Tesis sobre el tema "Nonlinear Control"
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Manchanda, Sunil. "Nonlinear process control". Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336269.
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Sriniwas, Ganti Ravi. "Nonlinear model predictive control". Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/10267.
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Rysdyk, Rolf T. "Adaptive nonlinear flight control". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/12108.
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Fahmy, Sherif Farid Fahmy. "Nonlinear robust H∞ control". Thesis, University of Sheffield, 2006. http://etheses.whiterose.ac.uk/14887/.
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A new theory is proposed for the full-information finite and infinite horizontime robust H∞ control that is equivalently effective for the regulation and/or tracking problems of the general class of time-varying nonlinear systems under the presence of exogenous disturbance inputs. The theory employs the sequence of linear-quadratic and time-varying approximations, that were recently introduced in the optimal control framework, to transform the nonlinear H∞ control problem into a sequence of linearquadratic robust H∞ control problems by using well-known results from the existing Riccati-based theory of the maturing classical linear robust control. The proposed method, as in the optimal control case, requires solving an approximating sequence of Riccati equations (ASRE), to find linear time-varying feedback controllers for such disturbed nonlinear systems while employing classical methods. Under very mild conditions of local Lipschitz continuity, these iterative sequences of solutions are known to converge to the unique viscosity solution of the Hamilton-lacobi-Bellman partial differential equation of the original nonlinear optimal control problem in the weak form (Cimen, 2003); and should hold for the robust control problems herein. The theory is analytically illustrated by directly applying it to some sophisticated nonlinear dynamical models of practical real-world applications. Under a r -iteration sense, such a theory gives the control engineer and designer more transparent control requirements to be incorporated a priori to fine-tune between robustness and optimality needs. It is believed, however, that the automatic state-regulation robust ASRE feedback control systems and techniques provided in this thesis yield very effective control actions in theory, in view of its computational simplicity and its validation by means of classical numerical techniques, and can straightforwardly be implemented in practice as the feedback controller is constrained to be linear with respect to its inputs.
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Nevistić, Vesna. "Constrained control of nonlinear systems". Online version, 1997. http://bibpurl.oclc.org/web/26200.
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Rutherford, Simon John. "Modelling driver nonlinear steering control". Thesis, University of Cambridge, 2007. https://www.repository.cam.ac.uk/handle/1810/252062.
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Tatlicioglu, Enver. "Control of nonlinear mechatronic systems". Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1193079994/.
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Grönberg, Fredrik. "Crowd Control of Nonlinear Systems". Thesis, KTH, Reglerteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-138438.
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We study a multi-agent system in R2 where agents have unicycle dynamics with time varying speed and control inputs corresponding to acceleration and angular velocity. The system has a dynamic communication topology based on proximity. We propose a novel decentralized control algorithm derived from a double integrator model using a pairwise potential function. By using an energy function we show that a leaderless system converges to a set where connected agents have equal direction and velocity and potential contributions to the control action cancel each other out. The concept of formation density is defined and studied by numerical simulation. We find a relation between parameters of the controller and the system that makes the system converge to a formation with low density, corresponding to agents being at appropriate distances from each other, also when agents are not restricted to communicating only with their closest neighbors. The algorithm is tested for a system with leaders and properties of this system are investigated numerically. The results confirm that the proportion of leaders needed to guide a certain proportion of the agent in average is nonlinear and decreasing with respect to the number of agents.
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Rong, Q. "Multiple-model based nonlinear control". Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412562.
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Samavat, Mohmoud. "Robust control of nonlinear systems". Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327647.
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Wlassich, John J. (John James). "Nonlinear force feedback impedance control". Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/15032.
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Bedrossian, Nazareth Sarkis. "Nonlinear control using linearizing transformations". Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/27998.
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Ashour, Osama Naim. "Nonlinear Control of Plate Vibrations". Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/26266.
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A nonlinear active vibration absorber to control the vibrations of plates is investigated. The absorber is based on the saturation phenomenon associated with dynamical systems with quadratic nonlinearities and a two-to-one internal resonance. The technique is implemented by coupling a second-order controller with the plate's response through a sensor and an actuator. Energy is exchanged between the primary structure and the controller and, near resonance, the plate's response saturates to a small value.
Numerical as well as experimental results are presented for a cantilever rectangular plate. For numerical studies, finite-element methods as well as modal analysis are implemented. The commercially available software ABAQUS is used in the finite-element analysis together with a user-provided subroutine to model the controller. For the experimental studies, the plate is excited using a dynamic shaker. Strain gages are used as sensors, while piezoelectric ceramic patches are used as actuators. The control technique is implemented using a dSPACE digital signal processing board and a modeling software (SIMULINK). Both numerical and experimental results show that the control strategy is very efficient.
A numerical study is conducted to optimize the location of the actuators on the structure to maximize its controllability. In this regard, the control gain is maximized for the PZT actuators. Furthermore, a more general method is introduced that is based on a global measure of controllability for linear systems.
Finally, the control strategy is made adaptive by incorporating an efficient frequency-measurement technique. This is validated by successfully testing the control strategy for a non-conventional problem, where nonlinear effects hinder the application of the non-adaptive controller.Ph. D.
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Niemoczynski, Bogdan. "Nonlinear Control of Magnetic Signatures". Master's thesis, Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/360321.
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Electrical EngineeringM.S.E.E.
Magnetic properties of ferrite structures are known to cause fluctuations in Earth's magnetic field around the object. These fluctuations are known as the object's magnetic signature and are unique based on the object's geometry and material. It is a common practice to neutralize magnetic signatures periodically after certain time intervals, however there is a growing interest to develop real time degaussing systems for various applications. Development of real time degaussing system is a challenging problem because of magnetic hysteresis and difficulties in measurement or estimation of near-field flux data. The goal of this research is to develop a real time feedback control system that can be used to minimize magnetic signatures for ferrite structures. Experimental work on controlling the magnetic signature of a cylindrical steel shell structure with a magnetic disturbance provided evidence that the control process substantially increased the interior magnetic flux. This means near field estimation using interior sensor data is likely to be inaccurate. Follow up numerical work for rectangular and cylindrical cross sections investigated variations in shell wall flux density under a variety of ambient excitation and applied disturbances. Results showed magnetic disturbances could corrupt interior sensor data and magnetic shielding due to the shell walls makes the interior very sensitive to noise. The magnetic flux inside the shell wall showed little variation due to inner disturbances and its high base value makes it less susceptible to noise. This research proceeds to describe a nonlinear controller to use the shell wall data as an input. A nonlinear plant model of magnetics is developed using a constant to represent domain rotation lag and a gain function to describe the magnetic hysteresis curve for the shell wall. The model is justified by producing hysteresis curves for multiple materials, matching experimental data using a particle swarm algorithm, and observing frequency effects. The plant model is used in a feedback controller and simulated for different materials as a proof of concept.
Temple University--Theses
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Abbaspour, Ali Reza. "Active Fault-Tolerant Control Design for Nonlinear Systems". FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3917.
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Faults and failures in system components are the two main reasons for the instability and the degradation in control performance. In recent decades, fault-tolerant control (FTC) approaches were introduced to improve the resiliency of the control system against faults and failures. In general, FTC techniques are classified into two major groups: passive and active. Passive FTC systems do not rely on the fault information to control the system and are closely related to the robust control techniques while an active FTC system performs based on the information received from the fault detection and isolation (FDI) system, and the fault problem will be tackled more intelligently without affecting other parts of the system.
This dissertation technically reviews fault and failure causes in control systems and finds solutions to compensate for their effects. Recent achievements in FDI approaches, and active and passive FTC designs are investigated. Thorough comparisons of several different aspects are conducted to understand the advantages and disadvantages of different FTC techniques to motivate researchers to further developing FTC, and FDI approaches.
Then, a novel active FTC system framework based on online FDI is presented which has significant advantages in comparison with other state of the art FTC strategies. To design the proposed active FTC, a new FDI approach is introduced which uses the artificial neural network (ANN) and a model based observer to detect and isolate faults and failures in sensors and actuators. In addition, the extended Kalman filter (EKF) is introduced to tune ANN weights and improve the ANN performance. Then, the FDI signal combined with a nonlinear dynamic inversion (NDI) technique is used to compensate for the faults in the actuators and sensors of a nonlinear system. The proposed scheme detects and accommodates faults in the actuators and sensors of the system in real-time without the need of controller reconfiguration.
The proposed active FTC approach is used to design a control system for three different applications: Unmanned aerial vehicle (UAV), load frequency control system, and proton exchange membrane fuel cell (PEMFC) system. The performance of the designed controllers are investigated through numerical simulations by comparison with conventional control approaches, and their advantages are demonstrated.
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Ali, Imran. "Spacecraft nonlinear attitude control with bounded control input". Thesis, University of Glasgow, 2010. http://theses.gla.ac.uk/1717/.
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The research in this thesis deals with nonlinear control of spacecraft attitude stabilization and tracking manoeuvres and addresses the issue of control toque saturation on a priori basis. The cascaded structure of spacecraft attitude kinematics and dynamics makes the method of integrator backstepping preferred scheme for the spacecraft nonlinear attitude control. However, the conventional backstepping control design method may result in excessive control torque beyond the saturation bound of the actuators. While remaining within the framework of conventional backstepping control design, the present work proposes the formulation of analytical bounds for the control torque components as functions of the initial attitude and angular velocity errors and the gains involved in the control design procedure. The said analytical bounds have been shown to be useful for tuning the gains in a way that the guaranteed maximum torque upper bound lies within the capability of the actuator and, hence, addressing the issue of control input saturation. Conditions have also been developed as well as the generalization of the said analytical bounds which allow for the tuning of the control gains to guarantee prescribed stability with the additional aim that the control action avoids reaching saturation while anticipating the presence of bounded external disturbance torque and uncertainties in the spacecraft moments of inertia. Moreover, the work has also been extended blending it with the artificial potential function method for achieving autonomous capability of avoiding pointing constraints for the case of spacecraft large angle slew manoeuvres. The idea of undergoing such manoeuvres using control moment gyros to track commanded angular momentum rather than a torque command has also been studied. In this context, a gimbal position command generation algorithm has been proposed for a pyramid-type cluster of four single gimbal control moment gyros. The proposed algorithm not only avoids the saturation of the angular momentum input from the control moment gyro cluster but also exploits its maximum value deliverable by the cluster along the direction of the commanded angular momentum for the major part of the manoeuvre. In this way, it results in rapid spacecraft slew manoeuvres. The ideas proposed in the thesis have also been validated using numerical simulations and compared with results already existing in the literature.
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Savvidis, Petros. "Nonlinear control : an LPV nonlinear predictive generalised minimum variance perspective". Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27947.
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This thesis describes new developments in nonlinear controllers for industrial applications. It first introduces the Nonlinear Generalised Minimum Variance (NGMV) control algorithm, for Linear Parameter Varying systems (LPV). This combines the benefits of the basic NGMV algorithm in dealing with nonlinearities, where a black box input model can be used, and adds an option to also approximate a nonlinear system with an LPV output subsystem. The models can therefore represent LPV systems and characteristics including saturation, discontinuities and time-varying dynamics. The next major contribution is in the nonlinear predictive control algorithms proposed that are also using the LPV model structure. The simplest is the Nonlinear Generalized Predictive Control (NGPC) algorithm that relates to the best known model predictive control law for linear systems. The final predictive control solution is one that may be specialized to either the NGMV or NGPC cases and is therefore the most general. This is referred to as a Nonlinear Predictive Generalized Minimum Variance Controller (NPGMV). When the algorithms use only the LPV structure to approximate the nonlinear system the solutions are particularly simple in unconstrained and constrained versions, and are relatively light computationally for implementation. Three representative industrial design examples have been chosen to validate the algorithms for different Bandwidth (BW) and nonlinear characteristics. All three examples were based on real application problems with company interest. In the first example (small BW) the basic state-space and LPV versions of the algorithm are used for the auto-manoeuvring and dynamic positioning of marine vessel. In this application the parameter variations were representative of wave disturbance changes with sea state, rather than due to approximating nonlinear behaviour. Actuator constraints were considered in the design. In the second industrial example (medium BW) the LPV-NPGMV was implemented for controlling the blade pitch and generator torque of a 5MW offshore wind turbine. The main objective here was to maintain the power produced at the rated value which requires compensation against wind disturbances, so that wind speed is the varying parameter. The LPV-NPGMV controller produced here used a parameterised system model involving the wind speed so that the controller performance changed with wind conditions. Actuator constraints were included and statistical performance assessed. The third example (fast BW) explores the stabilisation of a 2-axis gyroscopic electro-optical turret used in surveillance applications. This application was designed and employed on a real system. Because of the limitations imposed by BW requirements and the memory of the digital controller, only the basic state-space version of the algorithm was possible to implement. The main objective in this problem was to improve the tracking performance around the NADIR singularity point (a discontinuity) in the trajectory. In all three examples the NGMV controllers showed notable improvement in comparison to the baseline controllers without the need for scheduled gains or re-configuration when moving across different operating points.
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Pimentel, Guilherme Araujo. "Nonlinear Modeling, Identification and Control of Membrane Bioreactors". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS219/document.
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Cette thèse propose un modèle dynamique d'un bioréacteur à membrane submergée (sMBR) comprenant les comportements physiques et biologiques du processus. La filtration (aspect physique) est un modèle de résistances en série composé de la résistance réversible (liée au processus de formation d'un gâteau qui peut être enlevé par lavage de l'air) et de la résistance à colmatage irréversible. La fonction biologique est mise en œuvre par l'extension du modèle de chemostat simple avec un mécanisme de filtration.L'analyse du modèle comprend : l'analyse asymptotique, l'observabilité, la contrôlabilité et l'étude dynamique lente et rapide. Cette dernière, basée sur le théorème de Tikhonov, révèle la possibilité de simplifier la dynamique du modèle en découplant le processus en trois échelles de temps : l'évolution du colmatage à long terme (dynamique lente), la dégradation biologique ( dynamique rapide) et la formation du gâteau (dynamique ultrarapide). Comme les processus avec sMBRs sont relativement nouveaux, les données réelles de processus sont difficiles à obtenir. Ainsi, une installation pilote d'un système de recirculation de l'aquaculture avec une sMBR est conçue, construite et automatisée. Des mesures en ligne du processus, tels que la température, les matières en suspension (MES), l'ammoniac et les concentrations des effluents nitrates, la croisée de l'air et des débits d'effluents et la pression transmembranaire, sont réunis afin de valider le modèle proposé.Pour mettre en évidence le cadre général du modèle proposé, le même modèle est composé d'ensembles de données réelles obtenues à partir d'une installation de traitement des eaux usées à sMBR. Par conséquent, une identification de paramètre est organisée en trois étapes correspondant aux trois échelles de temps obtenues à partir de l'analyse analytique. L'identification de paramètre est implémentée en utilisant une fonction de coût aux moindres carrés pondérés et l'inverse de la Fisher Matrix Information (FIM), qui est utilisé pour obtenir les intervalles de confiance des paramètres calculées par une borne inférieure sur la matrice de covariance des estimations des paramètres. La capacité du modèle à prédire la pression transmembranaire et la dégradation biologique est prouvée par la validation du modèle et la validation croisée des résultats.Concernant le contrôle du processus, deux approches différentes sont utilisées : un contrôleur partielle linéaire basé sur la théorie de Lyapunov est conçu afin de stabiliser la production encrassement en actionnant dans la croisée de l'air et les flux d'effluents; une commande prédictive de modèle non linéaire (NMPC) est mise en œuvre afin d'optimiser le taux de production d'effluent et de maximiser la période entre deux opérations de lessivage chimique.Les résultats présentés dans cette thèse montrent l'importance des études analytiques sur des modèles afin de traiter la cognition et la simplification de modèle. Un autre point important est la structure du modèle dynamique simple avec une petite quantité de paramètres. Ce travail montre que cette structure est suffisante pour mettre en œuvre des stratégies de contrôle avancé sur les processus sMBR et même de prédire la dégradation biologique et la dynamique de croissance du colmatageThis thesis proposes a simple submerge membrane bioreactor (sMBR) dynamic model that comprises physical and biological process behaviors. The filtration, physical aspect, is a resistance-in-series model that is composed with reversible resistance, linked to sludge cake formation process that can be detached by air scouring, and the irreversible fouling resistance. The biological feature is implemented extending the simple chemostat model to the filtration mechanism. The model asymptotic analysis, observability, controllability and fast and slow dynamic study are carried out. The latter, based on the Tikhonov's theorem, reveals the possibility to simplify model dynamics by decoupling the process in three time scales, i.e. long-term fouling evolution (slow dynamic), biological degradation (fast dynamic) and fouling cake formation (ultrafast dynamic). As sMBR processes are relativity new, real process data are scarce. Thus, a recirculating aquaculture system pilot plant with an sMBR is design, build and automated. Process online measurements such as: temperature, total suspended solids (TSS), ammonia and nitrate effluent concentrations, air cross- and effluent flow rates and trans-membrane pressure are gathered in other to validate the proposed model. To evidence the model general framework the same model is confronted with real data sets obtained from an sMBR wastewater treatment plant. Therefore, a parameter identification is organized in three steps corresponding to the three time scales obtained from the analytical analysis. The parameter identification is implemented using a weighted least-squares cost function and the inverse of the Fisher Information Matrix (FIM), which is used to obtain the parameters confidence intervals, is computed by a lower bound on the covariance matrix of the parameter estimates. The model capacity to predict trans-membrane pressure and biological degradation is proved by model validation and cross-validation results, in which an accurate correlation coefficients (R^2) of approximately 0.83 are obtained. Concerning the process control, two different approach are used: a partial-linearizing feedback Lyapunov controller is designed in order to stabilize the fouling production by actuating in the air cross- and effluent flows; and a nonlinear model predictive control (NMPC) is implemented in other to optimize the effluent production rate and maximize the period between two chemical cleaning procedures. The results included in this thesis show the importance of analytical model studies in order to process cognition and model simplification. Another important point is the simple dynamic model structure, with a small quantity of the parameters, which is adequate to implement advanced control strategies on sMBR processes and, similarly, to predict biological degradation and fouling build-up dynamics
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Cheung, Wan Sup. "Identification, stabilisation and control of nonlinear systems using neural network-based parametric nonlinear modelling". Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333732.
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Li, Liangmin. "Continuous time nonlinear system identification". Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341867.
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Wellman, Brandon. "Root Locus Techniques With Nonlinear Gain Parameterization". UKnowledge, 2012. http://uknowledge.uky.edu/me_etds/21.
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This thesis presents rules that characterize the root locus for polynomials that are nonlinear in the root-locus parameter k. Classical root locus applies to polynomials that are affine in k. In contrast, this thesis considers polynomials that are quadratic or cubic in k. In particular, we focus on constructing the root locus for linear feedback control systems, where the closed-loop denominator polynomial is quadratic or cubic in k. First, we present quadratic root-locus rules for a controller class that yields a closed-loop denominator polynomial that is quadratic in k. Next, we develop cubic root-locus rules for a controller class that yields a closed-loop denominator polynomial that is cubic in k. Finally, we extend the quadratic root-locus rules to accommodate a larger class of controllers. We also provide controller design examples to demonstrate the quadratic and cubic root locus. For example, we show that the triple integrator can be high-gain stabilized using a controller that yields a closed-loop denominator polynomial that is quadratic in k. Similarly, we show that the quadruple integrator can be high-gain stabilized using a controller that yields a closed-loop denominator polynomial that is cubic in k.
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Zhang, Guoming. "Model reference control for nonlinear plants". Thesis, University of Manchester, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314208.
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Noiey, A. Ranjbar. "Sensorless nonlinear control of asynchronous machines". Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/844099/.
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An alternative to the existing technique of controlling induction machines - vector control - was investigated. In the new technique, sensorless nonlinear control, the mathematical model of the machine was transformed to a linear form and those states which were not measured (sensed) were reconstructed. It was shown possible to maintain stability despite the errors which the use of observers introduces into the control loop. The investigation is founded primarily on a study of the theory. Demonstration of the proposed scheme has been done mainly by means of simulation. The stability of the computer code for simulation was verified by a study of the stiffness and modes (eigenvalues) of the overall system. Furthermore, modifications to the simulation such as the introduction of noise, were made to increase its validity. The main findings were as follows: 1. In the new technique the decoupling of the speed (torque) and flux control is perfect. 2. The linearised model separates into two subsystems, one mechanical and one electromagnetic. 3. The control scheme is robust against disturbances (step change of load). 4. An asymptotic observer can successfully reconstruct both flux and speed states when the whole system is under the linearisation approach. Therefore sensorless nonlinear control is made possible and effective. 5. By selecting initial value(s) for the estimated state(s) close to the command(s) the transient demand on the power supply is reduced. Thus it may be possible to use smaller and cheaper power converters in a drive system. 6. This technique is also able to counteract some of the model uncertainties resulting from temperature variations. The significance of these findings is as follows: 1. Maximum torque and efficiency are achievable only by the new technique. In contrast, in field-weakening under vector control a near optimum is achievable only at the price of degrading the transient behaviour. 2. Direct measurement of flux and speed is avoided, which has, in practice economic benefit. 3. Although the proposed control technique is more complex than field-oriented control, its stability has been analytically proven and, in addition, the rate of convergence (for both the control and the estimator) is adjustable. 4. A sensitivity investigation shows the robustness of the proposed method when the most critical parameter i.e. the rotor resistance, varies slightly from its nominal value. 5. The simulation approach was developed to the point where it was believed possible to investigate the capability of the proposed technique and to identify potential practical problems with the nonlinear control strategy. Moreover the same code can easily be modified for compiling into a microprocessor, so allowing easy implementation of the scheme. 6.The proposed control is easily implementable in commercial drives due to the modest voltage and current demand, even in the initial transient.
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Ashman, J. A. "Adaptive control of uncertain nonlinear systems". Thesis, University of Bath, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260256.
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Tshemese, Nomzamo. "Design and PLC implementation of nonlinear PID cControllers for control of nonlinear processes". Thesis, Cape Peninsula University of Technology, 2014. http://hdl.handle.net/20.500.11838/1180.
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Thesis submitted in fulfillment of the requirements for the degree
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2014A new control strategy for control of the nonlinear process of Dissolved Oxygen (DO) concentration in the aerobic tank of wastewater treatment process is proposed. It provides means to improve the performance of the Linear Proportional Integration and Derivative (LPID) controller by extending it to a Nonlinear Proportional Integration and Derivative (NLPID) controller. The aim of the thesis is to develop methods, algorithms and software for design, simulation, and programmable logic controller (PLC) implementation of NLPID controllers in order to control the nonlinear process of dissolved oxygen. The thesis investigates the possibilities the widely used in theory and industry methods for the design of the LPID controllers for linear processes as Ziegler- Nichols and Pole Placement, to be applied to the design of NLPID controllers for the nonlinear process of DO concentration. Three cases are considered: Case 1: Application of the values of the parameters the linear PID controller designed by the Ziegler-Niched method for the linearized DO process model to be used as parameters of the nonlinear PID controllers to control the DO nonlinear process. Case 2: Application of the values of the parameters of the linear PID controller designed by the Pole placement method for the linearized DO process model, to be used as parameters of the nonlinear PID controller to control the nonlinear DO process. Case 3: Novel, proposed in the thesis, method based on the Pole placement method for direct design of the parameters of the linear and nonlinear PID controllers to control the nonlinear DO process. Software is developed to simulate in MATLAB environment the behavior of the closed loop DO process for the considered cases of controller designs. The results of the simulations show that in the Case1 and the Case 2 it is not possible to use the values of the LPID controller parameters designed for the linearized DO process, directly to control the nonlinear process by the NPID controllers. Additional tuning for some of the parameters is needed. The simulation in the Case 3 shows the excellent behaviors of the closed loop system for all linear and nonlinear PID controllers which prove that the new method is effective and applicable. Real-time simulations of the closed loop system are done in a TwinCAT 3 simulation environment of the Bechkoff EX5020 PLC. The deliverables of the thesis are applicable to many type nonlinear processes in chemical, manufacturing, and other industries.
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Tjønnås, Johannes. "Nonlinear and Adaptive Dynamic Control Allocation". Doctoral thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-2320.
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This work addresses the control allocation problem for a nonlinear over-actuated time-varying system where parameters a¢ ne in the actuator dynamics and actuator force model may be assumed unknown. Instead of optimizing the control allocation at each time instant, a dynamic approach is considered by constructing update-laws that represent asymptotically optimal allocation search and adaptation. A previous result on uniform global asymptotic stability (UGAS) of the equilibrium of cascaded time-varying systems, is in the thesis shown to also hold for closed (not necessarily compact) sets composed by set-stable subsystems of a cascade. In view of this result, the optimal control allocation approach is studied by using Lyapunov analysis for cascaded set-stable systems, and uniform global/local asymptotic stability is guaranteed for the sets described by; the system dynamics, the optimizing allocation update-law and the adaptive update-law.
The performance of the proposed control allocation scheme is demon- strated throughout the thesis by simulations of a scaled-model ship manoeuvred at low-speed. Furthermore, the application of a yaw stabilization scheme for an automotive vehicle is presented. The stabilization strategy consists of; a high level module that deals with the vehicle motion control objective (yaw rate reference generation and tracking), a low level module that handles the braking control for each wheel (longitudinal slip control and maximal tyre road friction parameter estimation) and an intermediate level dynamic control allocation module. The control allocation module generates longitudinal slip reference for the low level brake controller and commands front wheel steering angle corrections, such that the actual torque about the yaw axis tends to the desired torque calculated by the high level module. The conditions for uniform asymptotic stability are given and the scheme has been implemented in a realistic nonlinear multi-body vehicle simulation environment. The simulation cases show that the control strategy stabilizes the vehicle in extreme manoeuvres where the nonlinear vehicle yaw dynamics otherwise become unstable in the sense of over- or understeering.
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Karagiannis, Dimitrios. "Nonlinear adaptive control design with applications". Thesis, Imperial College London, 2005. http://hdl.handle.net/10044/1/8320.
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Ali, Shaaban Aerospace Civil & Mechanical Engineering Australian Defence Force Academy UNSW. "Intelligent adaptive control for nonlinear applications". Awarded by:University of New South Wales - Australian Defence Force Academy, 2008. http://handle.unsw.edu.au/1959.4/39185.
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The thesis deals with the design and implementation of an Adaptive Flight Control technique for Unmanned Aerial Vehicles (UAVs). The application of UAVs has been increasing exponentially in the last decade both in Military and Civilian fronts. These UAVs fly at very low speeds and Reynolds numbers, have nonlinear coupling, and tend to exhibit time varying characteristics. In addition, due to the variety of missions, they fly in uncertain environments exposing themselves to unpredictable external disturbances. The successful completion of the UAV missions is largely dependent on the accuracy of the control provided by the flight controllers. Thus there is a necessity for accurate and robust flight controllers. These controllers should be able to adapt to the changes in the dynamics due to internal and external changes. From the available literature, it is known that, one of the better suited adaptive controllers is the model based controller. The design and implementation of model based adaptive controller is discussed in the thesis. A critical issue in the design and application of model based control is the online identification of the UAV dynamics from the available sensors using the onboard processing capability. For this, proper instrumentation in terms of sensors and avionics for two platforms developed at UNSW@ADFA is discussed. Using the flight data from the remotely flown platforms, state space identification and fuzzy identification are developed to mimic the UAV dynamics. Real time validations using Hardware in Loop (HIL) simulations show that both the methods are feasible for control. A finer comparison showed that the accuracy of identification using fuzzy systems is better than the state space technique. The flight tests with real time online identification confirmed the feasibility of fuzzy identification for intelligent control. Hence two adaptive controllers based on the fuzzy identification are developed. The first adaptive controller is a hybrid indirect adaptive controller that utilises the model sensitivity in addition to output error for adaptation. The feedback of the model sensitivity function to adapt the parameters of the controller is shown to have beneficial effects, both in terms of convergence and accuracy. HIL simulations applied to the control of roll stabilised pitch autopilot for a typical UAV demonstrate the improvements compared to the direct adaptive controller. Next a novel fuzzy model based inversion controller is presented. The analytical approximate inversion proposed in this thesis does not increase the computational effort. The comparisons of this controller with other controller for a benchmark problem are presented using numerical simulations. The results bring out the superiority of this technique over other techniques. The extension of the analytical inversion based controller for multiple input multiple output problem is presented for the design of roll stabilised pitch autopilot for a UAV. The results of the HIL simulations are discussed for a typical UAV. Finally, flight test results for angle of attack control of one of the UAV platforms at UNSW@ADFA are presented. The flight test results show that the adaptive controller is capable of controlling the UAV suitably in a real environment, demonstrating its robustness characteristics.
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Lemch, Ekaterina S. "Nonlinear and hierarchical hybrid control systems". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0032/NQ64600.pdf.
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Maalouf, Elie. "Nonlinear control of wheeled mobile robots". Mémoire, Montréal : École de technologie supérieure, 2005. http://wwwlib.umi.com/cr/etsmtl/fullcit?pMR06031.
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Thèse (M. Ing.)--École de technologie supérieure, Montréal, 2005."Thesis presented to École de technologie supérieure as a partial requirement to obtain a masters in electrical engineering". Bibliogr.: f. [140]-142. Également disponible en version électronique.
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Nath, Nitendra. "Nonlinear control techniques for robot manipulators". Connect to this title online, 2006. http://etd.lib.clemson.edu/documents/1173994815/.
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Kim, Byoung Soo. "Nonlinear flight control using neural networks". Diss., Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/12242.
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Chryssochoos, Ioannis. "Optimization based control of nonlinear systems". Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399165.
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Zhu, Quan Min. "Identification & control of nonlinear systems". Thesis, University of Warwick, 1989. http://wrap.warwick.ac.uk/62723/.
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This thesis investigates some problems on nonlinear system identification, parameter estimation, and signal processing. Random signal spectral analysis and system frequency response estimation are studied from incomplete time series. Both recursive and direct estimators are presented based on either an unbiased or minimum mean square error criterion. Nonlinear system identification and parameter estimation are studied. A quantisation technique is developed to give a clear geometrical interpretation for structure detection and parameter estimation. A new concept, state amplitude distance between current and previous operating states, is introduced, and results in a Variable Weighted Least Squares (VWLS) algorithm. A modified version makes on-line application possible. Jump resonance is predicted by the VWLS algorithm as one of the applications. Self-tuning controllers, including a nonlinear general predictive controller and a nonlinear deadbeat controller, are designed. A vector backward shift operator is defined to simplify the expression of the Hammerstein model, and is introduced to analyse the general feedback controller design problem for nonlinear plant described by the Hammerstein model. A fast root-solver developed facilitates nonlinear model treatment in on-line applications. Theoretical results are confirmed by simulation studies.
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Youssef, Ahmed Medhat Mohamed. "Nonlinear predictive flight control system design". Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401502.
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Bekit, Biniam Weldai. "Robust nonlinear control of robot manipulators". Thesis, King's College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321945.
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Alrashidi, Azizah. "Nonlinear control for non-Newtonian flows". Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5777/.
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PDE-constrained optimization is an important area in the field of numerical analysis, with problems arising in a wide variety of applications including optimal design, optimal control and parameter estimation. The aim of such problems is to minimize a functional J(u,d) whilst adhering to constraints posed by a system of partial differential equations (PDE), with u and d used respectively to denote the state and control of the system. In this thesis, we describe the steady-state generalized Stokes equations for incompressible fluids. We proceed to derive the weak formulation of the problem, and show that the resulting system may be written in terms of a mixed formulation of the Stokes problem. Based on this formulation, the problem is discretized through use of the Galerkin finite element method, before investigating control problems based on the generalized Stokes equations, along with numerical experimentation. This work will be used to achieve the main aim of this thesis, namely the exploration and investigation of solution methods for optimal control problems constrained by non- Newtonian flow. Ultimately, an iterative solution method designed for such problems coupled with an appropriate preconditioning strategy will be described and analyzed, and used to produce effective numerical results.
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Sanders, Seth Robert. "Nonlinear control of switching power converters". Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14426.
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Gao, Yang. "Adaptive fuzzy control of nonlinear systems". Mémoire, Université de Sherbrooke, 2006. http://savoirs.usherbrooke.ca/handle/11143/1335.
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Fuzzy logic provides human reasoning capabilities to capture uncertainties that cannot be described by precise mathematical models. An adaptive fuzzy system is a fuzzy logic system equipped with a learning algorithm. A"learning system" possesses the capability to improve its performance over time by interacting with its environment, so an adaptive control system has the ability to improve the performance of the closed-loop system by generating command inputs to the plant and utilizing feedback information from the plant. This thesis proposes a fast approach for system modeling by neuro-fuzzy networks (NFNs), which can successfully model the nonlinear system dynamics and its uncertainties. This algorithm can construct a system model by NFN, i.e., fuzzy rules can be generated automatically in the learning process from training data without partitioning the input space and selecting initial parameters a priori. This thesis presents an adaptive fuzzy control method of nonlinear systems using the NFN controller, which can be constructed by the fast learning algorithm proposed in this thesis. In simulation studies, an inverted pendulum system can track the desired trajectory very well and the control system has good robustness to disturbances using the adaptive control method proposed. The inverted pendulum is controlled by the proposed adaptive fuzzy control method, classical PID control method and nonadaptive fuzzy control method respectively; the control results show that the adaptive fuzzy control system has the best performances among the three control systems in terms of transient and steady-state results.
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Gilbert, James Michael. "Nonlinear control of an industrial robot". Thesis, University of Hull, 1989. http://hydra.hull.ac.uk/resources/hull:11077.
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The precise control of a robot manipulator travelling at high speed constitutes a major research challenge. This is due to the nonlinear nature of the dynamics of the arm which make many traditional, linear control methodologies inappropriate. An alternative approach is to adopt controllers which are themselves nonlinear. Variable structure control systems provide the possibility of imposing dynamic characteristics upon a poorly modelled and time varying system by means of a discontinuous control signal. The basic algorithm overcomes some nonlinear effects but is sensitive to Coulomb friction andactuator saturation. By augmenting this controller with compensation terms, these effects may largely be eliminated. In order to investigate these ideas, a number of variable structure control systems ~re applied to a low cost industrial robot having a highly nonlinear and flexible drive system. By a combination of hardware enhancements and control system developments, an improvement in speed by a factor of approximately three was achieved while the trajectory tracking accuracy was improved by a factor of ten, compared with the manufacturer's control system. In order to achieve these improvements, it was necessary to develop a dynamic model of the arm including the effects of drive system flexibility and nonlinearities. The development of this model is reported in this thesis, as is work carried out on a comparison of numerical algorithms for the solution of differential equations with discontinuous right hand sides, required in the computer aided design of variable structure control systems.
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Sangelaji, Zahra. "Angular representations of nonlinear control systems". Thesis, University of Sheffield, 2005. http://etheses.whiterose.ac.uk/14880/.
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The aim of this thesis is to examine and extend the angular approach, which is a new approach for designing control and analysis of nonlinear systems. In this approach, the system is converted into two subsystems. One subsystem, the so-called spherical subsystem, is defined on a sphere, whilst the other subsystem, the radial subsystem, is one dimensional. A suitable control is designed using the radial subsystem. Various new methods are presented for the stabilisation and control design of a general class of nonlinear systems, based upon the angular approach. The advantage of this approach is that the stabilisation and control design problem of a nonlinear system is replaced by a one-dimensional control design and stabilisation problem. In addition, the control design using the angular approach is a straightforward, systematic method which is applicable to a wide class of nonlinear systems with and without uncertainty. Whenever the input map of the radial subsystem is zero, the radial control is not accessible and the control should be modified such that the defined control is accessible everywhere within the entire operating region. Several methods are considered for modifying the radial control including dynamical radial method. An adaptive angular method is also proposed to design an angular control for stabilisation of a nonlinear system with unknown parameters. The optimal control of nonlinear systems based upon the associated angular approach is also studied in this thesis. After decoupling the two associated (radial and spherical) subsystems and considering only the radial system, a finite-horizon radial optimal control is designed which minimises the appropriate radial cost function. Then the successive approximation technique is introduced in which the equations are replaced by a sequence of linear, time-varying approximations. The resulting optimal control is then applied to the original angular system. This control forces the original angular system to an equilibrium point. In addition, the control design and stabilisation problem for multi-input nonlinear systems using the angular approach is also studied.
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Bando, Mai. "Nonlinear Adaptive Control and Its Applications". 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/57268.
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This thesis is concerned with the adaptive control theory and its applications to the autonomous flight control system of unmanned aerial vehicle. First we propose a adaptive control system based on multiple module architecture and new learning algorithm based on Lyapunov design methods that is applicable in practical problems are proposed. We examine the performance of the proposed method both in simulations and experiments. It is shown that multiple modules are successfully trained and specialized for different domains in the state space in a cooperative way. Furthermore, the control system which consists of several online modules is applied to the autonomous flight control system of aero-robot, and we evaluate our method by flight experiments. Second, the output regulation problem for linear time-invariant systems with unknown parameters is considered. Based on the Lyapunov stability theory, a stabilizing adaptive controller is derived. It is shown that an adaptive controller can be designed using the solution of the parameter dependent Riccati equation if the derivative of the solution is sufficiently small. Then sufficient conditions for the output regulation problem with full information to be solvable are established. Furthermore, the condition on the solution of the Riccati equation imposed above is relaxed. Finally, adaptive output regulation for nonlinear systems described by multiple linear models with unknown parameters is considered. We design a local stabilizing controller for affine nonlinear system using the solution of the state dependent Riccati equation and local output regulation is established using a state dependent regulator equation. Then locally stabilizing adaptive state-feedback controllers for nonlinear systems described by multiple linear models with unknown parameters are designed based on the Lyapunov stability theory. Local adaptive output regulation is also established using a state dependent regulator equation. We extend our method to output feedback control. The adaptive laws are derived from Lyapunov stability analysis which guarantees that observer error and parameter estimation error are bounded provided that the state and the control are bounded. Simulation results are given to illustrate the theory.Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第13819号
工博第2923号
新制||工||1432(附属図書館)
26035
UT51-2008-C735
京都大学大学院工学研究科航空宇宙工学専攻
(主査)教授 市川 朗, 教授 椹木 哲夫, 教授 松久 寛
学位規則第4条第1項該当
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Chudoung, Jerawan. "Robust Control for Hybrid, Nonlinear Systems". Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/26983.
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We develop the robust control theories of stopping-time nonlinear systems and switching-control nonlinear systems. We formulate a robust optimal stopping-time control problem for a state-space nonlinear system and give the connection between various notions of lower value function for the associated game (and storage function for the associated dissipative system) with solutions of the appropriate variational inequality (VI). We show that the stopping-time rule can be obtained by solving the VI in the viscosity sense. It also happens that a positive definite supersolution of the VI can be used for stability analysis. We also show how to solve the VI for some prototype examples with one-dimensional state space.
For the robust optimal switching-control problem, we establish the Dynamic Programming Principle (DPP) for the lower value function of the associated game and employ it to derive the appropriate system of quasivariational inequalities (SQVI) for the lower value vector function. Moreover we formulate the problem in the L2-gain/dissipative system framework. We show that, under appropriate assumptions, continuous switching-storage (vector) functions are characterized as viscosity supersolutions of the SQVI, and that the minimal such storage function is equal to the lower value function for the game. We show that the control strategy achieving the dissipative inequality is obtained by solving the SQVI in the viscosity sense; in fact this solution is also used to address stability analysis of the switching system. In addition we prove the comparison principle between a viscosity subsolution and a viscosity supersolution of the SQVI satisfying a boundary condition and use it to give an alternative derivation of the characterization of the lower value function. Finally we solve the SQVI for a simple one-dimensional example by a direct geometric construction.Ph. D.
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Siller-Alcalá, Irma Irasema. "Nonlinear continuous-time generalised predictive control". Thesis, University of Glasgow, 1998. http://theses.gla.ac.uk/2090/.
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The development of the nonlinear version of the Continuous-time Generalised Predictive Control (NCGPC) is presented. Unlike the linear version, the nonlinear version is developed in state-space form and shown to include Nonlinear Generalised Minimum Variance (NGMV), and a new algorithm, Nonlinear Predictive Generalised Minimum Variance (NPGMV), as special cases. Through simulations, it is demonstrated that NCGPC can deal with nonlinear systems whose relative degree is not well defined and nonlinear systems with unstable zero dynamics. Geometric approaches, such as exact linearisation, are shown to be included in the NCGPC as special cases.
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Zhu, Jinghao. "Some results on nonlinear optimal control". Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-10042006-143910/.
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Vela, Patricio Antonio Burdick Joel Wakeman. "Averaging and control of nonlinear systems /". Diss., Pasadena, Calif. : California Institute of Technology, 2003. http://resolver.caltech.edu/CaltechETD:etd-05282003-094253.
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Seki, Hiroya. "Feedback Control of Nonlinear Chemical Reactors". 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149439.
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Shwan, Kurdi Mir. "Nonlinear Attitude Control ofa Generic Aircraft". Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261696.
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Determining suitable controllers for the process of evaluating dynamic per-formance of multiple versions of an aircraft’s aerodynamical, geometric and propulsive properties in its conceptual stage is an expensive task.In this report a proposition is made to utilize a generalized feedback lin-earizing controller that o˙ers the aircraft designer valuable insight into the manoeuvre performance of their aircraft. This is carried out by first estab-lishing fundamental requirements for a controller capable of treating a generic airframe, and formulating the resulting control laws.It is shown in this report, that with a suÿciently simple aerodynamic and propulsive model explicit feedback linearization is possible with satisfactory performance and robustness. Whereas it would be necessary to implement INDI if explicit inverse mappings are not obtainable. Which in turn would introduce additional tuning parameters.Robustness verification is performed in two stages, firstly by introducing a high model uncertainty within the flight control system and showing, via simulation, that the control system successfully performs desired multi-axial manoeuvres whilst managing to maintain the induced side slip below 0.1◦. Secondly by disturbing the aircraft with a discrete side slip. Critical side slip disturbance angle was found to be considerably larger than that for regular aircraft entailing that the used case study may be somewhat over dimensioned with respect to yaw control authority.
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To, Lap C. "Nonlinear control techniques in alumina refineries". Thesis, Curtin University, 1996. http://hdl.handle.net/20.500.11937/130.
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Nonlinearities exist in all process control systems. The use of linear control techniques is valid only in a narrow range of operation. Therefore, in this thesis, multivariable nonlinear control techniques are considered. The target process is the single effect evaporative process of the liquor burning unit in Alcoa's alumina refinery in Kwinana and the proposed triple effects unit in the Wagerup refinery. Two types of nonlinear control strategies using differential geometry were studied, namely, the input output linearization (Kravaris and Soroush, 1990) and the input state linearization (Hunt et al, 1983a). The research has successfully demonstrated the superiority and simplicity of the nonlinear controller through simulations and plant implementations. An integrated software package using MAPLE V.3 as the computing environment was developed to automate the solution algorithms and to graphically simulate the closed loop dynamics of different processes using the two nonlinear control strategies.The issue of robustness of the nonlinear controller was addressed by developing a procedure called uncertainty vector adjustment. The effectiveness of the new strategy was successfully demonstrated on the simulated liquor burning process. Furthermore, the stability of the adjustment technique was proved and its theoretical bounds were established using Lyapunov function analysis.A comparative study of geometric nonlinear filter and extended Kalman filter was conducted to reduce the requirement of full state feedback necessary for nonlinear control using either input output linearization or input state linearization. The simulation of the single effect evaporation unit of the liquor burning process showed that the geometric nonlinear filter is superior to the extended Kalman filter in terms of nonlinear tracking performances.The plant trials of the input output linearization in Alcoa's Kwinana alumina refinery demonstrated the practicability and feasibility of implementing nonlinear control in an industrial setting and also fostered a closer gap between academia and industry. The trials established guidelines for implementing a global linearizing controller on site, including conversion of the relevant constraints and the output of an industrial proportional and integral controller to the equivalent proportional and integral action required by the nonlinear controller. The results showed that the performance of the nonlinear controller was better than the current linear controller on site in terms of responsiveness and resistance to disturbances. Hence, the nonlinear control strategy enables the process to settle faster.All in all, efforts have been made in this thesis to minimise the use of abstract mathematical language and, in some cases, simplify the language so that nonlinear control theory can be understood by a wider range of audience, especially industrial practitioners. It is hoped that the insights provided in the dissertation will encourage more industrial implementations of nonlinear controllers and forge more interaction to close the widening gap between academic and industrial practice in process control.Keywords: nonlinear control, differential geometry, symbolic algebra, evaporator process, uncertainty vector adjustment, geometric nonlinear filter.
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To, Lap C. "Nonlinear control techniques in alumina refineries". Curtin University of Technology, School of Chemical Engineering, 1996. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=12276.
Texto completoResumen
Nonlinearities exist in all process control systems. The use of linear control techniques is valid only in a narrow range of operation. Therefore, in this thesis, multivariable nonlinear control techniques are considered. The target process is the single effect evaporative process of the liquor burning unit in Alcoa's alumina refinery in Kwinana and the proposed triple effects unit in the Wagerup refinery. Two types of nonlinear control strategies using differential geometry were studied, namely, the input output linearization (Kravaris and Soroush, 1990) and the input state linearization (Hunt et al, 1983a). The research has successfully demonstrated the superiority and simplicity of the nonlinear controller through simulations and plant implementations. An integrated software package using MAPLE V.3 as the computing environment was developed to automate the solution algorithms and to graphically simulate the closed loop dynamics of different processes using the two nonlinear control strategies.The issue of robustness of the nonlinear controller was addressed by developing a procedure called uncertainty vector adjustment. The effectiveness of the new strategy was successfully demonstrated on the simulated liquor burning process. Furthermore, the stability of the adjustment technique was proved and its theoretical bounds were established using Lyapunov function analysis.A comparative study of geometric nonlinear filter and extended Kalman filter was conducted to reduce the requirement of full state feedback necessary for nonlinear control using either input output linearization or input state linearization. The simulation of the single effect evaporation unit of the liquor burning process showed that the geometric nonlinear filter is superior to the extended Kalman filter in terms of nonlinear tracking performances.The plant trials of the input output linearization ++in Alcoa's Kwinana alumina refinery demonstrated the practicability and feasibility of implementing nonlinear control in an industrial setting and also fostered a closer gap between academia and industry. The trials established guidelines for implementing a global linearizing controller on site, including conversion of the relevant constraints and the output of an industrial proportional and integral controller to the equivalent proportional and integral action required by the nonlinear controller. The results showed that the performance of the nonlinear controller was better than the current linear controller on site in terms of responsiveness and resistance to disturbances. Hence, the nonlinear control strategy enables the process to settle faster.All in all, efforts have been made in this thesis to minimise the use of abstract mathematical language and, in some cases, simplify the language so that nonlinear control theory can be understood by a wider range of audience, especially industrial practitioners. It is hoped that the insights provided in the dissertation will encourage more industrial implementations of nonlinear controllers and forge more interaction to close the widening gap between academic and industrial practice in process control.Keywords: nonlinear control, differential geometry, symbolic algebra, evaporator process, uncertainty vector adjustment, geometric nonlinear filter.