La commande du système de Direction Assistée Electrique (DAE) est un défi majeur en raison de ses multiples objectifs et de la nécessitée de réaliser plusieurs mesures pour la mettre en oeuvre. La commande doit assurer : le suivi du couple d’assistance de référence tout en assurant la stabilité du système et sans introduire des retards, l’atténuation des vibrations provoquées par chacune des entrées du système, la transmission des informations de la route au conducteur pour un bon confort et une meilleure sensation de conduite, l’amélioration de la performance de retour au centre. La commande doit également être robuste vis-à-vis des erreurs de modélisation, des incertitudes des paramètres, et des perturbations extérieures. En outre, la mise en oeuvre de la commande nécessite plusieurs mesures telles que : l’angle au volant, l’angle du moteur, la vitesse du moteur, le couple conducteur et le couple de réaction de la route. / The control of Electric Power Assisted Steering (EPAS) system is a challengingproblem due to the multiple objectives and the need of several pieces of information to implement the control. The control objectives are to generate assist torque with fast responses to driver’s torque commands, insure system stability, attenuate vibrations, transmit the road information to the driver, and improve the steering wheel returnability and free control performance. The control must also be robust against modeling errors and parameter uncertainties. In addition, several pieces of information are required to implement the control, such as steering wheel angle, motor velocity, driver torque and road reaction torque.

[ES] Aquesta tesi presenta els resultats de la feina de recerca dut a terme sobre el modelatge i el disseny de controladors per a micro-aeronaus no tripulades mitjançant tècniques d'optimització multi-objectiu. Dos principals camps d'estudi estan presents al llarg d'ella. D'una banda, l'estudi de com modelar i controlar plataformes aèries de petita envergadura. I, de l'altra, l'estudi sobre l'ús de tècniques heurístiques d'optimització multi-objectiu per aplicar en el procés de parametrització de models i controladors en micro-aeronaus no tripulades. S'obtenen com a resultat principal una sèrie d'eines que permeten prescindir d'experiments en túnels de vent o de sensòrica d'alt cost, passant directament a la utilització de dades de vol experimental a la identificació paramètrica de models dinàmics. A més, es demostra com la utilització d'eines d'optimització multi-objectiu en diferents fases de desenvolupament de controladors ajuda a augmentar el coneixement sobre la plataforma a controlar i augmenta la fiabilitat i robustesa dels controladors desenvolupats, disminuint el risc de passar de les fases prèvies de el disseny a la validació en vol real. / [CA] Esta tesis presenta los resultados del trabajo de investigación llevado a cabo sobre el modelado y el diseño de controladores para micro-aeronaves no tripuladas mediante técnicas de optimización multi-objetivo. Dos principales campos de estudio están presentes a lo largo de ella. Por un lado, el estudio de cómo modelar y controlar plataformas aéreas de pequeña envergadura. Y, por otro, el estudio sobre el empleo de técnicas heurísticas de optimización multi-objetivo para aplicar en el proceso de parametrización de modelos y controladores en micro-aeronaves no tripuladas. Se obtienen como resultado principal una serie de herramientas que permiten prescindir de experimentos en túneles de viento o de sensórica de alto coste, pasando directamente a la utilización de datos de vuelo experimental en la identificación paramétrica de modelos dinámicos. Además, se demuestra como la utilización de herramientas de optimización multi-objetivo en diferentes fases del desarrollo de controladores ayuda a aumentar el conocimiento sobre la plataforma a controlar y aumenta la fiabilidad y robustez de los controladores desarrollados, disminuyendo el riesgo de pasar de las fases previas del diseño a la validación en vuelo real. / [EN] This thesis presents the results of the research work carried out on the modelling and design of controllers for micro-unmanned aerial vehicles by means of multi-objective optimization techniques. Two main fields of study are present throughout it. On one hand, the study of how to model and control small aerial platforms. And, on the other, the study on the use of heuristic multi-objective optimization techniques to apply in the process of models and controllers parameterization in micro-unmanned aerial vehicles. The main result is a series of tools that make it possible manage without wind tunnel experiments or high-cost air-data sensors, going directly to the use of experimental flight data in the parametric identification of dynamic models. In addition, a demonstration is given on how the use of multi-objective optimization tools in different phases of controller development helps to increase knowledge about the platform to be controlled and increases the reliability and robustness of the controllers developed, reducing the risk of hoping from the initial design phases to validation in real flight. / Velasco Carrau, J. (2020). Unmanned Aerial Vehicles Modelling and Control Design. A Multi-Objective Optimization Approach [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/156034 / TESIS

The purpose of this thesis work was to develop a Hardware-in-the-Loop imaging setup that enables experimenting with an event-based and frame-based camera under simulated space conditions. The generated data sets were used to compare visual navigation algorithms in terms of an event-based and frame-based feature detection and tracking algorithm. The comparative analyses of the feature detection and tracking algorithms were used to get insights into the feasibility of event-based vision near-space space objects. Event-based cameras differ from frame-based cameras by how they produce an asynchronous and independent stream of events caused by brightness changes at each pixel instead of capturing images at a fixed rate. The setup design is based on a theoretical framework incorporating optical calculations. These calculations indicating the asteroid model needed to be scaled down by a factor of 3192 to fit inside the camera depth-of-view. This resulted in a scaled Bennu asteroid with a size of 16.44 centimeters.The cameras under testing conducted three experiments to generate data sets. The utilization of a feature detection and tracking algorithm on both camera data sets revealed that the absolute number of tracked features, computation time, and robustness in various scenarios of the frame-based camera algorithm outperforms the event-based camera algorithm. However, when considering the percentages of tracked features relative to the total detected features, the event-based algorithm tracks a significantly higher percentage of features for at least one key frame than the frame-based algorithm.  The comparative analysis of the experiments performed in space-simulated conditions during this project showed that the feasibility of an event-based camera using solely events is low compared to the frame-based camera.

No description available.

Information and communication technologies are being implemented more than ever in the power industry in order to make smarter power grids, termed as cyber-physical power systems (CPPSs). Along with the privileges of such modern power networks like reducing the total operation cost for end-use customers, they may be negatively affected by cyberattacks, above all false data injection (FDI) attacks as they are easier to be performed. As a case in point, an adversary can detour security systems, penetrate into the cyber layer of a typical CPPS, and manipulate the information, finally leading to security threats. Although prevention and detection mechanisms are significant tools to be utilized by power system operators to improve the reliability of such systems against cyberattacks, they cannot ensure the security of power grids since some FDI attacks might be designed to bypass the detection stage. Hence, a more powerful tool will be required, which is called remedial action scheme (RAS), to be implemented by power system operators to recover the targeted power grid in a timely manner. Toward this end, different RAS frameworks are presented in this dissertation in transmission, distribution, and microgrid levels to highlight the effectiveness of such reaction mechanisms in case of cyber threats targeting modern power systems. In the transmission level, optimal power flow (OPF) integrated with thyristor controlled series capacitor (TCSC) have been utilized to design a RAS to mitigate the negative impacts of FDI attacks, resulting in system congestion or power outages. In the distribution level, system operators take advantage of static VAR compensator (SVC) through solving a customized version of distribution feeder reconfiguration (DFR) problem to mitigate voltage violations in the form of overvoltages and undervolatges, caused by FDI cyberattacks. In light of the fact that some FDI attacks bypass the employed detection methods, it is crucial to prepare in advance for such scenarios. Hence, in this dissertation, a real-world framework is also proposed for mitigating false data injection (FDI) attacks targeting a lab-scale wind/PV microgrid and resulting in power shortage. The proposed RAS is developed as a hardware-in-the-loop (HIL) testbed within the cyber-physical structure of the smart microgrid. Finally, as a prerequisite of the proposed intelligent RAS, which is able to be used on different levels of a CPPS, power system operator is being in attacker’s shoe to scrutinize different scenarios of cyberattacks to make an initial archive set. The design of such mechanisms incorporates long-short-term memory (LSTM) cells into a deep recurrent neural network (DRNN) for the processing of archived data, termed intelligent archive framework (IAF), identifying the proper reaction mechanisms for different FDI cyberattacks. To react to cyberattacks for which similar pre-investigated remedial measures were not saved in the IAF, a power flow analysis is considered to a) examine the interdependency between transmission and distribution sectors and b) generate appropriate RASs in real time.

No description available.

An accurate estimation of the charging time of an automotive traction battery is possible only with the knowledge of different parameters of the battery and the vehicle. If this information is not available to the driver, the full time needed for charging of the battery may have to be assessed only from experience. A long route planning and estimation of required service life of the vehicle are therefore only roughly possible. Furthermore, with a better knowledge of estimated charging time, better management of public charging stations and better utilization of charging equipment can be achieved. An algorithm based on Matlab/Simulink model is made in the present thesis to estimate the charging time of a Li-ion battery pack which consists of 32 cells with 40 Ah each, as well as to investigate the impact of different cell balancing methods and different charging strategies on charging process. The theoretical background of the battery and charging modelling is investigated and different battery models are compared to get the best trade-off between the model accuracy and computation complexity. In the end, an electrical equivalent circuit model from reference [1], consists of a series resistor and two ZARC elements, is chosen to represent the battery cell. The parameters of the equivalent circuit are updated according to the SOC, current and temperature changes during the charging process. The whole simulation model of the algorithm consists of a charging controller (implementing the charging strategy), cell balancing logic controller, and cell balancing hardware simulation circuit and battery cell models. Different balancing criteria: based on SOC (with PWM drive) and based on terminal voltage (with/without advance) are implemented in the cell balancing logic controller, as well as different balancing windows, to investigate their impact on charging time. As for charging strategy, traditional CCCV is investigated, further investigation is conducted into improved CCCV method. The impact of initial SOC, charging rate and aging factor on charging behavior are investigated as well. Experiment results are validated by the comparison of the results with the ones got from a Hardware-in-the-loop simulation system. / En noggrann estimering av laddtiden hos batterier avsedda för traktionsapplikationer kräver kunskap kring batteriets och dess tillhörande laddsystems parametervärden. Utan tillgång till denna information kan laddtiden endast uppskattas från fordonsägarens tidigare erfarenheter vilket försvårar t.ex. ruttplanering. En estimering av laddtiden med tillräcklig noggrannhet kan även möjliggöra bättre utnyttjade av laddutrusting inklusive nyttjandet av publika laddstationer. I detta examensarbete har en algoritm, implementerad i Matlab/Simulink, för att estimera laddtiden hos ett litiumjonbatteripack bestående av 32 celler på vardera 40 Ah tagits fram. Med hjälp av modellen har olika laddstrategier och metoder för att balansera cellerna studerats. Ett antal olika batterimodeller har jämförts i termer av noggrannhet och krav på beräkningsprestanda. En elektriskt ekvivalent krets från referens [1], bestående av en serieresistans samt två ZARC-element, valdes slutligen för att representera battericellen. Den ekvivalenta kretsens parametrar uppdateras vid förändringar i SOC, ström och temperatur. Hela simuleringsmodellen består av en laddregulator (i vilken laddstrategin är implementerad), cellbalanseringregulator och modeller för cell och cellbalanseringens hårdvara. Ett antal metoder för att balanser cellerna har jämförts med hänsyn till påverkan på den resulterande laddtiden. En traditionell samt modifierad CCCV laddstrategi har implementerats och jämförts med avseende på variationer i inledande SOC, total laddtid samt åldring. Experimentella resultat från en hardware-in-the-loop simulering har använts för att delvis kunna verifiera de framtagna resultaten.

Stability and sustainability of operation of interconnected power converter systems has been an important focus of study in the field of power electronics and power systems. With ever-increasing application of electrical machines by means of electrification of vehicles, airplanes and shipboards, detailed study of the relating dynamics is very important to ensure the proper implementation and stable behavior of the overall system. In this work, the application of the black box approach study of the power converters has been expanded to the electrical machines. Using this modeling method, it is possible of have accurate behavior of electrical and mechanical terminals of the machine without the detailed information about the internal structure of the machine, material characteristics or topology of the machine. Instead, accurate model of electrical and mechanical terminals of the machine are achieved by measuring specific frequency responses of the machine to distinguish dynamic relation of the various electrical and mechanical quantities of the machine. The directly measured frequency responses, are coupled with the dynamics of the source and load in the electrical and mechanical terminals of the machine thus in order to decoupled the described couplings a mathematical process is used that results in decoupling of the controller and drive on the electrical side and the dynamics of the mechanical load and mechanical shaft at the mechanical terminal of the machine. Resulting model is the linear time invariant representation of the electrical machine at a specific operating point. Additionally, this work represents the application of this modeling method for accurate measurement of internal parameters of the machine such as inductances and mechanical inertia and characterization of the mechanical shaft coupler. Resulting unterminated model of the machine is a very important matter of information for system integrators and electrical and mechanical designs related to the application of the machine, to ensure the stable and sustainable operation of the machine. This work for the first time, represents the experimental implementation of this terminal behavioral modeling method for studying electrical machines as well as describes some of the practical limitations of this methodology. By incorporating and integrating a combination of commercially available devices such as frequency response analyzer, Hardware-In-The-Loop (HIL), Power-Hardware-In-The-Loop (PHIL), a test setup has been developed that is capable of control, operate and study arbitrary frame small-signal related measurements required for terminal behavioral study of the electrical machines. Resulting model of the machine that has been extracted from this modeling method is then used to compare in time domain with the real machine in the case of transient change in the mechanical load on the shaft to discover the validity of this modeling procedure. / Master of Science / According to the data from the International Energy Agency, around half of the electricity used globally is consumed by electric motors. Moreover, the growth in the electrical vehicle industry will increase their application even further, hence the development of high-fidelity models of electric machines for real-time emulation, system-level analyses, and stability studies still stands out as an important and needed research focus. New modeling concepts that go beyond the standard industry practice can be used at the design and integration stage to ensure the stable behavior of the overall system. Furthermore, convenient testing and identification pressures can help ensure the long-term operation of the system. Aligned with this trend, this thesis is studying permanent magnet synchronous machines (PMSM) using small-signal terminal-behavioral three-port networks. Having such a behavioral model of the machine available provides many opportunities for system integrators, and even enables an in-situ system observation and stability assessment at both the machine's electrical and mechanical interfaces. This capability can undoubtedly be of high importance in practice, as it is offering new insights into dynamic interactions of the electro-mechanical systems, the governor or turbine control design in ships, aircrafts, electrical vehicles, and even large synchronous machines in power plants. A so-called characterization testbed has been built that combines Hardware-In-The-Loop (HIL) and Power-Hardware-In-The-Loop (PHIL) environments, with sensor-interface boards that are used to properly scale measured signals for machine control. The Frequency-Response-Analyzer is used to sweep the proper electrical or mechanical terminal of the machine by perturbing the proper control signal within the machine controller running in PHIL and reading d-q currents, voltages, torque, and speed variables whose dynamic ratios are then obtained without the need for interrupting the normal operation of the electrical machine. The capability of acquiring such a detailed model of the machine while the machine is in operation is an important benefit of this modeling method, in comparison to the conventional identification methods widely applied in the industry. The resulting model is a linearized time invariant representation of the electrical machine at a specific operating point of interest, and can be used by system integrators to ensure the stability of the system using well known stability assessment methodologies. Furthermore, this modeling strategy has been experimentally verified for the first time on electrical machines, and the resulting model has been compared with the transient behavior of the machine in the presence of a step change in the mechanical load of the machine.

The electromechanical design and development of a sophisticated roller rig testing facility at the Railway Technologies Laboratory (RTL) of Virginia Polytechnic and State University (VT) is presented. The VT Roller Rig is intended for studying the complex dynamics and mechanics at the wheel-rail interface of railway vehicles in a controlled laboratory environment. Such measurements require excellent powering and driving architecture, high-performance motion control, accurate measurements, and relatively noise-free data acquisition systems. It is critical to accurately control the relative dynamics and positioning of rotating bodies to emulate field conditions. To measure the contact forces and moments, special care must be taken to ensure any noise, such as mechanical vibration, electrical crosstalk, and electromagnetic interference (EMI) are kept to a minimum. This document describes the steps towards design and development of all electromechanical subsystems of the VT Roller Rig, including the powertrain, power electronics, motion control systems, sensors, data acquisition units, safety and monitoring circuits, and general practices followed for satisfying the local and international codes of practice. The VT Roller Rig is comprised of a wheel and a roller in a vertical configuration that simulate the single-wheel/rail interaction in one-fourth scale. The roller is five times larger than the scaled wheel to keep the contact patch distortion that is inevitable with a roller rig to a minimum. This setup is driven by two independent AC servo motors that control the velocity of the wheel and roller using state-of-the-art motion control technologies. Six linear actuators allow for adjusting the simulated load, wheel angle of attack, rail cant, and lateral position of the wheel on the rail. All motion controls are performed using digital servo drives, manufactured by Kollmorgen, VA, USA. A number of sensors measure the contact patch parameters including force, torque, displacement, rotation, speed, acceleration, and contact patch geometry. A unified communication protocol between the actuators and sensors minimizes data conversion time, which allows for servo update rates of up to 48kHz. This provides an unmatched bandwidth for performing various dynamics, vibrations, and transient tests, as well as static steady-state conditions. The VT Roller Rig has been debugged and commissioned successfully. The hardware and software components are tested both individually and within the system. The VT Roller Rig can control the creepage within 0.3RPM of the commanded value, while actively controlling the relative position of the rotating bodies with an unprecedented level of accuracy, no more than 16nm of the target location. The contact force measurement dynamometers can dynamically capture the contact forces to within 13.6N accuracy, for up to 10kN. The instantaneous torque in each driveline can be measured with better than 6.1Nm resolution. The VT Roller Rig Motion Programming Interface (MPI) is highly flexible for both programmers and non-programmers. All common motion control algorithms in the servo motion industry have been successfully implemented on the Rig. The VT Roller Rig MPI accepts third party motion algorithms in C, C++, and any .Net language. It successfully communicates with other design and analytics software such as Matlab, Simulink, and LabVIEW for performing custom-designed routines. It also provides the infrastructure for linking the Rig's hardware with commercial multibody dynamics software such as Simpack, NUCARS, and Vampire, which is a milestone for hardware-in-the-loop testing of railroad systems. / Ph. D.

Formation and tracking control are critical for of today's vehicle applications in and this will be true for future vehicle technologies as well. Although the general function of these controls is for data collection and military applications, formation and tracking control may be applied to automobiles, drones, submarines, and spacecraft. The primary application here is the investigation of formation keeping and tracking solutions for realistic, real-time, and multi-vehicle simulations. This research explores the creation of a predictive navigation and control algorithm for formation keeping and tracking, raw measurement data collection, and building a real-time GNSS closed HWIL testbed for simulations of different vehicles. The L1 frequency band of the Global Positioning System (GPS) constellation is used to observe and generate raw measurement data that encompasses range, pseudo-range, and Doppler frequency. The closed HWIL simulations are implemented using Spirent's Communication Global Navigation Satellite system (GNSS) 6560 and 8000 hardware simulators along with Ashtech, G-12 and DG-14, and Novetel OEM 628 receivers. The predictive navigation control is similar to other vision-based tracking techniques, but relies mainly on vector projections that are controlled by acceleration, velocity magnitude, and direction constraints to generate realistic motion. The current state of the testbed is capable of handling one or more vehicle applications. The testbed can model simulations up to 24 hours. The vehicle performance during simulations can be customized for any required precision by setting a variety of vehicle parameters. The testbed is built from basic principles and is easily upgradable for future expansions or upgrades. / Master of Science