Dissertations / Theses on the topic 'H2/H∞ robust control'
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1
Nakashima, Paulo Hiroaqui Ruiz. "Controle H2, H∞ e H2/H∞ aplicados a um robô manipulador subatuado." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/18/18133/tde-08062017-122423/.
Abstract:
Este trabalho apresenta os resultados da aplicação de três técnicas de controle utilizadas no projeto e implementação do controle de um manipulador subatuado planar de três juntas em série e de elos rígidos, projetado e construído pela Universidade Carnegie Mellon, EUA. Devido ao alto grau de não-linearidade deste sistema, seria muito difícil implementar um controlador H2, H∞ ou H2/H∞ que atuasse sozinho. Assim, propõe-se a utilização de um método de controle combinado: torque computado/H2, H∞ ou H2/H∞. No controle combinado, a porção correspondente ao torque computado lineariza e pré-compensa a dinâmica do modelo da planta nominal, enquanto a porção correspondente ao controle H2, H∞ ou H2/H∞ realiza uma pós-compensação dos erros residuais, que não foram completamente eliminados pelo método torque computado. Testes de acompanhamento de trajetória e testes de robustez são realizados aqui para comprovar a eficiência destes controladores, com resultados de implementação bastante satisfatórios.This work presents the application results of three control techniques used for the control design and implementation of a serial planar underactuated manipulator with three joints and rigid links, designed and built by the Carnegie Mellon University, USA. Due to the high non-linearity degree of this system, it would be very difficult to implement an H2, H∞ or H2/ H∞ control which would actuate on the system by itself. Therefore, it is proposed a combined control method: computed torque/ H2, H∞ or H2/H∞. In the combined control, the portion corresponding to the computed torque linearizes and pre-compensates the dynamics of the nominal model, while the portion corresponding to the H2, H∞ or H2/H∞ control realizes a pos-compensation of the residual errors, not completely removed by the computed torque method. Trajetory tracking and robustness tests are performed here to demonstrate the efficiency of these controllers, with very satisfatory implementation results.
2
Olcer, Tuncay Ugurlu. "H2/h." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615636/index.pdf.
Abstract:
In fin actuation systems, the performance of classical linear control systems is not satisfactory due to uncertainty of the system parameters and disturbances of the working medium. For this reason, sliding mode, H2 or H&infinrobust controllers are widely used in literature for such systems. However, use of such controllers results in very conservative system responses. Based on this fact, in this thesis, development of a more effective robust controller is aimed via integration of the optimum properties of the existent pure H2 and H&infin
type robust controllers. To achieve this, during the controller synthesizing procedure, some of the optimization parameters are weighted according to H2 norm minimization, and parameter uncertainties and other variables are weighted according to H&infin
theorem. First, the system set up to be controlled is physically constructed and performed system identification processes. Then, two different types of robust controllers H2 and H&infin
controllers are designed and tested over both the real system and simulation. Finally an H2/H&infin
mixed type controller synthesized and the results are compared with the outputs of the robust controllers of the previous step.
3
Hartley, Gerald A. "F-18 robust control design using H2 and H-infinity methods." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA242562.
Abstract:
Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, September 1990.Thesis Advisor(s): Collins, Daniel J. Second Reader: Schmidt, Louis V. "September 1990." Description based on title screen as viewed on December 29, 2009. DTIC Identifier(s): Flight control systems, control theory, computer files, theses, input output processing, F-18 aircraft. Author(s) subject terms: Modern control theory, H infinity control theory, H2 control theory, multivariable robustness, F-18 control design or synthesis, super augmented aircraft. Includes bibliographical references (p. 110). Also available in print.
4
Liang, Yu. "H[subscript 2] optimal control under robust stability and controller degree constraint /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20LIANG.
5
Noack, Matti. "Mixed H2/H∞ control for infinite dimensional systems." Master's thesis, Pontificia Universidad Católica del Perú, 2017. http://tesis.pucp.edu.pe/repositorio/handle/123456789/9251.
Abstract:
The class of infinite dimensional systems often occurs when dealing with distributed
parameter models consisting of partial differential equations. Although forming a
comprehensive description, they mainly become manageable by finite dimensional approximations
which likely neglect important effects, but underlies a certain structure.
In contrast to common techniques for controlling infinite dimensional systems, this
work focuses on using robust control methods. Thus, the uncertainty structure that
occurs due to the discretization shall be taken into account particularly. Additionally,
optimal performance measures can be included into the design process. The mixed
H2/H∞ control approach handles the inclusion of disturbances and inaccuracies while
guaranteeing specified energy or magnitude bounds.
In order to include various of these system requirements, multi-objective robust control
techniques based on the linear matrix inequality framework are utilized. This offers
great flexibility concerning the formulation of the control task and results in convex
optimization problems which can be solved numerically efficient by semi-definite programming.
A flexible robot arm structure serves as the major application example during this
work. The model discretization leads to an LTI system of specified order with an uncertainty
model which is obtained by considering the concrete approximation impact
and frequency domain tests. A structural analysis of the system model relates the
neglected dynamics to a robust characterization. For the objective selection, stability
shall be ensured under all expected circumstances while the aspects of optimal H2 performance,
passive behavior and optimal measurement output selection are included.
The undesirable spillover effect is thoroughly investigated and thus avoided.Tesis
6
Achnib, Asma. "Développement de la commande CRONE avec effet anticipatif robuste." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0056/document.
Abstract:
Le travail présenté dans cette thèse s'inscrit dans le cadre de l'étude de l'efficacité de la commande CRONE avec effet anticipatif robuste dans les problèmes de poursuite et de régulation pour les systèmes monovariables et multivariables. L'objectif de l'anticipation est de concevoir des algorithmes de commande capables de minimiser un critère quadratique basé sur l'erreur entre la sortie du système et le signal de référence avec modération du niveau du signal de commande. La solution proposée repose sur l'association d'une commande robuste de type feedback à une commande anticipative de type feedforward. L'action feedforward utilise un filtre anticipatif synthétisé dans le domaine fréquentiel en utilisant des critères d'optimalité et de contraintes de type $mathcal{H}_2$ et $mathcal{H}_infty$. La réduction du nombre de paramètres du filtre anticipatif en utilisant une période d'échantillonnage plus lente a été traitée. Des exemples académiques illustrent les développements théoriques. Une application pratique sur un système de régulation hydraulique a montré la pertinence de cette nouvelle approcheThe work presented in this thesis is part of the study of the effectiveness of CRONE control with anticipative effect in the problems of tracking and control for monovariable and multivariable systems. The anticipation objective is to design a control algorithm that minimizes a quadratic error between the reference and the output of the system and at the same time achieve a good level of the control signal. The proposed solution combines a robust feedback control with a feedforward control. The feedforward action uses optimality criteria and an anticipative filter which is designed in the frequency domain using a mix of $mathcal{H}_2$ et $mathcal{H}_infty$ constraints. The reduction of the number of parameters of the anticipative filter by using a slower sampling period for the anticipative filter is treated. Academic examples highlight the theoretical developments. A practical application on a hydraulic control system has shown the efficiency of the developed approach
7
Fry, Jedediah Micah. "On Integral Quadratic Constraint Theory and Robust Control of Unmanned Aircraft Systems." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/102615.
Abstract:
This dissertation advances tools for the certification of unmanned aircraft system (UAS) flight controllers. We develop two thrusts to this goal: (1) the validation and improvement of an uncertain UAS framework based on integral quadratic constraint (IQC) theory and (2) the development of novel IQC theorems which allow the analysis of uncertain systems having time-varying characteristics.
Pertaining to the first thrust, this work improves and implements an IQC-based robustness analysis framework for UAS. The approach models the UAS using a linear fractional transformation on uncertainties and conducts robustness analysis on the uncertain system via IQC theory. By expressing the set of desired UAS flight paths with an uncertainty, the framework enables analysis of the uncertain UAS flying about any level path whose radius of curvature is bounded. To demonstrate the versatility of this technique, we use IQC analysis to tune trajectory-tracking and path-following controllers designed via H2 or H-infinity synthesis methods. IQC analysis is also used to tune path-following PID controllers. By employing a non-deterministic simulation environment and conducting numerous flight tests, we demonstrate the capability of the framework in predicting loss of control, comparing the robustness of different controllers, and tuning controllers. Finally, this work demonstrates that signal IQCs have an important role in obtaining IQC analysis results which are less conservative and more consistent with observations from flight test data.
With regards to the second thrust, we prove a novel theorem which enables robustness analysis of uncertain systems where the nominal plant and the IQC multiplier are linear time-varying systems and the nominal plant may have a non-zero initial condition. When the nominal plant and the IQC multiplier are eventually periodic, robustness analysis can be accomplished by solving a finite-dimensional semidefinite program. Time-varying IQC multipliers are beneficial in analysis because they provide the possibility of reducing conservatism and are capable of expressing uncertainties that have unique time-domain characteristics. A number of time-varying IQC multipliers are introduced to better describe such uncertainties. The utility of this theorem is demonstrated with various examples, including one which produces bounds on the UAS position after an aggressive Split-S maneuver.Doctor of Philosophy
8
Andrade, Lucas Henrique Salame de. "Técnicas de controle robusto misto H2/H [infinito] aplicadas a um sistema multivariável não-linear." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/3212.
Abstract:
Este trabalho consiste na investigação, síntese e validação prática de um sistema de controle robusto baseado na minimização das normas H2 e H∞, por meio da utilização de desigualdades matriciais lineares, para a estabilização de um processo multivariável. Propõe-se a utilização de um sistema não-linear com duas entradas e duas saídas, que consistem no controle de variáveis de temperatura e nível de fluido em um reservatório. Serão apresentados os principais aspectos estruturais e tecnológicos do sistema a ser utilizado, assim como os fundamentos de estratégias de controle robusto moderno. As estruturas de controle serão implementadas por meio de controlador programável para automação CompactRIO, em conjunto com o software de desenvolvimento LabVIEW.This work consists of the investigation, synthesis and practical validation of a robust control system based on minimization of H2 and H∞ norms, using linear matrix inequalities, for stabilization of a multivariable process. A study case on a nonlinear system with two imputs and two outputs is proposed, which consists of the control of temperature variables and fluid level in a reservoir. The main structural and system technology to be used and the fundamentals of modern control strategies will be presented. Control structures will be implemented by the programmable automation controller CompactRIO, together with LabVIEW software development.
9
Feng, Yu. "Commande H2 - H∞ non standard des systèmes implicites." Phd thesis, Ecole des Mines de Nantes, 2011. http://tel.archives-ouvertes.fr/tel-00678501.
Abstract:
Les systèmes implicites (dits aussi " descripteurs ") peuvent décrire des processus régis à la fois par des équations dynamiques et statiques et permettent de préserver la structure des systèmes physiques. Ils comportent trois types de modes : dynamiques finis, infinis (réponse temporelle impulsive (en cas continu) ou acausale (en cas discret)) et statiques. Dans le cadre du formalisme descripteur, les contributions de cette thèse sont triples : i) revisiter des résultats existants pour les systèmes d'état, ii) étendre certains résultats classiques au cas des systèmes implicites, iii) résoudre rigoureusement des problèmes de commande non standard. Ainsi, le présent mémoire commence par revisiter les résultats concernant la caractérisation LMI stricte de la dissipativité, les caractérisations de l'admissibilité et des performances H2 ou H∞ par LMI étendues et les équations de Sylvester et de Riccati généralisées. Il aborde dans un deuxième temps, le problème de stabilisation simultanée, avec ou sans critère H∞, à travers l'extension de certains résultats récents au cas des systèmes implicites. La solution proposée s'appuie sur la résolution combinée d'une équation algébrique de Riccati généralisée (GARE) et d'un problème de faisabilité sous contrainte LMI stricte. Il traite enfin des problèmes H2 et H∞ non standards : i) en présence de pondérations instables voire impropres, ii) sous contraintes de régulation; dans le cas des systèmes implicites. Ces dernières contributions permettent désormais de traiter rigoureusement, sans approximations ou transformations, de nombreux problèmes H2 ou H∞ formalisant des problèmes pratiques de commande, dont ceux faisant intervenir une pénalisation haute fréquence de la commande ou un modèle interne instable des signaux exogènes.
10
Legrand, Romain. "Suivi de trajectoire autonome et robuste en milieu agricole." Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2022. http://www.theses.fr/2022IMTA0330.
Abstract:
L’automatisation des véhicules agricoles est aujourd’hui un enjeu majeur de la mutation des pratiques agricoles. Munis des capteurs ad hoc, il est question ici de leur capacité à suivre une trajectoire prédéfinie, de manière robuste afin d’assurer leur mission en dépit d’un sol complexe. Cette thèse contribue au sujet en revisitant les problématiques de contrôle des dynamiques latérales et longitudinales. Dans le but de générer une commande robuste des angles de braquage, le suivi latéral du chemin de référence proposé s’appuie sur une approche multi-objectif H2/H∞ et multi-modèle, de manière à optimiser le compromis performances/robustesse à partir des incertitudes explicitées. Le contrôle longitudinal proposé est novateur à plusieurs points de vue. Quoique conçu indépendamment du contrôle latéral, il tient compte des aspects liés à la dynamique latérale, et vise à prévenir les pertes d’adhérence et risques de renversement. La prise en compte de telles contraintes et la nécessité d’anticipation ont induit le choix d’une commande prédictive non-linéaire. Au final, la pertinence de la solution et de la méthode est illustrée par le biais d’un simulateur réaliste, sur la base de scénarios faisant intervenir des configurations multiples de pentes et de vitessesThe automation of off-road vehicles has become nowadays a strategic line of research given the recent and profound mutations of agricultural practices. This thesis deals with the conception of two independent controllers of an off-road vehicle, regulating both longitudinal and lateral dynamics. The first regulator aims to minimize the deviations with respect to a reference path by controlling the steering angles. It relies on anextended bicycle model that accounts for the slopes and load transfers. The H2/H∞ multi-objective synthesis allows the consideration of large model uncertainties. The adaptability of this controller is enhanced by the feedback/feedforward architecture which ensures the global robustness of the regulator. The second controller regulates the longitudinal dynamics of the vehicle. It lies on model predictive control. Anti-slip and anti-rollover constraints are explicitly defined during the synthesis of the regulator to ensure the stability of the off-road vehicle operating on slippery sloping grounds. The designed controllers have been tested on a realistic simulator which takes account of great load transfers within the vehicle, which are common in agricultural context. Both controllers have demonstrated satisfactory performances while exploring a variety of slopes and speeds
11
Mustaki, Simon Éliakim. "Outils de pré-calibration numérique des lois de commande de systèmes de systèmes : application aux aides à la conduite et au véhicule autonome." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2019. http://www.theses.fr/2019IMTA0142/document.
Abstract:
Cette thèse est dédiée à la pré-calibration des nouveaux systèmes d’aides à la conduite (ADAS). Le développement de ces systèmes est devenu aujourd’hui un axe de recherche stratégique pour les constructeurs automobiles dans le but de proposer des véhicules plus sûrs et moins énergivores. Cette thèse contribue à une vision méthodologique multi-critère, multi-modèle et multi-scénario. Elle en propose une instanciation particulière pour la pré-calibration spécifique au Lane Centering Assistance (LCA). Elle s’appuie sur des modèles dynamiques de complexité juste nécessaire du véhicule et de son environnement pour, dans le cadre du formalisme H2/H∞, formaliser et arbitrer les compromis entre performance de suivi de voie, confort des passagers et robustesse. Les critères élaborés sont définis de manière à être d’interprétation aisée, car directement liés à la physique, et facilement calculables. Ils s’appuient sur des modèles de perturbations exogènes (e.g. courbure de la route ou rafale de vent) et de véhicules multiples mais représentatifs, de manière à réduire autant que possible le pessimisme tout en embrassant l’ensemble des situations réalistes. Des simulations et des essais sur véhicules démontrent l’intérêt de l’approcheThis thesis deals with the tuning of the new Advanced Driving Assistance Systems (ADAS). The development of these systems has become nowadays a strategic line of research for the automotive industry towards the conception of safer and fuel-efficient vehicles.This thesis contributes to a multi-criterion, multi-modeland multi-scenario methodological vision of the tuning process. It is presented through a specific application of the tuning of the Lane Centering Assistance (LCA). It relies on vehicle and environment’s dynamical models of adequate complexity in the aim of formalizing and managing, in a H2/H∞ framework, the trade-off between performance, comfort and robustness. The formulated criteria are easy to compute and defined in a way to be understandable, closely linked to practical specifications. The whole methodology is driven by the research of a pertinent trade-off between realism (being as closest as possible to reality) and complexity (quick evaluation of the criterion). The efficiency and the robustness of the approach is demonstrated through high-fidelity simulations and numerous tests on real vehicles
12
Fahmy, Sherif Farid Fahmy. "Nonlinear robust H∞ control." Thesis, University of Sheffield, 2006. http://etheses.whiterose.ac.uk/14887/.
Abstract:
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.
13
Yu, Ningbo. "A mixed H2/H[infinity] problem with degree constraint /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20YU.
Abstract:
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005.On t.p. "2" is lower case and "[infinity]" appears as the infinity symbol. Includes bibliographical references (leaves 110-116). Also available in electronic version.
14
Patek, Stephen D. (Stephen David). "Robust H[infinity] control via quadratic stabilization." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12276.
Abstract:
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.On t.p., "[infinity]" appears subscript, as the mathematical symbol.
Includes bibliographical references (leaves 126-129).
by Stephen David Patek.
M.S.
15
Monnet, Dominique. "Global minmax optimization for robust H∞ control." Thesis, Brest, École nationale supérieure de techniques avancées Bretagne, 2018. http://www.theses.fr/2018ENTA0009/document.
Abstract:
La commande H∞ est de nos jours utilisée pour la régulation de nombreux systèmes. Cette technique de contrôle permet de synthétiser des lois de commande robustes, dans le sens où le comportement du système régulé est peu sensible aux perturbations externes. De plus, la commande H∞ permet de prendre en compte des incertitudes liés au modèle décrivant le système à réguler. Par conséquence, cette technique de contrôle est robuste vis-à-vis des perturbations et des incertitudes de modèle. Afin de synthétiser une loi de commande robuste, les spécifications des performances du système en boucle fermée sont traduites en critères H∞ à partir desquels est formulé un problème d'optimisation. La loi de commande est une solution de ce problème, qui est non convexe dans le cas général. Les deux principales approches pour la résolution de ce problème sont basées sur la reformulation convexe et les méthodes d'optimisations locales, mais ne garantissent pas l'optimalité de la loi de commande vis-à-vis des critères H∞. Cette thèse propose une approche de la commande H∞ par des méthodes d'optimisation globales, rarement considérées jusqu'à présent. Contrairement aux approches classiques, bien qu'au prix d'une complexité algorithmique supérieure, la convergence vers la loi de commande optimale est garantie par les méthodes globales. De plus, les incertitude de modèle sont prises en compte de manière garantie, ce qui n'est pas nécessairement le cas avec les approches convexes et localesH∞ control is nowadays used in many applications. This control technique enables to synthesize control laws which are robust with respect to external disturbances. Moreover, it allows to take model uncertainty into account in the synthesis process. As a consequence, H∞ control laws are robust with respect to both external disturbances and model uncertainty. A robust control law is a solution to an optimization problem, formulated from H∞ criteria. These criteria are the mathematical translations of the desired closed loop performance specifications. The two classical approaches to the optimization problem rely on the convex reformulation and local optimization methods. However, such approaches are unable to guarantee the optimality, with respect to the H∞ criteria, of the control law. This thesis proposes to investigate a global optimization approach to H∞ control. Contrary to convex and local approaches, global optimization methods enable to guarantee the optimality of the control, and also to take into account model uncertainty in a reliable way
16
Haghighizadeh, Navin. "TCP/AQM Congestion Control Based on the H2/H∞ Theory." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35222.
Abstract:
This thesis uses a modern control approach to address the Internet traffic control issues in the Transport Layer. Through literature review, we are interested in using the H2/H∞ formulation to obtain the good transient performance of an H2 controller and the good robust property from an H∞ controller while avoiding their deficiencies. The H2/H∞ controller is designed by formulating an optimization problem using the H2-norm and the H∞-norm of the system, which can be solved by an LMI approach using MATLAB.
Our design starts with the modeling of a router and the control system by augmenting the network plant function with the Sensitivity function S, the Complementary Sensitivity function T and the Input Sensitivity function U. These sensitivity functions along with their weight functions are used to monitor the closed-loop dynamics of the traffic control. By choosing different combinations of the sensitivity functions, we can obtain the SU, the ST and the STU controllers. Both the window-based and rate-based version of these different types of H2/H∞ controllers have been designed and investigated. We have also proved that these controllers are stable using Lyapunov’s First Method.
Next, we verify the performance of the controllers by OPNET simulation using different performance measures of queue length, throughput, queueing delay, packet loss rate and goodput. Our performance evaluation via simulation has demonstrated the robustness and the better transient response such as the rise/fall time and the peak queue value. We have also investigated the controller performances subject to network dynamics as well as through comparison with other controllers.
Finally, we have improved these controllers for real-time application. They are capable to update/renew the controller in a short time whenever new network parameter values are detected so that the optimum performance can be maintained.
17
DeVilbiss, Stewart L. "System Identification for H(Infinity) Robust Control Design /." The Ohio State University, 1994. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487859313345322.
18
Davis, Robert Andrew. "Model validation for robust control." Thesis, University of Cambridge, 1995. https://www.repository.cam.ac.uk/handle/1810/251990.
19
Ma, Fangwu. "Robust H control of off-road vehicle suspension systems." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405134.
20
Yucelen, Tansel. "Real-time H[infinity] approach for robust optimal control /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1559856341&sid=8&Fmt=2&clientId=1509&RQT=309&VName=PQD.
21
Friml, Dominik. "Porovnání H-nekonečno a LQG regulace." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413201.
Abstract:
This thesis deals with the MIMO system analysis, with a comparison of a different frequency charactersitics, and including singular values characteristic. The H2 and H norms are defined for signals and a MIMO systems. A MIMO optimal control using an LQG, an H2 and an H control is defined and described. Their general advantages, disadvantages and similarities are summed up. An H2 and an H state controller and state observer synthesis is implemented in a MATLAB using linear matrix inequalities. Control of an inverted pendulum is designed using the H optimal cascade control, the H2 state control and the H state control. The results are compared with each other. The theoretical possibility of same H2 and H optimal state controller design is presented.
22
Papageorgiou, George. "Robust control system design : H∞ loop sharing and aerospace applications." Thesis, University of Cambridge, 1998. https://www.repository.cam.ac.uk/handle/1810/272494.
23
CHAOUBAH, ALFREDO. "ROBUST H2 CONTROL IN RESPECT OF NOM-STRUCTURED PERTUBATIONS: A NORMALIZID COPRIME FACTORS APPROACH." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1999. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=7810@1.
Abstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOREsta tese teve como objetivo o estudo do problema de Desempenho H2 Robusto, com enfase para o caso de perturbações lineares não estruturadas nos fatores coprimos normalizados da função de transferência que representa uma determinada planta nominal. A primeira parte desta tese foi dedicada à determinação de um novo índice de Desempenho H2 Robusto pela utilização de limitantes superiores, levando em conta dois fatores: melhoria destes limitantes com relação aos limitantes propostos na literatura e viabilidade de sua implementação numérica. A parte seguinte da tese foi dedicada à determinação de elementos que influenciam no Desempenho H2 Robusto. Estes elementos serviram de base para a definição de problemas de controle multiobjetivos que, por sua vez, geraram uma classe de controladores sobre a qual foi otimizado o índice de Desempenho H2 Robusto proposto nesta tese.
The objective of this thesis was the study of the Robust H2 Performance problem, with emphasis on the case of linear and unstructured perturbations on the normalized coprime factors of the transfer function that represents the nominal plant. The first was dedicated to the determination of a new Robust H2 Performance index, by the utilization of upper bounds, taking into accunt two factors: better upper bounds, with relation to upper bonds proposed in the literature, and numerical implementation viability. The second part was dedicated to the determination of elements that have influence in the Robust H2 Performance. These elements became a basis for the definition of multiobjetive control problems, that generate a class of controllers, over which the Robust H2 Performance index, proposed in the first part of this thesis, was optimizated.
24
Wu, Qinghe. "An application of H{unendlich}⁻theory to decentralized robust control /." Zürich, 1990. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=9116.
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Chumalee, Sunan. "Robust gain-scheduled H [infinity] control for unmanned aerial vehicles." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/6775.
Abstract:
This thesis considers the problem of the design of robust gain-scheduled ight controllers for conventional xed-wing unmanned aerial vehicles (UAVs). The design approaches employ a linear parameter-varying (LPV) control technique, that is based on the principle of the gain-scheduled output feedback H1 control, because a conventional gain-scheduling technique is both expensive and time-consuming for many UAV applications. In addition, importantly, an LPV controller can guarantee the stability, robustness and performance properties of the closed-loop system across the full or de ned ight envelope. A ight control application problem for conventional xed-wing UAVs is considered in this thesis. This is an autopilot design (i.e. speed-hold, altitude-hold, and heading-hold) that is used to demonstrate the impacts of the proposed scheme in robustness and performance improvement of the ight controller design over a fuller range of ight conditions. The LPV ight controllers are synthesized using single quadratic (SQLF) or parameterdependent (PDLF) Lyapunov functions where the synthesis problems involve solving the linear matrix inequality (LMI) constraints that can be e ciently solved using standard software. To synthesize an LPV autopilot of a Jindivik UAV, the longitudinal and lateral LPV models are required in which they are derived from a six degree-of-fredoom (6-DOF) nonlinear model of the vehicle using Jacobian linearization. However, the derived LPV models are nonlinearly dependent on the time-varying parameters, i.e. speed and altitude. To obtain a nite number of LMIs and avoid the gridding parameter technique, the Tensor-Product (TP) model transformation is applied to transform the nonlinearly parameter-dependent LPV model into a TP-type convex polytopic model form. Hence, the gain-scheduled output feedback H1 control technique can be applied to the resulting TP convex polytopic model using the single quadratic Lyapunov functions. The parameter-dependent Lyapunov functions is also used to synthesize another LPV controller that is less conservative than the SQLF-based LPV controller. However, using the parameter-dependent Lyapunov functions involves solving an in nite number of LMIs for which a number of convexifying techniques exist, based on an a ne LPV model, for obtaining a nite number of LMIs. In this thesis, an a ne LPV model is converted from the nonlinearly parameter-dependent LPV model using a minimum least-squares method. In addition, an alternative approach for obtaining a nite number of LMIs is proposed, by simple manipulations on the bounded reallemma inequality, a symmetric matrix polytope inequality form is obtained. Hence, the LMIs need only be evaluated at all vertices. A technique to construct the intermediate controller variables as an a ne matrix-valued function in the polytopic coordinates of the scheduled parameter is also proposed. The time-varying real parametric uncertainties are included in the system statespace model matrices of an a ne LPV model as a linear fractional transformation (LFT) form in order to improve robustness of the designed LPV controllers in the presence of mismatch uncertainties between the nonlinearly parameter-dependent LPV model and the a ne LPV model. Hence, a new class of LPV models is obtained called an uncertain a ne LPV model which is less conservative than the existing parameter-dependent linear fractional transformation model (LPV/LFT). New algorithms of robust stability analysis and gain-scheduled controller synthesis for this uncertain a ne LPV model using single quadratic and parameter-dependent Lyapunov functions are proposed. The analysis and synthesis conditions are represented in the form of a nite number of LMIs. Moreover, the proposed method is applied to synthesize a lateral autopilot, i.e. heading-hold, for a bounded ight envelope of the Jindivik UAV. The simulation results on a full 6-DOF Jindivik nonlinear model are presented to show the e ectiveness of the approach.
26
Eagen, Sean Evans. "Robust Optimal Control of a Tailsitter UAV." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/104214.
Abstract:
Vertical Takeoff and Landing (VTOL) Unmanned Aerial Vehicles (UAVs) possess several beneficial attributes, including requiring minimal space to takeoff, hover, and land. The tailsitter is a type of VTOL airframe that combines the benefits of VTOL capability with the ability to achieve efficient horizontal flight. One type of tailsitter, the Quadrotor Biplane (QRBP), can transition the vehicle from hover as a quadrotor to horizontal flight as a biplane. The vehicle used in this thesis is a QRBP designed with special considerations for fully autonomous operation in an outdoor environment in the presence of model uncertainties. QRBPs undergo a rotation of 90° about its pitch axis during transition from vertical to horizontal flight that induces strong aerodynamic forces that are difficult to model, thus necessitating the use of a robust control method to overcome the resulting uncertainties in the model. A feedback-linearizing controller augmented with an H-Infinity robust control is developed to regulate the altitude and pitch angle of the vehicle for the whole flight regime, including the ascent, transition forward, and landing. The performance of the proposed control design is demonstrated through numerical simulations in MATLAB and outdoor flight tests. The H-Infinity controller successfully tracks the prescribed trajectory, demonstrating its value as a computationally inexpensive, robust control technique for QRBP tailsitter UAVs.Master of Science
Vertical Takeoff and Landing (VTOL) Unmanned Aerial Vehicles (UAVs) are a special type of UAV that can takeoff, hover, and land vertically, which lends several benefits. VTOL aircraft have recently gained popularity due to their potential to serve as fast and efficient payload delivery vehicles for e-commerce. One type of VTOL aircraft, the Quadrotor Biplane (QRBP) combines the ability of a quadrotor aircraft to hover, with the efficient horizontal flight of a biplane. Such a vehicle is able to takeoff and land in confined spaces, and also travel large distances on a single battery. However, the takeoff maneuver of a QRBP involves pitching from vertical to horizontal flight, which causes the vehicle to experience strong aerodynamic effects that are difficult to accurately model. Thus, to autonomously perform this unique maneuver, a robust control technique is necessary. A robust UAV controller is one that functions even when there is a degree of uncertainty in the predicted behavior of the vehicle, such as differences between estimated and actual vehicle parameters, or the presence of external disturbances such as wind. Therefore, a robust controller known as H-Infinity is developed to regulate the altitude and pitch angle of the QRBP as it takes off, transitions to forward flight, flies as a biplane, transitions back to vertical flight, and lands. The performance of the proposed control design is validated using numerical simulations performed in MATLAB, and flight tests. The H-Infinity controller successfully tracks the prescribed trajectory, demonstrating its value as a reliable, computationally inexpensive, robust control technique for QRBP UAVs.
27
Neumann, Donald. "Síntese de controladores robustos H2/H[infinito] D- estáveis via algoritmos evolutivos : uma abordagem LMI / Donald Neumann ; orientador, Humberto Xavier de Araújo." reponame:Biblioteca Digital de Teses e Dissertações da PUC_PR, 2006. http://www.biblioteca.pucpr.br/tede/tde_busca/arquivo.php?codArquivo=547.
Abstract:
Dissertação (mestrado) - Pontifícia Universidade Católica do Paraná, Curitiba, 2006Inclui bibliografia
Este trabalho aborda o problema de controle misto H2/H1 de sistemas lineares incertos por realimentação de saída estática ou dinâmica, sujeitos à D-estabilidade. As incertezas do sistema são do tipo paramétricas e os elementos das matrizes dinâmicas do si
28
Cheang, Sek Un. "Robust control system design : H∞ loop shaping for double inverted pendulum." Thesis, University of Macau, 2002. http://umaclib3.umac.mo/record=b1445662.
29
譚漢雄 and Hon-hung Tam. "Robust robot-manipulator control using hybrid H-infinity/adaptive controller structures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31219925.
30
Tam, Hon-hung. "Robust robot-manipulator control using hybrid H-infinity/adaptive controller structures /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19712704.
31
Sim, Hua Heng Allan. "A constrained optimisation approach for designing reliable robust H∞ control systems." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/2626.
Abstract:
This research addresses passive fault-tolerant control problems for linear uncertain systems via reliable state feedback and output feedback robust H∞ controllers. Structured uncertainties considered are required to satisfy integral quadratic constraints. These controllers are to obtain an absolutely stable closed-loop system with a specified disturbance attenuation level. Solutions to these control problems involve solving parameterised Riccati equation(s). A feasible set of parameters used to solve the Riccati equation(s) is computed using a differential evolution algorithm.
32
Malakorn, Tanit. "Multidimensional Linear Systems and Robust Control." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/26845.
Abstract:
This dissertation contains two parts: Commutative and Noncommutative Multidimensional ($d$-D) Linear Systems Theory. The first part focuses on the development of the interpolation theory to solve the $H^{\infty}$ control problem for $d$-D linear systems. We first review the classical discrete-time 1D linear system in the operator theoretical viewpoint followed by the formulations of the so-called Givone-Roesser and Fornasini-Marchesini models. Application of the $d$-variable $Z$-transform to the system of equations yields the transfer function which is a rational function of several complex variables, say $\mathbf{z} = (z_{1}, \dots, z_{d})$.
We then consider the output feedback stabilization problem for a plant $P(\mathbf{z})$. By assuming that $P(\mathbf{z})$ admits a double coprime factorization, then a set of stabilizing controllers $K(\mathbf{z})$ can be parametrized by the Youla parameter $Q(\mathbf{z})$. By doing so, one can convert such a problem to the model matching problem with performance index $F(\mathbf{z})$, affine in $Q(\mathbf{z})$. Then, with $F(\mathbf{z})$ as the design parameter rather than $Q(\mathbf{z})$, one has an interpolation problem for $F(\mathbf{z})$. Incorporation of a tolerance level on $F(\mathbf{z})$ then leads to an interpolation problem of multivariable Nevanlinna-Pick type. We also give an operator-theoretic formulation of the model matching problem which lends itself to a solution via the commutant lifting theorem on the polydisk.
The second part details a system whose time-axis is described by a free semigroup $\mathcal{F}_{d}$. Such a system can be represented by the so-called noncommutative Givone-Roesser, or noncommutative Fornasini-Marchesini models which are analogous to those in the first part. Application of a noncommutative $d$-variable $Z$-transform to the system of equations yields the transfer function expressed by a formal power series in several noncommuting indeterminants, say $T(z) = \sum_{v \in \mathcal{F}_{d}}T_{v}z^{v}$ where $z^{v} = z_{i_{n}} \dotsm z_{i_{1}}$ if $v = g_{i_{n}} \dotsm g_{i_{1}} \in \mathcal{F}_{d}$ and $z_{i}z_{j} \neq z_{j}z_{i}$ unless $i = j$. The concepts of reachability, controllability, observability, similarity, and stability are introduced by means of the state-space interpretation. Minimal realization problems for noncommutative Givone-Roesser or Fornasini-Marchesini systems are solved directly by a shift-realization procedure constructed from appropriate noncommutative Hankel matrices. This procedure adapts the ideas of Schützenberger and Fliess originally developed for "recognizable series" to our systems.Ph. D.
33
Prakash, Om. "Multivariable control of the space shuttle remote manipulator system using H2 and H[infinity] optimization." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/42489.
Abstract:
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1991.On t.p., "[infinity]" appears as the infinity sign in subscript.
Includes bibliographical references (leaves 119-120).
by Om Prakash, II.
M.S.
34
Bianco, Santino Joseph. "Robust Impedance Control of a Four Degree of Freedom Exercise Robot." Cleveland State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=csu1560110051211548.
35
Hague, Tyler Nicklaus 1975. "An application of robust H₂/H[infinity] control synthesis to launch vehicle ascent by Tyler Nicklaus Hague." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/9247.
Abstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.Also available online at the MIT Theses Online homepage
In title on t.p., "[infinity]" appears as the symbol in subscript.
Includes bibliographical references (p. 283-286).
This thesis explores the application of H2/H [infinity] control synthesis methods to launch vehicle ascent, specifically the pitch-plane control of the Kistler Aerospace launch vehicle, K1. A classical single-input, single-output design is also presented in order to assess the true applicability of a modern control synthesis approach to launch vehicle ascent. In addition, the K1 dynamics are developed to include aerodynamic, fuel-sloshing, tail-wags-dog, and body-bending effects. The objective of the modern control synthesis approach presented here is to design compensation for pitch tracking and disturbance rejection. It combines techniques in optimal H2, optimal H [infinity], and sub-optimal control synthesis to create pitch control laws that provide 6 dB of gain margin and 302 of phase margin. The sensitivity and high-order of traditional H2/H [infinity] synthesis are addressed through the implementation of uncertainty in the design model and the application of balanced, model order reduction on the resulting controllers. To reduce the complexity in applying these methods, a hierarchical approach and design strategy is employed. Additionally, a graphical user interface is presented that exploits the capabilities of commercial software during the design. A comparison of the two design methods, classical and modern, reveals that each design architecture is capable of creating controllers of equivalent order with both nominal and robust performance. The advantages of the modern approach are realized in the design process itself. The hierarchical methodology and intuitive nature of the modern approach helps to manage the selection of design parameters. Whereas, classical methods provide less insight into strategies for parameter selection and control design. Additionally, the ability to address disturbances and uncertainty in the modern approach offers a more direct alternative to the ad hoc and iterative nature of classical methods, and although not fully exploited here, the modern approach does allow coupling between channels to be accommodated. These conclusions confirm the viability of a modern control synthesis approach and establish the foundation for future development of modern-based, ascent control laws.
S.M.
36
Claase, Etienne H. "Robust multi-H2 output-feedback approach to aerial refuelling automation of large aircraft via linear matrix inequalities." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80195.
Abstract:
Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: In recent years the aviation industry has shown an interest in the airborne refuelling of large transport aircraft to enable increased payload mass at take-off and to extend aircraft range. Due to the large volume of fuel to be transferred, a boom and receptacle refuelling system with a larger fuel transfer rate is employed. The refuelling operation is particularly difficult and strenuous for the pilot of the receiver aircraft, because the position of the receptacle relative to the tanker aircraft must be maintained within a narrow window for a relatively long period of time. The airborne refuelling of a large aircraft is typically much more difficult than that of a fighter aircraft, since the large aircraft is more sluggish, takes much longer to refuel, and has a relatively large distance between its refuelling receptacle and its centre of mass. These difficulties provide the motivation for developing flight control laws for Autonomous In-Flight Refuelling (AIFR) to alleviate the workload on the pilot. The objective of the research is to design a flight control system that can regulate the receptacle of a receiver aircraft to remain within the boom envelope of a tanker aircraft in light and medium turbulence. The flight control system must be robust to uncertainties in the aircraft dynamic model, and must obey actuator deflection and slew rate limits. Literature on AIFR shows a wide range of approaches, including Linear Quadratic Regulator (LQR), μ-synthesis and neural-network based adaptive control, none of which explicitly includes constraints on actuator amplitudes, actuator rates and regulation errors in the design/synthesis. A new approach to designing AIFR flight control laws is proposed, based on Linear Matrix Inequality (LMI) optimisation. The relatively new LMI technique enables optimised regulation of stochastic systems subject to time-varying uncertainties and coloured noise disturbance, while simultaneously constraining transient behaviour and multiple outputs and actuators to operate within their amplitude, saturation and slew rate limits. These constraints are achieved by directly formulating them as inequalities.
AFRIKAANSE OPSOMMING: Die lugvaart industrie toon huidiglik ’n belangstelling in die brandstof oordrag tussen twee groot vervoervliegtuie gedurende vlug, met die doel om die maksimum opstyggewig kapasiteit sowel as die maksimum ononderbroke vlugafstand vermoë van die hervulde vliegtuig te vermeerder. ’n Boom hervulling-stelsel word geïmplementeer om die hoë spoed van brandstof oordrag te voorsien. Die verrigting van vluggebonde hervulling van ’n groot, trae vliegtuig is moeiliker en meer veeleisend as bv. van ’n vegvliegtuig, veral vir die vlieënier van die hervulde vliegtuig, wat sy boom-skakel moet reguleer binne ’n relatiewe klein boom bewegingsruimte vir ’n relatiewe lang tydperk. Die kinematika betrokke speel ook ’n groter rol in ’n groot hervulde vliegtuig a.g.v. die langer afstand tussen die boom-skakel en die massa middelpunt/ draaipunt. Hierdie bied die motivering om ’n beheerstelsel te ontwikkel wat die taak outomaties uitvoer. Die doel van die navorsing is om ’n beheerstelsel te ontwerp wat die boom-skakel van die hervulde vliegtuig outomaties reguleer binne die bewegingsruimte van die boom, gedurende ligte en matige turbulensie. Daar word van die beheerder vereis om robuust te wees teen onsekerhede in die vliegtuig se meganika, sowel as om die beheer oppervlaktes en turbines van die vliegtuig binne hul defleksie-, wringkrag- en sleurtempo-perke te hou. Daar bestaan reeds ’n groot verskeidenheid van benaderings tot die outomatisering van luggebonde hervulling, onder andere LQR, μ-sintese en neurale-netwerk gebaseerde aanpasbare beheer, waarvan geeneen perke op aktueerders en regulasie foute direk in die ontwerp insluit nie. ’n Nuwe benadering word voorgestel wat gebaseer is op Linear Matrix Inequality (LMI) optimering. Die LMI tegniek is relatief nuut in die gebruik van beheerstelsel ontwerp. Dit stel die ontwerper in staat om ’n stogastiese stelsel, onderworpe aan tydvariante-stelsel-variasie en gekleurde ruis versteurings, optimaal te reguleer, terwyl aktueerders en stelsel gedrag direk beperk word.
37
Tsiakkas, Mihalis. "Foundations of a Bicoprime Factorisation theory : a robust control perspective." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/foundations-of-a-bicoprime-factorisation-theory-a-robust-control-perspective(3d007de0-dcbe-4508-a072-f96afb77c26c).html.
Abstract:
This thesis investigates Bicoprime Factorisations (BCFs) and their possible uses in robust control theory. BCFs are a generalisation of coprime factorisations, which have been well known and widely used by the control community over the last few decades. Though they were introduced at roughly the same time as coprime factorisations, they have been largely ignored, with only a very small number of results derived in the literature. BCFs are first introduced and the fundamental theory behind them is developed. This includes results such as internal stability in terms of BCFs, parametrisation of the BCFs of a plant and state space constructions of BCFs. Subsequently, a BCF uncertainty structure is proposed, that encompasses both left and right coprime factor uncertainty. A robust control synthesis procedure is then developed with respect to this BCF uncertainty structure. The proposed synthesis method is shown to be advantageous in the following two aspects: (1) the standard assumptions associated with H-infinity control synthesis are directly fulfilled without the need of loop shifting or normalisation of the generalised plant and (2) any or all of the plant's unstable dynamics can be ignored, thus leading to a reduction in the dimensions of the Algebraic Riccati Equations (AREs) that need to be solved to achieve robust stabilisation. Normalised BCFs are then defined, which are shown to provide many advantages, especially in the context of robust control synthesis. When using a normalised BCF of the plant, lower bounds on the achievable BCF robust stability margin can be easily and directly computed a priori, as is the case for normalised coprime factors. Although the need for an iterative procedure is not completely avoided when designing an optimal controller, it is greatly simplified with the iteration variable being scalar. Unlike coprime factorisations where a single ARE needs to be solved to achieve normalisation, two coupled AREs must be satisfied for a BCF to be normalised. Two recursive methods are proposed to solve this problem. Lastly, an example is presented where the theory developed is used in a practical scenario. A quadrotor Unmanned Aerial Vehicle (UAV) is considered and a normalised BCF controller is designed which in combination with feedback linearisation is used to control both the attitude and position of the vehicle.
38
Lo, Wai Bun. "Physical modelling and H[infinity] filtering for robust spatio-temporal estimation /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20LO.
Abstract:
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2003.On t.p. "[infinity]" appears as the infinity symbol. Includes bibliographical references (leaves 88-92). Also available in electronic version. Access restricted to campus users.
39
Liu, Yong. "Asymptotic design of H2[subscript] and H[subscript infinity] control, regional stability problems, and case studies /." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487846354484377.
40
Rajnošek, Michal. "Robustní řízení synchronních motorů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219677.
Abstract:
This work is focused on robust control theory especially on methods H and analysis (structured singular value). The first part of the thesis contains theoreticle background to uncertainty modeling, to robust controller designs and to permanent magnet synchronous machine modeling. The second part presents concrette robust controller design which is tested in simulations and validated on a real motor. The influence of parameter changes on stability of closed loop system is discussed and description of obtained results is given in conclusions.
41
Maccari, Junior Luiz Antonio. "Projeto e validação experimental de um controlador robusto h2 aplicado a conversores Boost." Universidade Federal de Santa Maria, 2011. http://repositorio.ufsm.br/handle/1/8492.
Abstract:
Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThis dissertation presents as the main contribution the design and experimental validation of a robust H2 controller applied to boost converters with variations on the parameters load resistance, input voltage and operating point duty cycle. First, a polytopic model of the plant is presented, allowing to represent all the possible variations of the parameters within intervals previously established. Design conditions for a robust H2 controller, optimal under the quadratic stability, are detailed and used, allowing to efficiently calculate the controller gains. These gains are implemented with analog circuitry and the closed-loop system is tested by means of simulation and experimental results, which show a good match and illustrate a good performance. Finally, the small perturbation rejection capacity of the closed-loop system subject to parametric variations is evaluated using the H∞ guaranteed cost.
Esta dissertação apresenta como principal contribuição o projeto e a validação experimental de um controlador robusto H2 aplicado a conversores boost com variações nos parâmetros resistência de carga, tensão de entrada e razão cíclica do ponto de operação. Primeiramente, um modelo politópico da planta é apresentado, permitindo representar todas as situações de variações possíveis dos parâmetros mencionados, dentro de intervalos previamente estabelecidos. Condições de projeto de um controlador robusto H2, ótimo sob a estabilidade quadrática, são detalhadas e utilizadas, permitindo calcular eficientemente os ganhos do controlador. Estes ganhos são implementados de forma analógica e o sistema em malha fechada é testado por meio de resultados experimentais e de simulação, que apresentam uma boa correspondência e ilustram um bom desempenho. Por fim, a capacidade de rejeição de pequenas perturbações do sistema em malha fechada sujeito a variações paramétricas é avaliada utilizando o custo garantido H∞.
42
Tucker, Mark Richard. "Continuous H∞ and discrete time-varying finite horizon robust control with industrial applications." Thesis, University of Leicester, 1998. http://hdl.handle.net/2381/30169.
Abstract:
This thesis considers two areas of robust control. Part I considers continuous H control. The theory is applied to a scalar flexible transmission system that has non-minimum phase zeros and lightly damped modes that vary with applied load. A robust solution is obtained that gives good performance results. The capabilities of H techniques are more fully demonstrated on a research civil aircraft model (RCAM) flight control problem. A novel architecture for an autopilot to fly the RCAM along the final approach to landing is designed. Good results are obtained for the autopilot that incorporates controllers designed using both two degree-of-freedom H mixed sensitivity and H loop shaping techniques. In terms of a pre-defined mission scenario the overall results for performance, robustness, ride quality, safety and control effort are some of the best published, they demonstrate to the aerospace community the applicability and benefits of the methods. Part II considers discrete time-varying finite horizon control. A number of new results in this area are presented, some being specialisations or extensions of existing finite horizon and time-invariant results, for example, means of computing the finite horizon norm and relationships between symplectic matrix equations and Riccati equations. Furthermore, normalised (coprime) factorisations and controller parameterisation results have enabled the optimum norm for the normalised left factored plant problem to be explicitly formulated. Formulae for a particular class of the problem are presented. A simplifying formula for the solution to the control Riccati equation of the problem is derived and a class of sub-optimal solutions, using non-zero terminal weights, is considered. The controller formulae are applied to a one-degree-of-freedom intercept problem with encouraging results. Robustness to relative lateral position errors and target acceleration perturbations are compared for the zero and non-zero terminal state weight cases.
43
Yang, Lin. "Linear robust H-infinity stochastic control theory on the insurance premium-reserve processes." Thesis, University of Liverpool, 2015. http://livrepository.liverpool.ac.uk/2037227/.
Abstract:
This thesis deals with the stability analysis of linear discrete-time premium-reserve (P-R) systems in a stochastic framework. Such systems are characterised by a mixture of the premium pricing process and the medium- and long- term stability in the accumulated reserve (surplus) policy, and they play a key role in the modern actuarial literature. Although the mathematical and practical analysis of P-R systems is well studied and motivated, their stability properties have not been studied thoughtfully and they are restricted in a deterministic framework. In Engineering, during the last three decades, many useful techniques are developed in linear robust control theory. This thesis is the first attempt to use some useful tools from linear robust control theory in order to analyze the stability of these classical insurance systems. Analytically, in this thesis, P-R systems are first formulated with structural properties such that time-varying delays, random disturbance and parameter uncertainties. Then as an extension of the previous literature, the results of stabilization and the robust H-infinity control of P-R systems are modelled in stochastic framework. Meanwhile, the risky investment impact on the P-R system stability condition is shown. In this approach, the potential effects from changes in insurer's investment strategy is discussed. Next we develop regime switching P-R systems to describe the abrupt structural changes in the economic fundamentals as well as the periodic switches in the parameters. The results for the regime switching P-R system are illustrated by means of two different approaches: markovian and arbitrary regime switching systems. Finally, we show how robust guaranteed cost control could be implemented to solve an optimal insurance problem. In each chapter, Linear Matrix Inequality (LMI) sufficient conditions are derived to solve the proposed sub-problems and numerical examples are given to illustrate the applicability of the theoretical findings.
44
Hellman, Daniel. "Tidsvariabla system och robust styrning." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2399.
Abstract:
Dynamiken för en starkt accelerande robot har modellerats. Modellen linjäriseras så att roboten beskrivs som ett linjärt tidsvariabelt system. Denna representation beskriver roboten väl då robotens anblåsningsvinkel, vilket är vinkeln mellan robotkroppen och robotens hastighet, är liten. Eftersom det ej är möjligt att mäta alla robotens tillstånd har en observatör tagits fram i form av ett Kalmanfilter. Problematik vid framtagandet av observatören diskuteras i rapporten. Den linjära tidsvariabla modellen har använts till att ta fram två regulatorer. En LQ-regulator och en H∞-regulator. Hur dessa tas fram och vilka problem som finns diskuteras i rapporten. För att kunna se fördelar och nackdelar beträffande prestanda och robusthet har en mängd tester gjort. Testerna visar på olika fördelar hos de olika reglersystemen. Till exempel är det lättare att få bra prestanda med LQ-regulatorn än H∞-regulatorn om systemet som styrs stämmer bra överens med systemet som använts vid reglerdesignen. H∞-regulatorn har bättre förmåga att anpassa sig till modellförändringar givet att observatören gör bra skattningar. Det är dock svårt att utnämna en generell vinnare.
45
Osinuga, Mobolaji. "Weight optimization in H∞ loop-shaping control and applications." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/weight-optimization-in-hinfinity-loopshaping-control-and-applications(58102c35-9a75-44af-9879-4f142ca4aa09).html.
Abstract:
The primary objective of this thesis is to leverage on the framework of H∞ loop-shaping control to formulate efficient and powerful optimization algorithms in LMI framework for the synthesis of performance loop-shaping weights. The H∞ loop-shaping design procedure is an efficient controller synthesis technique that combines classical loop-shaping concepts with H∞ synthesis. This procedure establishes a good tradeoff between robust stability and robust performance of a closed-loop system in a systematic manner. However, the selection of pre- and/or post-compensators, a crucial step in the design procedure, is nontrivial as factors such as the right half plane poles/zeros of the nominal plant, roll-off rate around the crossover frequency, strength of cross-coupling in multi-input multi-output systems, expected bandwidth, etc. must be adequately considered.Firstly, a frequency-dependent weight optimization framework is formulated in state-space form in order to remove the dependency on frequency while retaining the objective of maximizing the robust stability margin of a closed-loop system. This formulation facilitates the synthesis of low-order controllers, which is desirable from an implementation perspective.A weight optimization framework that incorporates smoothness constraints in order to prevent the cancellation of important modes of the system, for example, lightly damped poles/zeros of flexible structures, is subsequently formulated. The proposed formulation is intuitive from a design perspective as the smoothness constraints are expressed as gradient constraints on a log-log scale in dB/decade, consistent with the notation used in Bode plot for single-input single-output systems and singular value plots for multi-input multi-output systems.Thereafter, an optimization framework that maximizes the robust performance of a closed-loop system is presented. The philosophy in this framework is in line with practical design objectives that give the best achievable robust performance on a particular problem once a level of robust stability margin is demanded.Lastly, a novel unmanned vehicle is proposed. The vehicle uses a full six-degree-of-freedom tri-rotor actuation, capable of fully decoupled thrust and torque vectoring in all the 3D space. This vehicle can act as an unmanned ground vehicle or unmanned aerial vehicle, but the objective herein is restricted to the upright stability of the vehicle while operating on the ground as this is a precursor to rolling motion. The full nonlinear model of the vehicle is derived and linearized for subsequent controller synthesis, and this is thereafter validated by means of numerical simulations.
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King, Diego Melo. "Controle H2 / H "Infinito' via desigualdades matriciais lineares para atenuação de vibrações em estruturas flexiveis." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265042.
Abstract:
Orientador: Alberto Luiz SerpaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Este trabalho tem como objetivo verificar a ação de uma formulação obtida para o controle misto H2/ Hoo via realimentação de saída de uma estrutura modelada por elementos finÍtos. Para isso, também se verificaram as respectivas formulações via realimentação de saída dos controles H2 e Hoo isoladamente, para que os resultados obtidos em cada um deles pudessem validar o equacionamento descrito neste trabalho para o controle misto e servissem de parâmetro para balizar os seus resultados esperados. Os equacionamentos dos controladores seguiram a formulação da programação semi-definida, isto é, minimizam um objetivo linear sujeito a restrições em forma de LMI. Estas LMI representam as condições de estabilidade a que o sistema está sujeito, e as características da interação entre o modelo e a ação do controlador. Uma vez definidas todas estas condições, o problema de minimização, que é convexo, foi implementado para ser resolvido através do Matlab. Os resultados obtidos pela formulação para o controle misto também foram comparados com resultados produzidos pelas formulações clássicas do próprio Matlab, para que este último também servisse como um aferidor dos resultados da formulação apresentada neste trabalho. O modelo da estrutura, definida para uma viga engastada em balanço, também foi calculado através do Matlab, discretizada nos elementos finÍtos apropriados. As determinações das matrizes de massa, de rigidez elástica e de amortecimento, esta determinada pelo modelo de amortecimento proporcional, fazem a ligação com as matrizes de estado que representam o sistema na formulação utilizada para os controladores. Os resultados do controle misto mostram que a formulação convexa do controle via realimentação de saída é viável. Os valores apresentados pelas normas H2 e Hoominimizadas do sistema, e as respostas deste a uma entrada aleatória exógena, exibem a capacidade do controlador misto. Mesmo para um controle não-colocado, as vibrações da estrutura são atenuadas junto com a minimização do sinal de controle, e os picos da resposta em freqüência, vistos nas funções de resposta em freqüência, são reduzidos
Abstract: This work has the goal to verify the action of a mixed H2/ Hoo control formulation through output feedback for a structure modelIed in finite elements. Therefore, the pure H2 and Hoo control formulations through output feedback are also verified to validate the described equations in this work for the mixed control and show a reference to their expected results. These formulations are based on the semi-definite programming formulation, and consist of minimizing a linear objective subjected to LMI constraints. These LMI represent the system stability conditions and interaction characteristics between the model and the controller. Once all these conditions are settled, the minimization problem, which is convex, was solved through the Matlab software. The results obtained for the mixed control formulation were compared to the classical results obtained with the Matlab. The purpose is to validate the results ofthe formulation obtained in this work. The structure model, defined for a cantilever beam, was also obtained through the Matlab using the finite elements technique. The mass, stiffness and damping matrices, this last one obtained by the proportional damping model, make the connections to the state-space matrices representing the system for the controller formulation. The results obtained for the mixed control show the convex formulation to output feedback may offer good results. The minimized values of H2 and H00 norms and the behaviour of the controlIed systeIl! for the external random input show the capability of mixed control. Even for a noncollocated control problem the structure vibrations are reduced together with the control signal minimization, and the frequency response peaks, visible in the frequency response graphs, are also reduced.
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica
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Silva, João Henrique Pereira [UNESP]. "Controle robusto h-infinito chaveado para sistemas lineares." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/87077.
Abstract:
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silva_jhp_me_ilha.pdf: 1343237 bytes, checksum: 23b5f5f368f8d9c7eb211e7c5d1826a7 (MD5)Neste trabalho são propostas condições suficientes para o controle H∞ chaveado de sistemas lineares incertos contínuos no tempo. A técnica abordada para este estudo consiste na utilização de uma função quadrática de Lyapunov e em um caso mais específico, uma função quadrática de Lyapunov por partes. A análise de estabilidade é descrita por meio de Desigualdades Matriciais Lineares (em inglês: Linear Matrix Inequalities), LMIs, que, quando factíveis, são facilmente resolvidas por meio de ferramentas disponíveis na literatura de programação convexa. Assim é apresentada uma metodologia de chaveamento do ganho de realimentação do vetor de estado, que assegura também o critério de desempenho H∞, cuja estratégia busca a obtenção do mínimo valor da derivada de uma função de Lyapunov quadrática. O método foi estendido com o emprego de uma função de Lyapunov quadrática por partes, cujo projeto é baseado nas desigualdades de Lyapunov-Metzler. É demonstrado que esta nova estratégia de chaveamento, além de uma implementação simples, oferece uma flexibilização das LMIs em comparação com os métodos convencionais que também utilizam o controle H∞. A teoria é ilustrada através de exemplos, que permitem comprovar o bom desempenho dos métodos propostos, incluindo a implementação em laboratório do controle de um helicóptero 3-DOF de bancada da QUANSER, sujeito a falhas estruturais.
Sufficient conditions for the switched H∞ control of continuous-time uncertain linear systems are proposed. The technique discussed in this study is based on quadratic Lyapunov functions and a piecewise quadratic Lyapunov functions. The stability analysis is described by LMIs that, when feasible, are easily solved by available tools in the convex programming literature. Thus, a methodology for designing the switching of state vector feedback gains, which also ensures H∞ performance criterion, is presented. This new procedure chooses the state feedback gain that returns the minimum value of the time derivative of the Lyapunov function. The method was extended to a piecewise quadratic Lyapunov function and is designed from the solution of Lyapunov-Metzler inequalities. It is shown that this switching strategy, beyond a simple implementation, offers a relaxation in the LMIs, when compared with the conventional methods used in H∞ control. The procedure are illustrated by means of examples, including an implementation in the control of a 3-DOF helicopter, subject to structural failures.
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Silva, João Henrique Pereira. "Controle robusto h-infinito chaveado para sistemas lineares /." Ilha Solteira, 2013. http://hdl.handle.net/11449/87077.
Abstract:
Orientador: Marcelo Carvalho Minhoto TeixeiraBanca: Edvaldo Assunção
Banca: Márcio Roberto Covacic.
Resumo: Neste trabalho são propostas condições suficientes para o controle H∞ chaveado de sistemas lineares incertos contínuos no tempo. A técnica abordada para este estudo consiste na utilização de uma função quadrática de Lyapunov e em um caso mais específico, uma função quadrática de Lyapunov por partes. A análise de estabilidade é descrita por meio de Desigualdades Matriciais Lineares (em inglês: Linear Matrix Inequalities), LMIs, que, quando factíveis, são facilmente resolvidas por meio de ferramentas disponíveis na literatura de programação convexa. Assim é apresentada uma metodologia de chaveamento do ganho de realimentação do vetor de estado, que assegura também o critério de desempenho H∞, cuja estratégia busca a obtenção do mínimo valor da derivada de uma função de Lyapunov quadrática. O método foi estendido com o emprego de uma função de Lyapunov quadrática por partes, cujo projeto é baseado nas desigualdades de Lyapunov-Metzler. É demonstrado que esta nova estratégia de chaveamento, além de uma implementação simples, oferece uma flexibilização das LMIs em comparação com os métodos convencionais que também utilizam o controle H∞. A teoria é ilustrada através de exemplos, que permitem comprovar o bom desempenho dos métodos propostos, incluindo a implementação em laboratório do controle de um helicóptero 3-DOF de bancada da QUANSER, sujeito a falhas estruturais.
Abstract: Sufficient conditions for the switched H∞ control of continuous-time uncertain linear systems are proposed. The technique discussed in this study is based on quadratic Lyapunov functions and a piecewise quadratic Lyapunov functions. The stability analysis is described by LMIs that, when feasible, are easily solved by available tools in the convex programming literature. Thus, a methodology for designing the switching of state vector feedback gains, which also ensures H∞ performance criterion, is presented. This new procedure chooses the state feedback gain that returns the minimum value of the time derivative of the Lyapunov function. The method was extended to a piecewise quadratic Lyapunov function and is designed from the solution of Lyapunov-Metzler inequalities. It is shown that this switching strategy, beyond a simple implementation, offers a relaxation in the LMIs, when compared with the conventional methods used in H∞ control. The procedure are illustrated by means of examples, including an implementation in the control of a 3-DOF helicopter, subject to structural failures.
Mestre
49
Moghaddam, Majid M. "Robust H¦0¦0 - based control of flexible joint robots with harmonic drive transmission." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ28295.pdf.
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Gibson, Scott Brian. "Improved Dynamic Modeling and Robust Control of Autonomous Underwater Vehicles." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/84468.
Abstract:
In this dissertation, we seek to improve the dynamic modeling and control of autonomous underwater vehicles (AUVs). We address nonlinear hydrodynamic modeling, simplifying modeling assumptions, and robust control for AUVs. In the literature, various hydrodynamic models exist with varying model complexity and with no universally accepted model. We compare various hydrodynamic models traditionally employed to predict the motion of AUVs by estimating model coefficients using least-squares and adaptive identifier techniques. Additionally, we derive several dynamic models for an AUV employing varying sets of simplifying assumptions. We experimentally assess the efficacy of invoking typical assumptions to simplify the equations of motion.
For robust control design, we develop a procedure for designing robust attitude controllers based on loop-shaping ideas. We specifically address the challenge of adjusting the desired actuator bandwidth in a loop-shaping design framework. Finally, we present a novel receding horizon H-infinity control algorithm to improve the control of autonomous vehicle systems working in high-disturbance environments, employing a Markov jump linear system framework to model the stochastic and non-stationary disturbances experienced by the vehicle. Our main results include a new Bounded Real Lemma for stability analysis and an output feedback H-infinity control synthesis algorithm.
This work uses numerical simulations and extensive field trials of autonomous underwater vehicles to identify and verify dynamic models and to validate control algorithms developed herein.Ph. D.