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1
Zou, Qingze. "Preview-based system-inversion for output-tracking : theory & application /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/7136.
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2
Kurtulmus, Ergin. "Locomotion And Control Of A Modular Snake Like Robot." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612533/index.pdf.
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In recent years, there has been a significant increase in the interest for snake like modular robots due to their superior locomotion capabilities in terms of versatility, adaptability and scalability. Passive wheeled planar snake like robots are a major category and they are being actively researched. Due to the nonholonomic constraints imposed on them, certain configurations lead to the singularity which must be avoided at all costs. Furthermore, it is vital to generate a locomotion pattern such that they can track a wide range of trajectories. All of these objectives must be accomplished smoothly and in an energy efficient manner. Studies indicate that meeting all of these requirements is a challenging problem. In this study, a novel form of the serpenoid curve is proposed in order to make the robot track arbitrary paths. A controller has been designed using the feedback linearization method. Afterwards, a new performance measure, considering both the efficiency and sustainability of the locomotion, has been proposed to evaluate the locomotion. Optimal parameters for the proposed serpenoid curve and the linear controller have been determined for efficient locomotion by running series of simulations. Relations between the locomotion performance, locomotion speed and eigenvalues of the linear controller have been demonstrated. Simulation results show striking differences between the locomotion by using the proposed serpenoid curve with optimal parameters and the locomotion by purely tracking a given path. Obtained results also indicate that the aforementioned requirements are met successfully and confirm the validity and consistency of the proposed performance measure.
3
Rollins, Elizabeth S. M. Massachusetts Institute of Technology. "Optimization of neural network feedback control systems using automatic differentiation." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/59691.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 95-97).
Optimal control problems can be challenging to solve, whether using analytic or numerical methods. This thesis examines the application of an adjoint method for optimal feedback control, which combines various algorithmic techniques into an original numerical method. In the method investigated here, a neural network defines the control input in both trajectory and feedback control optimization problems. The weights of the neural network that minimize a cost function are determined by an unconstrained optimization routine. By using automatic differentiation on the code that evaluates the cost function, the gradient of the cost with respect to the weights is obtained for the gradient search phase of the optimization process. Automatic differentiation is more efficient than hand-differentiating code for the user and provides exact gradients, allowing the optimization of the neural network weights to proceed more rapidly. Another benefit of this method comes from its use of neural networks, which are able to represent complex feedback control policies, because they are general nonlinear function approximators. Neural networks also have the potential to be generalizable, meaning that a control policy found using a sufficiently rich training set will often work well for other initial conditions outside of the training set. Finally, the software implementation is modular, which means that the user only needs to adjust a few codes in order to set up the method for a specific problem. The application of the adjoint method to three control problems with known solutions demonstrates the ability of the method to determine neural networks that produce near-optimal trajectories and control policies.
by Elizabeth Rollins.
S.M.
4
Wadoo, Sabiha Amin. "Feedback Control and Nonlinear Controllability of Nonholonomic Systems." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/30963.
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In this thesis we study the methods for motion planning for nonholonomic systems. These systems are characterized by nonholonomic constraints on their generalized velocities. The motion planning problem with constraints on the velocities is transformed into a control problem having fewer control inputs than the degrees of freedom. The main focus of the thesis is on the study of motion planning and design of the feedback control laws for an autonomous underwater vehicle: a nonholonomic system. The nonlinear controllability issues for the system are also studied. For the design of feedback controllers, the system is transformed into chained and power forms. The methods of transforming a nonholonomic system into these forms are discussed. The work presented in this thesis is a step towards the initial study concerning the applicability of kinematic-based control on underwater vehicles.Master of Science
5
Huang, Rui. "OUTPUT FEEDBACK TRACKING CONTROL OF NONLINEAR TIME-VARYING SYSTEMS BY TRAJECTORY LINEARIZATION." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1178906759.
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6
Damweber, Michael Frank. "Model independent offset tracking with virtual feature points." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/17651.
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7
Garner, Harry Douglas Jr. "Development of a real-time vision based absolute orientation sensor." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17022.
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8
Jeong, Daehwa. "Analysis and design of a discrete time repetitive control system /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/7079.
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9
Imsland, Lars. "Topics in nonlinear control. : Output Feedback Stabilization and Control of Positive Systems." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-355.
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The contributions of this thesis are in the area of control of systems with nonlinear dynamics. The thesis is divided into three parts. The two first parts are similar in the sense that they both consider output feedback of rather general classes of nonlinear systems, and both approaches are based on mathematical programming (although in quite different ways). The third part contains a state feedback approach for a specific system class, and is more application oriented.
The first part treats control of systems described by nonlinear difference equations, possibly with uncertain terms. The system dynamics are represented by piecewise affine difference inclusions, and for this system class, piecewise affine controller structures are suggested. Controller synthesis inequalities for such controller structures are given in the form of Bilinear Matrix Inequalities (BMIs). A solver for the BMIs is developed. The main contribution is to the output feedback case, where an observer-based controller structure is proposed. The theory is exemplified through two examples.
In the second part the output feedback problem is examined in the setting of Nonlinear Model Predictive Control (NMPC). The state space formulation of NMPC is inherently a state feedback approach, since the state is needed as initial condition for the prediction in the controller. Consequently, for output feedback it is natural to use observers to obtain estimates of the state. A high gain observer is applied for this purpose. It is shown that for several existing NMPC schemes, the state feedback stability properties ``semiglobally'' hold in the output feedback case. The theory is illuminated with a simple example.
Finally, a state feedback controller for a class of positive systems is proposed. Convergence of the state to a certain subset of the first orthant, corresponding to a constant ``total mass'' (interpreting states as masses) is obtained. Conditions are given under which convergence to this set implies asymptotic stability of an equilibrium. Simple examples illustrate some properties of the controller. Furthermore, the control strategy is applied to the stabilization of a gas-lifted oil well, and simulations on a rigorous multi-phase dynamic simulator of such a well demonstrate the controller performance.
10
Fairley, Stuart Martin. "A stereo tracking and structure recovery system." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670262.
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Meurer, Thomas. "Feedforward and feedback tracking control of diffusion convection reaction systems using summability methods." [S.l. : s.n.], 2005. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-27360.
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Falkner, Catherine M. "Robust output feedback controllers for power system stabilization." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/14802.
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13
Lai, Haoyu. "On the design of nonlinear gain scheduled control systems." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176486900.
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Odelius, Johan. "Generation of probe signal for feedback cancellation systems." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2095.
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A common problem of hearing aids is whistling caused by feedback from the loudspeaker back to the microphone. A method of reducing the negative effects, caused by the feedback, is called feedback cancellation. A variant of feedback cancellation uses a probe signal, which is applied to the speaker of the hearing aid and is used to continuously estimate the feedback. Oticon A/S has suggested a master's thesis with the purpose of designing and evaluating an algorithm generating a probe signal for feedback cancellation systems. The challenge was to find an inaudible probe signal with as much energy as possible.
Two approaches have been investigated for generating a probe signal. In the first approach the psychoacoustic principle of masking was used to estimate how much noise that could be added to a signal without being heard. Psychoacoustic models, including masking, are used in MPEG (Moving Pictures Expert Group) audio coding and one of these models has been examined in the thesis. In the second approach a standard LPC (Linear Prediction Coding) algorithm was used. In both the MPEG and the LPC approach, warped signal processing has been utilized improving the methods.
A listening test was performed, evaluating the methods generating the probe signal. The purpose of the test was to determine whether the noise, generated using the MPEG and LPC approach, was inaudible. A hearing aid system with feedback cancellation, using the probe signal, was also simulated. The listening test showed that the noise (probe signal) had to be lowered, much more than expected, to be inaudible. As a consequence, shown in the simulations, the feedback cancellation system, using the probe signal, had trouble identifying the feedback of the hearing aid.
15
Maree, Johannes Philippus. "Fault detection for the Benfield process using a closed-loop subspace re-identification approach." Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-11262009-224053/.
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Thesis (M.Eng.(Faculty of Engineering, The Built Environment and Information Technology))--University of Pretoria, 2009.Abstracts in English and Afrikaans. Includes bibliographical references (leaves 180-187).
16
Wise, Richard. "UAV guidance control laws for autonomous coordinated tracking of a moving ground target /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/9959.
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Maeda, Ken. "Nonlinear control system of inverted pendulum based on input-output linearization." Diss., Online access via UMI:, 2006.
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18
Zhang, Zhen. "Adaptive robust periodic output regulation." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1187118803.
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Loepelmann, Peter. "Design and Analysis of an adaptive λ-Tracking Controller for powered Gearshifts in automatic Transmissions." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-163167.
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To meet the continuously increasing goals in vehicle fuel efficiency, a number of measures are taken in automotive powertrain engineering, such as the combination of electric drives and conventional combustion engines in hybrid vehicles or the increase in gear ratios. This development leads to more complex powertrain systems, such as automatic transmissions. At the same time, the need for complex control systems is increased to achieve this desired functionality.
Automatic transmissions are controlled by an electro-hydraulic control unit that governs all operations such as gear shifting and starting. Since most of the control software is designed in the form of open-loop control, most of the operations have to be calibrated manually. Thus, there exists a large number of calibration parameters in the control software that have to be tuned individually for each combination of engine, transmission and vehicle model. This process is therefore time-consuming and costly. Hence, it would be advantageous to reduce the need for calibration and in the end shorten the development process for automatic transmissions by reducing software complexity while maintaining functionality and performance.
The goal of this thesis is to replace parts of the control software responsible for conducting the gearshifts that require extensive tuning by implementing control systems that have no need for calibration: adaptive high-gain λ-tracking controllers. In order to obtain the control parameters, i.e., the feedback gains, without calibration, an adaption law is implemented that continuously computes these parameters during operation of the controller. Thus, calibration is no longer needed. Since the system has to be high-gain-stabilizable, an extensive system analysis is conducted to determine whether an adaptive λ-tracking controller can be implemented. A nonlinear model of the clutch system dynamics is formulated and investigated.
As a result, high-gain stability is proven for the system class and validated in simulation. Following the stability analysis, the devised adaptive controller is implemented into the control software running on the series production transmission control unit. Extensive simulations with a comprehensive vehicle model running the extended transmission software are conducted to design and to test the adaptive controllers and their underlying parameters during transmission operation in order to evaluate the control performance. The control software containing the adaptive controller is then implemented in two distinct vehicles with different automatic transmissions equipped with series production control hardware for the purpose of hardware experiments and validation. The resulting reduction of calibration efforts is discussed.
20
Gumpert, Ben Allen. "A recursive Gauss-Newton method for model independent eye-in-hand visual servoing / by Ben Allen Gumpert." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17260.
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Hacinecipoglu, Akif. "Development Of Electrical And Control System Of An Unmanned Ground Vehicle For Force Feedback Teleoperation." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614807/index.pdf.
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Teleoperation of an unmanned vehicle is a challenging task for human operators especially when the vehicle is out of line of sight. Improperly designed and applied display interfaces directly affect the operation performance negatively and even can result in catastrophic failures. If these teleoperation missions are human-critical then it becomes more important to improve the operator performance by decreasing workload, managing stress and improving situational awareness. This research aims to develop electrical and control system of an unmanned ground vehicle (UGV) using an All-Terrain Vehicle (ATV) and validate the development with investigation of the effects of force feedback devices on the teleoperation performance. After development, teleoperation tests are performed to verify that force feedback generated from the dynamic obstacle information of the environment improves teleoperation performance. Results confirm this statement and the developed UGV is verified for future research studies. Development of UGV, algorithms and real system tests are included in this thesis.
22
Winck, Ryder Christian. "Simultaneous control of coupled actuators using singular value decomposition and semi-nonnegative matrix factorization." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45907.
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This thesis considers the application of singular value decomposition (SVD) and semi-nonnegative matrix factorization (SNMF) within feedback control systems, called the SVD System and SNMF System, to control numerous subsystems with a reduced number of control inputs. The subsystems are coupled using a row-column structure to allow mn subsystems to be controlled using m+n inputs. Past techniques for controlling systems in this row-column structure have focused on scheduling procedures that offer limited performance. The SVD and SNMF Systems permit simultaneous control of every subsystem, which increases the convergence rate by an order of magnitude compared with previous methods. In addition to closed loop control, open loop procedures using the SVD and SNMF are compared with previous scheduling procedures, demonstrating significant performance improvements. This thesis presents theoretical results for the controllability of systems using the row-column structure and for the stability and performance of the SVD and SNMF Systems. Practical challenges to the implementation of the SVD and SNMF Systems are also examined. Numerous simulation examples are provided, in particular, a dynamic simulation of a pin array device, called Digital Clay, and two physical demonstrations are used to assess the feasibility of the SVD and SNMF Systems for specific applications.
23
Olsson, Claes. "Active Vibration Control of Multibody Systems : Application to Automotive Design." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5818.
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Schmidt, Bernd [Verfasser], Johann [Akademischer Betreuer] Reger, Alan [Akademischer Betreuer] Zinober, and Enric [Akademischer Betreuer] Fossas-Colet. "H∞ Suboptimal Tracking Control for Bilinear Power Converter Systems with Dynamic Feedback - Theory and Experiment / Bernd Schmidt. Gutachter: Alan Zinober ; Enric Fossas-Colet. Betreuer: Johann Reger." Ilmenau : Universitätsbibliothek Ilmenau, 2011. http://d-nb.info/101661988X/34.
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Teoh, Pek Loo. "A study of single laser interferometry-based sensing and measuring technique in robot manipulator control and guidance. Volume 1." Monash University, Dept. of Mechanical Engineering, 2003. http://arrow.monash.edu.au/hdl/1959.1/9565.
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Ekutekin, Vedat. "Navigation And Control Studies On Cruise Missiles." Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608142/index.pdf.
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A cruise missile is a guided missile that uses a lifting wing and a jet propulsion system to allow sustained flight. Cruise missiles are, in essence, unmanned aircraft and they are generally designed to carry a large conventional or nuclear warhead many hundreds of miles with excellent accuracy. In this study, navigation and control studies on cruise missiles are performed. Due to the variety and complexity of the subsystems of the cruise missiles, the main concern is limited with the navigation system. Navigation system determines the position, velocity, attitude and time solutions of the missile. Therefore, it can be concluded that an accurate self-contained navigation system directly influences the success of the missile. In the study, modern radar data association algorithms are implemented as new Terrain Aided Navigation (TAN) algorithms which can be used with low-cost Inertial Measurement Units (IMU&rsquos). In order to perform the study, first a thorough survey of the literature on mid-course navigation of cruise missiles is performed. Then, study on modern radar data association algorithms and their implementations to TAN are done with simple simulations. At the case study part, a six degree of freedom (6 DOF) flight simulation tool is developed which includes the aerodynamic and dynamic model of the cruise missile model including error model of the navigation system. Finally, the performances of the designed navigation systems with the implemented TAN algorithms are examined in detail with the help of the simulations performed.
27
Riviello, Luca. "Rotorcraft trim by a neural model-predictive auto-pilot." Thesis, Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-04142005-203616/unrestricted/riviello%5Fluca%5F200505%5Fmast.pdf.
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Thesis (M. S.)--Aerospace Engineering, Georgia Institute of Technology, 2005.Bottasso, Carlo, Committee Chair ; Hodges, Dewey, Committee Member ; Bauchau, Olivier, Committee Member. Includes bibliographical references.
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Pektas, Seda. "On-line Controller Tuning By Matlab Using Real System Responses." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605596/index.pdf.
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This thesis attempts to tune any controller without the mathematical model knowledge of the system it is controlling. For that purpose, the optimization algorithm of MATLAB®6.5 / Nonlinear Control Design Blockset (NCD) is adapted for real-time executions and combined with a hardware-in-the-loop simulation provided by MATLAB®
6.5 / Real-Time Windows Target (RTWT). A noise-included model of a DC motor position control system is obtained in MATLAB®
/ SIMULINK first and simulated to test the modified algorithm in some aspects. Then the presented methodology is verified using the physical plant (DC motor position control system) where tuning algorithm is driven mainly by the real system data and the required performance parameters specified by a user defined constraint window are successfully satisfied. Resultant improvements on the step response behavior of DC motor position control system are shown for two case studies.
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Hou, Zhicheng. "Modeling and formation controller design for multi-quadrotor systems with leader-follower configuration." Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2259/document.
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Cette thèse propose des solutions aux problématiques inhérentes au contrôle de formations aériennes de type leader-suiveur pour des flottes de quadrirotors. Au regard des travaux existants, les stratégies qui sont proposés dans notre travail, considère que le(s) leader{s) a une interaction avec les suiveurs. En outre, les rôles de leader et de suiveur sont interchangeables lors de la formation. Dans un premier temps, la modélisation mathématique d'un seul quadrirotor et celle de la formation de quadrirotors est développée. Ensuite, le problème de suivi de trajectoire pour un seul quadrirotor est étudié. Au travers de l'analyse de 1, dynamique du système pour la conception d'une commande par platitude, il apparait que le suivi de trajectoire pour chaque quadrirotor équivaut à déterminer les sorties plates désirées. Un contrôleur pour système plats permettant l'asservissement des drones pour le suivi de trajectoire est donc proposé. Étant donné la propriété de double-boucle de la dynamique du quadrirotor en boucle fermée, un contrôleur d'attitude avec des grands gains est conçu, selon la théorie « singular perturbation system ». Puisque la dynamique du quadrirotor en boucle fermée fonctionne sur deux échelles de temps, la dynamique de rotation (boundary-layer mode) est contrôlée sur l'échelle de temps la plus rapide. La conception du contrôleur de formation dépend seulement de la dynamique de translation (modèle réduit dans une échelle de temps lente). Ce résultat a simplifié la conception du contrôleur de formation, de telle sorte que le modèle réduit du quadrirotor est utilisé au lieu du modèle complet. Étant donné que le modèle réduit du quadrirotor a une caractéristique de double-intégrateur, un algorithme de consensus pour des systèmes caractérisés par de multiple double-intégrateurs est proposé. Pour traiter le problème de la formation leader-suiveur, une matrice d'interaction est initialement proposée basée sur la matrice de Laplacienne. Nous montrons que la condition de convergence et la vitesse de convergence de l'erreur de formation dépendent de la plus petite valeur propre de la matrice d'interaction. Trois stratégies de contrôle de la formation avec une topologie fixe sont ensuite proposées. Le contrôle de formation par platitude est proposé pour obtenir une formation agressive, tandis que les dérivées de grands ordres de la trajectoire désirée pour chaque UAV sont estimées en utilisant un observateur; la méthode Lyapunov redesign est implémentée pour traiter les non-linéarités de la dynamique de la translation des quadrotors; une loi de commande bornée par l'utilisation, entre autre, de la fonction tangente hyperbolique est développée avec un feedback composite non linéaire, afin d'améliorer les performances de la formation. De plus, une commande de commutation saturée de la formation est étudiée, car la topologie de la formation est variable. La stabilité du système est obtenue grâce aux théories “convex hull » et « common Lyapunov function ». Cette stratégie de commande de commutation permet le changement des leaders dans la formation. Inspirée par certains travaux existants, tels que le contrôle de la formation avec des voisins anonymes, nous proposons, finalement, une loi de commande avec des voisins pondérés, qui montre une meilleure robustesse que le contrôle avec des voisins anonymes. Les résultats de simulation obtenus avec Matlab illustrent premièrement nos stratégies de contrôle que nous proposons De plus, en utilisant le langage de programmation C ++, nos stratégies sont mises en œuvre dans un framework de simulation et d'expérimentation développé au laboratoire Heudiasyc. Grâce aux nombreux tests variés que nous avons réalisés en simulation et en temps-réel, l'efficacité et les avantages de nos stratégies de contrôle de la formation proposées sont présentésIn this thesis, we address a leader-follower (L-F) formation control problem for multiple UAVs, especially quadrotors. Different from existing works, the strategies, which are proposed in our work, consider that the leader(s) have interaction with the followers. Additionally, the leader(s) are changeable during the formation. First, the mathematical modeling of a single quadrotor and of the formation of quadrotors is developed. The trajectory tracking problem for a single quadrotor is investigated. Through the analysis of the flatness of the quadrotor dynamical model, the desired trajectory for each quadrotor is transferred to the design of the desired at outputs. A flatness-based trajectory tracking controller is, then, proposed. Considering the double-loop property of the closed-loop quadrotor dynamics, a high-gain attitude controller is designed, according to the singular perturbation system theory. Since the closed-loop quadrotor dynamics performs in two time scales, the rotational dynamics (boundary-layer model) is controlled in a fast time scale. The formation controller design is then only considered for the translational dynamics: reduced model in a slow time scale. This result has simplified the formation controller design such that the reduced model of the quadrotor is considered instead of the complete model. Since the reduced model of the quadrotor has a double-integrator characteristic, consensus algorithm for multiple double-integrator systems is proposed. Dealing with the leader-follower formation problem, an interaction matrix is originally proposed based on the Laplacian matrix. We prove that the convergence condition and convergence speed of the formation error are in terms of the smallest eigenvalue of the interaction matrix. Three formation control strategies with fixed formation topology are then proposed. The flatness-based formation control is proposed to deal with the aggressive formation problem, while the high-order derivatives of the desired trajectory for each UAV are estimated by using an observer; the Lyapunov redesign is developed to deal with the nonlinearities of the translational dynamics of the quadrotors; the hyperbolic tangent-based bounded control with composite nonlinear feedback is developed in order to improve the performance of the formation. In an additional way, a saturated switching control of the formation is investigated, where the formation topology is switching. The stability of the system is obtained by introducing the convex hull theory and the common Lyapunov function. This switching control strategy permits the change of the leaders in the formation. Inspired by some existing works, such as the anonymous neighbor-based formation control, we finally propose a weighted neighbor-based control, which shows better robustness than the anonymous neighbor-based control. Simulation results using Matlab primarily illustrate our proposed formation control strategies. Furthermore, using C++ programming, our strategies are implemented on the simulator-experiment framework, developed at Heudiasyc laboratory. Through a variety of tests on the simulator and real-time experiments, the efficiency and the advantages of our proposed formation control strategies are shown. Finally, a vision-based inter-distance detection system is developed. This system is composed by an on-board camera, infrared LEDs and an infrared filter. The idea is to detect the UAVs and calculate the inter-distance by calculating the area of the special LEDs patterns. This algorithm is validated on a PC, with a webcam and primarily implemented on a real quadrotor
30
Ozturk, Taha. "Angular Acceleration Assisted Stabilization Of A 2-dof Gimbal Platform." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612318/index.pdf.
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In this thesis work construction of the angular acceleration signal of a 2-DOF gimbal
platform and use of this signal for improving the stabilization performance is aimed.
This topic can be divided into two subtopics, first being the construction of angular
acceleration and the second being the use of this information in a way to improve
system performance. Both problems should be tackled in order to get satisfactory
results. The most important output of this work is defined as the demonstration of
the improvements obtained both theoretically and on experimental setup. Although
the system to be studied is a two axis gimbal platform, the results obtained can be
applied to other servo control problems. It is possible to define different performance
criteria for a servo control problem and different techniques will be addressed with
different control objectives. For this thesis work, the performance criterion is defined
as the stabilization performance of the platform. As a result, disturbance rejection
characteristics of the controller emerges as the main topic and methods for rejecting
these disturbances such as the friction torques and externally applied moments are
focused on throughout the studies. As expected, remarkable improvement is achieved
as a result of the use of acceleration feedback.
31
Kilicaslan, Sinan. "Unconstrained Motion And Constrained Force And Motion Control Of Robots With Flexible Links." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606011/index.pdf.
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New control methods are developed for the unconstrained motion and constrained force and motion control of flexible robots. The dynamic equations of the flexible robots are partitioned as pseudostatic equilibrium equations and deviations from them. The pseudostatic equilibrium considered here is defined as a hypothetical state where the tip point variables have their desired values while the modal variables are instantaneously constant. Then, the control torques for the pseudostatic equilibrium and for the stabilization of the deviation equations are formed in terms of tip point coordinates, modal variables and contact force components. The performances of the proposed methods are illustrated on a planar two-link robot and on a spatial three-link robot. Unmodeled dynamics and measurement noises are also taken into consideration. Performance of the proposed motion control method is compared with the computed torque method.
32
Unnikrishnan, Suraj. "Adaptive Envelope Protection Methods for Aircraft." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11478.
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Carefree handling refers to the ability of a pilot to operate an aircraft without the need to continuously monitor aircraft operating limits. At the heart of all carefree handling or maneuvering systems, also referred to as envelope protection systems, are algorithms and methods for predicting future limit violations. Recently, envelope protection methods that have gained more acceptance, translate limit proximity information to its equivalent in the control channel. Envelope protection algorithms either use very small prediction horizon or are static methods with no capability to adapt to changes in system configurations. Adaptive approaches maximizing prediction horizon such as dynamic trim, are only applicable to steady-state-response critical limit parameters. In this thesis, a new adaptive envelope protection method is developed that is applicable to steady-state and transient response critical limit parameters. The approach is based upon devising the most aggressive optimal control profile to the limit boundary and using it to compute control limits. Pilot-in-the-loop evaluations of the proposed approach are conducted at the Georgia Tech Carefree Maneuver lab for transient longitudinal hub moment limit protection. Carefree maneuvering is the dual of carefree handling in the realm of autonomous Uninhabited Aerial Vehicles (UAVs). Designing a flight control system to fully and effectively utilize the operational flight envelope is very difficult. With the increasing role and demands for extreme maneuverability there is a need for developing envelope protection methods for autonomous UAVs. In this thesis, a full-authority automatic envelope protection method is proposed for limit protection in UAVs. The approach uses adaptive estimate of limit parameter dynamics and finite-time horizon predictions to detect impending limit boundary violations. Limit violations are prevented by treating the limit boundary as an obstacle and by correcting nominal control/command inputs to track a limit parameter safe-response profile near the limit boundary. The method is evaluated using software-in-the-loop and flight evaluations on the Georgia Tech unmanned rotorcraft platform- GTMax. The thesis also develops and evaluates an extension for calculating control margins based on restricting limit parameter response aggressiveness near the limit boundary.
33
Hoang, Trong bien. "Switched observers and input-delay compensation for anti-lock brake systems." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-00994114.
Full textAbstract:
Many control algorithms for ABS systems have been proposed in the literature since the introduction of this equipment by Bosch in 1978. In general, one can divide these control algorithms into two different types: those based on a regulation logic with wheel acceleration thresholds that are used by most commercial ABS systems; and those based on wheel slip control that are preferred in the large majority of academic algorithms. Each approach has its pros and cons [Shida 2010]. Oversimplifying, one can say that the strength of the first ones is their robustness; while that of the latter ones their short braking distances (on dry grounds) and their absence of limit cycles. At the midpoint of this industry/academy dichotomy, based on the concept of extended braking stiffness (XBS), a quite different class of ABS control strategies has been proposed by several researchers (see, e.g., [Sugai 1999] and [Ono 2003]). This concept combines the advantages from both the industrial and academic approaches. Nevertheless, since the slope of the tyre characteristic is not directly measurable, it introduces the question of real-time XBS estimation. The first part of this thesis is devoted to the study of this estimation problem and to a generalization of the proposed technique to a larger class of systems. From the technological point of view, the design of ABS control systems is highly dependent on the ABS system characteristics and actuator performance. Current ABS control algorithms on passenger cars, for instance the Bosch ABS algorithm, are based on heuristics that are deeply associated to the hydraulic nature of the actuator. An interesting observation is that they seem to work properly only in the presence of a specific delay coming from the hydraulic actuation [Gerard 2012]. For brake systems that have different delays compared to those of hydraulic actuators, like electric in-wheel motors (with a smaller delay) or pneumatic trailer brakes (with a bigger delay), they might be no longer suitable [Miller 2013]. Therefore, adapting standard ABS algorithms to other advanced actuators becomes an imperative goal in the automobile industry. This goal can be reached by the compensation of the delays induced by actuators. The second part of this thesis is focused on this issue, and to the generalization of the proposed technique to a particular class of nonlinear systems. Throughout this thesis, we employ two different linearization techniques: the linearization of the error dynamics in the construction of model-based observers [Krener 1983] and the linearization based on restricted state feedback [Brockett 1979]. The former is one of the simplest ways to build an observer for dynamical systems with output and to analyze its convergence. The main idea is to transform the original nonlinear system via a coordinate change to a special form that admits an observer with a linear error dynamics and thus the observer gains can be easily computed to ensure the observer convergence. The latter is a classical method to control nonlinear systems by converting them into a controllable linear state equation via the cancellation of their nonlinearities. It is worth mentioning that existing results for observer design by error linearization in the literature are only applied to the case of regular time scalings ([Guay 2002] and [Respondek 2004]). The thesis shows how to extend them to the case of singular time scalings. Besides, the thesis combines the classical state feedback linearization with a new method for the input delay compensation to resolve the output tracking problem for restricted feedback linearizable systems with input delays.
34
Akcay, Emre Mustafa. "Land Vehicle Navigation With Gps/ins Sensor Fusion Using Kalman Filter." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12610327/index.pdf.
Full textAbstract:
Inertial Measurement Unit (IMU) and Global Positioning System (GPS) receivers are
sensors that are widely used for land vehicle navigation. GPS receivers provide
position and/or velocity data to any user on the Earth&rsquos surface independent of his position. Yet, there are some conditions that the receiver encounters difficulties, such as weather conditions and some blockage problems due to buildings, trees etc. Due to these difficulties, GPS receivers&rsquo
errors increase. On the other hand, IMU works with respect to Newton&rsquo
s laws. Thus, in stark contrast with other navigation sensors (i.e. radar, ultrasonic sensors etc.), it is not corrupted by external signals. Owing to this feature, IMU is used in almost all navigation applications. However, it has some disadvantages such as possible alignment errors, computational errors and instrumentation errors (e.g., bias, scale factor, random noise, nonlinearity etc.). Therefore, a fusion or integration of GPS and IMU provides a more accurate navigation data compared to only GPS or only IMU navigation data. v In this thesis, loosely coupled GPS/IMU integration systems are implemented using feed forward and feedback configurations. The mechanization equations, which convert the IMU navigation data (i.e. acceleration and angular velocity components) with respect to an inertial reference frame to position, velocity and orientation data with respect to any desired frame, are derived for the geographical frame. In other words, the mechanization equations convert the IMU data to the Inertial Navigation System (INS) data. Concerning this conversion, error model of INS is developed using the perturbation of the mechanization equations and adding the IMU&rsquo
s sensor&rsquo
s error model to the perturbed mechanization equation. Based on this error model, a Kalman filter is constructed. Finally, current navigation data is calculated using IMU data with the help of the mechanization equations. GPS receiver supplies external measurement data to Kalman filter. Kalman filter estimates the error of INS using the error mathematical model and current navigation data is updated using Kalman filter error estimates. Within the scope of this study, some real experimental tests are carried out using the software developed as a part of this study. The test results verify that feedback GPS/INS integration is more accurate and reliable than feed forward GPS/INS. In addition, some tests are carried out to observe the results when the GPS receiver&rsquo
s data lost. In these tests also, the feedback GPS/INS integration is observed to have better performance than the feed forward GPS/INS integration.
35
Romero, Velázquez José Guadalupe. "Commande robuste par façonnement d’énergie de systèmes non-linéaires." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112019/document.
Full textAbstract:
Cette thèse porte sur la conception de commandes robustes pour les systèmes non linéaires, mettant l'accent sur les systèmes mécaniques. Des résultats concluants sont présentés pour résoudre deux situations très abordées dans la théorie du contrôle : 1) La stabilité des systèmes non linéaires perturbés ; 2) Le suivi global de trajectoire dans les systèmes mécaniques en ayant seulement connaissance de la position. Nous avons commencé par donner une méthode de conception des commandes robustes pour assurer une régulation de sortie non passive. En outre, si le système est perturbé (pas appariés), des preuves rigoureuses pour les rejeter sont fournies. Ce résultat est principalement inspiré d'un changement de coordonnées et de l'action intégrale dynamique. Si le scénario à traiter concerne des systèmes mécaniques avec des perturbations variant dans le temps, nous dotons le système de propriétés comme IISS (Integral Input- State Stable) et ISS (Input-State Stable). Ce résultat est obtenu en modifiant la procédure de conception de manière à rejeter les perturbations constantes (pas appariés). Cependant, en raison de la non-linéarité du système, les commandes qui en résultent ont une grande complexité. Pour le même problème, un deuxième et élégant résultat est donné au cas où un changement préalable de variable (impulsions) est réalisé. Finalement, une réponse convaincante au problème de suivi de trajectoire pour les systèmes mécaniques est donnée en tenant compte uniquement des informations de position. Nous résolvons ce problème en deux étapes. Premièrement, quelques modifications sont apportées à la preuve de stabilité d'un observateur de vitesse basée sur la théorie de l'invariance et l’Immersion récemment publié. Notez que ceci est un observateur satisfaisant la convergence exponentielle de vitesse dans les systèmes mécaniques. Deuxièmement et sur la base du changement de coordonnées (impulsions), un contrôleur de suivi avec stabilité exponentielle, tenant compte de la position et de la vitesse, est proposé. De telle sorte qu'avec la combinaison des deux résultats, le suivi de trajectoire exponentielle avec retour de position est donnéThis thesis focuses on the design of robust control for nonlinear systems, mainly on mechanical systems. The results presented are to two situations widely discussed in control theory: 1) The stability of nonlinear systems disturbed; 2) The global tracking trajectory in mechanical systems having only knowledge of the position. We started giving a design method of robust controls to ensure regulation on non-passive output. In addition, if the system is perturbed (constant unmatched), rigorous proof to its rejection is provided. This result is based mainly on change of coordinates and integral dynamic control. When the scenario to deal are mechanical systems with time-varying matched and unmatched, disturbance, the system is endowed with strong properties as IISS (Integral Input-State Stable) and ISS (Input-State Stable). This is achieved based on the design method to rejection of constant disturbances (unmatched). However, due to the nonlinearity of the system, the controllers have a high complexity. For the same problem, a second and elegant result is given making a initial change of coordinate on the momenta variable, such that the controller significantly simplifies, preserving the aforementioned robustness properties. Finally, a convincing answer to the problem of global exponential tracking of mechanical systems is given taking into account only the position information. We solve this problem in two steps. First, some slight variation is presented to the proof of stability of a speed observer based on Immersion and Invariance theory recently published. Note that this is a speed observer satisfying the exponential convergence speed in mechanical systems. Secondly, and based on the change of coordinates (momenta), a globally exponentially stable tracking controller with position and velocity known is proposed. The combination of both results give the first global exponential tracking controller of mechanical systems without velocity measurements
36
De, Hillerin Safta. "Commande robuste de systèmes non linéaires incertains." Thesis, Supélec, 2011. http://www.theses.fr/2011SUPL0015/document.
Full textAbstract:
Cette thèse étudie l'approche LPV pour la commande robuste des systèmes non linéaires. Son originalité est de proposer pour la première fois un cadre rigoureux permettant de résoudre efficacement des problèmes de synthèse non linéaire. L'approche LPV a été proposée comme une extension de l'approche H-infini dans le contexte des systèmes LPV (« Linéaires à Paramètres Variant dans le temps »), voire non linéaires. Quoique prometteuse, cette approche pour la commande des systèmes non linéaires restait peu utilisée. En effet, au-delà même de certaines limitations théoriques, la nature des solutions obtenues semblait inadéquate. Cette question ouverte est notre point de départ. Nous montrons tout d'abord que la faible variation des correcteurs constatée est due avant tout à la nature du schéma informationnel utilisé traditionnellement lors de la synthèse LPV, et que sous des hypothèses raisonnables, le cadre LPV peut permettre de recouvrir des stratégies de type « linéarisation par bouclage ». Ce point étant acquis, une deuxième difficulté réside dans l'obtention effective de correcteurs non linéaires donnant des garanties de performance. Nous proposons un cadre rigoureux permettant de résoudre efficacement un problème de synthèse incrémentale pondérée, par la résolution d'un problème LPV associé à un schéma informationnel spécifique compatible avec celui identifié dans la première partie. Cette étude et son aboutissement à la définition d'un cadre formel et d'une procédure complète d'obtention de correcteurs, incluant des méthodes de réduction de complexité, donnent des arguments puissants en faveur de l'approche LPV pour la commande robuste de systèmes non linéairesThis thesis studies the LPV approach for the robust control of nonlinear systems. Its originality is to propose for the first time a rigorous framework allowing to solve efficiently nonlinear synthesis problems.The LPV approach was proposed as an extension of the H-infinity approach in the context of LPV (Linear Parameter-Varying) systems and nonlinear systems. Although this approach seemed promising, it was not much used in practise. Indeed, beyond certain theoretical limitations, the nature itself of the obtained solutions did not seem adequate. This open question constitutes the starting point of our work.We first prove that the observed weak variation of the controllers is in fact mostly due to the information structure traditionally used for LPV synthesis, and that under reasonable assumptions, the LPV framework can overlap feedback linearization strategies. This point having been resolved, a second difficulty lies in the actual achievement of nonlinear controllers yielding performance guarantees. We propose a rigorous framework allowing to solve efficiently an incremental synthesis problem, through the resolution of an LPV problem associated to a specific information structure compatible with the one identified in the first part.This study and its corollary description of a formal framework and of a complete controller synthesis procedure, including complexity reduction methods, provide powerful arguments in favor of the LPV approach for the robust control of nonlinear systems
37
Bezzaoucha, Souad. "Commande tolérante aux défauts de systèmes non linéaires représentés par des modèles de Takagi-Sugeno." Phd thesis, Université de Lorraine, 2013. http://tel.archives-ouvertes.fr/tel-00948345.
Full textAbstract:
Cette thèse porte sur la représentation T-S des systèmes non linéaires et les non-linéarités qui leur sont associées (saturation et paramètres variants dans le temps) pour la commande et le diagnostic. Ainsi, une nouvelle approche utilisant la transformation par secteurs non linéaires permet de ré-écrire le système sous forme polytopique en prenant en compte la présence de paramètres variants dans le temps. Cette forme polytopique est ensuite utile pour la synthèse d'observateurs assurant l'estimation simultanée de l'état et des paramètres du système. Une application au diagnostic est également considérée en comparant les valeurs des paramètres estimés en ligne avec leurs valeurs nominales supposées connues et représentatives du mode de fonctionnement non défaillant. Concernant la commande, la contrainte de saturation est représentée sous forme de modèle T-S et est intégrée au modèle du système. La synthèse de plusieurs lois de commande assurant la stabilité du système bouclé, en prenant en compte les limites de saturation est proposée. La poursuite de modèle de référence est également traitée avec la mise en évidence des conditions structurelles de poursuite pour les modèles non linéaires sous forme T-S. L'accent est mis sur les différents critères de choix de commande en fonction des buts recherchés.
38
Fortin, Benoît. "Méthodes conjointes de détection et suivi basé-modèle de cibles distribuées par filtrage non-linéaire dans les données lidar à balayage." Phd thesis, Université du Littoral Côte d'Opale, 2013. http://tel.archives-ouvertes.fr/tel-01021085.
Full textAbstract:
Dans les systèmes de perception multicapteurs, un point central concerne le suivi d'objets multiples. Dans mes travaux de thèse, le capteur principal est un télémètre laser à balayage qui perçoit des cibles étendues. Le problème desuivi multi-objets se décompose généralement en plusieurs étapes (détection, association et suivi) réalisées de manière séquentielle ou conjointe. Mes travaux ont permis de proposer des alternatives à ces méthodes en adoptant une approche "track-before-detect" sur cibles distribuées qui permet d'éviter la succession des traitements en proposant un cadre global de résolution de ce problème d'estimation. Dans une première partie, nous proposons une méthode de détection travaillant directement en coordonnées naturelles (polaires) qui exploite les propriétés d'invariance géométrique des objets suivis. Cette solution est ensuite intégrée dans le cadre des approches JPDA et PHD de suivi multicibles résolues grâce aux méthodes de Monte-Carlo séquentielles. La seconde partie du manuscrit vise à s'affranchir du détecteur pour proposer une méthode dans laquelle le modèle d'objet est directement intégré au processus de suivi. C'est sur ce point clé que les avancées ont été les plus significatives permettant d'aboutir à une méthode conjointe de détection et de suivi. Un processus d'agrégation a été développé afin de permettre une formalisation des données qui évite tout prétraitement sous-optimal. Nous avons finalement proposé un formalisme général pour les systèmes multicapteurs (multilidar, centrale inertielle, GPS). D'un point de vue applicatif, ces travaux ont été validés dans le domaine du suivi de véhicules pour les systèmes d'aide à la conduite.
39
Zhu, Jianzhong. "Synthesis and Analysis of Design Methods in Linear Repetitive, Iterative Learning and Model Predictive Control." Thesis, 2018. https://doi.org/10.7916/D87S918J.
Full textAbstract:
Repetitive Control (RC) seeks to converge to zero tracking error of a feedback control system performing periodic command as time progresses, or to cancel the influence of a periodic disturbance as time progresses, by observing the error in the previous period. Iterative Learning Control (ILC) is similar, it aims to converge to zero tracking error of system repeatedly performing the same task, and also adjusting the command to the feedback controller each repetition based on the error in the previous repetition. Compared to the conventional feedback control design methods, RC and ILC improve the performance over repetitions, and both aiming at zero tracking error in the real world instead of in a mathematical model. Linear Model Predictive Control (LMPC) normally does not aim for zero tracking error following a desired trajectory, but aims to minimize a quadratic cost function to the prediction horizon, and then apply the first control action. Then repeat the process each time step. The usual quadratic cost is a trade-off function between tracking accuracy and control effort and hence is not asking for zero error. It is also not specialized to periodic command or periodic disturbance as RC is, but does require that one knows the future desired command up to the prediction horizon.
The objective of this dissertation is to present various design schemes of improving the tracking performance in a control system based on ILC, RC and LMPC. The dissertation contains four major chapters. The first chapter studies the optimization of the design parameters, in particular as related to measurement noise, and the need of a cutoff filter when dealing with actuator limitations, robustness to model error. The results aim to guide the user in tuning the design parameters available when creating a repetitive control system. In the second chapter, we investigate how ILC laws can be converted for use in RC to improve performance. And robustification by adding control penalty in cost function is compared to use a frequency cutoff filter. The third chapter develops a method to create desired trajectories with a zero tracking interval without involving an unstable inverse solution. An easily implementable feedback version is created to optimize the same cost every time step from the current measured position. An ILC algorithm is also created to iteratively learn to give local zero error in the real world while using an imperfect model. This approach also gives a method to apply ILC to endpoint problem without specifying an arbitrary trajectory to follow to reach the endpoint. This creates a method for ILC to apply to such problems without asking for accurate tracking of a somewhat arbitrary trajectory to accomplish learning to reach the desired endpoint. The last chapter outlines a set of uses for a stable inverse in control applications, including Linear Model Predictive Control (LMPC), and LMPC applied to Repetitive Control (RC-LMPC), and a generalized form of a one-step ahead control. An important characteristic is that this approach has the property of converging to zero tracking error in a small number of time steps, which is finite time convergence instead of asymptotic convergence as time tends to infinity.
40
Ghommam, Jawhar. "Commande Nonlinéaire et Navigation des Véhicules Marins Sous-actionnés." Phd thesis, 2008. http://tel.archives-ouvertes.fr/tel-00261791.
Full textAbstract:
Dans cette thèse nous adressons le problème de commande des véhicules marins sous-actionnés. La motivation clé de ce sujet de recherche vient du fait qui les systèmes sous-actionnés posent des défis aussi bien théoriques et pratiques pour l'ingénieur automaticien. En fait, ces systèmes ne peuvent pas être stabilisés par des commandes lisses invariantes dans le temps. De plus, en dépit du nombre de méthodes disponibles pour la commande des systèmes mécaniques sous-actionnés, peu ont adressé des points pratiques importantes tels que l'inclusion explicite de dynamique dans la formulation de problème de commande et le besoin de faire face aux perturbations environnementales résultants des courants des vagues, par exemple. Cette thèse attaque certains de ces problèmes, formule et résout les problèmes de commande de positionnement dynamique, de la poursuite de trajectoire et du suivie de chemin des véhicules marins sous-actionnés. La première partie de cette thèse (Chapitres 3 et 4) constituent les éléments théoriques fondamentaux pour l'analyse du modèle et la synthèse des commandes pour les véhicules marins sous-actionnés. Particulièrement, nous montrons au chapitre 3 que le modèle de véhicule marin sous-actionné ne satisfait pas la condition de nécessaire Brockett pour la stabilisation des systèmes nonlinéaires par actions continues et invariantes dans le temps. Cependant, Il sera montré qu'il est possible d'atteindre la stabilisation en utilisant une commande discontinue ou variable dans le temps. Le chapitre 4 consiste à appliquer des résultats récents sur les systèmes cascades nonlinéaires pour résoudre le problème de déterminer des lois de commande qui stabilisent à l'origine la position et l'orientation d vaisseau sous-actionnés. Deux transformations sont introduites pour représenter le système dans une forme de cascade. Par quelques propriétés du modèle, nous montrons en premier que la stabilisation globale et asymptotique du système se réduit a stabiliser une forme en chaîne de troisième ordre. Une approche discontinue par backstepping est ensuite employée pour la stabilisation du système de forme en chaîne via un retour d'état partiel. Nous montrons que la loi de commande proposée stabilise exponentiellement le modèle réduit dans un ensemble défini, assurant le stabilisation asymptotique, local et uniforme du modèle de vaisseau marin sous-actionné. Pour assurer la stabilité uniforme globale cependant, un backstepping et le temps combinés variant l'approche de contrôle est donc employée. Prochain, nous exploitons la structure de cascade pour construire une trajectoire convenable produite par les équations dynamiques d'un véritable sous-actionnés bateau. Nous montrons ensuite que la stabilisation globale peut être assurée par une par une combinaison de la commande par backstepping et une commande variable dans le temps. Ensuite nous abordons le problème de poursuite de trajectoire. Dans lequel la trajectoire de référence est générée par un navire sous-actionné virtuel. Nous montrons ensuite qu'il existe une commande qui force exponentiellement le navire à la poursuite de la trajectoire partant d'une condition initiale quelconque. Utilisant une approche des Systems cascades, nous montrons que la dynamique de l'erreur de poursuite peut être vue comme une cascade d'un système linéaire et d'un système en chaine de deuxième ordre. La deuxième partie de cette thèse (Chapitre 5, 6 et 7) est consacrée au problème de la manoeuvre du vaisseau sous-actionné le long d'un chemin désiré avec une dynamique prescrite. La conception de la loi de commande est abordée par deux approches. La première vient d'une observation qu'il est plausible en pratique de manoeuvrer le véhicule tel qu'il soit sur son chemin de référence est que sa vitesse totale soit tangente au chemin. Il sera aussi supposé que le véhicule voyage le long du chemin avec une vitesse directe constante. La seconde approche ne conditionne pas la vitesse directe pour être constante. Dans le Chapitre 5, nous exploitons l'approche abordée pour le suivi de chemin pour résoudre le problème de coordinations d'un groupe de véhicules marins. Il est objet de manoeuvrer le mouvement de chaque véhicule tel que le mouvement du groupe est prescrit par un comportement désiré. Ainsi, le mouvement indépendant est coordonné comme une formation selon le comportement désirée. Dans ce chapitre nous considérerons le problème de formation ou plusieurs véhicules sont synchronisés de manière qu'ils soient commandés comme une formation de structure virtuelle. Le chapitre 6, est dévouée au problème général de la commande par retour de sortie pour la stabilisation globale des véhicules marins sous-actionnés. Une application de tel observateur est ensuite faite au problème de la poursuite de trajectoire d'un vaisseau sous-actionné.
41
Kvaternik, Karla. "Globally stabilizing output feedback methods for nonlinear systems." Master's thesis, 2009. http://hdl.handle.net/10048/528.
Full textAbstract:
Thesis (M. Sc.)--University of Alberta, 2009.Title from pdf file main screen (viewed on Aug. 27, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Control, Department of Electrical and Computer Engineering, University of Alberta." Includes bibliographical references.
42
Lee, Ching Hsiang, and 李慶祥. "Output Feedback Adaptive Fuzzy-based H_infinity Tracking Control Design in Unknown Nonlinear Systems." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/95339819360687559477.
Full textAbstract:
博士國立清華大學
電機工程學系
85
An H_infinity tracking design method via adaptive fuzzy control techinique fora class of nonlinear systems is proposed to extend from state-feedback controlcase to output-feedback control case where the state variables are unavailable.The perfect matching via adaptive fuzzy logic systems is generally deemed impossible. The H_infinity adaptive fuzzy algorithm is only considered as a rough tunning. The effect of approximation error, the estimation error and external disturbance on tracking error must be attenuated to a prescribed level in order for practical control applications.A filtered-output feedback control loop is employed in this work. State transformation is introduced during the design process of the filter. Output-feedback control of nonlinear systems where the system functions f(x) and g(x) are known attracts a lot of research interest currently. It is the purpose of this work to combine the adaptive fuzzy control, the output-feedback control and the H_infinity control to solve the tracking control problem of unknown nonlinear systems when the state variables are unavailable. Four examples including the control of an inverted pedulum and the two-link robot are finally given to illustrate the performance of the proposed method. Computer simulation results confirm that the effect of both the fuzzy approximation error and external disturbance on tracking error can be attenuated efficiently by the proposed method.
43
"Multi-variable control techniques for greenhouses." Thesis, 2012. http://hdl.handle.net/10210/5421.
Full textAbstract:
M.Ing.This research project is dedicated to the automation of environmental control within greenhouses. To create an optimal climate in the greenhouse, the main environmental parameters that need to be controlled are temperature, humidity and light intensity. As a result of process dead times and the extreme interdependence of these parameters, the control problem can be classified as non-linear and multi-variable. In the past, most greenhouse environmental control systems depended on the decision making of an experienced human operator. This often gave rise to trial and error, especially when new species were established. With the current advances in "intelligent" control systems and high accuracy sensors, more and more of the decisions involved in greenhouse control can be automated. In this way more emphasis can be placed on emulating the abilities of an expert operator, by means of a computerbased automatic control system. In this research project, "intelligent" as well as "non-intelligent" control techniques, for addressing the problem of automated climate control in a greenhouse, are investigated. These include PID-control as a "non-intelligent" technique, and rule-based fuzzy logic control and self-learning fuzzy logic control as two "intelligent" control techniques. These techniques are all applied to experimental greenhouse which is equipped with management mechanisms, such as fans, heaters, sprinklers and lights. The results of the experiments are evaluated according to two performance parameters: the Control Performance Index (CPI) and the Mean Square Error (MSE). The three techniques are not only assessed for their efficiency, but also for their applicability to the greenhouse environmental problem. Each of the control techniques has a unique characteristic response to the non-linear, non-stationary, multi-variable problem of environmental control and are subsequently addressed in the respective chapter.
44
Kranz, Richard John III. "Parameter plane analysis of automatic control systems using an IBM compatible microcomputer." Thesis, 1988. http://hdl.handle.net/10945/23341.
Full textAbstract:
Approved for public release; distribution is unlimitedA group of lesser used analog control system design techniques, generally termed parameter plane methods, is examined through the use of an IBM compatible microcomputer program developed as part of this thesis. The coefficients of a system's characteristic polynomial are determined by the plant and any added compensators. As these coefficients are varied , so too are the roots of the characteristic equation and therefore the system response in terms of bandwidth, settling time, etc. In the parameter plane method, a designer selects two parameters of a system's compensator(s) . The parameters commonly represent such attributes as a compensator gain, pole, or zero but can be any linear system function. One or more system characteristics dictating desired system performance, such as relative damping or undamped natural frequency, are computer model inputs. The associated parameter values to achieve the input characteristics are output in graphical and/or tabular form.
http://archive.org/details/parameterplanean00kran
Lieutenant Commander, United States Navy
45
Holzapfel, Frank G. "Fuzzy logic control of an inverted pendulum with vision feedback." Thesis, 1994. http://hdl.handle.net/1957/35160.
Full textAbstract:
Recent technical progress has made new forms of controller
implementations on computers possible. Especially the technique of Fuzzy Logic
Control has found a growing number of applications. Also the development of fast
A/D converters has made the acquisation of data with vision based systems
possible. In this project we combine the two techniques of Fuzzy Logic Control
and Vision Feedback to control an inverted pendulum and to determine their
usefulness and limitations.
The experiment was conducted and provided us with the data necessary to
judge the performance of the new control strategy.
The gathered data support the hypothesis that it is possible to control the
inverted pendulum with Fuzzy Logic Control using Vision Feedback, though not
without limitations.Graduation date: 1995
46
Liu, Cheng-Chieh, and 劉承傑. "OUTPUT FEEDBACK TRACKING CONTROL OF UNCERTAIN NONLINEAR SYSTEMS WITH NON-SYMMETRIC DEAD-ZONE INPUT." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/08995588627313133086.
Full textAbstract:
碩士大同大學
電機工程學系(所)
99
In this thesis, an observer-based robust adaptive fuzzy control strategy is presented for uncertain nonlinear dynamical systems subject to non-symmetric dead-zone nonlinearity. Within this scheme, fuzzy logic systems are used to estimate unknown nonlinear function of the dynamic system and unknown upper bounds of unmatched uncertainties, respectively. A state observer based on state variable filters is designed to estimate all the states which are not available for measurement in the system. Moreover, the adaptive scheme requires only the information about the bounds of the dead-zone slopes. By the Lyapunov function stability theorem, the asymptotical stability of the resulting closed-loop system can be guaranteed, and the output tracking performance of the whole system can be achieved. Finally, some simulation results are introduced to verify the effectiveness of the proposed controller.
47
Liu, Yin-Tso, and 劉殷作. "ADAPTIVE FUZZY ROBUST OUTPUT TRACKING CONTROL OF PARAMETRIC STRICT-FEEDBACK NONLINEAR TIME-DELAY SYSTEMS." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/54368234540658125670.
Full textAbstract:
碩士大同大學
電機工程學系(所)
98
This thesis proposes robust time-delay dependent adaptive fuzzy control and robust time-delay independent adaptive fuzzy control schemes to deal with the tracking control problem of time delay parametric strict-feedback nonlinear systems in the presence of nonparametric uncertainties. It is well-known that the presence of perturbations is a very common problem in various kinds of engineering systems, and external disturbances are discussed in this thesis. Fuzzy logic systems and adaptive laws are applied to approximate the upper bounds of the disturbances and nonlinear functions of delay time due to complex structure of perturbations and unknown nonlinear functions. Based on Lyapunov stability theorem, the proposed control scheme not only ensures the robust stability of the overall closed-loop system but also obtains good tracking performance. Finally, a simulation example is given to illustrate the effectiveness of the proposed control scheme.
48
Tagami, Shinsuke. "A fast trajectory tracking adaptive controller for robot manipulators." Thesis, 1993. http://hdl.handle.net/1957/36095.
Full textAbstract:
An adaptive decentralized nonlinear controller for a robot manipulator
is presented in this thesis. Based on the adaptive control schemes designed
by Seraji [18], Dai [30], and Jimenez [31], we redesigned and further
simplified the control algorithm and, as a consequence, we achieved better
path tracking performance.
The proposed adaptive controller is made of a PD feedback controller
which has time varying gains, a feedforward compensator based on the idea
of inverse dynamics, and an auxiliary signal. Due to its adaptive structure,
the controller shows robustness against disturbances and unmodeled
dynamics. In order to ensure asymptotic tracking we select a Lyapunov
function such that the controller forces the negative definiteness of the time
derivative of such a Lyapunov function. To do this, the tracking position and
velocity error are penalized and used as a part of the adaptive control gain.
The main advantages of this scheme are the comparably faster
convergence of tracking error, relatively simpler structure, and smoother
control activity. This controller only requires the position and angular speed
measurement, it does not require any knowledge about the mathematical
model of the robot manipulator. Simulation shows the capacity of this
controller and its robustness against disturbances.Graduation date: 1993
49
Shih, Ming-Chieh, and 施明杰. "OUTPUT TRACKING CONTROL FOR A CLASS OF PERTURBED STRICT-FEEDBACK NONLINEAR SYSTEMS USING ROBUST ADAPTIVE FUZZY CONTROL APPROACH." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/rzzhmw.
Full textAbstract:
碩士大同大學
電機工程學系(所)
95
In this thesis, robust adaptive fuzzy control and robust adaptive fuzzy sliding mode control schemes are proposed to deal with the tracking control problem of a class of single-input single-output (SISO) nonlinear perturbed strict-feedback systems in the presence of parametric uncertainties. It is well-known that the presence of perturbations is a very common problem in various kinds of engineering systems, and these perturbations involve unmodelled dynamics, external disturbances and time variations. Because of the complexity of structure of the perturbations, the upper bounds of these perturbations are often difficult to be obtained. Therefore, within these above-mentioned approaches, fuzzy logic systems and adaptive laws are applied to approximate the upper bounds of the perturbations. By introducing Lyapunov stability theorem as well as the theory of variable structure control, the robust stability of the overall closed-loop system can be ensured, and good tracking performance can be also obtained at the same time. Finally, two simulation examples are demonstrated to confirm the effectiveness and the feasibility of the proposed control schemes.
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"Global robust output regulation for nonlinear output feedback systems and its applications." Thesis, 2010. http://library.cuhk.edu.hk/record=b6074850.
Full textAbstract:
ii) An adaptive output regulation design is proposed for the systems with ISS inverse dynamics and an uncertain exosystem. When the exosystem contains uncertain parameters, the direct approach can not be implemented any longer. To deal with this issue in the general case, by introducing an observer, we first derive an extended system composed of the plant and the observer. Then the output regulation problem of the extended system is solved. It is further shown that the unknown parameter vector of the exosystem can be exactly estimated if a controller containing a minimal internal model is employed.iii) A sufficient solvability condition of the global output regulation for the systems with iISS inverse dynamics is proposed. Since the concept of iISS is strictly weaker than the ISS one, the result allows us to handle a much larger class of nonlinear systems.
In the past ten years or so, the output regulation of the strict output feedback systems has attracted a lot of attention. In contrast with the strict output feedback systems, the output feedback systems is more general since it not only involves the nonlinearity of the system output but also the unmodeled dynamics. Therefore, the usual design method is not applicable, which motivates us to develop some new methodology for the output regulation design of the output feedback systems.
One of the motivations of the case study is to deal with the output regulation problem of a shunt-connected DC motor whose inverse dynamics is iISS but not ISS. As an illustration, a disturbance rejection problem of the shunt-connected DC motor is solved.
The application of the result leads to the solution of several interesting control problems such as the global disturbance rejection of the FitzHugh-Nagumo (FHN) system and the robust output synchronization of the generalized third and fourth-order Lorenz system and the Harmonic system.
The main results of the thesis are outlined as follows. i) A direct approach is proposed for the output regulation of the systems with ISS inverse dynamics and unknown control directions. The internal model is first designed for the control input. The output feedback control design is further achieved based on a type of partial state observer which is designed for the transformed augmented system. The Nussbaum function technique is successfully incorporated in the stabilization design to deal with the case of unknown control directions.
The nonlinear output regulation is a central control problem that involves nonlinear stabilization, tracking control and disturbance rejection as special cases. The control objective is to find a feedback controller to achieve asymptotic tracking and/or disturbance rejection while maintaining closed-loop stability. The output regulation study has experienced rapid developments in the past two decades or so. It is now well known that the problem can be systematically approached according to the general framework of tackling nonlinear output regulation that is composed of the following two steps. The first step is the problem conversion: from nonlinear output regulation to stabilization. The output regulation is generally more complicated than the stabilization problem. Therefore the problem conversion indeed reduces the complexity and makes it possible to be handled. In this step, the output regulation is converted into the stabilization of an augmented system consisting of the original plant and a suitable dynamic compensator called internal model. The second step is the stabilization of the augmented system whose solvability implies solvability of the output regulation problem.
The result is applied to solve a tracking control problem associated with the well known Lorenz system and a class of generalized fourth-order Lorenz systems. By certain system decomposition, it is proved that the Lorenz system contains certain ISS inverse dynamics and the output feedback control is successfully realized.
The thesis is concerned with the global robust output regulation for nonlinear systems in the output feedback form by using output feedback control. For the nonlinear output feedback systems, we mainly study three typical output regulation problems. The first one is the output regulation problem with unknown control directions and input-to-state stable (ISS) inverse dynamics using a direct approach. The second one is the adaptive output regulation problem with an uncertain exosystem and ISS inverse dynamics. The third one is a case study on the solvability of the systems with integral input-to-state stable (iISS) inverse dynamics.
Xu, Dabo.
Adviser: Jie Huang.
Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: .
Thesis (Ph.D.)--Chinese University of Hong Kong, 2010.
Includes bibliographical references (leaves 107-113).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.