<div>Pressure compensated vane pump systems are an attractive solution in many automotive applications to supply hydraulic power required for cooling, lubrication, and actuation of control elements such as transmission clutches. These systems feature variable displacement vane pumps which offer reductions in parasitic loads on the engine and in wasted hydraulic energy at high engine speeds when compared to traditional fixed displacement supply pumps. However, oscillations in a currently available pressure compensation system limits the achievable performance and therefore the application of this solution.</div><div>This dissertation presents the development and experimental validation of a lumped parameter model in MATLAB/Simulink of a current pressure compensated vane pump system for an automatic transmission oil supply application. An analysis of the performance of this system using the validated pump model and a developed black box control system model reveals that the low cost solenoid valve present in the control circuit to set the regulation pressure limits the achievable bandwidth to 1.84Hz and causes a significant time delay in the response. To address this limitation, as well as eliminate a non-minimum phase zero introduced by the case study’s control circuit architecture, an actively controlled electrohydraulic pressure compensation system is proposed. This proposed system is explored both experimentally and in simulation making use of the accuracy of the presented variable displacement vane pump model. Significant improvements in the achievable system performance are shown with both a simple PI control law (47% reduction in the pressure response time) and an advanced cascaded model following controller based on feedback linearization (58% reduction in the pressure response time). An analysis of these results reveals that implementing the proposed control system with a 5(L/min)/bar proportional valve with a 20Hz at ±100% (60Hz at ±50%) amplitude bandwidth and a PI control law is an economical path to achieving the best performance improvements for this automotive application.</div>

Submitted by Maicon Juliano Schmidt (maicons) on 2015-07-15T14:25:14Z No. of bitstreams: 1 João Olegário de Oliveira de Souza.pdf: 4255697 bytes, checksum: 53d282b67d9c0e2f0b8d76e886a38a6f (MD5) / Made available in DSpace on 2015-07-15T14:25:14Z (GMT). No. of bitstreams: 1 João Olegário de Oliveira de Souza.pdf: 4255697 bytes, checksum: 53d282b67d9c0e2f0b8d76e886a38a6f (MD5) Previous issue date: 2013-01-31 / Nenhuma / Os controladores do tipo Proporcional, Integral e Derivativo, comumente denominados de PID, são largamente utilizados no controle de processos industriais, tanto em sistemas monovariáveis quanto em sistemas multivariáveis. Hoje, cerca de 95% dos controladores utilizam este tipo de estrutura na indústria. O grande problema é que grande parte deles estão mal sintonizados, comprometendo em muitos casos o desempenho de malhas industriais. Neste trabalho é apresentada uma revisão geral sobre os algoritmos inspirados na natureza, Simulated Annealing e Algoritmos Genéticos (fundamentos, características, parâmetros, operadores) e sua aplicação ao problema da sintonia de controladores PID monovariáveis e multivariáveis. É estabelecida, através de estudo de casos, uma análise comparativa entre estas sintonizações com metaheurísticas e os métodos consagrados na literatura em aplicações industriais convencionais, utilizando como função de avaliação o índice Integral do Erro Absoluto ponderado pelo Tempo (ITAE). O trabalho também propõe o estudo de controladores PID através de Algoritmos Genéticos Multiobjetivos, que satisfaçam dois critérios de desempenho: overshoot e o índice de desempenho Integral do Erro Quadrático ponderado pelo Tempo (ITSE). Conforme demonstrado pelos resultados obtidos, pode-se afirmar que a metaheurística Algoritmos Genéticos é um método eficiente e confiável para a otimização de problemas de sintonia de controladores PID. / The Proportional, Integral and Derivative controllers, commonly called PID controllers, are widely used in industrial process control, in both SISO and multivariable systems. Today about 95% of controllers use this type of structure in the industry. The big problem is that most of them are poorly tuned, in many cases compromising the performance of industrial loops. This work presents a general review on nature-inspired algorithms, Simulated Annealing and Genetic Algorithms (basement, characteristics, parameters, operators) and its application in the problem of tuning PID controllers in both single variable and multivariable systems. There will be through case studies, a comparative analysis of these metaheuristics with established methods in the literature in conventional industrial applications using as evaluation function the Integral of time multiplied by the Absolute Error (ITAE) index. The work also proposes the study of PID controllers using multiobjective genetic algorithms which meet two performance criteria: overshoot and the Integral Time Square Error (ITSE) index. The results obtained confirm that Genetic Algorithms are an effective and reliable method to optimize complex problems.

In recent years, research in the field of automation has been advancing quickly in the direction of wireless networks of sensors and actuators. This development has introduced a need to reduce the amount of communication. A number of different alternative schemes have been proposed. They are usually divided into event-triggered schemes and self-triggered ones. The main purpose of this Master's thesis was to further develop and evaluate the sesampling schemes, focusing on their needed communication. The effect on control performance by the different schemes was also taken into account. Because of the difficulty in performing a theoretical comparison, the thesis focused on evaluating the schemes in simulations and in experiments on real industrial processes. The results indicate that simply using a slower periodic scheme may reduce as much communication without losing much performance as the more flexible schemes. This would imply that investing further into the other schemes may be of waste. However, using an event-triggered scheme with improvements introduced in this report may offer some advantages when it comes to performance and simplicity in setup. Maybe more importantly, it is safer during rapidly changing conditions, which also makes it very unlikely that a slow periodic sampler would ever be implemented on a real system. The results in general are very positive with communication reductions of over 90% when using a well tuned base sampling interval and over 99% when the comparison is made to current implementations in the industry, all without significant loss of performance.

Nowadays, high portion of tactical missiles use gimbaled seeker. For accurate target tracking, the platform where the gimbal is mounted must be stabilized with respect to the motion of the missile body. Line of sight stabilization is critical for fast and precise tracking and alignment. Although, conventional PID framework solves many stabilization problems, it is reported that many PID feedback loops are poorly tuned. In this thesis, recently introduced robot control method, proxy based sliding mode control, is adopted for the line of sight (LOS) stabilization. Before selecting the proposed method, adaptive neural network sliding mode control and fuzzy control are also implemented for comparative purposes. Experimental and simulation results show a satisfactory response of the proxy based sliding mode controller.

Η παρούσα διδακτορική διατριβή αναφέρεται σε έδρανα ολίσθησης. Συγκεκριμένα, αναφέρεται στο σχεδιασμό και την κατασκευή ενός νέου, πρωτότυπου υβριδικού εδράνου ολίσθησης, το οποίο έχει τη δυνατότητα να λειτουργεί είτε ως υδροδυναμικό, είτε ως ενεργό ηλεκτρομαγνητικό, είτε ως υβριδικό, δηλαδή υδροδυναμικό και ενεργό ηλεκτρομαγνητικό ταυτόχρονα. Προκειμένου να πραγματοποιηθεί ο σχεδιασμός και η κατασκευή του συγκεκριμένου υβριδικού εδράνου ολίσθησης, έγιναν υπολογισμοί και προσομοίωση του υδροδυναμικού πεδίου για τα υδροδυναμικά έδρανα ολίσθησης και του ηλεκτρομαγνητικού πεδίου για τα ηλεκτρομαγνητικά έδρανα στο πρόγραμμα ANSYS. Η προσομοίωση των υβριδικών εδράνων ολίσθησης έγινε με επαναληπτική διαδικασία μεταξύ του υδροδυναμικού και του ηλεκτρομαγνητικού πεδίου προκειμένου να υπολογίζεται το κάθε επιθυμητό μέγεθος. Για το σχεδιασμό του υβριδικού εδράνου ολίσθησης χρησιμοποιήθηκε το σχεδιαστικό πρόγραμμα CATIA. Για την προσομοίωση του ελέγχου του υβριδικού εδράνου ολίσθησης, χρησιμοποιήθηκε το πρόγραμμα Matlab, το οποίο ενεργοποιεί το πρόγραμμα Ansys για τον υπολογισμό των χαρακτηριστικών του υδροδυναμικού και του ηλεκτρομαγνητικού πεδίου του εδράνου και το Simulink module του Matlab για τον υπολογισμό των χαρακτηριστικών του ελέγχου, ώστε να γίνονται όλοι οι απαραίτητοι υπολογισμοί αυτοματοποιημένα. Τέλος, έγιναν υπολογισμοί και προσομοίωση δυναμικής περιστρεφόμενων αξόνων, με στήριξη του ρότορα σε δύο έδρανα και δίσκο προσαρμοσμένο στον ρότορα, στο πρόγραμμα Matlab, με σύνδεση με το Ansys για τον υπολογισμό των συντελεστών ελαστικότητας και απόσβεσης και το Simulink module του Matlab για τον υπολογισμό των χαρακτηριστικών του ελέγχου, με σκοπό την ολοκληρωμένη ανάλυση του συστήματος. Συμπερασματικά, μέσω της συγκεκριμένης διδακτορικής διατριβής αποδεικνύεται πως ο σχεδιασμός, η λειτουργία και η κατασκευή του συγκεκριμένου πρωτότυπου υβριδικού εδράνου ολίσθησης είναι εφικτά, και από τα αποτελέσματα προκύπτει πως η λειτουργία ενός τέτοιου υβριδικού εδράνου ολίσθησης, έχει πολλά πλεονεκτήματα σε σχέση με άλλα έδρανα στήριξης περιστρεφόμενων αξόνων, είτε αυτά είναι απλά είτε υβριδικά και μπορεί να εφαρμοστεί είτε σε εργαστηριακό επίπεδο είτε σε βιομηχανικές εφαρμογές. / The present doctoral thesis refers to hydrodynamic journal bearings. Specifically, it refers to the design and construction of a new, innovative hybrid journal bearing, which has the ability to function either as hydrodynamic or active magnetic or hybrid, i.e. both hydrodynamic and active magnetic, at the same time. In order to be performed the design and construction of the specific hybrid journal bearing, calculations and simulation of the hydrodynamic field for the hydrodynamic journal bearings in the program ANSYS, have been made. The simulation of the hybrid journal bearings has been made with iterative process, between the hydrodynamic and active magnetic field, so that every desired magnitude can be calculated. For the design of the hybrid journal bearing, the designing program CATIA has been used. For the simulation of the control of the hybrid journal bearing, the program Maltab has been used, which activates the program Ansys, for the calculation of the features of the hydrodynamic and active magnetic field of the bearing and the Simulink module of Maltab, for the calculation of the features of control, so that all necessary calculations can be made automated. Finally, calculations and simulation of rotor dynamics, with support of the rotor in two bearings and disc adjusted to the rotor, in Maltab, in connection to Ansys, for the calculation of the elastic and damping coefficients and the Simulink module of Maltab, for the calculation of the features of control, have been made, having as a purpose the complete analysis of the system. In conclusion, through the specific doctoral thesis, it is proved that the design, function and construction of the specific, new hybrid journal bearing, can be achieved and the results show that the function of such a hybrid journal bearing, has many advantages compared to other bearings of support of rotors, either they are simple or hybrid and it can be applied either to laboratory level or industrial applications.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-06-29T22:59:45Z No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Rejected by Vanessa Christiane (referencia@ufersa.edu.br), reason: Corrigir referência. on 2017-07-03T12:21:49Z (GMT) / Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2017-07-04T14:22:25Z No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-04T16:48:02Z (GMT) No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-04T16:58:07Z (GMT) No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) / Made available in DSpace on 2017-07-04T17:03:31Z (GMT). No. of bitstreams: 1 EdpoRM_DISSERT.pdf: 4900218 bytes, checksum: 0b5f0ce9961abf50eb5fe43f882601c0 (MD5) Previous issue date: 2017-02-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This dissertation proposes the development of a Fuzzy-PID hybrid controller for the height stability control of a four-engine type UAV. The work also contemplates the development of a classical PID controller, used to compare with the hybrid one purposed. The AuRoRA platform is used for the realization of tests with both of the control structures, being this one provided with the parameters of the Drone used. With the test results, it was possible to conclude that both of the controllers, the classical PID and the Fuzzy-PID, are able to perform the Drone height control, and the hybrid control obtained some advantages such as the ability of self-adjust with the system variation, that dispenses the manual tuning of the gains, besides presenting an improvement in the Drone height stability / Esta dissertação propõe o desenvolvimento de um controlador híbrido Fuzzy-PID para o controle de estabilidade de altura de um VANT do tipo quadrirrotor. O trabalho ainda contempla o desenvolvimento de um controlador PID clássico, utilizado para fins de comparação com o controlador híbrido proposto. A plataforma AuRoRA é utilizada para a realização dos testes com ambas as estruturas de controle, sendo a mesma munida dos parâmetros do Drone utilizado. Com os resultados dos testes, foi possível verificar que ambos controladores, PID clássico e Fuzzy-PID, são capazes de realizar o controle de altura do Drone, tendo o controle híbrido obtido algumas vantagens como a capacidade de auto ajuste mediante variações no sistema, o que dispensa as sintonias manuais dos ganhos, além de apresentar uma melhoria na estabilidade da altura do Drone / 2017-06-29

Made available in DSpace on 2015-05-08T14:59:50Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 5685009 bytes, checksum: 7c7cec127c61d91393979e6be4ef4ab5 (MD5) Previous issue date: 2012-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper presents a theoretical and experimental study of a PID control-Proportional, Integral and Derivative using PELTIER module that achieves precision of about 0.01oC. It is developed to study the integrated instrumentation and control heat transfer. Based on this we developed a heat signal generator on a flat surface and applied to the measurement of thermal properties, in a system similar to electrical circuit. After several experiments, the results indicates the validity of the proposal. / Neste trabalho apresenta-se um estudo teórico e experimental de um controle P.I.D.- Proporcional, Integral e Derivativo, utilizando módulos Peltier s que alcançam precisão de cerca de 0.01oC. É desenvolvido o estudo da instrumentação e controle integrado à transferência de calor. Baseado neste controle foi desenvolvido um gerador de sinais térmicos em uma superfície plana e aplicado na medida de propriedades térmicas, em um sistema semelhante ao circuito elétrico. Após vários ensaios experimentais usando amostras sólidas, os resultados indicam a validade da proposta.

Uma das técnicas de controle avançado que vem ganhando destaque no cenário econômico e ecológico, focando maior sustentabilidade e a otimização dos processos, é o controle preditivo, o qual já vem sendo aplicado em indústrias químicas e petroquímicas. Esta dissertação trata do desenvolvimento de um controle preditivo aplicado a uma planta piloto de neutralização de pH, presente no Laboratório de Controle de Processos Industriais da Escola Politécnica da Universidade de São Paulo. O desenvolvimento do projeto pode ser dividido em quatro etapas: implementação das malhas de controle regulatório, identificação dos sistemas, construção do controlador preditivo, aplicações e análises experimentais. Na primeira etapa foi necessário estudar o sistema em questão e implementar algumas malhas internas usando controladores PID. Na segunda etapa foi realizada a identificação do modelo da planta, ressaltando que pontos de operação e ajuste de parâmetros internos são determinantes para a modelagem. Já na terceira etapa desenvolveu-se um controlador preditivo, através de softwares auxiliares como o MATLAB e o IIT 800xA da ABB, que foram utilizados para o desenvolvimento e implementação do algoritmo de controle. Por fim, na última etapa, foi feita a análise e comparação dos resultados, quando se submete à planta a um controlador PID, quando aplicado um controlador preditivo em cascata com controladores PID e quando se utiliza apenas o controlador preditivo com ação direta nos atuadores. / The predictive control is an advanced control technique which has gained evidence in the economic and ecological context because the search for sustainability and process optimization. This control has already been applied by the chemical and petrochemical industries. The purpose of this project is to develop a predictive controller which will be applied in a pH neutralization plant located in the Industrial Processes Control Laboratory at Polytechnic School of the University of São Paulo. The development of this project can be divided into four stages: implementation of regulatory control loops, identification of the system, construction of the predictive controller, applications and experimental analysis. The first step is necessary in order to study the plant and to implement some internal loops using PID controllers. In the second step, the identification process of the plant model will be done. It is important to note that operating points and internal parameter settings are very important for modeling. In the third stage, using the model obtained from the identification process, a predictive controller is built from auxiliary software such as MATLAB and IIT 800xA (by ABB), which will be used for the development and implementation of the control algorithm. Finally, the last step consists in collecting and analyzing the results of the pH neutralization plant. At this stage the responses of each controller will be compared: PID controller, MPC controller in cascade mode with PID and MPC controller acting directly on actuators.

No description available.

Due to the unsustainable space debris environment in Low Earth Orbit, debris objects must be removed to ensure future safe satellite operations. One proposed concept for deorbiting larger space debris objects, such as decommissioned satellites or spent upper rocket stages, is to use a chaser spacecraft connected to the debris object by an elastic tether, but the required technology is immature and there is a lack of flight experience. The inoperable satellite, Envisat, has been chosen as a representative object for controlled re-entry by performing several high thrust burns. The aim of this paper is to develop a control system for the deorbit phase of such a mission. Models of the spacecraft dynamics, the tether, and sensors are developed to create a simulator. Two different tether models are considered: the massless model and the lumped mass model. A switched linear-quadratic-Gaussian (LQG) controller is designed to control the relative position of the debris object, and a switched proportional-integral-derivative (PID) controller is designed for attitude control. Feedforward compensation is used to counteract the couplings between relative position and attitude dynamics. An analysis of the system suggests that the tether should be designed in regard to the control system and it is found that the lumped mass model comes with higher cost than reward compared to the massless tether model in this case. Simulations show that the control system is able to control the system under the influence of modeling errors during a multi-burn deorbit strategy and even though more extensive models are suggested to enable assessment of the feasibility to perform this mission in reality, this study has resulted in extensive knowledge and valuable progress in the technical development. / En ökande mängd rymdskrot har lett till en ohållbar miljö i låga omloppsbanor och föremål måste nu tas bort för att säkerställa framtida satellitverksamhet. En föreslagen metod för att avlägsna större skrotföremål, såsom avvecklade satelliter och använda övre raketsteg, är att koppla en jagande rymdfarkost till föremålet med en elastisk lina. Dock är den teknik som behövs inte mogen och det finns en brist på praktisk erfarenhet. Den obrukbara satelliten Envisat har valts som representativt objekt för kontrollerat återinträde genom flera perigeumsänkande raketmanövrar. Syftet med detta arbete är att utveckla ett system för att kontrollera de två sammankopplade rymdfarkosterna under avlägsningsfasen under ett sådant uppdrag. Modeller för farkosternas dynamik, den sammankopplande linan och sensorer byggs för att utveckla en simulator. Två olika modeller för linan undersöks: den masslösa modellen och den klumpade nodmassmodellen. En omkopplande regulator designas genom minimering av kvadratiska kriterier för att kontrollera skrotföremålets relativa position till den jagande farkosten. Vidare designas en omkopplande proportionerlig-integrerande-deriverande (PID) regulator för att reglera pekningen hos den jagande farkosten. Kompensering genom framkoppling används för att motverka de korskopplingar som förekommer mellan translations- och rotationsdynamiken. En analys av systemet visar att linan bör designas med reglersystemet i åtanke och det framkommer att nackdelarna överväger fördelarna för den klumpade nodmassmodellen jämfört med den masslösa modellen. Simuleringar visar att reglersystemet klarar att kontrollera systemet under ett scenario med flera manövrar och under inverkan av modellfel. Även om mer omfattande modeller föreslås för att möjliggöra en fullständig bedömning av genomförbarheten för detta uppdrag så har denna studie resulterat i en omfattande kunskapsvinst och värdefulla framgångar i det tekniska utvecklingsarbetet.