to the past, with highly significant reduction of welding non-conformances, high quality level and lack of many critical issues of the previous lines thanks to corrective actions taken in the early process stages, during the pilot phase.


2020 - Robust Parameter Analysis of Compliant Part Models for Computer Aided Tolerancing [Relazione in Atti di Convegno]
VERGNANO, ALBERTO; GHERARDINI, Francesco; PETRUCCIOLI, ANDREA; BONAZZI, ENRICO; LEALI, Francesco
abstract

Sheet metal parts are widely used in automotive, aerospace, ship and consumer goods industries. The final dimensions of a sheet metal assembly result from the parts deformation, which in turn is affected by many variations in material, thickness and single parts dimensions. The tolerance analysis on sheet metal assemblies improve the knowledge about the process. Advanced simulations enable the optimization of product features, GD&T scheme and assembly process. Moreover, Variational Models of both the product and the assembly system enable to assess the sources of 3D error propagation from the different contributors. However, the simulation results are very affected by the modelling approach of critical components, such as the Fixture Systems. The present paper firstly introduces a strategy to model the Fixture System and the assembly process for compliant parts. Then, a robust analysis of the variations in the model with respect to the modelling factors is performed by a Design of Experiments. A case study on an automotive fender is discussed. The results demonstrate that the modelling strategy of the clamping operation have the main effects, while the modelling of locators scheme, spot joints and FEM meshing are less important.


2020 - The Systematic Design of Industrial Products through Design Archetypes: An Application on Mechanical Transmissions [Articolo su rivista]
Vergnano, Alberto; Gherardini, Francesco; Leali, Francesco
abstract

Engineering design is a knowledge intensive activity for both new and mature technical systems, such as mechanical transmissions. However, design knowledge is often transferred with conservative and unstructured approaches, although knowledge management would be of the utmost importance for modern industries. In this work, we introduce a design tool, called design archetype, for collecting and managing knowledge in systematic design processes. The design archetype addresses input design requirements for different design concepts, therefore, improving awareness of the design process by interactively modifying the design solution due to different input requirements. Finally, the design archetype updates the parameters of a first embodiment computer-aided design model of the concept. A method for the development of design archetypes is presented and applied to two case studies of mechanical transmission subassemblies. The results demonstrate the effectiveness of a systematic design method based on design archetypes stored in the company database.


2019 - A Co-Design Method for the Additive Manufacturing of Customised Assistive Devices for Hand Pathologies [Articolo su rivista]
Gherardini, Francesco; MASCIA, Maria Teresa; Bettelli, Valentina; Leali, Francesco
abstract

Additive Manufacturing technologies are particularly suitable for developing highly customised products, even in rehabilitation and occupational therapy fields. Nowadays it is easy and cheap to design and produce such artefacts, although they require systematic approaches and standardized tests to validate their effectiveness. Therefore, this paper proposes a methodological approach for the application of Additive Manufacturing technologies to the co-design of assistive devices, focusing on rheumatoid or scleroderma patients. These patients present hand and finger disorders that limit simple everyday tasks, and need assistive devices to protect the damaged joints. The commercial assistive devices available on the market generally lack of customisation in dimensions and morphology, or their aspect is too stigmatizing. In order to achieve a better correspondence between patients' needs and assistive devices, we propose to involve the patients in a co-design team, in order to directly transfer their desires and creativity in unconventional solutions. The assistive devices are parametrically modelled and virtually prototyped in order to assess their functionality and customisation, and then additively manufactured. Finally, their effectiveness is tested by patients by means of standardized assessment tests that generate useful feedback. The paper proposes a case study about an assistive device for daily living activities.


2019 - Enhancing heritage fruition through 3D virtual models and augmented reality: An application to Roman artefacts [Articolo su rivista]
Gherardini, Francesco; Santachiara, Mattia; Leali, Francesco
abstract

The spatial characteristics of museum exhibitions may limit visitors' experience of the artefacts on display. In the case of large artefacts, limited space may affect their whole visualization, or inhibit the visualization of the details farthest from the observer. In other cases, the storage of artefacts in distant sites (museums or archaeological areas) may influence their knowledge process or the possibility for comparative analysis. Moreover, the precarious state of preservation of some artefacts, with damaged or missing parts, makes it difficult to perceive their original appearance. To overcome these limitations, we propose an integrated approach based on 3D virtual models and Augmented Reality (AR) to enhance the fruition of artefacts, improving their visualization, analysis and personal/shared knowledge, also by overcoming space and time constraints. The final AR application is an easily accessible tool for most users from a mobile device, used both inside and outside museums, opening new perspectives for fruition. The framework encourages the use of free and open source software and standard devices, to maximize their dissemination and exploit the potential of such technologies, which is far greater than current use in the cultural heritage field. Selected case studies to test and validate the integrated framework are proposed, dealing with some Roman artefacts found in the area of Modena (Italy). The first is a Roman floor mosaic, found in Savignano sul Panaro (near Modena) in 2011, of which less than half of its original 4.5 x 6.9 m surface is preserved. The others are two Roman funerary lion sculptures: the first is one of two lions flanking the main door of Modena Cathedral, and the second, well-preserved but damaged, is housed in the Museo Lapidario Estense of Modena. Finally, the application was tested by museum experts and visitors both inside and outside the museum, and positively assessed.


2019 - Identification of the main contributors in the 3D tolerances assessment in mechanical transmissions [Relazione in Atti di Convegno]
Gherardini, Francesco; Panari, Davide; Leali, Francesco
abstract

The management of spatial dimensional variations and 3D tolerance stacks is a key issue to achieve high performance and robust solutions. The state of the art in 3D tolerance analysis addresses two main difficulties: On the one hand, the issue about the dimensioning and tolerancing methods, and the related annotation transfer from 2D drawings to 3D parts. On the other hand, the lack of integration of design methods for 3D tolerance stacks calculation in the design process and, moreover, the restricted application fields in which tolerance methods are applied, as in aerospace or automotive fields. In this scenario, we propose a Computer-Aided Tolerancing (CAT)-based approach, integrated within the embodiment design of the product development and able to support the analysis and the design of 3D tolerance stacks in mechanical assembly, by simulating the 3D effects of both the dimensional and geometrical tolerances. Focusing on a gearbox assembly, the CAT-based approach aims to identify the main contributors (sources) of variation within the tolerance stacks, by means of a statistical and sensitivity analysis. After defining the design inputs (involved parts, tolerances definition, assembly sequence, and required measurements), we follow a bottom-up approach, starting from the part tolerances as set by the designers, up to the assembly tolerances. The CAT software simulates how the tolerances vary within their ranges. Finally, we are able to identify the main contributors to variation, which may require tightening their tolerance values, in order to improve the performance of the gearbox assembly.


2018 - An Augmented Reality Application for the Visualization and the Pattern Analysis of a Roman Mosaic [Relazione in Atti di Convegno]
Santachiara, Mattia; Gherardini, Francesco; Leali, Francesco
abstract

The visualization and analysis of mosaics and pavements are often compromised by their large sizes, which do not enable the observer to perceive their whole arrangement or to focus on details placed in farthest areas from its boundaries. Moreover, the usual precarious state of conservation of these artefacts, often with damaged or missing areas, makes it difficult to perceive their original aesthetic value. To overcome these limitations, we propose an application of augmented reality able to support the observer in two ways: first, the application completes the missing surface of the mosaic or pavement by integrating the existent surface with a virtual reconstruction; second, it enables the analysis of the geometric pattern of the mosaic/pavement by overlaying virtual lines and geometric figures in order to explicit its geometric arrangements. The result is achieved via a custom Android application able to recognize and track the mosaic figure pattern and extra marker board, obtaining in that way a coordinate system used to render in real-time the reconstruction of the mosaic. Such rendering is overlaid to the video stream of the real scene. The application runs on a standard smartphone embedded in a Google Cardboard-compatible viewer and therefore is extremely affordable. As a case study, in order to reconstruct its aspects and to analyse its geometric pattern, we chose the roman mosaic re-found in Savignano sul Panaro (near Modena, Italy) in 2011, after 115 years from its first discovery, which is preserved less than half of its original 4.5 x 6.9 m surface.


2018 - Modelling and Simulation of a Hydrostatic Steering System for Agricultural Tractors [Articolo su rivista]
Zardin, Barbara; Borghi, Massimo; Gherardini, Francesco; Zanasi, Nicholas
abstract

The steering system of a vehicle impacts on the vehicle performance, safety and on the driver’s comfort. Moreover, in off-road vehicles using hydrostatic steering systems, the energy dissipation also becomes a critical issue. These aspects push and motivate innovation, research and analysis in the field of agricultural tractors. This paper proposes the modelling and analysis of a hydrostatic steering system for an agricultural tractor to calculate the performance of the system and determine the influence of its main design parameters. The focus here is on the driver’s steering feel, which can improve the driver’s behavior reducing unnecessary steering corrections during the working conditions. The hydrostatic steering system is quite complex and involves a hydraulic circuit and a mechanical mechanism to transmit the steering to the vehicle tires. The detailed lumped parameters model here proposed allows to simulate the dynamic behavior of the steering system and to both enhance the understanding of the system and to improve the design through parameters sensitivity analysis.


2018 - 3D Virtual Reconstruction and Augmented Reality Visualization of Damaged Stone Sculptures [Relazione in Atti di Convegno]
Gherardini, Francesco; Santachiara, Mattia; Leali, Francesco
abstract

This paper proposes the integration of photogrammetric reconstruction, 3D modelling and augmented reality application in order to achieve the complete visualization of a stone sculpture even if highly damaged or fragmentary. The first part of the research aims to the reconstruction of the original aspect of an incomplete sculpture, by using photogrammetry techniques based on standard resolution photos and free software in order to obtain a first model; then, we integrate this model with other 3D digital data (from other sculptures of the same period) or with 3D modelling based on historical sources and views from historians, aiming to achieve the original aspect of the sculpture. The second part of the research consists of the embedding of the obtained model in a custom application able to render in real-time the 3D reconstruction of the lion. Then, the rendering is overlaid to the video stream of the real scene and, as a result, a complete 3D digital model of the sculpture is achieved and could be visualized through a VR viewer. As a case study, we focus on a Roman stone sculpture of a male lion conserved in the Museo Estense of Modena (Italy), which lacks of its head and its four legs. The original aspect of the lion may be achieved by integrating the damaged sculpture with other photogrammetric reconstructions of lions sculptures of the same period and with 3D model based on historical sources. Finally, the lion is visualized through an augmented reality application which digitally overlays the reconstructed models on the original one.


2017 - A systematic user-centred framework for engineering product design in small- and medium-sized enterprises (SMEs) [Articolo su rivista]
Gherardini, Francesco; Renzi, Cristina; Leali, Francesco
abstract

The systematic integration of user needs in the product design is a key issue in industry, especially for small- and medium-sized enterprises (SMEs), which suffer a lack of engineering methods and resources. Moreover, most of the approaches described in the literature are not flexible enough to be tailored on the SMEs’ needs, involve users only in the early design phases and are not fully accessible due to the high cost in their implementation. The present paper proposes a user-centred design methodological framework specifically focused on SMEs, which supports the designer from both design and manufacturing aspects along the engineering product design process. The framework integrates engineering methods with Web-based software tools, which enable the communication and the concurrent work of the design team, and supports direct participation of users. Beside state-of-the-art methods, the framework allows the integration of specifically tailored techniques. The framework is successfully validated through an industrial case study developed in collaboration with an Italian SME. As a result, the design of an injection-moulded housing and the related interfaces of a biomedical electronic device are achieved with a reduction of uncertainty and development time, by involving users throughout the design phases and suggesting methods and tools on the basis of the designers’ know-how and SME’s specific resources.


2017 - Reciprocal Frames in Temporary Structures: An Aesthetical and Parametric Investigation [Articolo su rivista]
Gherardini, Francesco; Leali, Francesco
abstract

This paper deals with the use of reciprocal frames in temporary gridshell structures, such as architectural pavilions in expositions and installations. These architectural examples can benefit from the use of short, easy to handle, generally joint-free, and repeatable “modules” in order to create particular self-supporting structures. The lightweight and interwoven grid obtained by connecting short elements according to the reciprocity principle is structurally efficient and, at the same time, aesthetically pleasing, mainly due to the resulting tessellation. The paper firstly investigates the connection between efficiency and aesthetics. The last part of the paper investigates some temporary architectural pavilions from both an aesthetical and parametric point of view. In order to deepen our understanding of these structures, they are re-modelled according to a bottom-up approach by means of a constraint-based parametric CAD modeller. In this way, a reciprocal frame can be explored and modified by the parametric arrangement of its generative elements, which, like a natural organism, grows in self-generating forms.


2016 - A Framework for 3D Pattern Analysis and Reconstruction of Persian Architectural Elements [Articolo su rivista]
GHERARDINI, Francesco; LEALI, Francesco
abstract

Persian architecture is characterised by shapes and patterns, which can be analysed through mathematical models. Beside 2D patterns, many of the traditional geometric ornaments are realised on 3D surfaces such as domes or vaults. Literature mainly addresses the 3D problem by means of a 2D scheme, which is an important and synthetic representation but is not exhaustive and lacks of clarity. This paper proposes a framework based on the integration of 2D drawings, as in the traditional approach, and a photogrammetric 3D model based on a sample of standard resolution images (tourist pictures). The framework is tested on a muqarnas, a characteristic Persian ornament, in order to study and analyse its modular design and hierarchy of elements. As a case study, the entrance iwan of the Shah Mosque in Isfahan, Iran, is considered. The result is a link between the 3D patterns and the geometry of architectural elements, which completes and overcomes their schematic 2D representation.


2016 - A parametric CAD-based method for modelling and simulation of positive displacement machines [Articolo su rivista]
Gherardini, Francesco; Zardin, Barbara; Leali, Francesco
abstract

We present an efficient and user-friendly parametric CAD-based design method for the graphical description of positive displacement machines, exploiting commercial parametric CAD software and a tailored interface. An executable module simulates the motion of the machine components, analyzes the machine geometry, and automatically extrapolates the geometrical data from the 3D CAD model, generating data files that can be directly used for following fluid dynamic analyses. The graphical approach supports investigation of the machine performance and exploring optimized design variants. The method has been applied to three industrial test cases: An external gear pump, an axial piston pump, and a gerotor pump. A complete case study focused on the external gear pump is proposed, as well as the results from the other two types are summarized. We validate the CAD-based method by comparing the obtained data with the data coming from the application of state-of-the-art analytical methods.


2016 - APPLICAZIONE DELLA NORMA ISO 16792:2006 PER LA SPECIFICAZIONE GEOMETRICA DI PRODOTTO 3D IN AMBITO AUTOMOTIVE [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Gherardini, Francesco; Renzi, Cristina; Bonazzi, Enrico; Leali, Francesco
abstract

Accanto alla documentazione tecnica di prodotto mediante disegni ed annotazioni 2D, nella pratica industriale è fortemente sentita l’esigenza di gestire le informazioni tecniche di prodotto direttamente nell’ambiente di modellazione CAD 3D. Con l’obiettivo di migliorare la gestione del ciclo di vita di prodotto tramite modelli 3D, i produttori di software CAD 3D commerciali e l’industria stessa, soprattutto in ambito automotive ed aerospace, hanno generato molteplici soluzioni che tuttavia risultano individualizzate e non univoche. La normativa tecnica ISO definisce linee guida per la specificazione geometrica di prodotto 3D, che tuttavia risultano solamente in parte accolte da un punto di vista industriale e commerciale. In questo scenario, il presente studio vuole verificare l’implementazione dei contenuti della norma ISO 16792:2006 in alcuni CAD 3D commerciali selezionati. Mediante un benchmark industriale opportunamente identificato, i CAD 3D sono comparati sulla base di criteri redatti secondo la norma ISO 16792:2006 stessa. I risultati ottenuti permettono di individuare, per ogni CAD 3D analizzato, eventuali gap operativi ed i relativi interventi volti a garantire il raggiungimento di un livello comune di applicabilità della norma e di leggibilità della documentazione tecnica 3D generata.


2016 - Genetic algorithm optimization and robustness analysis for the computer aided design of fixture systems in automotive manufacturing [Relazione in Atti di Convegno]
Ansaloni, Matteo; Bonazzi, Enrico; Gherardini, Francesco; Leali, Francesco
abstract

Fixture Systems (FSs) have great importance in machining, welding, assembly, measuring, testing and other manufacturing processes. One of the most critical issue in FS design is the choice of both the type of fixing devices such as clamps, locators, and support points, (configuration), and their arrangement with respect to workpieces (layout). Several authors deal with the problem of determine the most suitable solution for FSs, often investigating their layout without considering the change of the type of locators. A computer aided design method is proposed to compare and evaluate different configurations for a FS, optimizing the locator type and analysing the roboustness of the solution. A multi-objective optimization based on a genetic algorithm is presented and the selection of the most suitable configuration is performed through the definition of robustness indexes. The effectiveness of the design method is demonstrated for an automotive case study.


2012 - Metodo di progettazione di sistemi di fixture per l’assemblaggio di telai automobilistici mediante analisi di sensibilità [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Ansaloni, Matteo; Berselli, Giovanni; Bonazzi, Enrico; Gherardini, Francesco; Leali, Francesco; Pellicciari, Marcello; Pini, Fabio; Renzi, Cristina; Vergnano, Alberto
abstract

I sistemi di fixture influenzano enormemente i processi di assemblaggio in molti campi della meccanica, in quanto influiscono direttamente sul calcolo della catena di tolleranza. La memoria illustra un metodo di progettazione che permette di comparare e valutare differenti sistemi di fissaggio, considerando sia la posizione che il tipo di locatori. Poiché i sistemi di fixture possono essere considerati dei sistemi multi-prestazionali, il confronto viene eseguito attraverso l’impiego di opportuni indici di sensibilità. Il metodo è stato applicato ad un caso di studio in ambito automotive relativo alla saldatura in continuo di estrusi in allumino, con l’obiettivo di garantire misure di gap con la minore variabilità possibile.


2011 - Design Of Simulation Experiments method for Injection Molding process optimization [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Gherardini, Francesco; Leali, Francesco; Pellicciari, Marcello; Vergnano, Alberto
abstract

Purpose:Many studies demonstrate that DOE, CAE and optimization tools can be very effective in product and process development, however their integration is still under investigation, hampering the applicability of such engineering methods in Industry. This paper presents a Design Of Simulation Experiments (DOSE) method, developed to determine the optimal set of process parameters (factors) for given product requirements (responses).Method:The method is developed performing an original selection and integration of engineering procedures and techniques based on DOE, CAE and multi-objective optimization, chosen according to the following criteria: ease of application, time-saving and use of reduced resources.Result:The developed method consists of two main steps: a first screening of factors based on a fractional DOE is followed by a systematic experimental plan based on the Response Surface Methodology (RSM), in which only key factors are investigated. A regression model is finally developed to describe the responses as functions of key factors and a multi-objective optimization is proposed to obtain optimal responses by tuning the process factors in their variability range. The DOSE method is finally validated on the design of an injection molded housing for a biomedical application. This thin shell component has dimension 45mmx37mmx16mm, wall thickness from 2mm to 0,5mm and is made of polyphenylsulfone (PPSU), a high performance thermoplastic.Discussion & Conclusion:The design method achieves good responses in terms of dimensional and geometrical requirements (e.g. warpage, shrinkage, sink marks), and improves the shell moldability. The DOSE method can be easily adopted in industrial product/process development to define the optimal process parameters for a better final quality of the products.


2011 - Una metodologia innovativa di progettazione integrata per l'analisi e la caratterizzazione della sensitività delle performance [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Ansaloni, Matteo; Gherardini, Francesco; Leali, Francesco; Pellicciari, Marcello; Pini, Fabio; Vergnano, Alberto
abstract

Il presente lavoro è volto all’analisi e alla caratterizzazione della sensitività delle performance dei processi tecnologici. Le tradizionali tecniche di Robust Design utilizzate per l’analisi e l’ottimizzazione di processi e prodotti non sono state sviluppate con l’obiettivo dell’analisi della sensitività e, pertanto, presentano alcune carenze applicative. Il presente articolo propone un approccio alternativo che integra, estendendola ai processi tecnologici, la teoria della Performance Sensitivity Distribution (PSD), originariamente proposta nell’ambito dell’analisi dei meccanismi e, in particolare, nell’analisi dei manipolatori. Questo nuovo approccio, denominato specialized PSD, descrive il problema della sensitività delle performance attraverso la definizione di parametri chiave del progetto, suddivisi in Design Variables (DV) e Design Parameters (DP), e la formalizzazione di Performance Functions (PF). In accordo con la teoria PSD, la sensitività delle PF è espressa in funzione delle deviazioni dei DV e dei DP dai relativi valori nominali: essa è geometricamente descritta da un iperellissoide costruito nello spazio delle deviazioni, e valutata attraverso l’introduzione di indici di sensitività. La complessità nell’estensione dell’approccio PSD all’analisi dei processi tecnologici è legata alla necessità di ottenere la descrizione matematica delle PF in funzione dei parametri di progetto. Il metodo proposto, tuttavia, permette di superare tale problematica mediante un approccio legato all’analisi di regressione su dati sperimentali. Una strategia di Design Of Experiments viene applicata allo studio dei processi, così da campionare il comportamento delle PF in funzione della variazione dei parametri di progetto. Un caso di stampaggio ad iniezione di un provino è riportato al fine della validazione del metodo. In un’ottica di progettazione integrata, il metodo proposto si rivela utile per la caratterizzazione delle performance, specialmente nelle prime fasi di sviluppo di prodotto e processo.


2010 - Metodi di progettazione integrata di sistemi automatici adattivi [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Faretra, Marco; Gherardini, Francesco; Guerra, Alessandro; Leali, Francesco; Pellicciari, Marcello; Pini, Fabio; Vergnano, Alberto
abstract

Le prestazioni dei moderni sistemi automatici di assemblaggio derivano sempre più dall’integrazione di apparati meccanici con attuatori programmabili, sensori, sistemi di elaborazione dati e complesse logiche di controllo. La disponibilità di tali tecnologie permette di affrontare nuove sfide tecniche ma comporta una rivoluzione nel modo di concepire meccanismi e macchine. I tradizionali modelli di progettazione, orientati alla definizione per funzioni degli apparati e strutturati con l’intervento sequenziale delle diverse aree di conoscenza dell’ingegneria, non permettono di sfruttare tutte le potenzialità delle diverse tecnologie coinvolte e di progettare comportamenti adattivi. È dunque necessario costruire nuovi metodi di progettazione che consentano di produrre sistemi in grado di interagire con l’ambiente circostante, di adattare autonomamente il proprio comportamento e di massimizzare e/o ottimizzare le prestazioni. Il presente lavoro descrive un metodo per la progettazione integrata di sistemi automatici adattivi attraverso la modellazione e la prototipazione virtuale dei comportamenti. Il metodo segue un approccio sistematico e considera, a diversi livelli di dettaglio, l’evoluzione dinamica dei comportamenti sia tempo-continua che guidata da eventi discreti. L’integrazione delle conoscenze e delle tecnologie in un ambiente virtuale può portare all’evoluzione in nuovi principi risolutivi, alla creazione delle basi di conoscenza su cui sono basate le logiche adattive, ad avanzate strategie di sensorizzazione ed attuazione, all’ottimizzazione complessiva del sistema ed alla compressione dei tempi di sviluppo. Questa memoria riporta infine l’applicazione del metodo proposto nella progettazione di un sistema di assemblaggio automatico.


2009 - Metodi di visione artificiale in sistemi robotizzati per il settore automotive [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Pellicciari, Marcello; Leali, Francesco; Vergnano, Alberto; Pini, Fabio; Gherardini, Francesco; Faretra, Marco
abstract

Il presente articolo descrive un nuovo approccio di programmazione e guida robot capace di generare, automaticamente e in tempo reale, percorsi di lavorazione ottimizzati in funzione di singoli componenti. Tale metodo è stato validato sperimentalmente applicandolo al processo di sbavatura di una piccola serie di testate per motori a elevate prestazioni. Infatti i moderni sistemi robotizzati di produzione sono spesso impiegati in operazioni complesse su componenti che sono caratterizzati, specialmente nel settore automotive, da profili e geometrie multiformi, che variano radicalmente da un lotto produttivo a un altro e, nel caso di tecnologie che generano bave e difetti superficiali, anche all’interno di uno stesso lotto. Per ottenere l’elevata qualità richiesta dall’Industria, tali sistemi, molto ripetibili ma intrinsecamente poco precisi rispetto ai tradizionali centri CNC, richiedono la definizione di percorsi utensile composti da migliaia di punti e da articolati programmi robot, all’interno dei quali i parametri cinematici, dinamici e di lavoro vengono continuamente modificati. L’impiego di sistemi di guida robot a elevate prestazioni assume, dunque, un’importanza strategica nel processo di generazione del percorso utensile, specialmente all’interno di settori industriali nei quali è ancora largamente diffusa la pratica di generare manualmente, in autoapprendimento, le istruzioni di movimento dei robot e nei quali l’impiego di sistemi di programmazione offline CAD/CAE stenta ancora a trovare vasta applicazione. Di conseguenza, la fase di programmazione robot e il tempo a essa dedicato, rappresenta un aspetto che incide profondamente sulla reale flessibilità e produttività dei sistemi robotizzati.


2009 - Metodi e strumenti di prototipazione virtuale per il progetto e l’ottimizzazione di macchine e sistemi di automazione industriale [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Leali, Francesco; Pellicciari, Marcello; Faretra, Marco; Gherardini, Francesco; Pini, Fabio; Vergnano, Alberto
abstract

A seguito della drastica evoluzione del mercato il settore industriale della meccanica ha mostrato l’esigenza di interagire in modo sempre più efficace con il mondo della ricerca e dell’Università, con l’obiettivo primario di sviluppare prodotti e processi produttivi innovativi. Tale andamento si è concretizzato, da parte delle aziende, nell’orientamento al raggiungimento di un’elevata qualità durante tutto il ciclo di sviluppo prodotto/processo e nell’interesse alla (ri)-qualificazione dei propri addetti o all’acquisizione di nuove figure professioni di alto profilo. L’Università di Modena e Reggio Emilia, in collaborazione con altri Atenei emiliani e con la Regione Emilia Romagna ha operato con continuità, negli ultimi anni, per favorire e sostenere un efficace processo di trasferimento tecnologico dal mondo della ricerca verso il tessuto imprenditoriale. La costituzione del laboratorio SIMECH per la progettazione integrata e la simulazione, oggi confluito nella più ampia aggregazione INTERMECH, e la presentazione del progetto di creazione di un Polo Tecnologico per la Meccanica Avanzata e la Motoristica, con sede presso il Dipartimento di Ingegneria Meccanica e Civile di Modena, hanno costituito le tappe fondamentali di un’aggregazione orientata al consolidamento delle attività di ricerca di interesse del mondo produttivo e al loro rapido trasferimento industriale. Il presente articolo presenta due delle attività svolte negli ambiti del progetto, con particolare riferimento allo sviluppo di metodi e strumenti di prototipazione virtuale e all’ottimizzazione di macchine e sistemi per l’automazione industriale. Il primo caso presentato tratta lo sviluppo e la progettazione di una linea robotizzata di lavorazione ed assemblaggio di telai automobilistici in alluminio, svolta in collaborazione con SIR S.p.A., azienda leader nell’integrazione di sistemi industriali robotizzati, ed Alcoa Inc., importante gruppo specializzato nella produzione di telai, per conto di un’importante azienda automobilistica modenese. La seconda attività di trasferimento descrive il lavoro svolto in collaborazione con Dassault Systèms Italia nello sviluppo di metodi di progettazione di sistemi meccatronici adattativi di lavorazione basati su tecniche avanzate di Virtual Commissioning, attualmente implementati all’interno di alcuni importanti gruppi aziendali del territorio nazionale.


2009 - Progettazione orientata alla robustezza di prodotto e processo [Articolo su rivista]
Andrisano, Angelo Oreste; Gherardini, Francesco; Pini, Fabio; Vergnano, Alberto
abstract

Progettare componenti per automobili di lusso ad elevate prestazioni implica la definizione di traguardi funzionali e prestazionali da perseguire con techiche orientate alla qualità totale del prodotto finale, valutata anche in termini di contenuti emozionali, senza tralasciare comunque la riduzione dei costi e l'ottimizzazione dei tempi e delle risorse aziendali.La multidisciplinarietà e la complessità del problema rende quindi necessario un approccio strutturato basato su metodi di ingegneria simultanea e sul coinvolgimento dei fornitori nelle attività di progettazione, almeno nelle fasi più critiche di definizione della catena di valore. Attraverso un approccio integrato basato sulla modellazione CAD/CAM e sull'adozione di tecniche SPC (Statistical Process Control) e FMEA (Failure Mode and Effect Analysis), si è giunti al miglioramento generale del meccanismo e al conseguente incremento della qualità di tutta la famiglia di torrette cambio ad esso correlata, soprattutto in termini di qualità percepita dall'utente finale. I risultati ottenuti hanno, inoltre, portato allo sviluppo di una soluzione specifica finalizzata al miglioramento della robustezza del prodotto e del processo produttivo sull'intero ciclo di vita.


2008 - Metodi di progettazione integrata e simulazione di sottogruppi di macchine alternative [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Barbanti, Giovanni; Pellicciari, Marcello; Leali, Francesco; Faretra, Marco; Gherardini, Francesco; Pini, Fabio; Vergnano, Alberto
abstract

I moderni criteri di progettazione dei sistemi meccanici, spesso finalizzati a fronteggiare le elevate prestazioni delle macchine e la drastica riduzione dei costi e dei tempi di consegna, richiedono di considerare ed ottimizzare in tempi ridotti numerosi parametri funzionali all’interno di scenari operativi eterogenei, in cui gli aspetti strutturali, cinematici e dinamici non possono essere valutati indipendentemente. I metodi tradizionali di progettazione spesso affrontano questi aspetti in modo necessariamente approssimato e richiedono onerosi test su prototipi reali per la verifica e la messa a punto del sistema. La prototipazione virtuale utilizza diversi strumenti CAE (Computer Aided Engineering) per realizzare modelli di sistemi meccanici reali che tuttavia vengono ancora prevalentemente utilizzati come strumenti di verifica di sistemi già definiti con tecniche tradizionali. Nel presente lavoro si discute un metodo di progettazione che, pur fondandosi su solide basi di conoscenza tradizionali, permette di identificare con certezza i principali parametri progettuali su cui intervenire ed utilizza estesamente la prototipazione virtuale come strumento di progettazione. Si presenta inoltre la sua applicazione nella progettazione di un sistema per la sperimentazione di una macchina alternativa


2008 - Metodi e strumenti PLM per la progettazione integrata di sistemi meccatronici [Relazione in Atti di Convegno]
Andrisano, Angelo Oreste; Gherardini, Francesco; Leali, Francesco; Pellicciari, Marcello; Pini, Fabio; Vergnano, Alberto
abstract

Lo sviluppo di prodotti e sistemi meccatronici implica attività multidisciplinari e concorrenti da svolgere con metodi e strumenti di sviluppo molto diversi tra loro. L’integrazione di tali attività è fondamentale per il raggiungimento degli obiettivi prestazionali ed il successo del prodotto e rappresenta uno dei maggiori problemi da risolvere a livello progettuale. Il trasferimento di conoscenze ed informazioni tra aree di competenza intrinsecamente diverse, da sincronizzare nei relativi processi di sviluppo, risulta il maggior limite da superare ed è spesso la causa principale di ritardi o di prestazioni non completamente ottimizzate. Nuovi ambienti di simulazione comportamentale sull’intero ciclo di vita permettono finalmente di disporre degli strumenti e tecnologie abilitanti per trasferire le reciproche conoscenze tra i diversi gruppi di lavoro e giungere in tempi ridotti ad una reale ottimizzazione dei sistemi. Gli autori hanno effettuato diverse esperienze nella progettazione di sistemi meccatronici nel campo della robotica ed automazione ed hanno ideato specifici metodi e strategie di impiego degli strumenti della piattaforma Delmia, che hanno permesso di sfruttarne le potenzialità raggiungendo vantaggi valutati e comparati rispetto allo stato dell’arte.