The goal of this research was to explore a new and improved software development tool for the implementation of control algorithms on Xilinx Field Programmable Gate Arrays (FPGA). The Simulink plug in, System Generator, complements traditional Hardware Description Language (HDL) by providing a higher level graphical language for the development of FPGA designs. The design is then translated into the lower level required by the Xilinx's ISE program. By utilizing this graphical based higher level of abstraction at the design entry level, the requirement of a detailed knowledge of HDL languages is no longer required. Because of this new environment the time required to implement the previously developed control design on the FPGA is reduced. The initial work began with a study of System Generator capabilities. One of the primary areas of interest is the difference on how the mathematical model representations are implemented between Simulink and the logic based hardware. From this initial work, a methodology for conversion between the developed and verified Simulink design and hardware implementation was obtained. As a case study, a control design was implemented for a Simulink model of an Unmanned Ground Vehicle (UGV) based on an RC-Truck. The control system consists of a simple mission planner to generate a vector of waypoints, a proportional-integral velocity controller and a proportional heading controller. The derived hardware design process is then utilized and validated by converting the control system into the available System Generator blocks. The final verification of the FPGA design was a hardware-in-the-loop simulation utilizing a Xilinx prototyping board. This design example demonstrated the validity of the presented approach as an efficient and reliable method for rapid system prototyping for designs developed within the Simulink environment.

The purpose of this Master Thesis is to improve the driving performance of mine hoists. The work is divided into two parts. The first and main part deals with simulation of the rope elongation that occurs at load changes in the mine hoist. A mathematical load model of the elongation in the ropes at a mine hoist is made for four types of mine hoists. Mass less springs and dampers are used to get the elastic behaviour of the ropes. The mathematical model is implemented in Matlab and Simulink for all four hoist types to make load simulations possible. The implementation in the laboratory HoistLab is made by modifying an existing program with the line elongation functionality. It is only done for the tower mounted friction hoist. There are several functions that are modified to make the simulations realistic. The task for the second part of this Master Thesis is to do a pilot study to decide if it is worth making further investigations about how the derivative part will improve the drive performances. A PI controller is designed and gives an acceptable rollback as result when the brakes are released. Then the controller model is extended with the derivative part, D-part, which improves the results essentially. It is still too uncertain how sensitive the system will be for noise when using the derivative part, but the performance potential is clear so the recommendation is to make further investigations. / Syftet med detta examensarbete är att förbättra driftegenskaperna för gruvspel. Arbetet är uppdelat i två olika delar. Den första och största delen handlar om simulering av den lintöjning som uppkommer vid lastförändringar i gruvspel. Matematiska modeller för detta är framtagna för fyra olika sorters typer av gruvspel. Elasticiteten i linorna är modellerad genom masslösa fjädrar och dämpare. De matematiska sambanden är implementerade i Matlab och som modeller i Simulink för att utföra simuleringar. I HoistLab är modellen realiserad genom att utöka ett befintligt lastsimuleringsprogram med de nya funktionerna för lintöjning. Detta är utfört enbart för den toppmonterade typen av friktionsspel. Ett flertal funktioner fick ändras för att få realistiska simuleringar. Den andra delen av examensarbetet går ut på att göra en förstudie kring den deriverande delen i PID-regulatorer och hur den påverkar gruvspelets prestanda. För denna del är en PI-regulator som ger ett acceptabelt resultat av backgången när bromsarna släpps designad. Därefter är modellen utökad med den deriverande delen, D-delen, vilket ger väsentligt bättre resultat. Det är dock osäkert hur bruskänsligt systemet blir när den deriverande delen används men eftersom förbättringspotentialen är tydlig är rekommendationen att göra vidare undersökningar kring D-delen.

In chip-multiprocessor (CMP) designs, when the number of core increases, the size of on-chip communication fabric and data storage grows accordingly and therefore the chip power challenge is exacerbated. This thesis work considers the power management for networks-on-chip (NoC) and the last level cache, which constitute the uncore in CMP designs. NoC is regarded as a scalable approach to cope with the increasing demand for on-chip communication bandwidth. The last level cache is shared among all cores. The focus of this work is on the control techniques for uncore dynamic voltage and frequency scaling. A realistic but not well-studied scenario is investigated. That is, the entire uncore shares a single voltage/frequency domain, as opposed to separated domains in most of previous works. One appealing advantage here is that data packets no longer experience the interfacing overhead across different voltage/frequency domains. The classic PI (Proportional and Integral) control method is adopted due to its simplicity, flexibility and low implementation overhead. This thesis research outcome includes three parts. First, stability of the PI control is analyzed. Second, a model-assisted PI control scheme is proposed and studied. The model assist is to address the problem that no universally good reference point exists for the control. Third, the windup issue for the PI control is investigated. Full architecture simulations are performed on public benchmark suites to validate the proposed techniques. The result show 76% energy reduction with less than 6% performance degradation compared to constantly high voltage/frequency for uncore.

Thesis submitted in compliance with the requirements for the Master's Degree in Technology: Electrical Engineering - Light Current, Durban University of Technology, Department of Electronic Engineering, 2008. / Linear control systems can be easily tuned using classical tuning techniques such as the Ziegler-Nichols and Cohen-Coon tuning formulae. Empirical studies have found that these conventional tuning methods result in an unsatisfactory control performance when they are used for processes experiencing the negative destabilizing effects of strong nonlinearities. It is for this reason that control practitioners often prefer to tune most nonlinear systems using trial and error tuning, or intuitive tuning. A need therefore exists for the development of a suitable tuning technique that is applicable for a wide range of control loops that do not respond satisfactorily to conventional tuning. Emerging technologies such as Swarm Intelligence (SI) have been utilized to solve many non-linear engineering problems. Particle Swarm Optimization (PSO), developed by Eberhart and Kennedy (1995), is a sub-field of SI and was inspired by swarming patterns occurring in nature such as flocking birds. It was observed that each individual exchanges previous experience, hence knowledge of the “best position” attained by an individual becomes globally known. In the study, the problem of identifying the PID controller parameters is considered as an optimization problem. An attempt has been made to determine the PID parameters employing the PSO technique. A wide range of typical process models commonly encountered in industry is used to assess the efficacy of the PSO methodology. Comparisons are made between the PSO technique and other conventional methods using simulations and real-time control.

This master's thesis has been on modeling, identification and control of a hexarotor system. It has been carried out on behalf of UAS Europe in Link\"{o}ping. A set of non-linear dynamic equations describing the motion of the hexarotor were derived. These equations were then implemented in Matlab/Simulink, which became a good simulation environment for further studies. A decentralized control system using P-PD controllers was successfully implemented in both simulation and on a hexarotor platform. The non-linear simulation model and the hexarotor platform were then identified using black box identification between virtual controls and angular rates. The result from identification of the hexarotor platform was not bad at all, but left some room for improvements. These linear models ware then used to tune the parameters of the inner PD controllers using a method called placement of dominant poles. This method worked well in simulation environment but unfortunately not as well on the real platform.

This thesis reports the design and control of the ??GreenWeeder??, a non-herbicidal autonomous weeding robot, in order to autonomously track crop rows for weeding through electrocution in the inter-row space. The four wheel mobile robot platform was designed and built with a motorised Ackerman steering system allowing the robot to steer up to 30 degree left and right. It was also equipped with an electronically geared rear wheel drive, a pair of stereo cameras, a SICK LMS-291 laser range finder to localize itself with respect to the crop rows, a GPS system for obtaining the robot position in the field and a long-range communication system for tele-supervision by operators. The first prototype of the robot electrocution system was also designed and constructed to ignite 22kV electrical arcs to destroy weeds. Its operation was tested in the research field of the University of Sydney and the results of this experiment were analysed to improve the efficiency of this first prototype. An improved prototype of the electrocution system was then constructed and attached to a cradle extending out at the back of the mobile robot platform. The testing of this improved prototype was conducted at Lansdowne farm, a research field of the University of Sydney. After the construction of the robot platform, the robot control was considered with the demands for robot localization with respect to crop rows, an autonomously tracking control system and a manual control mode in order to take the robot to transportation vehicles. Firstly, the robot localization was accomplished by utilizing SICK LMS-291 laser range finder sensor for the sensing and perception of the robot. Secondly, the robot control system was developed with a PID controller, a second order model of the robot system and a first order filter. The PID controller is in the standard form with the filtered derivative and the PI part being in automatic reset configuration. The second order model was identified using Matlab System Identification toolbox based on the robot kinematic analysis. The first order filter is utilized for filtering out the lateral deviations of the robot with respect to the crop rows received from the SICK laser sensor. A Simulink simulation model of the robot control system was also built in order to fine-tune PID and filter parameters. Thirdly, the manual control mode of the robot was produced. In this mode, a joystick can be attached to a notebook to wirelessly drive the robot around or it can be plugged into a USB port at the back of the robot to drive it without the notebook. After the robot control was implemented and simulated, some experiments were conducted with the robot autonomously tracking a strip of reflective tape mimicking a crop row stuck into the ground of a laboratory. Depending on distances from the row assigned to the controller, the robot tried to keep those distances away from the row. The results showed the lateral errors of the robot with respect to the row were approximately 4.5 cm which were sufficient for our current agricultural application.

This thesis reports the design and control of the ??GreenWeeder??, a non-herbicidal autonomous weeding robot, in order to autonomously track crop rows for weeding through electrocution in the inter-row space. The four wheel mobile robot platform was designed and built with a motorised Ackerman steering system allowing the robot to steer up to 30 degree left and right. It was also equipped with an electronically geared rear wheel drive, a pair of stereo cameras, a SICK LMS-291 laser range finder to localize itself with respect to the crop rows, a GPS system for obtaining the robot position in the field and a long-range communication system for tele-supervision by operators. The first prototype of the robot electrocution system was also designed and constructed to ignite 22kV electrical arcs to destroy weeds. Its operation was tested in the research field of the University of Sydney and the results of this experiment were analysed to improve the efficiency of this first prototype. An improved prototype of the electrocution system was then constructed and attached to a cradle extending out at the back of the mobile robot platform. The testing of this improved prototype was conducted at Lansdowne farm, a research field of the University of Sydney. After the construction of the robot platform, the robot control was considered with the demands for robot localization with respect to crop rows, an autonomously tracking control system and a manual control mode in order to take the robot to transportation vehicles. Firstly, the robot localization was accomplished by utilizing SICK LMS-291 laser range finder sensor for the sensing and perception of the robot. Secondly, the robot control system was developed with a PID controller, a second order model of the robot system and a first order filter. The PID controller is in the standard form with the filtered derivative and the PI part being in automatic reset configuration. The second order model was identified using Matlab System Identification toolbox based on the robot kinematic analysis. The first order filter is utilized for filtering out the lateral deviations of the robot with respect to the crop rows received from the SICK laser sensor. A Simulink simulation model of the robot control system was also built in order to fine-tune PID and filter parameters. Thirdly, the manual control mode of the robot was produced. In this mode, a joystick can be attached to a notebook to wirelessly drive the robot around or it can be plugged into a USB port at the back of the robot to drive it without the notebook. After the robot control was implemented and simulated, some experiments were conducted with the robot autonomously tracking a strip of reflective tape mimicking a crop row stuck into the ground of a laboratory. Depending on distances from the row assigned to the controller, the robot tried to keep those distances away from the row. The results showed the lateral errors of the robot with respect to the row were approximately 4.5 cm which were sufficient for our current agricultural application.

Thesis (Ph.D.)--Memorial University of Newfoundland, 1999. / Bibliography: leaves 182-191.

Thesis (M. Phil.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 111-127). Also available in print.

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica / Made available in DSpace on 2012-10-23T16:43:45Z (GMT). No. of bitstreams: 0 / As máquinas de relutância variável vêm recebendo significativa atenção tanto do setor acadêmico quanto da indústria na última década. Apesar das características favoráveis como simplicidade de construção, melhor relação conjugado/volume, baixa inércia, apresentam uma elevada oscilação de conjugado decorrente de sua estrutura de dupla saliência e dos efeitos de chaveamento de corrente entre fases. O conjugado é geralmente controlado via malha interna de corrente. Para se obter mínima oscilação de conjugado, a malha de controle de corrente é uma das mais importantes em um sistema de acionamento baseado em máquinas de relutância variável. A modelagem apropriada da malha de corrente da máquina de relutância variável é essencial na implementação de seu controle. Esta tese apresenta uma nova técnica de identificação baseada na resposta em freqüência do sistema e sem necessitar do prévio conhecimento dos parâmetros da máquina. Entre os controladores mais utilizados, destacam-se o controle de histerese e PWM, geralmente implementado com controlador PI ou PID. O primeiro é indicado para operações em alta velocidade enquanto o segundo é mais eficiente em baixas e médias velocidades. Uma alternativa aos controladores anteriores, quando requisitos de desempenho mais rigorosos se fazem necessário, são os controladores preditivos e auto-ajustáveis, os quais são proposições deste trabalho. Duas técnicas de controle preditivo, GMV e GPC, para sintonia de controladores PI, são utilizadas no controle de corrente do sistema de acionamento com o MRV. Simulações foram realizadas para verificação inicial do comportamento e da viabilidade de implementação dos controladores propostos. A avaliação dos controladores é feita através de índices de desempenho e análise de estabilidade robusta. Os resultados de simulações e resultados experimentais comprovam a viabilidade das técnicas apresentadas. O emprego das estratégias de controle preditivo para o controle da malha de corrente de sistema de acionamento baseado em máquina à relutância variável pode ser considerado uma contribuição deste trabalho à literatura. Um protótipo experimental foi também implementado com um controlador DSP e um conversor do tipo meia-ponte assimétrica para o acionamento de um MRV de 12/8. In the last decade Switched Reluctance Machines (SRMs) are receiving significant attention not only in the academic section but also in industry. In spite of presenting favorable characteristics such as construction simplicity, better relationship torque/volume, low inertia, they present a high torque ripple due to the your structure of couple saliency and switching current effects among the phases. The torque is often controlled via an inner current loop. To achieve good torque control, accurate command tracking for the current control is required. It means that the current loop control is one of the most important in the system drive for variable reluctance machines. An appropriate model of the switched reluctance motor is essential to its control implementation. This thesis presents a new technique for experimental linear model identification based on the system frequency response and without needing the previous knowledge of the parameters of the machine. Among the classical controllers working for the SRMs, there are the hysteresis control and PWM, typically implemented with PI or PID controller. The first is indicated for operations in high-speed while the second is more efficient in drops and averages speeds. An alternative to improve behavior of the previous controllers when more rigorous acting requirements are made necessary are the predictive and self-tuning controllers, which are investigated in this work. Two techniques of predictive control, GMV and GPC, for PI tuning are used in the control current of the system SRM drive. Numerical simulations were accomplished for the initial verification of the system behavior and for viability of the proposed controller implementation. The controller evaluation is made through performance indices and analysis of robust stability. Simulations and experimental results have proved the viability of the presented control techniques. The employment of predictive control strategies for the loop current control of system drive of the machine to the variable reluctance can be considered a contribution from this work to the literature. An experimental prototype was implemented with a DSP controller and with a power converter of the type asymmetric bridge for the drive of a SRM 12/8.