Дисертації з теми "Positional electric drive"

Thesis (MScEng)--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: The aim of this study is to critically evaluate the voltage injection position sensorless control technique as applied to the reluctance synchronous machine (RSM) drive and to implement the technique on a 5.5 kW RSM and a 110 kW RSM. The technique is evaluated by using an accurate mathematical model of the RSM in a simulation package, called Simuwin. The negative effects that cross-magnetisation and the slotted air-gap have on the technique are intensively investigated. It was showed that these effects can cause an error in the position estimation of up to 30°. The TMS320F240 DSP was used as the controller for the RSM drives to implement the position sensorless control technique. Measurements on both RSM drives confirm the simulated results.
AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om die spannings-injeksie posisie sensorlose beheer tegniek soos toegepas op die reluktansie sinchroon masjien (RSM) aandryfstelsel, krities te evalueer en te implementeer op 'n 5.5 kW RSM en op 'n 110 kW RSM. Die tegniek is geevalueer deur 'n akkurate wiskundige model van die RSM saam te stel en die model te gebruik in 'n simulasie pakket, genaamd Simuwin. Daar is veral klem gele op die negatiewe invloed wat kruis-magnetisering en 'n gegleufde lug-spleet op die tegniek het. Dit is bewys dat hierdie eienskappe van die RSM 'n fout in die posisie afskatting van tot 30° kan veroorsaak. Die TMS320F240 DSP is gebruik as beheerder vir die RSM aandryfstelsels om sodoende posisie sensorlose beheer op altwee masjiene toe te pas. Metings op albei stelsels bevestig die simulasies.

Диссертация на соискание ученой степени кандидата технических наук по специальности 05.13. 03 – системы и процессы управления. – Национальный технический университет "Харьковский политехнический институт", Харьков, 2016. Диссертация посвящена решению научно-практической задачи усовершенствования оптимальной по затратам энергии системы управления. В диссертационной работе рассмотрен метод оптимального управления в линейной системе при квадратичном критерии качества с учётом ограничений на управляемые координаты, применительно к разомкнутой системе. Показано, что существует шесть вариантов алгоритмов оптимального управления, в зависимости от сочетания ограничений, накладываемых на управляемые координаты. В зависимости от длительности процесса оптимального управления, алгоритмы располагаются в определённом порядке, относительно друг друга, образуя тем самым область решения задачи, ограниченную временем максимального быстродействия с одной стороны и временем минимальных затрат с другой. Математические зависимости для определения этих ограничений, а также границ соседних алгоритмов внутри этой области выведены в диссертации. В работе предложена функциональная схема двухуровневой системы оптимального управления. На верхнем уровне осуществляется выбор алгоритма оптимального управления и расчёт длительностей его интервалов. Основанием для вычислений служат внешние управляющие данные. При расчёте используются параметры объекта, идентифицированные на нижнем уровне. Контроллер нижнего уровня осуществляет выработку управляющих воздействий на объект, форма и длительность которых определена ЭВМ верхнего уровня. На контроллере нижнего уровня реализована система подчинённого регулирования, с целью удержания объекта на выбранной траектории оптимального движения в фазовом пространстве. Дополнительно, локальный контроллер реализовывает функции нейронного идентификатора параметров.
The thesis for scientific degree of candidate of technical sciences in the specialty 05.13.03 – control systems and processes. – National Technical University "Kharkov Polytechnic Institute", Kharkov, 2016. The thesis is devoted to solving scientific and practical problems of improvement of cost effective energy control system. In the thesis has given the method of optimal control in a linear open-loop system with quadratic criteria of quality. It is shown that there are six variants of the algorithms of optimal control, depending on the combination of constraints on the controlled axes. Depending on the duration, optimal control algorithms are arranged in a specific order, relative to each other, thereby forming a region of the problem solution by the time of maximum speed with one hand and minimal time costs with other. Mathematical dependences for definition of these limits and the borders of neighbour algorithms within this field are derived in the thesis. In the thesis is proposed a method for the identification of the drive parameters. This method based on recurrent neural network Elman. The mathematical relationship between the weight coefficients of the network layers and parameters of the engine allows using the network learning as a way of identification. The paper presents a functional diagram of a two-tier system of optimal control. On the upper level, there is a choice of algorithm of optimal control and calculation of intervals durations. The lower level controller performs the generation of control actions on the object, the shape and duration of which is determined the upper-level computer.

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.13. 03 – системи та процеси керування. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2016. Дисертація присвячена вирішенню науково-практичної задачі вдосконалення оптимальною за витратами енергії системи керування. У дисертаційній роботі розглянуто метод оптимального керування в лінійній системі при квадратичному критерії якості з урахуванням обмежень на керовані координати, стосовно до розімкнутої системи. Показано, що існує шість варіантів алгоритмів оптимального керування, в залежності від поєднання обмежень, що накладаються на керовані координати. В залежності від тривалості процесу оптимального керування, алгоритми розташовуються у певному порядку, відносно один одного, утворюючи область рішення, обмежену часом максимальної швидкодії з одного боку і часом мінімальних витрат з іншого. Математичні залежності для визначення цих обмежень, а також кордонів сусідніх алгоритмів всередині цієї області виведені в дисертації. В дисертації запропоновано метод ідентифікації параметрів позиційного приводу, заснований на рекурентної нейронної мережі Елмана. Математичний зв'язок між ваговими коефіцієнтами рекурентного і зовнішнього шарів мережі з параметрами двигуна дозволяє застосувати здатність мережі до навчання як спосіб ідентифікації. В роботі запропонована функціональна схема дворівневої системи оптимального керування. На верхньому рівні здійснюється вибір алгоритму оптимального керування і розрахунок тривалості його інтервалів. Контролер нижнього рівня здійснює вироблення керуючих впливів на об'єкт, форма і тривалість яких визначена ЕОМ верхнього рівня.
The thesis for scientific degree of candidate of technical sciences in the specialty 05.13.03 – control systems and processes. – National Technical University "Kharkov Polytechnic Institute", Kharkov, 2016. The thesis is devoted to solving scientific and practical problems of improvement of cost effective energy control system. In the thesis has given the method of optimal control in a linear open-loop system with quadratic criteria of quality. It is shown that there are six variants of the algorithms of optimal control, depending on the combination of constraints on the controlled axes. Depending on the duration, optimal control algorithms are arranged in a specific order, relative to each other, thereby forming a region of the problem solution by the time of maximum speed with one hand and minimal time costs with other. Mathematical dependences for definition of these limits and the borders of neighbour algorithms within this field are derived in the thesis. In the thesis is proposed a method for the identification of the drive parameters. This method based on recurrent neural network Elman. The mathematical relationship between the weight coefficients of the network layers and parameters of the engine allows using the network learning as a way of identification. The paper presents a functional diagram of a two-tier system of optimal control. On the upper level, there is a choice of algorithm of optimal control and calculation of intervals durations. The lower level controller performs the generation of control actions on the object, the shape and duration of which is determined the upper-level computer.

Thesis (PhD)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: The position sensorless controllability of the reluctance synchronous machine (RSM) is investigated in this thesis with the focus on industry applications where variable and dynamic torque is required from startup up to rated speed. Two low speed as well as one medium to high speed position sensorless control (PSC) method for RSMs are investigated. These methods are extended to operate in the entire rated speed region with a hybrid PSC structure that makes use of phase locked-loop synchronisation and a hysteresis changeover method. It is shown in this thesis that PSC of the lateral rib rotor RSM is not possible from zero up to ± 0.2 p.u current. It is shown through finite element (FE) simulations that PSC of the ideal rotor RSM however, is possible at zero reference current. A novel construction method is used to build two ideal rotor RSMs. Measured flux linkage curve results of the ideal rotor RSMs correlate well with simulation results and it is shown that the electrical angle of the machine can be tracked successfully at zero reference current. The FE simulation package is used to compare the saliency of the RSM on a per-unit scale to three types of field intensified permanent magnet (FI-PM) synchronous machines and a field weakening interior permanent magnet synchronous machine. It is shown that the saliency of the RSM is larger than that of the investigated PM machines from zero up to rated load. It is thus concluded that the RSM is well suited to saliency-based PSC (SB-PSC) methods, which are used to control synchronous machines at startup and low speeds. The hybrid PSC methods developed in this thesis, are tested and evaluated on three proposed industry applications. The first is a reluctance synchronous wind generator with an inverter output LC filter. The LC filter allows long cables to be used and reduces the voltage stress on the stator windings of the machine. The combination of the LC filter and hybrid PSC method allows the power electronics and controller to be stationed in the base of the turbine tower. A new stator quantity estimation method is derived to omit the need of current and voltage sensors on the machine side of the LC filter. Good maximum power point tracking laboratory results are shown with the high frequency injection-assisted hybrid PSC method. The second application investigated is a position sensorless controlled variable gear electric vehicle (EV) RSM drive. Simulation and measured results show good torque capabilities of the position sensorless controlled EV RSM. It is shown through simulation results that the fundamental current harmonic is dominant in the demodulation scheme of the high frequency injection position sensorless control (HFIPSC) method due to the high current rating of the proposed RSM. The HFI-PSC method is extended to reduce the effect of the fundamental current harmonic in the demodulation scheme without adding any additional filters. The final investigated application is a novel mine scraper winch, which uses two position sensorless controlled RSMs to retrieve ore from the blast site underground. The new design improves on the safety, efficiency and durability of the current scraper winch design. Measured results show that the position sensorless controlled winch RSM is able to deliver rated startup torque with both investigated SB-PSC methods. Finally an automation method is implemented and tested to limited the applied force on the scraper and automatically free itself when stuck.
AFRIKAANSE OPSOMMING: Die posisie sensorlose beheer eienskappe van die reluktansie sinchroonmasjien (RSM) word in hierdie tesis ondersoek met die fokus op industriële toepassings waar varierende dinamiese draaimoment vereis word vanaf stilstand tot by ken spoed. Twee lae spoed- en een ho¨e spoed posisie sensorlose beheer (PSB) metodes vir RSMe is ondersoek. Hierdie metodes is uitgebrei om twee hibriede PSB metodes to skep wat die RSM van stilstand tot by kenspoed posisie sensorloos kan beheer. Die ontwikkelde hibriede metodes maak gebruik van ’n histerese oorskakelings skema en fase geslote lus sinchronisasie Daar word in hierdie tesis bevestig dat die laterale rib RSM nie beheer kan word met die geondersoekte PSB metodes by nul stroom nie. Eindige element simulasie resultate wys egter daarop dat die ideale rotor RSM wel beheer kan word met die geondersoekte metodes by nul stroom. ’n Nuwe konstruksie metode is voorgestel om twee ideale rotor RSMe to bou. Gemete vloed omsluiting kurwes resultate korreleer baie goed met dié van die eindige element simulasies. Gemete resultate wys ook daarop dat PSB van die nuwe masjiene moontlik is by nul stroom. ’n Eindige element pakket is gebruik om die speek-koëffissiënt van die RSM te vergelyk met drie tipes veld-versterkte permanent magneet masjiene, asook een veld verswakte permanent magneet versinkte masjien. Die simulasie resultate wys dat die RSM se speek-koëffissiënt hoër is as die van die geondersoekte permanent magneet masjiene. Die RSM is dus geskik vir speek-koëffissiënt georienteerde PSB metodes, wat hoofsaaklik by stilstand en lae spoed gebruik word. Die ontwikkelde hibried PSB metodes is getoets en geëvalueer met drie voorgestelde industriële toepassings. Die eerste is ’n reluktansie sinchroon wind generator met ’n omsetter uittree laagdeurlaat filter. Die laagdeurlaat filter laat toe dat langer kabels vanaf die omsetter na die generator gebruik kan word. Die kombinasie van die laagdeurlaat filter en die PSB metodes laat toe dat die drywingselektronika en die beheerders in die toring basis geplaas kan word. Dit kan die gewig van die nasel verminder. Goeie maksimum drywingspunt volging laboratorium resultate word getoon met die hoë frekwensie ondersteunde hibried PSB metode. Die tweede geondersoekte toepassing is ’n posisie sensorlose beheerde, varierende ratkas elektriese voertuig RSM. Goeie simulasie en gemete draaimoment resultate van die RSM word getoon. Simulasie resultate toon dat die fundamentele q-as stroom harmoniek dominant is in die demodulasie skema van die hoë frekwensie PSB metode, as gevolg van die hoë ken stroom van die motor. Die hoë frekwensie PSB metode is uitgebrei om die fundamentele stroom harmoniek te onderdruk in die demodulasie skema sonder om enige filters by te voeg. Die finale toepassing is ’n nuwe myn windas wat van twee posisie sensorlose beheerde RSMe gebruik maak om klippe ondergronds te verplaas vanaf die ontploffings area. Die voorgestelde ontwerp verbeter die huidige ontwerp ten opsigte van die veiligheid, energie effektiwiteit en robuustheid. Gemete resultate wys dat ken draaimoment moontlik is met altwee speek-koëffissiënt metodes. ’n Automasie metode, wat die maksimum draaimoment op die windas beperk en automaties homself bevry indien hy vasval, is voorgestel en geëvalueer.

This thesis deals withmodeling and control of an electric drive equipped with a permanentmagnet assisted synchronous reluctance (PMSynRel) machine for a plug-in hybrid electric vehicle application. In the first part of the thesis, a special use of the PMSynRel machine in consideration, known as an integrated charger concept, is investigated. The integrated charger feature allows using the PMSynRel machine as a part of the vehicle’s on-board charging system when charging the battery from the grid. A finite-element based analysis is performed providing important insights into the machine operation during the charging process. Dynamic models are developed that facilitate the controller development and the estimation of the efficiency during charging. In the second part of the thesis, position sensorless control of the PMSynRel drive when applied in an automotive application is considered and analyzed thoroughly. First, a fundamental-excitation based rotor-position estimation technique is investigated. The study shows that the impact of current dynamics on the resulting torque dynamics has to be considered in some very demanding applications. Second, focus is put on signalinjection based sensorless control methods. Impacts of nonlinearities, such as magnetic saturation, cross-saturation and inductance spatial harmonics, on sensorless control performance are investigated and methods to improve the sensorless control quality are summarized and presented. An approach to determine the feasible region for operating sensorless at low-speeds without directly measuring the differential inductances is proposed. For the PMSynRel drive in consideration, the achievable maximum torque is limited when operating sensorless following the maximum-torque-per-ampere (MTPA) current reference trajectory at low-speeds. An optimization approach is therefore proposed which extends the output torque when operating sensorless while still maintaining a relatively high efficiency. To initialize the sensorless control correctly from standstill, the impact of the saturated magnetic bridges in the rotor is also investigated. Finally, torsional drive-train oscillations and active damping schemes are considered. An off-vehicle setup for implementing and evaluating different active damping schemes is proposed. Of particular interest for sensorless operation in automotive applications, the impact of slow speed estimation on the possibility to achieve good active damping control is investigated and a design approach that allows the implementation of an active damping scheme using estimated speed is suggested.

QC 20140114

This master thesis deals with the design of a two-axis manipulator according to entered parameters. In the first chapter provides description of kinematics structures of industrial robots and manipulators and their workspaces. Next parts focus on search in the used components, producers of manipulators and of current design manipulators at JCEE s.r.o. Lanškroun. The practical part deals with the design and construction of custom manipulator and its price calculation.

The work described in this Master’s Degree thesis was born after the collaboration with the company Maserati S.p.a, an Italian luxury car maker with its headquarters located in Modena, in the heart of the Italian Motor Valley, where I worked as a stagiaire in the Virtual Engineering team between September 2021 and February 2022. This work proposes the validation using real-world ECUs of a Driver Drowsiness Detection (DDD) system prototype based on different detection methods with the goal to overcome input signal losses and system failures. Detection methods of different categories have been chosen from literature and merged with the goal of utilizing the benefits of each of them, overcoming their limitations and limiting as much as possible their degree of intrusiveness to prevent any kind of driving distraction: an image processing-based technique for human physical signals detection as well as methods based on driver-vehicle interaction are used. A Driver-In-the-Loop simulator is used to gather real data on which a Machine Learning-based algorithm will be trained and validated. These data come from the tests that the company conducts in its daily activities so confidential information about the simulator and the drivers will be omitted. Although the impact of the proposed system is not remarkable and there is still work to do in all its elements, the results indicate the main advantages of the system in terms of robustness against subsystem failures and signal losses.

Thesis (MScEng)--Stellenbosch University, 2013.
Wind energy has proven to be a viable source of clean energy, and the worldwide demand is growing rapidly. Variable speed topologies, with synchronous generators and full-scale converters, are becoming more popular, and the e ective control of these systems is a current trend in wind energy research. The purpose of this study is the modelling, design, simulation and implementation of a small-scale, variable speed wind energy conversion system, incorporating the position sensorless direct torque control with space vector modulation, of a permanent magnet synchronous generator, including an RLC converter lter. Another aim is the development of a gain scheduling algorithm that facilitates the high level control of the system. Mathematical models of the combined lter-generator model, in the stationary and rotating reference frames, are presented and discussed, from which equivalent approximate transfer functions are derived for the design of the controller gains. The design of the controller gains, RLC lter components, gain scheduling concept and maximum power point tracking controller are presented. It is discovered that the RLC lter damping resistance has a signi cant e ect on the resonance frequency of the system. The system is simulated dynamically in both Simulink and the VHDL-AMS programming language. Additionally, the maximum power point tracking controller is simulated in the VHDL-AMS simulation, including a wind turbine simulator. The simulation results demonstrate good dynamic performance, as well as the variable speed operation of the system. The practical results of torque and speed controllers show satisfactory performance, and correlate well with simulated results. The detailed gain scheduling algorithm is presented and discussed. A nal test of the complete system yields satisfactory practical results, and con rms that the objectives of this thesis have been reached.

As a potential solution to the global energy and environmental pollution, design and synthesis of artificial photocatalysts with high activities have attracted increasing scientific interests worldwide. In recent years, the graphitic carbon nitride (g-C3N4) has shown new possible applications in the photocatalytic field due to its unique properties. However, the photocatalytic efficiency of the pristine g-C3N4 is greatly limited by the high recombination rate of the photo-induced electron-hole pairs. In this thesis, the aim is to design and fabricate efficient g-C3N4 based photocatalysts with enhanced photocatalytic activities under a visible light irradiation. In order to achieve this goal, two strategies have been employed in the present thesis. First, the as-obtained g-C3N4 was used as the host material to construct staggered-aligned composite photocatalysts by selecting semiconductors with suitable band positions. By this method, three kinds of g-C3N4-based composite photocatalysts such as g-C3N4/ZnS nanocage, g-C3N4/m-Ag2Mo2O7 and g-C3N4/MIL-88A were successfully fabricated. Second, the microstructure of the g-C3N4 was modified by the H2O2-treatment at an elevated temperature and ambient pressure. In this study, the g-C3N4 was prepared by a simple pyrolysis of urea. As for all the as-synthesized phtocatalysts, the structures, morphologies and the optical properties were carefully characterized by the following techniques: XRD, SEM, TEM, FT-IR and DRS. Also, the band edge positions of m-Ag2Mo2O7 and MIL-88A were studied by the Mott-Schottky methods. Thereafter, the photocatalytic activities were evaluated by using a solution of rhodamine B (RhB) as a target pollutant for the photodegradation experiments performed under a visible light irradiation. The results showed that all the aforementioned g-C3N4-based photocatalysts exhibited enhanced photocatalytic activities in comparison with the pristine g-C3N4. For the case of the g-C3N4-based composite photocatalysts, the enhancement factor over the pristine g-C3N4 can achieve values ranging from 2.6 to 3.4. As for the H2O2-treated g-C3N4, the degradation rate constant can be 4.6 times higher than that of the pristine g-C3N4. To understand the key factors in new materials design, we also devote a lot of efforts to elucidate the basic mechanisms during the photocatalytic degradation of organic pollutant. Based on the results of the active species trapping (AST) experiments, the main active species in each photocatalytic system were determined. In the g-C3N4/m-Ag2Mo2O7 and the g-C3N4/MIL-88A system, three kinds of active species of ·O2-, h+ and ·OH were found to be involved in the photocatalytic reaction. Among them, the ·O2- and h+ were the main active species. In the g-C3N4/ZnS and H2O2-treated g-C3N4 photocatalytic systems, the main active species was determined as the ·O2-. The reaction pathways of these active species were also demonstrated by comparing the band edge positions with the potentials of the redox couple. In addition, the relationship between the active species and the photocatalytic behaviors of N-de-ethylation and conjugated structure cleavage were studied. Finally, possible mechanisms to explain the enhanced photocatalytic activities were proposed for each photocatalytic system. The results in this thesis clearly confirm that the photocatalytic activity of the g-C3N4 based photocatalyst can efficiently be enhanced by constructions of staggered-aligned composites and by modification of the microstructure of the g-C3N4. The enhanced photocatalytic performance can mainly be ascribed to the efficient separation of the photo-induced electron-hole pairs and the increase of the active sites for the photocatalytic reaction.

QC 20150909

The automotive industry is repeatedly tasked with improving vehicles structural strength, optimizing active and passive safety features, reducing occupant injury potential, and hitting lean manufacturing goals. The challenge is to find solutions to reduce production and research costs, and to maximize the vehicle's capability in protecting its occupants in the event of an accident. The influence of impact loading on the dynamic responses of vehicle structures and occupants require special consideration in the field of vehicle crashworthiness. The main goal of this study is to address the fundamental aspect on the impact injury biomechanics of vehicle occupants and safety performance of vehicle structures, and the development of various new technologies aimed at enhancing the passive safety of road vehicles in side-impact accidents. Four case studies related to the dissipation of crash energy, impact injury biomechanics, injury prediction model and pre-crash sensing algorithm form the basis of this thesis. The application examples include the investigation of pre-deploying airbags as a potential solution in reducing occupants' injuries at higher speed side-impact crashes; examination of the vehicle structural responses with the inclusion of high-energy absorbing cellular materials within the door panels in side-impact accidents; development of injury prediction model to out-of-position occupants from frontal- and side- airbags using Design-of-Experiment methodologies; and the estimation of the relative driver fatality risks of two colliding vehicles using some quantitative measurements. A detailed methodology is developed for each application, and the results present several new technologies that can be implemented to enhance the safety performance of road vehicles. These goals are achieved through the use of finite element approaches, multi-body dynamic analyses and Design-of-Experiment statistical methods.
Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering

The master thesis deals with problems of electrical gears divided to the teoretical and practical part of submitted work. Thesis was created in conjuction with company VUES Brno s.r.o. The author of the master thesis accomplished three-month work experience at aforementioned company and consequently solved the national project: Automatic station with utilization of active synchronic brakes for testing electrical hand-held tools. The project included creating full-automatic station for testing life-time cyclic tests electrical hand-held tools. The author of the project engage in programme for frequency transmitter served as headstone of the master thesis.

碩士
國立清華大學
電機工程學系
103
This thesis develops an electric vehicle position sensorless interior permanent-magnet synchronous motor (IPMSM) drive powered by battery/supercapacitor (SC) having good driving and regenerative braking performances. In idle condition, it possesses grid-to-vehicle (G2V), vehicle-to-home (V2H) and vehicle-to-grid (V2G) capabilities using the embedded motor drive components. Moreover, an energy harvesting system is equipped to allow the energy support from the AC source and photovoltaic (PV). The battery and SC are respectively interfaced to the motor drive DC-link via an interleaved and a standard bidirectional DC/DC converters. The SC can assist the motor in acceleration and store the recovered regenerative braking energy and transfer to the battery. The high-frequency injection (HFI) based sensorless control technique with varied injection frequencies is proposed to avoid the back-EMF harmonic effects possessed by an IPMSM. Through proper control, good driving operation characteristics are preserved, including acceleration/deceleration, reversible and regenerative braking operations. In addition, the experimental comparative driving performance evaluation to the standard EV IPMSM drive is also conducted. In G2V operation, an on-board switch mode rectifier (SMR) based charger is formed to yield good battery charging performance with satisfactory line drawn power quality. As to the V2H/V2G operations, the 220V/110V 60Hz AC output voltages with good waveform quality are generated from the developed single-phase three-wire (1P3W) inverter to power home appliances for reducing the energy drawn from the mains, and even send the preset power back to the mains. For the developed energy harvesting system, the harvested PV energy can directly charge the battery under road driving condition. In idle case, both PV and single-phase AC source can be arranged to charge the battery using the schematic formed by the motor drive embedded circuit components.

In the design and test of electric drive control systems, computer simulations provide a useful way to verify the correctness and efficiency of various schemes and control algorithms before the final system is actually constructed, therefore, development time and associated costs are reduced. Nevertheless, the transition from the simulation stage to the actual implementation has to be as straightforward as possible. This document presents the design and implementation of a position control system for permanent magnet synchronous drives, including a review and comparison of various related works about non-linear control systems applied to this type of machine. The overall electric drive control system is simulated and tested in Proteus VSM software which is able to simulate the interaction between the firmware running on a microcontroller and analogue circuits connected to it. The dsPIC33FJ32MC204 is used as the target processor to implement the control algorithms. The electric drive model is developed using elements existing in the Proteus VSM library. As in any high performance electric drive system, field oriented control is applied to achieve accurate torque control. The complete control system is distributed in three control loops, namely torque, speed and position. A standard PID control system, and a hybrid control system based on fuzzy logic are implemented and tested. The natural variation of motor parameters, such as winding resistance and magnetic flux are also simulated. Comparisons between the two control schemes are carried out for speed and position using different error measurements, such as, integral square error, integral absolute error and root mean squared error. Comparison results show a superior performance of the hybrid fuzzy-logic-based controller when coping with parameter variations, and by reducing torque ripple, but the results are reversed when periodical torque disturbances are present. Finally, the speed controllers are implemented and evaluated physically in a testbed based on a brushless DC motor, with the control algorithms implemented on a dsPIC30F2010. The comparisons carried out for the speed controllers are consistent for both simulation and physical implementation.

abstract: Toward the ambitious long-term goal of a fleet of cooperating Flexible Autonomous Machines operating in an uncertain Environment (FAME), this thesis addresses various control objectives for ground vehicles. There are two main objectives within this thesis, first is the use of visual information to control a Differential-Drive Thunder Tumbler (DDTT) mobile robot and second is the solution to a minimum time optimal control problem for the robot around a racetrack. One method to do the first objective is by using the Position Based Visual Servoing (PBVS) approach in which a camera looks at a target and the position of the target with respect to the camera is estimated; once this is done the robot can drive towards a desired position (x_ref, z_ref). Another method is called Image Based Visual Servoing (IBVS), in which the pixel coordinates (u,v) of markers/dots placed on an object are driven towards the desired pixel coordinates (u_ref, v_ref) of the corresponding markers. By doing this, the mobile robot gets closer to a desired pose (x_ref, z_ref, theta_ref). For the second objective, a camera-based and noncamera-based (v,theta) cruise-control systems are used for the solution of the minimum time problem. To set up the minimum time problem, optimal control theory is used. Then a direct method is implemented by discretizing states and controls of the system. Finally, the solution is obtained by modeling the problem in AMPL and submitting to the nonlinear optimization solver KNITRO. Simulation and experimental results are presented. The DDTT-vehicle used within this thesis has different components as summarized below: (1) magnetic wheel-encoders/IMU for inner-loop speed-control and outer-loop directional control, (2) Arduino Uno microcontroller-board for encoder-based inner-loop speed-control and encoder-IMU-based outer-loop cruise-directional-control, (3) Arduino motor-shield for inner-loop speed-control, (4) Raspberry Pi II computer-board for outer-loop vision-based cruise-position-directional-control, (5) Raspberry Pi 5MP camera for outer-loop cruise-position-directional control. Hardware demonstrations shown in this thesis are summarized: (1) PBVS without pan camera, (2) PBVS with pan camera, (3) IBVS with 1 marker/dot, (4) IBVS with 2 markers, (5) IBVS with 3 markers, (6) camera and (7) noncamera-based (v,theta) cruise control system for the minimum time problem.
Dissertation/Thesis
Masters Thesis Electrical Engineering 2016