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Federico TRAMARIN
Professore Associato
Dipartimento di Ingegneria "Enzo Ferrari"
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Pubblicazioni
2023
- A Preliminary Prototype of Smart Healthcare Modular System for Cardiovascular Diseases Remote Monitoring
[Relazione in Atti di Convegno]
Di Pinto, V.; Tramarin, F.; Rovati, L.
abstract
2023
- A learning model for battery lifetime prediction of LoRa sensors in additive manufacturing
[Articolo su rivista]
Morato, A.; Fedullo, T.; Vitturi, S.; Rovati, L.; Tramarin, F.
abstract
Today, an innovative leap for wireless sensor networks, leading to the realization of novel and intelligent industrial measurement systems, is represented by the requirements arising from the Industry 4.0 and Industrial Internet of Things (IIoT) paradigms. In fact, unprecedented challenges to measurement capabilities are being faced, with the ever-increasing need to collect reliable yet accurate data from mobile, battery-powered nodes over potentially large areas. Therefore, optimizing energy consumption and predicting battery life are key issues that need to be accurately addressed in such IoT-based measurement systems. This is the case for the additive manufacturing application considered in this work, where smart battery-powered sensors embedded in manufactured artifacts need to reliably transmit their measured data to better control production and final use, despite being physically inaccessible. A Low Power Wide Area Network (LPWAN), and in particular LoRaWAN (Long Range WAN), represents a promising solution to ensure sensor connectivity in the aforementioned scenario, being optimized to minimize energy consumption while guaranteeing long-range operation and low-cost deployment. In the presented application, LoRa equipped sensors are embedded in artifacts to monitor a set of meaningful parameters throughout their lifetime. In this context, once the sensors are embedded, they are inaccessible, and their only power source is the originally installed battery. Therefore, in this paper, the battery lifetime prediction and estimation problems are thoroughly investigated. For this purpose, an innovative model based on an Artificial Neural Network (ANN) is proposed, developed starting from the discharge curve of lithium-thionyl chloride batteries used in the additive manufacturing application. The results of experimental campaigns carried out on real sensors were compared with those of the model and used to tune it appropriately. The results obtained are encouraging and pave the way for interesting future developments.
2023
- Driver Drowsiness Detection: A Machine Learning Approach on Skin Conductance
[Articolo su rivista]
Amidei, A.; Spinsante, S.; Iadarola, G.; Benatti, S.; Tramarin, F.; Pavan, P.; Rovati, L.
abstract
The majority of car accidents worldwide are caused by drowsy drivers. Therefore, it is important to be able to detect when a driver is starting to feel drowsy in order to warn them before a serious accident occurs. Sometimes, drivers are not aware of their own drowsiness, but changes in their body signals can indicate that they are getting tired. Previous studies have used large and intrusive sensor systems that can be worn by the driver or placed in the vehicle to collect information about the driver’s physical status from a variety of signals that are either physiological or vehicle-related. This study focuses on the use of a single wrist device that is comfortable for the driver to wear and appropriate signal processing to detect drowsiness by analyzing only the physiological skin conductance (SC) signal. To determine whether the driver is drowsy, the study tests three ensemble algorithms and finds that the Boosting algorithm is the most effective in detecting drowsiness with an accuracy of 89.4%. The results of this study show that it is possible to identify when a driver is drowsy using only signals from the skin on the wrist, and this encourages further research to develop a real-time warning system for early detection of drowsiness.
2023
- Evaluating the Integration of Wireless Time-Sensitive Networking with Software-Defined Networking for Dynamic Network Configuration
[Relazione in Atti di Convegno]
Morato, A.; Zunino, C.; Cheminod, M.; Vitturi, S.; Cavalcanti, D.; Sudhakaran, S.; Tramarin, F.
abstract
The introduction of Time-Sensitive Networking (TSN) is revolutionizing real-time networks and time-critical applications. Recent advancements in this field extended the TSN capabilities to wireless technologies, giving rise to the concept of wireless TSN (WTSN). This paper focuses on the integration of wireless TSN with Software-Defined Networking (SDN) to enable dynamic network configuration and improve the performance of time-sensitive applications. We present a practical test environment that uses a hybrid network configuration consisting of wireless and wired TSN links. The primary objective is to evaluate the effectiveness of combining a TSN-capable network with an SDN controller. This setup enables dynamic configuration and routing within the system, allowing for prompt actions to address network issues, such as seamlessly re-routing data paths between the two links due to an increase in latency or packet loss. A measurement setup using OpenVSwitch in the wireless TSN domain is presented, along with the evaluation of time synchronization and dynamic route selection capabilities.
2023
- Exploiting Blood Volume Pulse and Skin Conductance for Driver Drowsiness Detection
[Relazione in Atti di Convegno]
Poli, A.; Amidei, A.; Benatti, S.; Iadarola, G.; Tramarin, F.; Rovati, L.; Pavan, P.; Spinsante, S.
abstract
2023
- IEC 61850 on 5G Communication Infrastructure: Feasibility Analysis and Practical Considerations
[Relazione in Atti di Convegno]
Frigo, G.; Morato, A.; Fedullo, T.; Tramarin, F.
abstract
In recent years, electrical substations have been rapidly moving towards a fully digital paradigm. In this context, the IEC 61850 series of standards defines the communication infrastructure that allows full interoperability between different instruments and control actions, and in this paper we specifically consider the case of Phasor Measurement Units (PMUs). Unfortunately, distances between substations are a limiting factor for the adoption of high performance wired communication standards (i.e. Ethernet, TSN, etc.) due to the significant wiring costs. Therefore, we investigate here the possibility of transmitting their measurements using a 5G communication infrastructure. For this analysis, we reproduce a real distribution network and simulate plausible transmissions between several PMUs and a Phasor Data Concentrator (PDC). An average communication delay of 10 ms was observed. Based on the results obtained, it is reasonable to say that the 5G communication infrastructure may represent a valuable solution, especially in distribution networks where line lengths are reduced.
2023
- Image analysis algorithm for the Anterior Chamber Angle Closure estimation and Van Herick classification
[Relazione in Atti di Convegno]
Cassanelli, Davide; Gibertoni, Giovanni; Ferrazza, Manuela; Tramarin, Federico; Tanga, Lucia; Quaranta, Luciano; Oddone, Francesco; Rovati, Luigi
abstract
2023
- Measurement method for end-to-end Time synchronization of wired and wireless TSN
[Relazione in Atti di Convegno]
Sudhakaran, S.; Hall, C.; Cavalcanti, D.; Morato, A.; Zunino, C.; Tramarin, F.
abstract
Modern industrial systems require some important features such as clock synchronization, deterministic behavior, low latency, and well as high scalability, flexibility, and reliability. Time-sensitive networking (TSN) is the perfect candidate to meet these requirements since it is meant to seamlessly provide real-time performance both on wired and wireless networks. To achieve this, TSN deeply relies on the capability of synchronizing to a primary clock across the network. In this paper, we provide a measurement approach for end-to-end time synchronization in a wired and wireless heterogeneous TSN-capable network. The paper provides insight into a set of features available on commercial-grade TSN-ready devices, useful to measure time synchronization error with high accuracy and repeatability. Moreover, the paper also describes preliminary experimental results that validate the proposed measurement methodology.
2023
- Optimized 5G Communication Infrastructure for PMU-Based Distributed Measurement Systems
[Relazione in Atti di Convegno]
Morato, A.; Frigo, G.; Tramarin, F.
abstract
In recent years, there has been a rapid shift towards a fully digital paradigm in electrical substations. This shift is driven by the need for greater interoperability between different instruments and control actions, which is facilitated by the IEC 61850 series of standards. In this paper, we specifically focus on Phasor Measurement Units (PMUs) and their role in this digital transformation. One of the challenges in adopting high-performance wired communication standards such as Ethernet and TSN is the cost associated with wiring over long distances between substations. To overcome this limitation, we explore the feasibility of utilizing a 5G communication infrastructure to transmit PMU measurements. Our study simulates a real-world distribution network and assesses the worst-case latency between PMUs and Phasor Data Concentrator (PDC) by scaling the number of PMUs considered. With a mean communication latency of 20 ms, the 5G communication infrastructure proves to be a valuable solution, particularly in distribution networks where line lengths are relatively short.
2023
- Preface
[Prefazione o Postfazione]
Spinsante, S.; Iadarola, G.; Paglialonga, A.; Tramarin, F.
abstract
2023
- Time-Sensitive Networking to Improve the Performance of Distributed Functional Safety Systems Implemented over Wi-Fi
[Articolo su rivista]
Morato, A.; Vitturi, S.; Tramarin, F.; Zunino, C.; Cheminod, M.
abstract
Industry 4.0 has significantly improved the industrial manufacturing scenario in recent years. The Industrial Internet of Things (IIoT) enables the creation of globally interconnected smart factories, where constituent elements seamlessly exchange information. Industry 5.0 has further complemented these achievements, as it focuses on a human-centric approach where humans become part of this network of things, leading to a robust human–machine interaction. In this distributed, dynamic, and highly interconnected environment, functional safety is essential for adequately protecting people and machinery. The increasing availability of wireless networks makes it possible to implement distributed and flexible functional safety systems. However, such networks are known for introducing unwanted delays that can lead to safety performance degradation due to their inherent uncertainty. In this context, the Time-Sensitive Networking (TSN) standards present an attractive prospect for enhancing and ensuring acceptable behaviors. The research presented in this paper deals with the introduction of TSN to implement functional safety protocols for wireless networks. Among the available solutions, we selected Wi-Fi since it is a widespread network, often considered and deployed for industrial applications. The introduction of a reference functional safety protocol is detailed, along with an analysis of how TSN can enhance its behavior by evaluating relevant performance indexes. The evaluation pertains to a standard case study of an industrial warehouse, tested through practical simulations. The results demonstrate that TSN provides notable advantages, but it requires meticulous coordination with the Wi-Fi MAC layer protocol to guarantee improved performance.
2022
- A Comprehensive Review on Time Sensitive Networks with a Special Focus on Its Applicability to Industrial Smart and Distributed Measurement Systems
[Articolo su rivista]
Fedullo, T.; Morato, A.; Tramarin, F.; Rovati, L.; Vitturi, S.
abstract
The groundbreaking transformations triggered by the Industry 4.0 paradigm have dramati-cally reshaped the requirements for control and communication systems within the factory systems of the future. The aforementioned technological revolution strongly affects industrial smart and distributed measurement systems as well, pointing to ever more integrated and intelligent equipment devoted to derive accurate measurements. Moreover, as factory automation uses ever wider and complex smart distributed measurement systems, the well-known Internet of Things (IoT) paradigm finds its viability also in the industrial context, namely Industrial IoT (IIoT). In this context, communication networks and protocols play a key role, directly impacting on the measurement accuracy, causality, reliability and safety. The requirements coming both from Industry 4.0 and the IIoT, such as the coexistence of time-sensitive and best effort traffic, the need for enhanced horizontal and vertical integration, and interoperability between Information Technology (IT) and Operational Technology (OT), fostered the development of enhanced communication subsystems. Indeed, established tech-nologies, such as Ethernet and Wi-Fi, widespread in the consumer and office fields, are intrinsically non-deterministic and unable to support critical traffic. In the last years, the IEEE 802.1 Working Group defined an extensive set of standards, comprehensively known as Time Sensitive Networking (TSN), aiming at reshaping the Ethernet standard to support for time-, mission-and safety-critical traffic. In this paper, a comprehensive overview of the TSN Working Group standardization activity is provided, while contextualizing TSN within the complex existing industrial technological panorama, particularly focusing on industrial distributed measurement systems. In particular, this paper has to be considered a technical review of the most important features of TSN, while underlining its applicability to the measurement field. Furthermore, the adoption of TSN within the Wi-Fi technology is addressed in the last part of the survey, since wireless communication represents an appealing opportunity in the industrial measurement context. In this respect, a test case is presented, to point out the need for wirelessly connected sensors networks. In particular, by reviewing some literature contributions it has been possible to show how wireless technologies offer the flexibility necessary to support advanced mobile IIoT applications.
2022
- A simple Maxwellian optical system to investigate the photoreceptors contribution to pupillary light reflex
[Relazione in Atti di Convegno]
Gibertoni, Giovanni; Di Pinto, Valentina; Cattini, Stefano; Tramarin, Federico; Geiser, Martial; Rovati, Luigi
abstract
2022
- An IoT Measurement System Based on LoRaWAN for Additive Manufacturing
[Articolo su rivista]
Fedullo, T.; Morato, A.; Peserico, G.; Trevisan, L.; Tramarin, F.; Vitturi, S.; Rovati, L.
abstract
The Industrial Internet of Things (IIoT) paradigm represents a significant leap forward for sensor networks, potentially enabling wide-area and innovative measurement systems. In this scenario, smart sensors might be equipped with novel low-power and long range communication technologies to realize a so-called low-power wide-area network (LPWAN). One of the most popular representative cases is the LoRaWAN (Long Range WAN) network, where nodes are based on the widespread LoRa physical layer, generally optimized to minimize energy consumption, while guaranteeing long-range coverage and low-cost deployment. Additive manufacturing is a further pillar of the IIoT paradigm, and advanced measurement capabilities may be required to monitor significant parameters during the production of artifacts, as well as to evaluate environmental indicators in the deployment site. To this end, this study addresses some specific LoRa-based smart sensors embedded within artifacts during the early stage of the production phase, as well as their behavior once they have been deployed in the final location. An experimental evaluation was carried out considering two different LoRa end-nodes, namely, the Microchip RN2483 LoRa Mote and the Tinovi PM-IO-5-SM LoRaWAN IO Module. The final goal of this research was to assess the effectiveness of the LoRa-based sensor network design, both in terms of suitability for the aforementioned application and, specifically, in terms of energy consumption and long-range operation capabilities. Energy optimization, battery life prediction, and connectivity range evaluation are key aspects in this application context, since, once the sensors are embedded into artifacts, they will no longer be accessible.
2022
- Artificial Intelligence - Based Measurement Systems for Automotive: a Comprehensive Review
[Relazione in Atti di Convegno]
Fedullo, T.; Morato, A.; Tramarin, F.; Cattini, S.; Rovati, L.
abstract
The development of ever intelligent systems in various application fields is nowadays a hot research topic. Artificial Intelligence (AI) techniques become a key enabler of the transition between classical static, hard-coded algorithms and innovative, flexible ones. Actually, the automotive sector can undoubtedly benefit from the usage of the aforementioned techniques, aiming at building a novel smart automotive industry. Indeed, the application of AI spreads all round the automotive sector, ranging from on-board measuring systems to customer satisfaction analysis and demand prediction. This paper aims to review the possible applications of Artificial Intelligence techniques to the automotive sector, with a special focus on innovative measurement systems and metrology. Indeed the focus will be, between others, on Advanced Driver Assistance Systems (ADAS), in-vehicle IoT systems and intelligent industrial measuring systems, thus allowing to both increase road safety and design accurate predictive maintenance, additive manufacturing systems and, in substance, to build the smart automotive factory of the future.
2022
- Assessment of a Vision-Based Technique for an Automatic Van Herick Measurement System
[Articolo su rivista]
Fedullo, T.; Cassanelli, D.; Gibertoni, G.; Tramarin, F.; Quaranta, L.; Riva, I.; Tanga, L.; Oddone, F.; Rovati, L.
abstract
The adoption of Artificial Intelligence methods within the instrumentation and measurements field is nowadays an attractive research area. On the one hand, making machines learn from data how to perform an activity, rather than hard code sequential instructions, is a convenient and effective solution in many modern research areas. On the other hand, AI allows for the compensation of inaccurate or not complete models of specific phenomena or systems. In this context, this paper investigates the possibility to exploit suitable Machine Learning techniques in a vision-based ophthalmic instrument to perform automatic Anterior Chamber Angle (ACA) measurements. In particular, two CNN–based networks have been identified to automatically classify acquired images and select the ones suitable for the Van–Herick procedure. Extensive clinical trials have been conducted by clinicians, from which a realistic and heterogeneous image dataset has been collected. The measurement accuracy of the proposed instrument is derived by extracting measures from the images of the aforementioned dataset, as well as the system performances have been assessed with respect to differences in patients’ eye color. Currently, the ACA measurement procedure is performed manually by appropriately trained medical personnel. For this reason, Machine Learning and Vision–Based techniques may greatly improve both test objectiveness and diagnostic accessibility, by enabling an automatic measurement procedure.
2022
- Drive-by-Wi-Fi: Model-Based Control Over Wireless at 1 kHz
[Articolo su rivista]
Branz, F.; Antonello, R.; Pezzutto, M.; Vitturi, S.; Tramarin, F.; Schenato, L.
abstract
In this work, we address the problem of remotely controlling possibly unstable systems using wireless channels with communication and control rates on the order of 1 kHz. While remote control over wireless has been used for applications in the kHz control rate range via low-bitrate communication protocols such as IEEE 802.15.4 (Zigbee) and IEEE 802.15.1 (Bluetooth), this represents the first successful demonstration of remotely controlling an unstable system, namely a balancing robot, using the high-bitrate IEEE 802.11 standard (Wi-Fi) with a control/communication rate in the kHz range, thus being suitable for time-critical industrial applications. This is achieved through a suitable design of both the communication and the control layer; the Wi-Fi protocol parameters are modified to reduce communication latency while still abiding to the standard and a model-based controller is implemented using a time-varying buffered Kalman filter to compensate for the sensor-to-controller lossy communication and using a packetized predictive controller to compensate for the controller-to-actuator lossy communication. The validity of this architecture is experimentally tested on a balancing robot, which adopts off-the-shelf embedded hardware (Rasperry Pi) and software (Arduino) within an industrial-like environment where substantial channel interference is present due to coexisting Wi-Fi networks, showing major improvements compared to more traditional emulation-based architectures.
2022
- Driver Drowsiness Detection based on Variation of Skin Conductance from Wearable Device
[Relazione in Atti di Convegno]
Amidei, A.; Poli, A.; Iadarola, G.; Tramarin, F.; Pavan, P.; Spinsante, S.; Rovati, L.
abstract
2022
- On the Use of Artificial Intelligence and Sensor Fusion to Develop Accurate Eye Tracking and Driver's Emotional State Estimation Systems
[Relazione in Atti di Convegno]
Fedullo, T.; Pinto, V. D.; Morato, A.; Tramarin, F.; Cattini, S.; Rovati, L.
abstract
The estimation of the driver's emotional state is a fundamental activity to both improve the quality of driving and increase road safety. Indeed, on the one hand, the deployment of an accurate on-board measurement system for the emotional state of the driver allows the vehicle to tune some on-board settings (e.g. music, the screen brightness or the information given to the pilot). On the other hand, the estimation of the drowsiness of the pilot with such a measurement system can prevent dangerous situations by warning in advance the driver. Starting from an eye tracking system already presented in a previous article, our final project aims at merging information coming from the driver, the vehicle and the environment to properly estimate the emotional state of the driver. This paper discusses about the possibility to use Artificial Intelligence (AI) algorithms and sensor fusion to design a complete driver's emotional and drowsiness state estimation system. The goal of the paper is twofold: firstly, this article aims at reviewing the current state-of-the-art on the field; secondly we want to outline the future improvements for our preliminary setup.
2022
- On the Use of an Hyperspectral Imaging Vision Based Measurement System and Machine Learning for Iris Pigmentation Grading
[Relazione in Atti di Convegno]
Fedullo, T.; Masetti, E.; Gibertoni, G.; Tramarin, F.; Rovati, L.
abstract
Nowadays, the ability to derive accurate measurements from images, i.e. the application of vision-based systems to the measurement field, is becoming an attractive research field. In this context, Machine Learning (ML) algorithms can be exploited to smartly and automatically perform the measurement activity. This paper presents an interesting application of ML techniques to an Hyperspectral Imaging System, devoted to the analysis of the iris pigmentation. Indeed, it is proven that the iris pattern evaluation gives a chance for the analysis of both possible loss of sight and future outbreak of several eye diseases. The proposed Vision-Based Measurement system (VBM) allows to illuminate the subject eyes in the spectral range 480 - 900 nm. In particular, the imaging system foresees to take 22 different images of 2048 x 1536 pixels, thus obtaining a spectral resolution of 20 nm and a spatial resolution of 10.7 μm. In this paper, as a first research step, we evaluate the possibility to develop a suitable Machine Learning algorithm to classify the iris color. In particular, the goal is to point out the possible ML techniques that can be employed, the needed dataset and the possible advantages offered by the hyperspectral approach, compared to the conventional visible light imaging.
2022
- Smart Measurement Systems Exploiting Adaptive LoRaWAN Under Power Consumption Constraints: a RL Approach
[Relazione in Atti di Convegno]
Fedullo, T.; Morato, A.; Tramarin, F.; Ferrari, P.; Sisinni, E.
abstract
2022
- Training of an artificial intelligence algorithm for automatic detection of the Van Herick grade
[Relazione in Atti di Convegno]
Cassanelli, Davide; Fedullo, Tommaso; Gibertoni, Giovanni; Saporito, Giorgia; Ferrazza, Manuela; Oddone, Francesco; Riva, Ivano; Quaranta, Luciano; Tramarin, Federico; Rovati, Luigi
abstract
2022
- Ultra-Wideband for Distance Measurement and Positioning in Functional Safety Applications
[Relazione in Atti di Convegno]
Peserico, G.; Fedullo, T.; Morato, A.; Tramarin, F.; Vitturi, S.
abstract
Positioning techniques based on wireless communication systems are nowadays spreading in several diverse fields, such as factory automation, process control, distributed measurement, smart homes, and healthcare. Focusing on factory automation, such techniques may reveal particularly helpful to implement functional safety systems for applications, like mobile robotics, that involve the coexistence, and possibly the collaboration, of robots and human operators. Indeed, an effective localization system may be exploited by safety procedures to avoid harmful contacts between people and mobile equipment. In this paper we address the use of the Ultra-Wide-Band (UWB) technology to achieve positioning data, in such contexts. Specifically, after a short description of UWB, as well as of the typical positioning techniques, we discuss the general features of functional safety systems for mobile robotics, focusing on their common requirements. Then we provide the outcomes of an extensive measurement campaign in which we used UWB commercial components to evaluate the distance between devices as well as the position of mobile nodes. The obtained results are encouraging, since on the one hand they confirm the suitability of the proposed system whereas, on the other hand, they pave the way to future promising developments.
2021
- A Machine Learning Approach for a Vision-Based Van-Herick Measurement System
[Relazione in Atti di Convegno]
Fedullo, Tommaso; Cassanelli, Davide; Gibertoni, Giovanni; Tramarin, Federico; Quaranta, Luciano; de Angelis, Giovanni; Rovati, Luigi
abstract
2021
- Adaptive LoRaWAN transmission exploiting reinforcement learning: The industrial case
[Relazione in Atti di Convegno]
Fedullo, T.; Morato, A.; Tramarin, F.; Bellagente, P.; Ferrari, P.; Sisinni, E.
abstract
Wireless technologies play a key role in the Industrial Internet of Things (IIoT) scenario, for the development of increasingly flexible and interconnected factory systems. A significant opportunity in this context is represented by the advent of Low Power Wide Area Network (LPWAN) wireless technologies, that enable a reliable, secure, and effective transmission of measurement data over long communication ranges and with very low power consumption. Nevertheless, reliability in harsh environments (as typically occurs in the industrial scenario) is a significant issue to deal with. Focusing on LoRaWAN, adaptive strategies can be profitably devised concerning the above tradeoff. To this aim, this paper proposes to exploit Reinforcement Learning (RL) techniques to design an adaptive LoRaWAN strategy for industrial applications. The RL is spreading in many fields since it allows the design of intelligent systems using a stochastic discrete-time system approach. The proposed technique has been implemented within a purposely designed simulator, allowing to draw a preliminary performance assessment in a real-world scenario. A high density of independent nodes per square km has been considered, showing a significant improvement (about 10%) of the overall reliability in terms of data extraction rate (DER) without compromising full compatibility with the standard specifications.
2021
- Assessment of Different OPC UA Implementations for Industrial IoT-Based Measurement Applications
[Articolo su rivista]
Morato, A.; Vitturi, S.; Tramarin, F.; Cenedese, A.
abstract
The industrial Internet of Things (IIoT) paradigm represents an attractive opportunity for new generation measurement applications, which are increasingly based on efficient and reliable communication systems to allow the extensive availability of continuous data from instruments and/or sensors, thus enabling real-time measurement analysis. Nevertheless, different communication systems and heterogeneous sensors and acquisition systems may be found in an IIoT-enabled measurement application, so that solutions need to be defined to tackle the issue of seamless, effective, and low-latency interoperability. A significant and appropriate solution is the open platform communications (OPCs) unified architecture (UA) protocol, thanks to its object-oriented structure that allows a complete contextualization of the information. The intrinsic complexity of OPC UA, however, imposes meaningful performance assessment to evaluate its suitability in the aforementioned context. To this aim, this article presents the design of a general yet accurate and reproducible measurement setup that will be exploited to assess the performance of the main open-source implementations of OPC UA. The final goal of this work is to provide a characterization of the impact of this protocol stack in an IIoT-enabled measurement system, in particular, in terms of both the latency introduced in the measurement process and the power consumption.
2021
- Functional safety networks and protocols in the industrial internet of things era
[Articolo su rivista]
Peserico, G.; Morato, A.; Tramarin, F.; Vitturi, S.
abstract
Functional safety networks are becoming of paramount importance in industrial systems, due to the progressive innovation introduced by the Industry 4.0 paradigm, characterized by high production flexibility, reliability and scalability. In this context, new and challenging applications have emerged such as hyperautomation, which refers to the combination of machine vision, robotics, communication, and learning, with the explicit involvement of humans. This requires the pervasive and ubiquitous connectivity encompassed by the Industrial Internet of Things, typically achieved via wireless systems. As an example, wireless communications are today fundamental to open up to new categories of autonomous devices that can actively collaborate with human personnel in the production process. This challenging scenario has important implications for safety. Indeed, a reliable coordination among sensors, actuators and computing systems is required to provide satisfactory levels of safety, especially in the case of innovative processes and technologies, such as mobile and collaborative robotics. Hence, it becomes imperative to ensure the correct transfer of safety-critical data via communication networks. In this paper, we address the challenges concerned with functional safety networks and protocols in Industrial Internet of Things ecosystems. We first introduce the design characteristics of functional safety networks and discuss the adoption of safety protocols over wireless networks. Then, we specifically address one of such protocols, namely Fail Safety over EtherCAT (FSoE), and provide the results of an extensive experimental session carried out exploiting a prototype system, implemented using commercial devices based on a WiFi network. Finally, the outcomes of the experiments are used as a basis for a discussion about future trends of functional safety in the Industrial Internet of Things era.
2021
- Guest Editorial: Industrial Cyber-Physical Systems - New Trends in Computing and Communications
[Articolo su rivista]
Tramarin, F.; Luvisotto, M.; Willig, A.; Yu, K.
abstract
2021
- SNR-based Reinforcement Learning Rate Adaptation for Time Critical Wi-Fi Networks: Assessment through a Calibrated Simulator
[Relazione in Atti di Convegno]
Peserico, G.; Fedullo, T.; Morato, A.; Tramarin, F.; Rovati, L.; Vitturi, S.
abstract
Nowadays, the Internet of Things is spreading in several different research fields, such as factory automation, instrumentation and measurement, and process control, where it is referred to as Industrial Internet of Things. In these scenarios, wireless communication represents a key aspect to guarantee the required pervasive connectivity required. In particular, Wi-Fi networks are revealing ever more attractive also in time- and mission-critical applications, such as distributed measurement systems. Also, the multi-rate support feature of Wi-Fi, which is implemented by rate adaptation (RA) algorithms, demonstrated its effectiveness to improve reliability and timeliness. In this paper, we propose an enhancement of RSIN, which is a RA algorithm specifically conceived for industrial real-time applications. The new algorithm starts from the assumption that an SNR measure has been demonstrated to be effective to perform RA, and bases on Reinforcement Learning techniques. In detail, we start from the design of the algorithm and its implementation on the OmNet++ simulator. Then, the simulation model is adequately calibrated exploiting the results of a measurement campaign, to reflect the channel behavior typical of industrial environments. Finally, we present the results of an extensive performance assessment that demonstrate the effectiveness of the proposed technique.
2021
- Tuning of a Simulation Model for the Assessment of Functional Safety over Wi-Fi
[Relazione in Atti di Convegno]
Morato, A.; Peserico, G.; Fedullo, T.; Tramarin, F.; Vitturi, S.
abstract
In recent years, Factory Automation is evolving towards the so-called Industry 4.0, and the creation of a smart factory ecosystem comprising of ubiquitously interconnected objects, namely the Industrial Internet of Things (IIoT), is gaining much research interest. This paradigm aims at developing new smart technological equipment and protocols, thus providing interconnection among “factory objects” anywhere and at any time. In this context, people and machines have to safely cooperate and a high level of protection needs to be guaranteed for both operators and the surrounding environment. For this reason, safety systems, aiming at decreasing risks and failure probabilities, are nowadays of uttermost importance. Several Functional Safety communication protocols have been developed during these years pointing to increase data integrity and guarantee protection in a safety system. Popular examples are Fail Safe over EtherCAT (FSoE), ProfiSAFE, and OPC-UA Safety. These protocols, although conceived for wired networks, can be in principle adopted also by wireless communication, as they are developed by using a black channel approach. Nevertheless, the implementation of these protocols over different wireless networks is challenging as they might not ensure the required Safety Integrated Level (SIL). This paper, moving from the aforementioned observations and the need for wireless solutions in the IIoT context, focuses on proposing a possible implementation of FSOE over Wi-Fi, running UDP at the transport layer. In particular, by using suitable experimental outcomes, an OMNeT++ simulator has been calibrated, thus enabling the possibility to analyze the proposed protocol in wide industrial systems.
2021
- Welcome message from the workshop chairs
[Relazione in Atti di Convegno]
Peretto, L.; Rovati, L.; Tinarelli, R.; Cattini, S.; Tramarin, F.; Di Sante, R.
abstract
2021
- Wi-Fi based Functional Safety: An Assessment of the Fail Safe over EtherCAT (FSoE) protocol
[Relazione in Atti di Convegno]
Peserico, G.; Fedullo, T.; Morato, A.; Tramarin, F.; Vitturi, S.
abstract
The introduction of the Industrial Internet of Things (IIoT) is dramatically changing the concept of manufacturing, ensuring better production flexibility, efficiency, safety and security. In this scenario, Functional Safety Networks are ever more deployed, being networks that allow to implement functional safety systems, integrated and cooperating with factory communication infrastructures that are ever more characterized by the deployment of wireless communication systems. Unfortunately, nowadays, the lack of safety protocols targeted for wireless networks represents a bottleneck in the novel smart factory development process. Thus, functional safety over wireless is becoming a hot research topic. In this paper, we address the adoption of Wi-Fi to implement functional safety networks by exploiting the black channel approach, which is at the basis of the most popular functional safety protocols designed for wired networks. In practice, with such an approach, the safety protocol is not aware of the underlying communication system. We focus on a specific protocol, namely FailSafe over EtherCAT (FSoE) and investigate its behavior over Wi-Fi. To this aim, we developed an experimental set-up and conducted several tests to adequately assess safety, reliability and timing performance. Specifically, we addressed the achievable Safety Integrated Level (SIL), the number of network re-initializations and the message delivery times. The analysis provided encouraging results and revealed different behaviors concerned with the use of different transport layer protocols (TCP and UDP) that suggest interesting future activities.
2020
- 1 kHz remote control of a balancing robot with Wi-Fi-in-the-loop
[Relazione in Atti di Convegno]
Branz, F.; Antonello, R.; Pezzutto, M.; Tramarin, F.; Schenato, L.
abstract
Countless industrial applications can potentially benefit from the implementation of wireless control systems, leading to a widespread research effort to investigate new solutions in the field. Nevertheless, currently available wireless communication standards for industrial automation are not able to achieve high control frequencies. In particular, time-critical applications (e.g. industrial robotics and manipulation) require high sampling frequencies to be properly implemented. The higher throughput provided by IEEE 802.11 (Wi-Fi) can theoretically tame critical applications, although reliability is a key issue. In this work Wi-Fi is adopted to increase the achievable control rates up to 1 kHz, while reliability is guaranteed by mitigating communication flaws through model-based estimation techniques. The core of the proposed approach relies on a modified Kalman filter that exploits a buffer of incoming measures to account for delayed data packets. The proposed solution is validated through a hardware-in-the-loop experiment that features actual Wi-Fi hardware and a commercial embedded PC board. The obtained results give a preliminary, yet valuable, validation of the proposed approach testing the solution on relevant hardware.
2020
- A Profinet Simulator for the Digital Twin of Networked Electrical Drive Systems
[Relazione in Atti di Convegno]
Morato, A.; Vitturi, S.; Fedullo, T.; Peserico, G.; Tramarin, F.
abstract
Modern industrial manufacturing plants, especially those using coordinated electrical drives with strict timing requirements, make extensive use of real-time communication networks. These systems, typically, are based on various topologies, include diverse protocols, and connect devices from different manufacturers, which may make them difficult to study, plan and optimize. As a solution, the adoption of digital twins allows to simulate such systems under various operating conditions in a low-cost and zero-risk environment. In this paper we address the digital twin of a networked electrical drive system, focusing on the real-time communication network used to connect the drives. In particular, we describe the simulation model of Profinet IO RT Class 1, implemented as an extension of the INET library of OMNeT++. Moreover, we present the outcomes of the tests carried out on a prototype simulated network and compare them with those of the equivalent real one.
2020
- Adaptive transmission rate for LQG control over Wi-Fi: A cross-layer approach
[Articolo su rivista]
Pezzutto, M.; Tramarin, F.; Dey, S.; Schenato, L.
abstract
This work studies the problem of LQG control when the link between the sensor and the controller relies on a Wi-Fi network. Unfortunately, the communication on a wireless medium is sensitive to noise in the transmission band, which is characterized by the Signal-to-Noise Ratio (SNR). Wi-Fi allows to switch among different bit-rates in real-time thus permitting to trade-off lower loss probabilities for larger latency or vice-versa to achieve better closed-loop performance. To exploit this feature, under a constant SNR scenario, we propose a cross-layer approach where the bit-rate is optimally selected based on a control performance metric (i.e. minimum LQG cost) and a model-based controller is used to compensate for the packet losses. Under time-varying SNR, we additionally propose a (sub-optimal) on-line rate adaptation strategy and we guarantee the closed-loop stability under some mild conditions. Numerical comparisons with emulation-based approaches using TrueTime, a realistic Matlab-based Wi-Fi simulator, are included to show the benefits of the adaptive approach under time-varying SNR scenarios.
2020
- An IIoT System to Monitor 3D-Printed Artifacts via LoRaWAN Embedded Sensors
[Relazione in Atti di Convegno]
Trevisan, L.; Vitturi, S.; Tramarin, F.; Morato, A.
abstract
In this paper we consider an Industrial Internet of Things (IIoT) system, based on the production of 3D-printed artifacts that are equipped with embedded sensors to monitor some environmental variables such as temperature, humidity, etc. These sensors allow to gather information during the production phase of the artifacts, as well as while they are deployed in their final locations, so that diverse operations (e.g. tuning of the production parameters, predictive maintenance, environmental monitoring) can be undertaken. Monitoring is implemented via LoRaWAN, a Low Power Wide Area Network (LPWAN) that allows to acquire data from the sensors embedded in the artifacts. After a description of the IIoT system, we provide the description of some experimental tests we carried out in this challenging context, aimed at investigating both the reliability of the transmission and the battery life time. The outcomes of such experiments indicate the actual feasibility of the proposed technique.
2020
- Assessment of Different OPC UA Industrial IoT solutions for Distributed Measurement Applications
[Relazione in Atti di Convegno]
Morato, A.; Vitturi, S.; Tramarin, F.; Cenedese, A.
abstract
The Industrial IoT scenario represents an interesting opportunity for distributed measurements systems, that are typically based on efficient and reliable communication systems, as well as the widespread availability of data from measurement instruments and/or sensors. The Open Platform Communications (OPC) Unified Architecture (UA) protocol is designed to ensure interoperability between heterogeneous sensors and acquisition systems, given its object-oriented structure allowing a complete contextualization of the information. Stemming from the intrinsic complexity of OPC UA, we designed an experimental measurement setup to carry out a meaningful performance assessment of its main open source implementations. The aim is to characterize the impact of the adoption of this protocol stack in a DMS in terms of both latency and power consumption, and to provide a general yet accurate and reproducible measurement setup.
2020
- Evaluation of LoRaWAN for sensor data collection in an IIoT-based additive manufacturing project
[Relazione in Atti di Convegno]
Vitturi, S.; Trevisan, L.; Morato, A.; Frigo, G.; Tramarin, F.
abstract
The continuous evolution of additive manufacturing allows to produce innovative objects that are adopted in several diverse fields of applications. This trend can be further enhanced by the spreading of the Industrial Internet of Things (IIoT) paradigm which ensures effective interconnection among distributed, possibly heterogeneous, components and allows remote access by means of commercial devices such as PCs, tablets and smartphones. In this paper, we address a large additive manufacturing project which effectively exploits an IIoT architecture by embedding sensors (temperature, humidity, light, etc.) within the produced artifacts, so that they can make available diverse measurement data collected during both the production process (in real-time) and the subsequent lifetime of the artifacts, enabling further off-line analyses. This clearly represents an innovative and challenging feature that needs to be adequately investigated. To this regard, after describing the automation system of the project, we focus on the wireless system that implements the collection of measurements by the sensors within the artifacts. The design process led to the selection of a Low Power Wide Area Network, namely LoRaWAN, as a suitable communication solution. In this respect, we present here the tests performed to assess the actual feasibility and performance of such network in this specific application context. The obtained results are encouraging, since the sensors within the artifacts revealed able to exchange the required measurement data with the automation system in an effective way.
2020
- Rate Adaptation by Reinforcement Learning for Wi-Fi Industrial Networks
[Relazione in Atti di Convegno]
Peserico, G.; Fedullo, T.; Morato, A.; Vitturi, S.; Tramarin, F.
abstract
Wireless technologies play a key role in the Industrial Internet of Things (IIoT) scenario, for the development of increasingly flexible and interconnected factory systems. Wi-Fi remains particularly attracting due to its pervasiveness and high achievable data rates. Furthermore, its Rate Adaptation (RA) capabilities make it suitable to the harsh industrial environments, provided that specifically designed RA algorithms are deployed. To this aim, this paper proposes to exploit Reinforcement Learning (RL) techniques to design an industry-specific RA algorithm. The RL is spreading in many fields since it allows to design intelligent systems by means of a stochastic discrete-time system based approach. In this work we propose to enhance the Robust Rate Adaptation Algorithm (RRAA) by means of a RL approach. The preliminary assessment of the designed RA algorithm is carried out through meaningful OMNeT++ simulations, that allow to recognize the beneficial impact of the introduction of RL with respect to several industry-specific performance indicators.
2020
- The impact of rate adaptation algorithms on wi-fi-based factory automation systems
[Articolo su rivista]
Fedullo, T.; Tramarin, F.; Vitturi, S.
abstract
Factory automation systems based on the IEEE 802.11 Wi-Fi standard may benefit from its Multi-Rate Support (MRS) feature, which allows for dynamically selecting the most suitable transmission rate for the targeted application context. The MRS is implemented by means of rate adaptation algorithms (RAAs), which has already demonstrated to be effective to improve both timeliness and reliability, which are typically strict requirements of industrial real-time communication systems. Indeed, some of such algorithms have been specifically conceived for reliable real-time communications. However, the computational complexity of such algorithms has not been effectively investigated yet. In this paper, we address such an issue, particularly focusing on the execution times of some specific rate adaptation algorithms, as well as on their impact on the automation tasks. In this respect, after a formal description of the algorithms, we present the outcomes of an extensive experimental session, which includes practical measurements and realistic simulations. The obtained results are encouraging, since the measured execution times indicate that rate adaptation algorithms can be profitably adopted by industrial automation systems, allowing for improving their reliability and timeliness without impacting on the overall performance.
2020
- Time-Critical Wireless Networked Embedded Systems: Feasibility and Experimental Assessment
[Articolo su rivista]
Branz, F.; Antonello, R.; Schenato, L.; Tramarin, F.; Vitturi, S.
abstract
In this article, we investigate an innovative solution, to implement high sampling frequency industrial control by means of networked embedded systems connected via WiFi. The basic idea relies on a co-design approach for the control application, which is then able to adapt its sampling period, as well as to tune the Wi-Fi parameters, according to the feedback coming from the network. To this end, we implemented a cross-layer architecture acting at both application and data-link layers, which features a robust frame-delay state estimator, a time-efficient communication policy, and a specific tuning of the critical protocol parameters. Suitable hardware-in-the-loop experiments have been carried out exploiting two different embedded systems available off-the-shelf. The preliminary results, obtained from an extensive experimental campaign, are encouraging since they show that the proposed architecture enables industrial control applications requiring a sampling rate up to 1000 Hz, even in presence of communication impairments.
2019
- An indoor localization system to detect areas causing the freezing of gait in Parkinsonians
[Relazione in Atti di Convegno]
Demrozi, F.; Bragoi, V.; Tramarin, F.; Pravadelli, G.
abstract
2019
- Comparative assessment of different OPC UA open-source stacks for embedded systems
[Relazione in Atti di Convegno]
Cenedese, A.; Frodella, M.; Tramarin, F.; Vitturi, S.
abstract
With the rise of Industry 4.0 and of the Industrial Internet, the computing and communication infrastructures achieved an essential role within process and factory automation, and cyberphysical systems in general. In this scenario, the OPC UA standard is currently becoming a widespread opportunity to enable interoperability among heterogeneous industrial systems. Nonetheless, OPC UA is characterized by a complex protocol architecture, that may impair the scalability of applications and may represent a bottleneck for its effective implementation in resource-constrained devices, such as low-cost industrial embedded systems. Several different OPC UA implementations are available, which in some significant cases are released under an open source license. In this context, the aim of this paper is to provide an assessment of the performance provided by some of these different OPC UA implementations, focusing specifically on potential development and resource bottlenecks. The analysis is carried out through an extensive experimental campaign explicitly targeting general purpose low-cost embedded systems. The final goal is to provide a comprehensive performance comparisons to allow devising some useful practical guidelines.
2019
- Drive-by-Wi-Fi: Testing 1 kHz control experiments over wireless
[Relazione in Atti di Convegno]
Branz, F.; Pezzutto, M.; Antonello, R.; Tramarin, F.; Schenato, L.
abstract
2019
- Embedded systems for time-critical applications over wi-fi: Design and experimental assessment
[Relazione in Atti di Convegno]
Branz, F.; Antonello, R.; Tramarin, F.; Fedullo, T.; Vitturi, S.; Schenato, L.
abstract
Networked embedded systems for industrial control based on wireless support provide several advantages over wired counterparts, but often reveal unsuitable for the most demanding industrial control applications, such as advanced manufacturing and cooperative robotics. Data exchange over IEEE 802.11 networks may theoretically represent an appropriate solution for time-critical applications, provided that unreliability and non- determinism issues are properly handled. In this respect, this paper hence proposes an original solution, based on a cross- layer approach, to allow the realization of high-speed industrial control-over-Wi-Fi networked embedded systems. The proposal implements a novel robust frame-delay state estimator, a time efficient communication policy, and a specific tuning of critical protocol parameters. Suitable hardware-in-the-loop experiments have been carried out implemented exploiting two different embedded systems. Preliminary results show that the proposed architecture enables industrial control applications requiring a sampling rate of up to 1 kHz, even in presence of non negligible communication errors.
2019
- Real-Time and Reliable Industrial Control Over Wireless LANs: Algorithms, Protocols, and Future Directions
[Articolo su rivista]
Tramarin, Federico; Mok, Aloysius K.; Han, Song
abstract
2019
- The Fail Safe over EtherCAT (FSoE) protocol implemented on the IEEE 802.11 WLAN
[Relazione in Atti di Convegno]
Morato, A.; Vitturi, S.; Cenedese, A.; Fadel, G.; Tramarin, F.
abstract
Wireless networks are ever more deployed in industrial automation systems in various types of applications. A significant example in this context is represented by the transmission of safety data that, traditionally, was accomplished by wired systems. In this paper we propose an implementation of the Fail Safe over EtherCAT (FSoE) protocol on the top of IEEE 802.11 WLAN. The paper, after a general introduction of FSoE, focuses on the implementation of such protocol on commercial devices running UDP at the transport layer and connected via the IEEE 802.11 Wireless LAN. Then the paper presents some experimental setups and the tests that have been carried out on them. The obtained results are encouraging, since they show that good safety performance can be achieved even in the presence of wireless transmission media.
2018
- A Calibrated Test-set for Measurement of Access-Point Time Specifications in Hybrid Wired/Wireless Industrial Communication
[Working paper]
Tramarin, Federico; Narduzzi, Claudio; Vitturi, Stefano; Bertocco, Matteo
abstract
2018
- A calibrated test-set for measurement of access-point time specifications in hybrid wired/wireless industrial communication
[Articolo su rivista]
Tramarin, Federico; Narduzzi, Claudio; Vitturi, Stefano; Bertocco, Matteo
abstract
2018
- A graph-based approach for mobile localization exploiting real and virtual landmarks
[Relazione in Atti di Convegno]
Demrozi, Florenc; Costa, Kevin; Tramarin, Federico; Pravadelli, Graziano
abstract
2018
- An Innovative Algorithmic Safety Strategy for Networked Electrical Drive Systems
[Relazione in Atti di Convegno]
Vitturi, Stefano; Morato, Alberto; Cenedese, Angelo; Fadel, Giampaolo; Tramarin, Federico; Fantinel, Riccardo
abstract
2018
- Assessing the impact of full-duplex wireless in real-time industrial networks
[Relazione in Atti di Convegno]
Luvisotto, Michele; Tramarin, Federico; Vitturi, Stefano
abstract
2018
- Characterization of electrical rotary distributors for real-time data communication
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Zunino, Claudio; Frigo, Guglielmo
abstract
2018
- On the Use of LoRaWAN for Indoor Industrial IoT Applications
[Articolo su rivista]
Luvisotto, Michele; Tramarin, Federico; Vangelista, Lorenzo; Vitturi, Stefano
abstract
2018
- SNR-triggered Communication Rate for LQG Control over Wi-Fi
[Relazione in Atti di Convegno]
Pezzutto, M.; Tramarin, F.; Dey, S.; Schenato, L.
abstract
2017
- A dynamic rate selection algorithm for IEEE 802.11 industrial wireless LAN
[Articolo su rivista]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele
abstract
2017
- A learning algorithm for rate selection in real-time wireless LANs
[Articolo su rivista]
Luvisotto, Michele; Tramarin, Federico; Vitturi, Stefano
abstract
2017
- An Energy Efficient Ethernet Strategy Based on Traffic Prediction and Shaping
[Articolo su rivista]
CENEDESE, ANGELO; TRAMARIN, FEDERICO; VITTURI, STEFANO
abstract
Recently, different communities in computer science, telecommunication, and control systems have devoted a huge effort towards the design of energy efficient solutions for data transmission and network management. This paper collocates along this research line and presents a novel energy efficient strategy conceived for Ethernet networks. The proposed strategy, which exploits the opportunities offered by the IEEE 802.3az amendment to the Ethernet standard (known as energy efficient Ethernet) is based on the possibility of predicting the future traffic from the analysis of the current data flow. In agreement with the results of such a dynamic prediction, Ethernet links can be forced into a low power consumption state for variable intervals. Theoretical bounds are derived to detail how the performance figures depend on the parameters of the designed strategy and scale with respect to traffic load. Furthermore, simulation results carried out with both real and synthetic traffic traces are presented to prove the effectiveness of the strategy, which leads to considerable energy savings at the cost of only a limited bounded delay in data delivery.
2017
- IEEE 802.11n for Distributed Measurement Systems
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele
abstract
2017
- IEEE 802.11s performance assessment: From simulations to real-world experiments
[Relazione in Atti di Convegno]
Flammini, Alessandra; Sisinni, Emiliano; Tramarin, Federico
abstract
2017
- Real-time wireless extensions of industrial ethernet networks
[Relazione in Atti di Convegno]
Luvisotto, Michele; TAGLIAPIETRA, ALESSIA; Romagnolo, Stefano; Tramarin, Federico; Vitturi, Stefano
abstract
2016
- An innovative approach to rate adaptation in IEEE 802.11 real-time industrial networks
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele
abstract
2016
- Isochronous wireless communication system for industrial automation
[Capitolo/Saggio]
Sisinni, E.; Tramarin, F.
abstract
2016
- On the use of IEEE 802.11n for industrial communications
[Articolo su rivista]
TRAMARIN, FEDERICO; VITTURI, STEFANO; LUVISOTTO, MICHELE; ZANELLA, ANDREA
abstract
In the last years, IEEE 802.11 Wireless LANs (WLANs) have proved their eectiveness for a wide range of real– time industrial communication applications. Nonetheless, the introduction of the important IEEE 802.11n amendment, which is commonly implemented in commercial devices, has not been adequately addressed in this operational framework yet. IEEE 802.11n encompasses several enhancements both at the physical (PHY) and medium access control (MAC) layers that may bring considerable improvements to the performance of WLANs deployed in real–time industrial communication systems. To this regard, in this paper we present a thorough investigation of the most important IEEE 802.11n features, addressing in particular specific performance indicators, such as timeliness and reliability, that are crucial for industrial communication systems. To this aim, after an accurate theoretical analysis, we implemented a suitable experimental setup and carried out several measurement sessions to obtain an exhaustive performance assessment. The outcomes of these experiments, on the one hand revealed that the adoption of IEEE 802.11n can actually provide significant improvements to the performance of the IEEE 802.11 WLAN in the industrial communication scenario. On the other hand, the assessment allowed to select, among the various options of IEEE 802.11n, the parameter settings which may ensure the best behavior in this specific (and demanding) field of application.
2016
- Performance analysis of IEEE 802.11 Rate Selection for Industrial Networks
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele
abstract
2015
- Energy efficient ethernet for real-time industrial networks
[Articolo su rivista]
Vitturi, Stefano; Tramarin, Federico
abstract
2015
- Enhancing the real-time behavior of IEEE 802.11n
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele
abstract
2015
- Ethernet powerlink
[Capitolo/Saggio]
Tramarin, F.; Vitturi, S.
abstract
Ethernet POWERLINK (EPL) represents a prominent example of real-time Ethernet (RTE) communication networks. It belongs to the IEC 61784 International Standard [1], where it is referred to as the Communication Pro©le (CP) #1 within the CP Family #13.
2015
- Improved Rate Adaptation strategies for real-time industrial IEEE 802.11n WLANs
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele
abstract
2015
- Strategies and services for energy efficiency in real-time ethernet networks
[Articolo su rivista]
Tramarin, Federico; Vitturi, Stefano
abstract
2015
- The IEEE 802.11n wireless LAN for real-time industrial communication
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele; Zanella, Andrea
abstract
2014
- An energy efficient traffic shaping algorithm for Ethernet-based multimedia industrial traffic
[Relazione in Atti di Convegno]
Cenedese, Angelo; Michielan, Marco; Tramarin, Federico; Vitturi, Stefano
abstract
Industrial communication systems, like the very popular real-time Ethernet networks, are ever more used to carry multimedia traffic, i.e. that generated by applications employing complex sensors such as, for example, video cameras. Ethernet networks, however, revealed to be quite inefficient in terms of energy saving since the power consumption of a link between any two devices does not decrease significantly during the (statistically long) idle periods, i.e. the intervals of time in which the link is not crossed by traffic. In this paper we present a novel traffic shaping technique that aims at saving energy when the multimedia industrial traffic has self similar characteristics. In particular, the proposed method combines the statistical properties of the traffic, with the opportunities offered by the recent amendment to the Ethernet standard, called Energy Efficient Ethernet (EEE), to design a strategy based on the analysis of current traffic levels and the prediction of the incoming data flow. Simulation results are presented to prove the effectiveness of the strategy which leads to considerable energy savings at the expense of only a limited bounded delay in frame delivery.
2014
- Performance assessment of an IEEE 802.11-based protocol for real-time communication in agriculture
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano; Luvisotto, Michele; Parrozzani, Raffaele
abstract
2014
- Resolution Enhancement by Compressive Sensing in Power Quality and Phasor Measurement
[Articolo su rivista]
Bertocco, M.; Frigo, G.; Narduzzi, C.; Tramarin, F.
abstract
Measurement in power systems and, particularly, in smart grids and smart microgrids is often concerned with harmonic analysis of voltage and current waveforms. The use of Fourier-based algorithms is widespread, and the limits following from the fundamental time-versus-frequency tradeoff that relates observation time to frequency resolution are well understood. This paper presents the application of an algorithm based on the principles of compressive sensing that can achieve an order-of-magnitude resolution improvement without significantly extending total observation time. For harmonic analysis in power systems, this means that accurate results can be obtained using shorter observation intervals, which allow to effectively track changes and reduce the effect of transients on measurements. The application of the algorithm to harmonics and interharmonics, as well as to phasor measurement, is considered and analyzed.
2014
- System-level performance of an automation solution based on industry standards
[Relazione in Atti di Convegno]
Ballarino, Andrea; Brusaferri, Alessandro; Cereia, Marco; Bertolotti, Ivan Cibrario; Durante, Luca; Hu, Tingting; Leo, Egidio; Nicolosi, Leonardo; Seno, Lucia; Spinelli, Stefano; Tramarin, Federico; Valenzano, Adriano; Vitturi, Stefano
abstract
2013
- Characterization of microgrid smart metering: phasor estimation under impaired conditions
[Relazione in Atti di Convegno]
Bertocco, Matteo; Narduzzi, Claudio; Tramarin, Federico
abstract
The development of smart microgrids requires the adoption of distributed algorithms for energy management and control. In a microgrid, smart meters should also provide measuring functions similar to a PMU with comparable accuracy yet, being connected to a low-voltage distribution grid, they will have to cope with different electrical disturbances.
This paper provides an accuracy analysis of known estimation techniques based on interpolated DFT (IpDFT) methods, under the impaired conditions of a low-voltage distribution grid. A brief discussion of expected impairments is provided first, then IpDFT is applied for the estimation of voltage phasors in the neighborhood of abrupt voltage amplitude variations.
Results of experiments, run with the aid of an emulated power network, suitable data acquisition devices and signal processing, are presented and figures of merit concerning accuracy performance are discussed.
2013
- Energy Efficient Ethernet for the industrial communication scenario
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano
abstract
2013
- Estimation and analysis of communication service time in a real-time wireless industrial network
[Relazione in Atti di Convegno]
Bertocco, Matteo; Narduzzi, Claudio; Tramarin, Federico; Seno, Lucia; Vitturi, Stefano
abstract
Wireless communication systems for industrial applications should cope with the demanding performance figures of real–time wired networks, providing high reliability and satisfying tight timeliness constraints. The implementation of a scheduling framework may represent a relevant method to deploy real–time behavior in distributed measurement, process control and supervision networks. A schedulability analysis, based on task parameters, determines if the network will be able to provide the guarantees required by the specified application. Nonetheless, this strategy and the related error recovery mechanism are often implemented at a high level protocol layer, without carefully considering the behavior of physical/data–link layers of the network. An effective characterization of the service time for packet delivery, as seen by the data link–layer, is instead required for a fine tuning of the scheduling algorithms.
We analyzed the case of an IEEE 802.11g based network, where a central scheduler manages the traffic. We derived a model for the transmission times, in particular accounting for retransmissions due to channel impairment and interference. An improved model for the service time is then proposed, based on a cross–layer analysis. This allows to reshape the statistical knowledge of the metric, hence improving the network performance and admission test outcomes. The provided case- study enables the reader to understand the effectiveness of the proposed method, which provide a reliable soft real–time data acquisition system.
2013
- Industrial wireless networks: The significance of timeliness in communication systems
[Articolo su rivista]
Vitturi, Stefano; Tramarin, Federico; Seno, Lucia
abstract
2013
- On the Rate Adaptation Techniques of IEEE 802.11 Networks for Industrial Applications
[Articolo su rivista]
VITTURI, STEFANO; SENO, LUCIA; TRAMARIN, FEDERICO; BERTOCCO, MATTEO
abstract
The performance of the IEEE 802.11 WLAN are influenced by the wireless channel characteristics that reflect on the Signal-to-Noise Ratio (SNR), particularly in industrial communication systems, that often operate in harsh environments.
In order to cope with SNR reductions, the IEEE 802.11 WLAN specification suggests to adapt (reduce) the transmission rate, since the modulation techniques employed at the lower rates are more robust. However, the standard does not define any Rate Adaptation (RA) technique, leaving the actual implementation to the device manufacturers choice. In this paper we focus on RA techniques for industrial communication systems that are typically subjected to tight reliability and timing requirements. In detail, we compare the performance figures of a general purpose widespread technique, namely the Automatic Rate Fallback (ARF), with those of the RA techniques actually implemented on two commercially available IEEE 802.11 devices via a set of practical experiments. The obtained results show that these techniques are characterized by a relevant number of packet retransmissions that may introduce a considerable randomness on the service time, possibly leading to performance degradation.
Consequently, we propose two new techniques and evaluate their behavior by means of numerical simulations carried out for typical industrial traffic profiles. The outcomes are encouraging since the proposed RA techniques show in most cases better performance than ARF.
2013
- Performance analysis of IEEE 802.11g multi-rate support for industrial applications
[Relazione in Atti di Convegno]
Tramarin, Federico; Vitturi, Stefano
abstract
2013
- Resolution enhancement in harmonic analysis by compressive sensing
[Relazione in Atti di Convegno]
Bertocco, Matteo; Frigo, Guglielmo; Narduzzi, Claudio; Tramarin, Federico
abstract
Measurement in power systems and, particularly, in smart grids and smart microgrids is often concerned with harmonic analysis of voltage and current waveforms, which can be obtained by Fourier-based algorithms (e.g., phasor measurements, power quality analysis). Any such measurement algorithm is characterized by a fundamental time-frequency resolution tradeoff that relates the sampling frequency and the signal
acquisition time. These well-known conditions determine basic limits of measuring equipment, for instance, when transient response times are considered. Phasor measurement reporting latency is also affected since, for any DFT-based algorithm, this time cannot be shorter than half the observation interval.
This paper presents the application of an algorithm, based on the principles of compressive sensing (CS), that enhances frequency resolution by jointly processing multiple sets of DFT coecients, computed from time-shifted acquisitions of the same waveform. By suitably merging such information, the CS algorithm can achieve an order-of-magnitude resolution improvement without significantly extending the total observation interval, since successive acquisitions can have a very large overlap. For harmonic
analysis in power systems, this means accurate results can be obtained using shorter observation intervals, which allow to effectively track changes and reduce the effect of transients on measurements.
2012
- A system architecture for distributed monitoring and control in a Smart Microgrid
[Relazione in Atti di Convegno]
Bertocco, M.; Tramarin, F.
abstract
The paper describes an architecture for a monitoring and control system that can be adopted in a Smart Micro Grid (SMG). The logical framework is firstly described, showing how the combined usage of Energy Gateways (EGs) and Energy Interfaces (EIs) will provide new interesting features to the grid. Then, the expected capabilities from the SMG components are discussed, providing a high level definition and analysis of both EGs' and EIs' requirements. A distributed monitoring and control system is then described based on the presented vision, highlighting critical requirements. Finally, a prototype system has been realized using embedded components. The provided experiments constitute a proof of concepts about the expected features of the SMG.
2012
- Estimation of the delay of network devices in hybrid wired/wireless real-time industrial communication systems
[Relazione in Atti di Convegno]
Bertocco, Matteo; Narduzzi, Claudio; Tramarin, Federico
abstract
Recent advances in the field of hybrid communication systems for factory automation have shown that the processing delay introduced by some network components may severely affect the performances of the communication system, introducing a high degree of randomness in the delivery time of packets. Real–time behavior could result not effectively satisfied and a high number of deadlines might result lost.
Measurements are hence needed in order to obtain a statistical description of such network devices: an information that is in turn useful at the design stage of an automation network. To this aim an original and effective method providing the required analysis is presented, exploiting a simple measurement setup and low instrumentation efforts. It is based on a substitution approach, in which a closed loop network is at first characterized.
The actual Device Under Test (DUT) is subsequently included in the measurement loop. The DUT characterization is obtained applying a suitable deconvolution algorithm to the data collected in these two steps.
An experimental session involving real devices is finally provided, showing the performances of the proposed measurement approach. Theory and comments to the obtained results may also provide specific guidance to a designer in order to optimize the performances of a control network.
2012
- Il ruolo delle misure nella progettazione di sistemi wireless per applicazioni industriali
[Relazione in Atti di Convegno]
Tramarin, F; Bertocco, M
abstract
2012
- Performance of industrial communication systems: Real application contexts
[Articolo su rivista]
Seno, Lucia; Tramarin, Federico; Vitturi, Stefano
abstract
2012
- Tecniche di adattamento automatico della velocità di trasmissione per reti di comunicazione industriale basate su IEEE 802.11
[Relazione in Atti di Convegno]
Tramarin, F; Bertocco, M
abstract
2012
- Tuning of IEEE 802.11 MAC for improving real-time in industrial wireless networks
[Relazione in Atti di Convegno]
Seno, Lucia; Vitturi, Stefano; Tramarin, Federico
abstract
2011
- A calibration method for planar inductors in EMC filters: analysis and experimental validation
[Relazione in Atti di Convegno]
Tramarin, F; Bertocco, M; Sona, A; DAL CANTON, T
abstract
2011
- A case for IEEE Std. 1451 in smart microgrid environments
[Relazione in Atti di Convegno]
Bertocco, Matteo; Giorgi, Giada; Narduzzi, Claudio; Tramarin, Federico
abstract
Smart microgrids exploit information and communication technologies to efficiently manage local renewable energy sources and energy storage devices, collectively known as distributed energy resources (DERs). This requires the inclusion of rather sophisticated sensing and/or actuating units within the DER interfaces. The definition of uniform procedures to access these interfaces is a system design issue of considerable importance, since a smart microgrid aims to be self-managing and should be able to deal with the peculiarities of different DERs while implementing distributed control and energy management techniques. This paper discusses the use of the IEEE 1451 "Standard for a Smart Transducer Interface for Sensors and Actuators" as the convergence layer enabling uniform access to smart microgrid resources, analyses its application and some of the benefits its features may bring.
2011
- A cross-layer simulator for industrial wireless communication systems
[Relazione in Atti di Convegno]
Tramarin, F; Bertocco, M
abstract
he paper presents a network simulator specifically
designed for the analysis of real-time wireless networks in
an industrial control context, and for time-space localization
applications. Critical issues associated to physical components
are accounted for, together with the performance of the commu-
nication channel in an interfering environment. A comparison
toward already available simulation schemes is provided in order
to show the importance associated to the above aspects in the
accuracy of simulation results. In particular, it is seen that
random processing delays and an accurate implementation of
communication protocol models both represent critical aspects
that deeply affect accuracy. Real-life experiments support the
models and the theory discussed
2011
- Experimental evaluation of the service time for industrial hybrid (wired/wireless) networks under non-ideal environmental conditions
[Relazione in Atti di Convegno]
Seno, Lucia; Vitturi, Stefano; Tramarin, Federico
abstract
2011
- Influence of real components behavior on the performance of wireless industrial communication systems
[Relazione in Atti di Convegno]
Seno, Lucia; Vitturi, Stefano; Tramarin, Federico
abstract
2011
- Meteodo di taratura per induttori planari su PCB
[Relazione in Atti di Convegno]
Tramarin, F; Sona, A; Bertocco, M
abstract
2011
- Metodo di taratura per induttori planari su PCB
[Relazione in Atti di Convegno]
M., Bertocco; Sona, A; Tramarin, F
abstract
I circuiti per applicazioni a radiofrequenza sono spesso realizzati tramite una fase di produzione durante la quale vengono finemente accordati valori di componenti discreti. Tale pratica ha degli svantaggi
considerevoli dovuti all’impiego di manodopera qualificata che incrementa notevolmente i costi di produzione. In talune situazioni, poi, risulta semplicemente inaccettabile ricorrere a operazioni manuali
a garanzia delle prestazioni dichiarate dei dispositivi in forma duratura e affidabile. Tra i vari componenti coinvolti in tale procedura gli induttori assumono un ruolo di primo piano. Per tale motivo la comunita` tecnica e scientifica e alla ricerca di soluzioni a basso costo di produzione che permettano di superare gli inconvenienti evidenziati. In questo contesto gli induttori planari su Printed Circuit Board (PCB) costituiscono un caso di studio notevole, a causa del loro crescente impiego nelle applicazioni
per telecomunicazioni e nella compatibilita` elettromagnetica, in particolare per la realizzazione di filtri.
I modelli della letteratura sono allo stato attuale non sono specificamente pensati per induttori su PCB, ed inoltre non sono note tecniche che permettano di l’accordo degli stessi in fase di produzione. Invece
sono disponibili parecchi risultati teorici nel caso di realizzazione su circuito integrato. Nel lavoro di ricerca brevemente riassunto in questa memoria, si sono analizzati i modelli disponibili per tecnologie
integrate, verificandone il grado di applicabilita` al caso della realizzazione su PCB, confrontando le varie proposte e evidenziando per ciascuna di esse i limiti di impiego. Si e inoltre messa a punto una
tecnica originale che permette di regolare finemente il valore dell’induttanza in fase di produzione e con costi estremamente contenuti. La tecnica proposta e stata validata sperimentalmente su prototipi verificandone anche la ripetibilita`.
2011
- Un simulatore per reti wireless di sensori
[Relazione in Atti di Convegno]
Tramarin, Federico; Giorgi, Giada; Bertocco, Matteo
abstract
si descrivono sinteticamente le caratteristiche fondamentali di un simulatore, realizzato in ambiente Omnet++, che prevede la possibilità di analizzare il comportamento simultaneo di più reti wireless valutando fenomeni d’interferenza e propagazione nel canale di trasmissione.
Il simulatore permette anche di analizzare correttamente alcuni effetti notevoli introdotti da dispositivi reali comunemente impiegati nell’infrastruttura di rete, come ad esempio i ritardi di elaborazione e quelli dovuti al comportamento fisico di dispositivi elettronici.
2010
- An effective and low-cost measurement system for EMC pre-compliance testing of radiated emissions in the range 2-8 GHz
[Relazione in Atti di Convegno]
Bertocco, M; Sona, A; Tramarin, F.
abstract
The pre-compliance measurement of radiated emissions
from printed circuit boards (PCBs) is here addressed.
In particular an effective and low-cost measurement system
is described for pre-compliance radiated emission tests in the
range 2–8 GHz and under far field conditions. The goal is
to propose an original test system through which estimating
the effectiveness of electromagnetic compatibility (EMC) design
solutions at PCB level. To this aim, a detailed description of the system is provided and an analisys of the system test repeatability given. In particular, a 0.5 dB repeatability level is assessed for devices under test having maximum dimension not larger than nearly 20 cm. Some practical case studies are finally presented, proving the effectiveness of the system after the adoption of some well-known EMC techniques at PCB level.
2010
- Banco di prova efficace ed economico per la valutazione in pre-compliance di emissioni irradiate nella banda 2-8 GHz
[Relazione in Atti di Convegno]
Bertocco, M; Sona, A; Tramarin, F.
abstract
Con il presente lavoro si intende presentare un sistema
per effettuare misure di emissione irradiata
ad alta frequenza (banda 2 – 8 GHz) in precompliance,
ovvero senza le restrizioni normative
sul sito di prova. Questo sistema presenta delle
caratteristiche molto interessanti di ripetibilità della
misura. Lo scopo del sistema
proposto è di permettere al progettista che abbia
già individuato le criticità del proprio circuito in
termini di emissioni irradiate, di effettuare in modo
rapido ed economico delle misure di emissione
per valutare l’efficacia delle soluzioni adottate per
la riduzione dei disturbi.
2010
- Coesistenza tra reti wireless per l'automazione: simulazioni di interferenza per l'analisi delle prestazioni
[Relazione in Atti di Convegno]
Bertocco, M; Sona, A; Tramarin, F.
abstract
In questa memoria sono analizzate alcune tecniche di simulazione volte a valutare il grado di coesistenza tra reti wireless per l'automazione ed il funzionamento delle stesse in presenza di interferenza. Sono inoltre analizzate e proposte alcune soluzioni di ottimizzazione di modelli a livello fisico e di accesso al mezzo. Sono infine descritti alcuni risultati sperimentali di validazione delle soluzioni considerate.
2010
- Design of experiments for the assessment of coexistence between wireless networks
[Relazione in Atti di Convegno]
Tramarin, Federico; Bertocco, Matteo; Sona, Alessandro
abstract
The paper investigates the reliability of simulation
models for the assessment of wireless network performances
under the effects of radio interference. In particular, some critical
issues affecting the accuracy of modern simulation tools are
addressed. The main purpose is to highlight the role of measurements
in the optimization of theoretical models. Accordingly,
some meaningful results from experiments are compared with the
corresponding ones obtained from simulations, and simulation
models have been consequently improved. Experiments and
simulations have been carried out by using a suitable testbed,
described in the paper, enlisting a set of IEEE 802.15.4 and
802.11b compliant devices operating in the 2.4 GHz industrial
scientific and medical band.
2010
- Retransmission strategies for cyclic polling over wireless channels in the presence of interference
[Articolo su rivista]
Gamba, G; Tramarin, F; Willig, A
abstract
In this paper, we consider retransmission strategies for centralized cyclic polling-based systems over wireless channels subject to external interference. The considered strategies differ in the time when retransmissions for one particular node are carried out, and in the number of retransmissions that can be carried out for one node. We show experimentally and by simulation that two related strategies introduced in this paper, called the queueing-based strategies, significantly outperform the traditional strategy (in which all admissible trials towards one node are carried out subsequently) in terms of the average number of nodes that cannot be successfully served in a cycle. These performance gains are achieved without increasing the average total transmission effort.
2009
- Analisi del protocollo WirelessHART e delle sue strategie di coesistenza mediante l'uso di un simulatore
[Relazione in Atti di Convegno]
Bertocco, Matteo; DE DOMINICIS C., M; Ferrari, P; Flammini, A; Giorgi, Giada; Narduzzi, Claudio; Sisinni, E; Tramarin, Federico
abstract
2009
- Investigating WirelessHART coexistence issues through a specifically designed simulator
[Relazione in Atti di Convegno]
DE DOMINICIS C., M; Ferrari, P; Flammini, A; Sisinni, E; Bertocco, Matteo; Giorgi, Giada; Narduzzi, Claudio; Tramarin, Federico
abstract
In this paper, the WirelessHART communication scheme is investigated. The protocol is at first described, in order to underline the key aspects of its design; then, a simulation tool is presented: it enables analysis that accounts for both protocol and physical layers issues. In particular, interference effects on protocol choices can be easily analyzed. The experimental results, obtained from simulations, highlight improvements of WirelessHART with respect to IEEE 802.15.4 standard, concerning the Packet Error Ratio (PER) degradation of interfering networks.
2009
- Retransmission strategies for cyclic polling over wireless channels in the presence of interference
[Relazione in Atti di Convegno]
Gamba, G; Tramarin, Federico; Willig, A.
abstract
2008
- Investigating wireless networks coexistence issues through an interference aware simulator
[Relazione in Atti di Convegno]
M., Bertocco; G., Gamba; A., Sona; Tramarin, F
abstract
In the modern wireless applications of factory automation,
interference phenomena among near operating wireless
networks can be the cause of severe performance
degradation. To avoid this possibility and prevent deleterious
system failures, simulations may offer a real and reliable
solution. In this paper a new simulator is presented,
allowing cross-layer analysis of interference phenomena
arising among IEEE 802.15.4 wireless sensor networks
(WSNs) and IEEE 802.11 wireless local area networks.
The purpose is to provide an accurate tool able to forecast
possible interference effects on a WSN and by which
optimize the setup of some suitable network parameters
such as the position of wireless nodes.
2008
- Simulatore per reti di sensori wireless per l'automazione
[Relazione in Atti di Convegno]
Bertocco, M; Gamba, G; Giorgi, G.; Flammini, A; Sisinni, E; Tramarin, F
abstract