Cogging torque reduction in brushless motors by a nonlinear control technique

This work addresses the problem of mitigating the effects of the cogging torque in permanent magnet synchronous motors, particularly brushless motors, which is a main issue in precision electric drive applications. In this work, a method for mitigating the effects of the cogging torque is proposed, based on the use of a nonlinear automatic control technique known as feedback linearization that is ideal for underactuated dynamic systems. The aim of this work is to present an alternative to classic solutions based on the physical modification of the electrical machine to try to suppress the natural interaction between the permanent magnets and the teeth of the stator slots. Such modifications of electric machines are often expensive because they require customized procedures, while the proposed method does not require any modification of the electric drive. With respect to other algorithmic-based solutions for cogging torque reduction, the proposed control technique is scalable to different motor parameters, deterministic, and robust, and hence easy to use and verify for safety-critical applications. As an application case example, the work reports the reduction of the oscillations for the angular position control of a permanent magnet synchronous motor vs. classic PI (proportional-integrative) cascaded control. Moreover, the proposed algorithm is suitable to be implemented in low-cost embedded control units

Processor-in-the-Loop Validation of a Gradient Descent-Based Model Predictive Control for Assisted Driving and Obstacles Avoidance Applications

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An Innovative Olive Pâté with Nutraceutical Properties

Food plays a central role in health, especially through consumption of plant-derived foods. Functional foods, supplements, and nutraceuticals are increasingly entering the market to respond to consumer demand for healthy products. They are foods, supplements, and ingredients which offer health benefits beyond the standard nutritional value. Some benefits are associated with phenolic compounds and phytochemicals with antioxidant properties. An olive pâté (OP) was added with antioxidants derived from olive mill wastewater (OMWW) to obtain a functional product rich in phenolic compounds. The olive pâté is produced from the ground olive pericarp, which shows an excellent natural antioxidant content. The OMWW is a waste product from oil processing, which is also rich in phenolic compounds. The result was a product rich in trans-resveratrol, OH tyrosol, and tyrosol in concentrations such as satisfying the European community’s claims regarding the possible antioxidant action on plasma lipids with excellent shelf-life stability. The total phenolic content was assayed by a colorimetric method, the antioxidant activity by the ABTS [(2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)] test, the phenolic profile by Q Exactive Orbitrap LC-MS/MS. The shelf-life stability was confirmed by yeast, molds, and total microbial count, pH, and water activity determinations, and the best pasteurization parameters were determined. The palatability was judged as excellent

Design and Testing Novel One-Class Classifier Based on Polynomial Interpolation With Application to Networking Security

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Proceedings of the Fifth Italian Conference on Computational Linguistics CLiC-it 2018

On behalf of the Program Committee, a very warm welcome to the Fifth Italian Conference on Computational Linguistics (CLiC-­‐it 2018). This edition of the conference is held in Torino. The conference is locally organised by the University of Torino and hosted into its prestigious main lecture hall “Cavallerizza Reale”. The CLiC-­‐it conference series is an initiative of the Italian Association for Computational Linguistics (AILC) which, after five years of activity, has clearly established itself as the premier national forum for research and development in the fields of Computational Linguistics and Natural Language Processing, where leading researchers and practitioners from academia and industry meet to share their research results, experiences, and challenges

Controllo Attivo Per La Diminuzione della Coppia di Cogging in Motori Brushless

Il controllo di macchina (elettrica) è una delle principali problematiche di cui si occupa la branca dell’Ingegneria Elettrica che va sotto il nome di Azionamenti Elettrici , la quale risulta essere una materia del tutto interdisciplinare e quindi di interesse anche nell’ambito dell’Ingegneria dell’Automazione . Le macchine elettriche sono una delle principali applicazioni delle leggi fisiche dell’elettromagnetismo di interesse ingegneristico , le quali hanno un funzionamento che presenta delle non linearità che nella maggior parte dei casi interferisce con le aspettative di progetto sia per quello che riguarda gli aspetti costruttivi (ad esempio flussi di dispersione al traferro legati al modo in cui le linee di campo attraversano realmente il materiale di statore e rotore o l’inevitabile attrito viscoso lungo l’asse di rotazione del motore che aggiunge perdite di energia) sia per quello che riguarda il controllo di macchina e/o di azionamento (ad esempio le armoniche di alta frequenza che rendono gli andamenti delle grandezze fisiche in gioco “spurio” rispetto ad una modellazione matematica) . In questo contesto ovviamente non si analizzano gli aspetti costruttivi in quanto l’obiettivo è quello di dare un contributo in termini di tecniche di controllo automatico per la compensazione di alcuni effetti derivanti per l’appunto dalla fisica del problema ed in particolare alla diminuzione di effetti oscillatori in termini di coppia erogata dalla macchina elettrica . La presenza di non idealità viene tipicamente trattata inserendo nel loop di controllo delle funzioni opportunamente scelte che rappresentano il legame tra le grandezze fisiche in modo da poter tener conto degli aspetti più realistici sul funzionamento globale della macchina e quindi dell’intero azionamento . L’approccio tipico è quello di progettare dei controllori con tecniche classiche di Controlli Automatici facendo alcune ipotesi sulle condizioni operative di interesse ed approssimando il funzionamento della macchina in un intorno di queste condizioni di funzionamento per arrivare a trattare un sistema che nel complesso sia lineare . Questo approccio presenta alcuni limiti importanti in quanto è difficile gestire delle non linearità oppure degli ingressi aleatori all’interno del loop di controllo perché le tecniche di valutazione della robustezza e della precisione del sistema complessivo non sono del tutto sistematiche soprattutto quando i sistemi hanno più ingressi e più uscite . Il contributo maggiore da parte dell’ingegnere dell’Automazione è quello di poter mettere a disposizione la conoscenza di tecniche di controllo avanzate progettabili direttamente su un modello non lineare senza la necessità di fare ipotesi sulle condizioni operative . Gli aspetti sopracitati sono del tutto comuni in qualsiasi azionamento elettrico indipendentemente dal tipo di macchina elettrica utilizzato in esso , ad ogni modo in questo lavoro di tesi si concentra l’attenzione sulla soluzione di alcuni problemi riguardanti le macchine trifase sincrone a magneti permanenti o Bruschless A.C . Nel Capitolo 1 , vengono presentati in maniera piuttosto semplicistica gli aspetti più generali delle macchine elettriche e degli azionamenti elettrici stessi in modo da fissare le idee sui punti in comune e far capire qual è il piano d’azione per il controllo delle grandezze fisiche elettromagnetiche (correnti elettriche e flussi magnetici) e meccaniche (posizione e velocità). Nel Capitolo 2 , si focalizza l’attenzione sui servo-azionamenti di tipo Brushless presentando la struttura generale dell’azionamento e le sue varianti in base agli obiettivi di controllo ed in base a caratteristiche fisiche della macchina stessa , presentando poi il principio di funzionamento soffermandosi molto brevemente sul comportamento magnetico dei magneti permanenti per poi arrivare alla modellazione matematica che richiederà anche l’introduzione di alcuni strumenti matematici specifici . Nel Capitolo 3 , si presenta il problema dell’oscillazione di coppia dovuta al fenomeno dell’impuntamento , descrivendolo da un punto di vista elettromagnetico e giustificando la scelta di progettare un controllore in retroazione al posto di modifiche fisiche della macchina . Nel Capitolo 4 , si presenta la tecnica di controllo in feedback linearizzation da un punto di vista teorico , elencando vantaggi e svantaggi del caso e la si applica nel contesto di un azionamento Brushless al fine di attenuare il disturbo descritto nel capitolo precedente , confrontando il caso in cui è possibile sfruttare una stima di detto disturbo col caso in cui non è ha disposizione tale stima , verificando la robustezza richiesta sui parametri per avere un risultato soddisfacente , il tutto ponendosi come obiettivo la soluzione di alcuni task di interesse pratico

Design of Adaptive Controller Exploiting Learning Concepts Applied to a BLDC-Based Drive System

This work presents an innovative control architecture, which takes its ideas from the theory of adaptive control techniques and the theory of statistical learning at the same time. Taking inspiration from the architecture of a classical neural network with several hidden levels, the principle is to divide the architecture of the adaptive controller into three different levels. Each level implements an algorithm based on learning from data and therefore we can talk about learning concepts. Each level has a different task: the first to learn the required reference to the control loop; the second to learn the coefficients of the state representation of a model of the system to be controlled; and finally, the third to learn the coefficients of the state representation of the actual controller. The design of the control system is reported from both a rigorous and an operational point of view. As an application example, the proposed control technique is applied on a second-order non-linear system. We consider a servo-drive based on a brushless DC (BLDC) motor, whose dynamic model considers all the non-linear effects related to the electromechanical nature of the electric machine itself, and also an accurate model of the switching power converter. The reported example shows the capability of the control algorithm to ensure trajectory tracking while allowing for disturbance rejection with different disturbance signal amplitude. The implementation complexity analysis of the new controller is also proposed, showing its low overhead vs. basic control solutions

Design of an Observer-Based Architecture and Non-Linear Control Algorithm for Cogging Torque Reduction in Synchronous Motors

The problem of cogging torque is due to a magnetic behavior, intrinsic to synchronous machines and due to the presence of permanent magnets themselves. Cogging torque is a significant problem when the servo drive is used for applications where high precision in terms of position control is required. In this paper we present a method of cogging torque reduction by means of a control technique based on mathematical modeling of the cogging phenomenon itself in order to exploit this knowledge directly in the controller design. The mathematical model is inserted in the dynamic model of the synchronous machine in order to exploit the feedback linearization, providing an expression of the control law in which the contribution of the deterministic knowledge of the phenomenon is directly present. The cogging phenomenon physically depends on the angular position of the rotor, as well as the deterministic model we use to define the control vector. This makes it interesting and innovative to determine whether the control algorithm can be inserted within a sensor-less architecture, where rotor position and angular velocity measurements are not available. For this purpose, we present the use of an extended Kalman filter (EKF) in the continuous-time domain, discussing the advantages of an observer design based on a dynamic motor model in three-phase and direct-square axes. Results are presented through very accurate simulation for a trajectory-tracking problem, completing with variational analysis in terms of variation of initial conditions between EKF and motor dynamics, and in terms of parametric variation to verify the robustness of the proposed algorithm. Moreover, a computational analysis based on Simulink Profiler is proposed, which provides some indication for possible implementation on an embedded platform

Model-Based Design of Embedded Control & Monitoring Algorithms for Advanced Mechatronic Systems

The research project aims to apply and improve a systematic design approach to automatic control systems and supervisory and monitoring algorithms for increasingly complex modern mechatronic processes. Chapter 1 addresses the problem of mitigating the effects of cogging torque in permanent magnet synchronous motors. In Chapter 2, the use of an extended Kalman filter (EKF) in the continuous-time domain is presented, discussing the advantages of an observer design based on a dynamic motor model in three-phase, direct-quadrature axes. In Chapter 3, a development method based on model-based design, co-simulation and formal verification is introduced. In Chapter 4, the use of the GRAMPC library is proposed for the implementation of an embedded platform of a control algorithm for assisted driving that includes the function of avoiding obstacles along the road. Chapter 5 presents the workflow for the design and verification of the electrical and thermal behaviour and the validation of the control algorithms, for an On-Board Charger (OBC), through a Model-Based Design (MBD) approach. Chapters 6 and 7 it is shown the design, implementation and experimental evaluation of the Intrusion Detection System (IDS) based on voltage fingerprinting and artificial intelligence. Chapter 8 it is presented the application of different machine-learning models to the problem of anomaly classification in the context of local area network (LAN) traffic analysis

Design and Experimental Assessment of Real-Time Anomaly Detection Techniques for Automotive Cybersecurity

In recent decades, an exponential surge in technological advancements has significantly transformed various aspects of daily life. The proliferation of indispensable objects such as smartphones and computers underscores the pervasive influence of technology. This trend extends to the domains of the healthcare, automotive, and industrial sectors, with the emergence of remote-operating capabilities and self-learning models. Notably, the automotive industry has integrated numerous remote access points like Wi-Fi, USB, Bluetooth, 4G/5G, and OBD-II interfaces into vehicles, amplifying the exposure of the Controller Area Network (CAN) bus to external threats. With a recognition of the susceptibility of the CAN bus to external attacks, there is an urgent need to develop robust security systems that are capable of detecting potential intrusions and malfunctions. This study aims to leverage fingerprinting techniques and neural networks on cost-effective embedded systems to construct an anomaly detection system for identifying abnormal behavior in the CAN bus. The research is structured into three parts, encompassing the application of fingerprinting techniques for data acquisition and neural network training, the design of an anomaly detection algorithm based on neural network results, and the simulation of typical CAN attack scenarios. Additionally, a thermal test was conducted to evaluate the algorithm’s resilience under varying temperatures