The GE Healthcare Life sciences organization develop and manufacture bioreactors, mixers, filtration skids and chromatography systems used together in a biomanufacturing platform. The platform is monitored and controlled by a distributed control system through a Programmable Logic Controller (PLC). The automation software controlling the platform is today tested and verified together with the physical units. The software use PROFIBUS, an industry standard for industrial automation, for communication and control of the units. Limited access to the physical units is usually a bottleneck and it's difficult to test abnormal situations to make sure the correct alarms are triggered. To reduce the hardware dependency and to provide support during test and verification, a virtual environment is developed to simulate the behavior of a bioreactor during execution. A .NET application has been developed together with a mathematical framework to simulate a cell culture and to return relevant process parameters such as pH, dissolved oxygen, temperature and weight. The results show that it's possible to simulate a bioreactor and to communicate with the control system. The software can be a valuable tool when developing and testing automation software but should not be used for process optimization or tuning of control parameters.

[pt] Os laboratórios projetados para testes de motores de combustão interna trabalham sob normas que especificam métodos de ensaios aplicados à avaliação do desempenho do motor. Um motor veicular testado em um dinamômetro de bancada possui equipamentos auxiliares necessários para garantir condições de ensaio específicas, tal como a temperatura do ar de admissão, que deve ser mantida dentro dos valores indicados nas condições-padrão de referência da aplicação pretendida. Diante deste cenário, é evidente a importância de um estudo dos sistemas de condicionamento presentes nas salas de testes de motores. Esta dissertação apresenta o projeto, dimensionamento e simulação de um sistema de condicionamento que controla a temperatura e umidade do ar de admissão para realização de testes de motores de combustão dispostos em dinamômetros de bancada, independente das condições ambientais. A modelagem dinâmica do condicionador de ar e seus componentes (trocador de calor de água gelada, aquecedor elétrico e umidificador) foi implementada no EES. O sistema de controle PID com dois esquemas de ajuste de ganhos (utilizando a fórmula de Ziegler-Nichols, e auto-sintonizado on-line por um sistema supervisório fuzzy) foi desenhado no MATLAB. Para avaliar o desempenho do condicionador e do seu sistema de controle foi estabelecida uma comunicação através do intercâmbio dinâmico de dados entre o MATLAB e o EES. Um estudo de simulação comparativa entre ambos esquemas de ajuste dos controladores, mostra que a estratégia de controle fuzzy supervisório PID proposta permite obter um melhor desempenho dinâmico do sistema condicionador, em termos de estabilidade diante variações tanto na vazão quanto nas condições do ar de admissão, segundo os resultados obtidos na simulação com dados experimentais de um motor Diesel testado sob o ciclo de ensaios dos 13 modos em estado estacionário (ESC test) para certificação de emissões. / [en] Engine testing laboratories designed for automotive vehicles operate under standards that specify test methods used to evaluate the performance of internal combustion engines. A vehicle engine tested on a dynamometer bench has auxiliary equipment required in order to ensure the test conditions, such as intake air temperature which must be maintained within the specified values by standard reference conditions of the intended application. Given this backdrop, it is clear the importance of study of conditioning systems present in engine test facilities. This dissertation presents the design, implementation and simulation of a conditioning system that controls temperature and humidity of the intake air for testing of combustion engines arranged in a dynamometer bench, regardless of ambient conditions. The dynamical modelling of the air conditioner and its components (chilled water heat exchanger, electric heater and humidifier) was implemented in EES. The PID control system with two gains adjustment schemes (using the Ziegler-Nichols formula, and self-tuned on-line with a fuzzy supervisory system) was designed in MATLAB. The conditioning unit performance and its control system was assessed using a communication established through of the dynamic data exchange between EES and MATLAB. A comparative simulation study on both schemes for tuning of controllers shows that the use of the PID supervisory fuzzy control strategy proposed allows for considerable improvements in dynamic performance of the system, in terms of stability on both variation in flow rate and conditions of the intake air, according to the results obtained in the simulation with experimental data of a heavy-duty Diesel engine over the test cycle 13 steady state modes (ESC test) for emission certification.

O elemento final de controle mais usado nas malhas de processo na indústria é a válvula de controle. Portanto, é necessário assegurar que ela possua o melhor desempenho possível, a fim de assegurar um funcionamento satisfatório da malha de controle. Devido ao desgaste natural das partes móveis e o ressecamento das gaxetas, as válvulas apresentam atrito que insere oscilações na abertura da válvula e devido a seu comportamento não linear que diminui a eficiência do controle. A presença de oscilações nas malhas de controle aumenta a variabilidade das variáveis de processo, o desgaste dos componentes e o consumo de energia, além de provocar o desperdício de materiais. Por isto, no presente trabalho são estudados e implementados diferentes compensadores de atrito existentes na literatura, visando reduzir o efeito do atrito nas válvulas e, por sua vez as oscilações na variável do processo. Estes métodos são aplicados na Planta Piloto de Neutralização de pH do Laboratório de Controle de Processos Industriais (LCPI). O processo de neutralização de pH é não-linear e apresenta características variantes no tempo, as quais tornam mais complexo o controle do processo. Inicialmente foi feita a implementação dos compensadores em um software acadêmico (MATLAB®), devido à familiaridade que se tem com ele, o que facilitou um melhor entendimento dos métodos de compensação junto com o controlador PID no processo. Em uma segunda etapa, a fim de trazer os estudos a um ambiente mais prático, foram implementados os algoritmos de compensação de atrito em um sistema de controle industrial (ABB®). Nos dois casos se realizaram testes em modo servo e regulatório e se avaliaram os resultados obtidos usando o índice ITAE (Integral Time Absolute Error). Os resultados evidenciam que os compensadores conseguem diminuir a variabilidade na válvula de controle, sendo que o compensador CR2 apresentou o melhor desempenho para o modo servo e regulatório. / The most used final control element in process loops in the industry is the control valve. It must ensure that it has the best possible performance in order to guarantee a satisfactory operation of the control loop. Due of the natural wear of moving parts and drying gaskets, valves exhibit friction. This friction inserts oscillations in the valve opening and due to its non-linear behavior; this causes the efficiency to decrease. The presence of oscillations in the control loop increases the variability of the process variables, the component wear, energy consumption and cause a waste of materials. Therefore, in this work we studied and implemented different friction compensation methods that exist in literature, in order to reduce the effect of friction on the valves and in turn the oscillations in the process variable. These methods are applied in the Pilot Plant Neutralization pH of Industrial Process Control Laboratory (LCPI), the pH neutralization process is nonlinear and presents time-varying characteristics, these characteristics become the control process more complex. Initially, it was made the implementation of compensation methods in academic software (MATLAB®), due to the familiarity that already exist with it, which facilitated a better comprehension of the compensation methods with the PID controller in the process. In a second step, in order to bring the study to a more practical environment, the friction compensation algorithms were implemented in an industrial control system (ABB®). In both cases were performed tests inn servo and regulatory mode, and evaluated the results using the ITAE index (Integral Time Absolute Error). The results show that in general terms that the compensating methods showing a very satisfactory performance, with the compensator CR2 showed the best performance for the servo and regulatory mode.

A identificação de sistemas industriais tem aplicação industrial principalmente na sintonia de malhas de controle. A sintonia freqüente das malhas de controle possibilita a manutenção das características de desempenho do processo industrial durante o ciclo de vida da produção. O fato de ser remota, neste trabalho realizada via as interfaces OPC e CyberOPC, possibilita inúmeras aplicações práticas como a terceirização do serviço por empresas especializadas ou a centralização da otimização nas empresas constituídas por áreas distribuídas. Este trabalho propõe e testa experimentalmente, em sistemas lineares de primeira ordem com tempo morto, uma ferramenta computacional de identificação e sintonia remota de malhas de controle em malha aberta ou fechada utilizando controladores PID em ambiente industrial, que preenche os requisitos acima citados em uma plataforma única, e desta forma tem aplicação no ambiente industrial para ajustar as malhas de controle e em ambiente acadêmico como ferramenta de estudo de aplicações de controle e de redes industriais. / The identification of industrial systems has industrial application mainly in control loop tuning. The frequent tuning of the control loop allows the maintenance of performance characteristics for industrial process during the production life cycle. Remote tuning, using OPC and CyberOPC interfaces, supports several practical applications, such as specialized companies outsourcing services or companies distributed in different areas centralizing optimization. This project proposes and validates experimentally in first order plus dead time systems a software tool for remote identification and tuning of open or close PID control loops in an industrial environment that fulfils the requirements described above, in a single platform. The software tool could be used in control loops tuning in industrial systems, as well as in an academic environment simulating control applications and industrial networks.

O objetivo deste trabalho é o desenvolvimento do modelo de uma microturbina a gás do tipo split-shaft com sistema de controle por retro-alimentação. Uma revisão bibliográfica dos trabalhos sobre controle de turbinas a gás indicou que praticamente inexistem trabalhos focando este tipo de turbina. O modelo foi desenvolvido a partir da geometria básica da turbina, aplicando-se os fundamentamentos de termodinâmica, mecânica newtoniana e mecânica dos fluidos mencionando os usos da primeira lei da termodinâmica, teoria de momento angular e atrito viscoso entre outros. O trabalho descreve os componentes, materiais e controles que podem ser usados em uma turbina split-shaft. O modelo foi simulado primeiramente sem controle e posteriormente com controle. Através dos resultados da simulação do modelo sem controle puderam ser vistos fenômenos que podem ocorrer em um sistema desse tipo como picos de temperatura, influência de uma turbina sobre a outra e a variação de injeção de combustível devido à variação de pressão na câmara de combustão entre outros. Para o modelo controlado, foram testados os controles PI, PID, PI-D, I-PD e PI-PD com feedback negativo. A escolha dos parâmetros de cada controle foi determinada pelo método ITAE dentro de um intervalo para cada parâmetro. O controle escolhido foi o PI-D por seu melhor desempenho e maior simplicidade. O controle fez com que as temperaturas de pico abaixassem em relação ao sistema sem controle e a rotação do gerador de energia elétrica foi mantida com uma variação máxima menor que 1% em relação à rotação de referência. Uma modelagem foi feita para um sistema lubrificante seguindo os mesmos princípios da modelagem da turbina split-shaft. Usou-se fundamentos de mecânica newtoniana e mecânica dos fluidos, com o equacionamento da conservação da quantidade de movimento, perdas de pressão localizada e distribuída entre outros. O modelo foi simulado primeiramente sem controle e posteriormente com controle. Através do modelo sem controle viu-se os efeitos do aumento da perda de carga em um dos ramos do sistema e os efeitos de uma entrada de referência em degrau. Esses efeitos são as variações das perdas no sistema e a variação do fluxo nos ramos do sistema. Para o modelo controlado foram testados os controles PI e PI-D com feedback negativo. Utilizou-se o método ITAE dentro de um intervalo para escolha dos parâmetros. O controle escolhido foi o PI porque a diferença de desempenho não foi significativa e a parte derivativa poderia tornar o erro maior devido à forma como o sistema foi modelado. A variável de processo foi controlada e os efeitos da variação de perda de carga em um dos ramos do sistema pôde ser observada. Os modelos são constituídos de várias partes simples, cada qual pode ser substituída por um modelo mais preciso. Assim, a modelagem funciona como um guia, mostrando as partes principais do sistema e podendo fornecer dados para a elaboração de novos modelos. / The objective of the present work is the development of the model of a split-shaft micro gas turbine with feed back control system. A bibliographical review of the works on control of gas turbines indicated that there are very few works dealing this type of gas turbines. The model was developed starting from the basic geometry of the turbine and applying the fundamentals of thermodynamics, newtonian mechanics and fluid mechanics. The components, materials and controls which can be used in a split-shaft turbine are described. The model is simulated firstly without control and later with control. The results showed that, for the uncontrolled model, typical phenomena which may happen in this type of system are seen such as temperature peaks, influence of one turbine on the other and fuel injection variation due to combustion chamber pressure variation amongst others. For the controlled model, the controls PI, PID, PI-D, I-PD and PI-PD with negative feedback are tested. The parameters choice of each control is determined by the ITAE method within an interval for each parameter. The PI-D control was chosen for its best performance and simplicity. The control made the peak temperatures lower than the uncontrolled system and the electricity generator rotation error was kept under 1% with respect to the reference value. A modeling is done for a lubrification system following the same principles of the split-shaft turbine modeling. Conservation laws of mechanics and fluid mechanics are used, such as momentum conservation and energy conservation equations (pressure loss). The model is simulated firstly without control and later with control. For the uncontrolled model, the effects on increasing the head loss in one branch of the system and the effects for a step reference was showed. These effects are the variations of system losses and the flow variation in the system branches. For the controlled model, the PI and PI-D controls with negative feedback were tested. The parameters choice of each control is determined by the ITAE method within an interval for each parameter. The PI control was chosen because the performance difference was not significant and the derivative part could turn the error bigger due to the way the system was modelled. The process variable was controlled and the effects on the variation head loss in one of the system branches was observed. The models have many simple parts; each one can be replaced by a more complex one if necessary. Thus, the present modeling may be used as guide for future improvements.

<p>To control the exhaust gas recirculation (EGR) and the exhaust brake, the position of a butterfly valve connected to a piston inside a pneumatic cylinder is controlled by altering the pressure inside the cylinder. This thesis evaluates the possibility to do this with pulse width modulation (PWM) controlled On/Off valves. The whole electro-pneumatic actuator system is built out of two On/Off valves and a cylinder.</p><p>A mathematical model of the system is constructed. The complete system model on state space form consists of nine states and is nonlinear. The model captures the dynamics of the system. The statics of the system is not captured as accurately. The model is still good enough to be used as aid when developing control strategies, since position feedback is available.</p><p>Automatic control strategies for the system are first developed and tested in simulation. The first approach is PID control. Because of the nonlinear properties of the system the results from a PID with a constant proportional part is unsatisfactory. To cope with the nonlinearities, a fuzzy controller is constructed; the results prove somewhat better, but not as good as expected due to implementation difficulties.</p><p>In a test bench the system is controlled by a P controller with feedforward from position. The feedforward strongly reduces the nonlinear behavior of the system. With this implementation the results that were hoped for with the fuzzy controller are reached.</p>

No description available.

During the uniform locomotion of legged robots with compliant legs, the body of the robot exhibits quasi-periodic oscillations that have a disturbing eect on dierent onboard sensors. Of particular interest is the camera sensor which suers from image degradation in the form of motion-blur as a result of this camera motion. The eect of angular disturbances on the camera are pronounced due to the perspective projection property of the camera. The thesis focuses on the particular problem of legged robots exhibiting angular body motions and attempts to analyze and overcome the resulting disturbances on a camera carrying platform (head). Although the full problem is in 3D with three independent axes of rotation, a planar analysis provides signicant insight into the problem and is the approach taken in the thesis. A carefully modeled planar version of an actual camera platform with realistic mechanical and actuator selections is presented. Passive (ltering) and active (controller) approaches are discussed to compensate/cancel motion generated disturbances. We consider and comparatively evaluate PID and LQR based active control. Since PID has the limitation of controlling only one output, PID-PID control is considered to iv control two states of the model. Due to its state-space formulation and the capability of controlling an arbitrary number of states, LQR is considered. In addition to standard reference signals, Gyroscope measured disturbance signals are collected from the actual robot platform to analyze the bandwidth and test the performance of the controllers. Inverted pendulum control performance is evaluated both on a Matlab-Simulink as well as a precise electro-mechanical test setup. Since construction of the planar head test setup is in progress, tests are conducted on simulation.

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.

Η παρούσα διπλωματική εργασία περιλαμβάνει την σχεδίαση και τον έλεγχο μέσω προγράμματος σε περιβάλλον LabView, ενός διπλού παράλληλου μηχανισμού με Τεχνητούς Πνευματικούς Μύες (Pneumatic Artificial Muscles (PAMs)). Η μηχανική διάταξη που κατασκευάστηκε είναι ένας διπλός παράλληλος μηχανισμός βασισμένος σε δύο τροποποιημένες πλατφόρμες τύπου Stewart. Ως ενεργοποιητές για την κίνηση στις πλατφόρμες χρησιμοποιήθηκαν Τεχνητοί Πνευματικοί Μύες ενώ για την στήριξη αυτών σε συγκεκριμένο ρυθμιζόμενο ύψος πνευματικά έμβολα διπλής δράσης, με μη περιστρεφόμενα πιστόνια. Παράλληλα, πάνω στις πλατφόρμες τοποθετήθηκαν δύο κλισιόμετρα προκειμένου να παρέχουν πληροφορίες για την κλίση αυτών. Ο έλεγχος της πίεσης του αέρα που υπάρχει στους μύες και στα έμβολα γίνεται μέσω αναλογικών ρυθμιστών πίεσης. Σε λειτουργία Ανοικτού Βρόγχου (Open loop Operation) ο μηχανισμός μπορεί να εκτελέσει παράλληλες ή περιστροφικές κινήσεις σε κάθε πλατφόρμα ξεχωριστά ή και στις δύο ταυτόχρονα. Ο χρήστης επιλέγει το εύρος της κίνησης αλλά και τη συχνότητα εκτέλεσής της. Στα πλαίσια της παρούσας διπλωματικής εργασίας, μελετήθηκε η ανταγωνιστική λειτουργία των μυών και εξετάστηκαν τρόποι για την βελτίωσή της. Σε λειτουργία κλειστού βρόγχου (Closed Loop Operation) ο χρήστης εισάγει στον υπολογιστή με τον οποίο είναι συνδεδεμένη η διάταξη, τις επιθυμητές γωνίες στις οποίες θέλει να βρεθεί η κάθε πλατφόρμα. Υλοποιείται αλγόριθμος ελέγχου τύπου PID για κάθε ζεύγος μυών και μέσω αυτών υπολογίζονται οι κατάλληλες πιέσεις που πρέπει να έχει ο κάθε μυς, ώστε οι πλατφόρμες να επιτύχουν την επιθυμητή γωνία. Όλες οι διεργασίες ελέγχου της πλατφόρμας τόσο σε λειτουργία ανοικτού όσο και σε λειτουργία κλειστού βρόχου υλοποιούνται μέσω τους προγραμματιστικού περιβάλλοντος LabView της εταιρείας National Instruments (NI). / This thesis, presents the development of a double parallel mechanism actuated by Pneumatic Artificial Muscles (PAMs) and controlled via LabView. The mechanical arrangement is a double parallel mechanism based on two modified Stewart platforms. PAMs have been used as platforms’ actuators and also non revolute double action pneumatic cylinders have been incorporated in order to support them at a user specified height. In addition two dual axis inclinometers have been utilized in order to provide the necessary angle feedback for the control loop. The pressure regulation in the PAMs and in the pneumatic cylinders is performed by proportional pressure regulators. In the Open Loop Operation, the mechanism can perform parallel or circular motions, in each platform independently or combined. The user chooses the range and the frequency of the performed motion. Furthermore the antagonistic operation of the PAMs has been studied. In the Closed Loop Operation the user inserts the platforms’ desired angles. A PID controller is implemented for every pair of antagonistic muscles, giving the necessary pressures in the antagonistic PAMs. All the control operations both in Open and Closed Loop are performed via National’s Instruments LabView software.