The main purpose of this thesis is to design a positioning system that matches the demand of the high-accuracy and the high-speed positioning. Hereon, the linear DC motor will be chosen as the main body of the whole system. Individually, we design the controller for macro model and micro model. Among them, using the genetic algorithms¡]GA¡^to find the near-optimum controller parameters for PID controller to complete the macro target. And adopting the relay-feedback auto-tuning PID controller to carry out the micro region position control. Through the dynamic transition condition, the two-step position control system is integrated. We hope that the positioning results can achieve the position sensor resolution, , in 0.2 second¡]positioning distance <1.0cm¡^. By adopting the principle and operation procedure of the genetic algorithms to make a search for the near-optimum controller parameters, and through the process of selection, reproduction, crossover, and mutation of genes, and then the performance of the closed-loop system with PID controller is improved. According to the computer simulations and the experimental results, it is obvious that the GA-based near-optimal controller can satisfactorily control the linear DC motor system.

<p>Auto-tuning has become an important function in distributed control systems (DCS) and is especially appreciated in large industries that can have hundreds of controllers. In the DCS 800xA manufactured by ABB, there is an auto-tuning method implemented based on a relay experiment to determine the ultimate gain and the ultimate period, with which the PID parameters are obtained using the modified Ziegler-Nichols tuning rules. The tuning procedure can then proceed with a step identification experiment to get additional parameters for kappa-tau tuning. In the previous DCS, called Advant, there was another auto-tuning approach implemented. This method was based on dominant pole design, which included an identification of the process. The purpose of this thesis is to compare these auto-tuning methods, to investigate if the dominant pole placement method should be migrated to the 800xA system.</p> / <p>Automatisk trimning har blivit en viktig funktion i distribuerade styrsystem (DCS och är speciellt av intresse för stora industrier som kan ha flera hundra regulatorer. Den automatiska trimningen som idag är implementerad i ABB:s DCS 800xA är baserad på ett reläexperiment för att bestämma den ultimata förstärkningen och den ultimata periodtiden. Modifierade Ziegler-Nichols trimningsregler används sedan för att bestämma PID parametrarna. Vidare kan trimningen fortsätta med ett stegsvars-experiment för att erhålla ytterliggare parametrar och trimma med kappa-tau metoden. Den automatiska trimningsmetoden som var implementerad i tidigare DCS, Advant, var baserad på dominant polplacering med identifiering av processen. Syftet med detta examensarbete är att jämföra dessa automatiska trimningsmetoder för att undersöka om den tidigare trimningsmetoden baserad på dominant polplacering ska implementeras i 800xA systemet.</p>

Auto-tuning has become an important function in distributed control systems (DCS) and is especially appreciated in large industries that can have hundreds of controllers. In the DCS 800xA manufactured by ABB, there is an auto-tuning method implemented based on a relay experiment to determine the ultimate gain and the ultimate period, with which the PID parameters are obtained using the modified Ziegler-Nichols tuning rules. The tuning procedure can then proceed with a step identification experiment to get additional parameters for kappa-tau tuning. In the previous DCS, called Advant, there was another auto-tuning approach implemented. This method was based on dominant pole design, which included an identification of the process. The purpose of this thesis is to compare these auto-tuning methods, to investigate if the dominant pole placement method should be migrated to the 800xA system. / Automatisk trimning har blivit en viktig funktion i distribuerade styrsystem (DCS och är speciellt av intresse för stora industrier som kan ha flera hundra regulatorer. Den automatiska trimningen som idag är implementerad i ABB:s DCS 800xA är baserad på ett reläexperiment för att bestämma den ultimata förstärkningen och den ultimata periodtiden. Modifierade Ziegler-Nichols trimningsregler används sedan för att bestämma PID parametrarna. Vidare kan trimningen fortsätta med ett stegsvars-experiment för att erhålla ytterliggare parametrar och trimma med kappa-tau metoden. Den automatiska trimningsmetoden som var implementerad i tidigare DCS, Advant, var baserad på dominant polplacering med identifiering av processen. Syftet med detta examensarbete är att jämföra dessa automatiska trimningsmetoder för att undersöka om den tidigare trimningsmetoden baserad på dominant polplacering ska implementeras i 800xA systemet.

In Scania’s single speed engines for industrial and marine use, the engine speed is controlled by a PI-controller. This controller is tuned independent of engine type and application. This brings certain disadvantages since the engines are used in a wide range of applications where the dynamics may differ. In this thesis, the possibility to tune the controller automatically for a specific engine installation has been investigated. The work shows that automatic tuning is possible. By performing an identification experiment on the engine, the parameters in a first order model describing the dynamics of the engine and the load aggregate are determined. The control parameters are then determined as functions of the model parameters. Measurements on a generator set show that the proposed method provides a controller which is able to follow changes in the reference value, and to compensate for load disturbances. / I Scania’s envarvsmotorer för industri- och marin-bruk regleras varvtalet av en PI-regulator. Denna regulator är inställd oberoende av motortyp och applikation. Detta medför vissa nackdelar då motorerna används i flera olika typer av applikationer där dynamiken kan variera. I detta arbete har det undersökts huruvida det är möjligt att automatiskt ställa in parametrarna i en PID-regulator för en enskild motorinstallation. Arbetet visar att automatisk inställning är möjlig. Genom att göra ett identifieringsexperiment på motorn bestäms parametrarna i en första ordningens modell som beskriver dynamiken för den aktuella konfigurationen av motor och belastande aggregat. Därefter bestäms regulatorparametrarna som funktion av modellparametrarna. Mätningar på ett generatoraggregat visar att man med hjälp av den föreslagna metoden erhåller en inställning av regulatorn som både klarar av att följa börvärdesförändringar och kompensera för laststörningar.

No description available.

Aircraft and satellite structures are exposed to a wide range of temperatures during normal operation cycles. These fluctuations in temperature may result in significant changes of the structural dynamics. Aircraft, automotive, and satellite structures are also subject to various vibration sources. Passive and active vibration suppression techniques have been developed to minimize acoustic noise and fatigue stress damage. Featuring low weight solutions and high performance, active control techniques are becoming increasingly common. Structures with varying dynamics require more sophisticated active control techniques, such as adaptive control. This research uses a special vibration test rig for evaluating the performance of different vibration suppression systems on a representative aircraft panel. The test panel is clamped rigidly in a frame and can be excited in various frequencies with an electromagnetic shaker. To simulate temperature fluctuations the temperature on the panel can be increased up to 65°C (150°F). Smart material based sensors and actuators are used to interface the mechanical system with the electronic controller. The active controller utilizes three positive position feedback (PPF) filters implemented through a digital signal processor board. This research develops two different adaptation methods to perform vibration suppression in the presence of thermally induced frequency changes of the representative panel. To adjust the PPF filter parameters an open-loop adaptation method and an auto-tuning method are investigated. The open-loop adaptation method uses a measurement of the plate temperature and a look-up table with pre-determined parameters to update the filters accordingly. The auto-tuning methods identifies the frequencies of the poles and zeros in the structure's collocated transfer function. From the knowledge of the pole and zero locations the optimal PPF parameters are calculated online. The results show that both adaptation methods are capable of reducing the vibration levels of the test specimen over the temperature range of interest. Three PPF filters with parameter adaptation through temperature measurement achieve magnitude reductions of the resonance peaks as high as 13.6 decibel. Using the auto-tuning method resonance peak reductions up to 17.4 decibel are possible. The pole/zero identification routine proves to detect the frequencies correctly. The average identification error remained at around one percent even in the presence of external disturbances. / Master of Science

Advances in transistor-integration technology and multi-core technology of the latest microprocessors have driven transient requirements to become more and more stringent. Rather than relying on the bulky output capacitors as energy-storage devices, increasing the control bandwidth (BW) of the multiphase voltage regulator (VR) is a more cost-effective and space-saving approach. However, it is found that the stability margin of current-mode control in high-BW design is very sensitive to operating conditions and component tolerance, depending on the performance of the current-sensing techniques, modulation schemes, and interleaving approaches. The primary objective of this dissertation is to investigate an advanced multiphase current-mode control, which provides accurate current sensing, enhances the stability margin in high-BW design, and adaptively compensates the parameter variations. Firstly, an equivalent circuit model for generic current-mode controls using DCR current sensing is developed to analyze the impact of component tolerance in high-BW design. Then, the existing state-of-the-art auto-tuning method used to improve current-sensing accuracy is reviewed, and the deficiency of using this method in a multiphase VR is identified. After that, enlightened by the proposed model, a novel auto-tuning method is proposed. This novel method features better tuning performance, noise-insensitivity, and simpler implementation than the state-of-the-art method. Secondly, the current state-of-the-art adaptive current-mode control based on constant-frequency PWM is reviewed, and its inability to maintain adequate stability margin in high-BW design is recognized. Therefore, a new external ramp compensation technique is proposed to keep the stability margin insensitive to the operating conditions and component tolerance, so the proposed high-BW constant-frequency control can meet the transient requirement without the presence of bulky output capacitors. The control scheme is generic and can be used in various kinds of constant-frequency controls, such as peak-current-mode, valley-current-mode, and average-current-mode configurations. Thirdly, an interleaving technique incorporating an adaptive PLL loop is presented, which enables the variable-frequency control to push the BW higher than proposed constant-frequency control, and avoids the beat-frequency input ripple. A generic small-signal model of the PLL loop is derived to investigate the stability issue caused by the parameter variations. Then, based on the proposed model, a simple adaptive control is developed to allow the BW of the PLL loop to be anchored at the highest phase margin. The adaptive PLL structure is applicable to different types of variable-frequency control, including constant on-time control and ramp pulse modulation. Fourthly, a hybrid interleaving structure is explored to simplify the implementation of the adaptive PLL structure in an application with more phases. It combines the adaptive PLL loop with a pulse-distribution technique to take the advantage of the high-BW design and fast transient response without adding a burden to the controller implementation. As a conclusion, based on the proposed analytical models, effective control concepts, systematic optimization strategies, viable implementations are fully investigated for high-BW current-mode control using different modulation techniques. Moreover, all the modeling results and the system performance are verified through simulation with a practical output filter model and an advanced mixed-signal experimental platform based on the latest MHz VR design on the laptop motherboard. In consequence, the multiphase VRs in future computation systems can be scalable easier with proposed multiphase configurations, increase the system reliability with proposed adaptive loop compensation, and minimize the total system footprint of the VR with the superior transient performance. / Ph. D.

O presente trabalho tem por objetivo a implementação de algoritmos de controle do tipo PID com sintonia automática de seus parâmetros para controle de processos térmicos de primeira ordem mais tempo morto. Existe um grande número de métodos para a sintonia automática, os quais requerem informações variadas sobre o processo. A sintonia automática dos parâmetros do controlador escolhida para implementação é baseada no método da realimentação a relê que utiliza o ganho estático e o período e amplitude críticos do processo e pode ser facilmente adotada na indústria. Este método foi implementado em um controlador industrial microprocessado que utiliza um microcontrolador da família 8051. A correta identificação dos parâmetros críticos do processo presume a geração de oscilações simétricas durante a realimentação a relê. O algoritmo de sintonia automática desenvolvido inclui correção em tempo real da amplitude do relê para evitar identificação falsa de um ciclo da oscilação e da assimetria na saída do processo durante a realimentação a relê. A implementação do algoritmo é simples e direta em termos de programação no ambiente de microcontroladores mesmo em linguagem de baixo nível (assembly). São apresentados resultados de simulação e os resultados experimentais realizados em um aparelho industrial comercial. / The objective of this work is the implementation of a PID control algorithm with auto-tuning for a thermal first order process plus dead-time. There is a number of methods for the auto-tuning of PID controllers which require different information on the process. The auto-tuning algorithm is implemented in a industrial controller based on the 8051 microcontroller family. The auto-tuning method considered for implementation is based on the relay feedback procedure which require the process steady state gain and the ultimate point on the Nyquist plot and can be easily adopted by industry. The method is also suited for pre-tuning adaptive controllers. The auto-tuning method used assume symmetrical oscillations during the relay feedback experiment to render the correct ultimate point on the Nyquist plot The proposed auto-tuning algorithm includes on-line correction for asymmetry oscillation and relay amplitude to avoid false capture of the limit cycle. The symmetrical oscillations are ensured by a DC bias signal added to the relay output. The algorithm is simply and straight to be written in a microcontroller programming language. Experimental results accomplished in a industrial PID auto-tuner are presented.

O presente trabalho tem por objetivo a implementação de algoritmos de controle do tipo PID com sintonia automática de seus parâmetros para controle de processos térmicos de primeira ordem mais tempo morto. Existe um grande número de métodos para a sintonia automática, os quais requerem informações variadas sobre o processo. A sintonia automática dos parâmetros do controlador escolhida para implementação é baseada no método da realimentação a relê que utiliza o ganho estático e o período e amplitude críticos do processo e pode ser facilmente adotada na indústria. Este método foi implementado em um controlador industrial microprocessado que utiliza um microcontrolador da família 8051. A correta identificação dos parâmetros críticos do processo presume a geração de oscilações simétricas durante a realimentação a relê. O algoritmo de sintonia automática desenvolvido inclui correção em tempo real da amplitude do relê para evitar identificação falsa de um ciclo da oscilação e da assimetria na saída do processo durante a realimentação a relê. A implementação do algoritmo é simples e direta em termos de programação no ambiente de microcontroladores mesmo em linguagem de baixo nível (assembly). São apresentados resultados de simulação e os resultados experimentais realizados em um aparelho industrial comercial. / The objective of this work is the implementation of a PID control algorithm with auto-tuning for a thermal first order process plus dead-time. There is a number of methods for the auto-tuning of PID controllers which require different information on the process. The auto-tuning algorithm is implemented in a industrial controller based on the 8051 microcontroller family. The auto-tuning method considered for implementation is based on the relay feedback procedure which require the process steady state gain and the ultimate point on the Nyquist plot and can be easily adopted by industry. The method is also suited for pre-tuning adaptive controllers. The auto-tuning method used assume symmetrical oscillations during the relay feedback experiment to render the correct ultimate point on the Nyquist plot The proposed auto-tuning algorithm includes on-line correction for asymmetry oscillation and relay amplitude to avoid false capture of the limit cycle. The symmetrical oscillations are ensured by a DC bias signal added to the relay output. The algorithm is simply and straight to be written in a microcontroller programming language. Experimental results accomplished in a industrial PID auto-tuner are presented.

In this thesis work we have extended the SkePU framework by designing a new container data structure for the representation of generic two dimensional sparse matrices. Computation on matrices is an integral part of many scientific and engineering problems. Sometimes it is unnecessary to perform costly operations on zero entries of the matrix. If the number of zeroes is relatively large then a requirement for more efficient data structure arises. Beyond the sparse matrix representation, we propose an algorithm to judge the condition where computation on sparse matrices is more beneficial in terms of execution time for an ongoing computation and to adapt a matrix's state accordingly, which is the main concern of this thesis work. We present and implement an approach to switch automatically between two data container types dynamically inside the SkePU framework for a multi-core GPU-based heterogeneous system. The new sparse matrix data container supports all SkePU skeletons and nearly all SkePU operations. We provide compression and decompression algorithms from dense matrix to sparse matrix and vice versa on CPU and GPUs using SkePU data parallel skeletons. We have also implemented a context aware switching mechanism in order to switch between two data container types on the CPU or the GPU. A multi-state matrix representation, and selection on demand is also made possible. In order to evaluate and test effectiveness and efficiency of our extension to the SkePU framework, we have considered Matrix-Vector Multiplication as our benchmark program because iterative solvers like Conjugate Gradient and Generalized Minimum Residual use Sparse Matrix-Vector Multiplication as their basic operation. Through our benchmark program we have demonstrated adaptive switching between two data container types, implementation selection between CUDA and OpenMP, and converting the data structure depending on the density of non-zeroes in a matrix. Our experiments on GPU-based architectures show that our automatic switching mechanism adapts with the fastest SkePU implementation variant, and has a limited training cost.