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Experimental results on the nonlinear H(infinity) control via quasi-LPV representation and game theory for wheeled mobile robots

INOUE, Roberto S.; SIQUEIRA, Adrian A. G.; TERRA, Marco H.
Fonte: CAMBRIDGE UNIV PRESS Publicador: CAMBRIDGE UNIV PRESS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
75.87%
In this paper, nonlinear dynamic equations of a wheeled mobile robot are described in the state-space form where the parameters are part of the state (angular velocities of the wheels). This representation, known as quasi-linear parameter varying, is useful for control designs based on nonlinear H(infinity) approaches. Two nonlinear H(infinity) controllers that guarantee induced L(2)-norm, between input (disturbances) and output signals, bounded by an attenuation level gamma, are used to control a wheeled mobile robot. These controllers are solved via linear matrix inequalities and algebraic Riccati equation. Experimental results are presented, with a comparative study among these robust control strategies and the standard computed torque, plus proportional-derivative, controller.

Linear parameter varying control design for rotating systems supported by journal bearings

Siqueira, Adriano Almeida Gonçalves; Nicoletti, Rodrigo; Norrick, Nicklas; Cavalca, Katia Lucchesi; de Castro, Helio Fiori; Bauer, Jens; Dohnal, Fadi
Fonte: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD; LONDON Publicador: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD; LONDON
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
75.89%
Linear parameter varying (LPV) control is a model-based control technique that takes into account time-varying parameters of the plant. In the case of rotating systems supported by lubricated bearings, the dynamic characteristics of the bearings change in time as a function of the rotating speed. Hence, LPV control can tackle the problem of run-up and run-down operational conditions when dynamic characteristics of the rotating system change significantly in time due to the bearings and high vibration levels occur. In this work, the LPV control design for a flexible shaft supported by plain journal bearings is presented. The model used in the LPV control design is updated from unbalance response experimental results and dynamic coefficients for the entire range of rotating speeds are obtained by numerical optimization. Experimental implementation of the designed LPV control resulted in strong reduction of vibration amplitudes when crossing the critical speed, without affecting system behavior in sub- or supercritical speeds. (C) 2012 Elsevier Ltd. All rights reserved.; CAPES/DAAD; CAPES-DAAD; CNPq; CNPq; FAPESP; Fapesp

Modelagem computacional de dados e controle inteligente no espaço de estado; State space computational data modelling and intelligent control

Annabell Del Real Tamariz
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/07/2005 PT
Relevância na Pesquisa
56.04%
Este estudo apresenta contribuições para modelagem computacional de dados multivariáveis no espaço de estado, tanto com sistemas lineares invariantes como com variantes no tempo. Propomos para modelagem determinística-estocástica de dados ruidosos, o Algoritmo MOESP_AOKI. Propomos, utilizando Redes Neurais Recorrentes multicamadas, algoritmos para resolver a Equação Algébrica de Riccati Discreta bem como a Inequação Algébrica de Riccati Discreta, via Desigualdades Matriciais Lineares. Propomos um esquema de controle adaptativo com Escalonamento de Ganhos, baseado em Redes Neurais, para sistemas multivariáveis discretos variantes no tempo, identificados pelo algoritmo MOESP_VAR, também proposto nesta tese. Em síntese, uma estrutura de controle inteligente para sistemas discretos multivariáveis variantes no tempo, através de uma abordagem que pode ser chamada ILPV (Intelligent Linear Parameter Varying), é proposta e implementada. Um controlador LPV Inteligente, para dados computacionalmente modelados pelo algoritmo MOESP_VAR, é concretizado, implementado e testado com bons resultados.; This study presents contributions for state space multivariable computational data modelling with discrete time invariant as well as with time varying linear systems. A proposal for Deterministic-Estocastica Modelling of noisy data...

Linear parameter varying control design for rotating systems supported by journal bearings

Goncalves Siqueira, Adriano Almeida; Nicoletti, Rodrigo; Norrick, Nicklas; Cavalca, Katia Lucchesi; de Castro, Helio Fiori; Bauer, Jens; Dohnal, Fadi
Fonte: Elsevier; London Publicador: Elsevier; London
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
75.89%
Linear parameter varying (LPV) control is a model-based control technique that takes into account time-varying parameters of the plant. In the case of rotating systems supported by lubricated bearings, the dynamic characteristics of the bearings change in time as a function of the rotating speed. Hence, LPV control can tackle the problem of run-up and run-down operational conditions when dynamic characteristics of the rotating system change significantly in time due to the bearings and high vibration levels occur. In this work, the LPV control design for a flexible shaft supported by plain journal bearings is presented. The model used in the LPV control design is updated from unbalance response experimental results and dynamic coefficients for the entire range of rotating speeds are obtained by numerical optimization. Experimental implementation of the designed LPV control resulted in strong reduction of vibration amplitudes when crossing the critical speed, without affecting system behavior in sub- or supercritical speeds. (C) 2012 Elsevier Ltd. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A vibroacoustic application of modeling and control of linear parameter-varying systems

De Caigny,Jan; Camino,Juan F.; Oliveira,Ricardo C. L. F.; Peres,Pedro L. D.; Swevers,Jan
Fonte: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM Publicador: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 EN
Relevância na Pesquisa
95.95%
This paper applies recent advances in both modeling and control of Linear Parameter-Varying (LPV) systems to a vibroacoustic setup whose dynamics is highly sensitive to variations in the temperature. Based on experimental data, an LPV model is derived for this system using the State-space Model Interpolation of Local Estimates (SMILE) technique. This modeling technique interpolates linear time-invariant models estimated at distinct operating conditions of the system (in this case, different temperatures). Using the obtained LPV model, gain-scheduled and robust multiobjective H2/H∞ state feedback controllers are designed such that can consider a priori known bounds on the rate of parameter variation. Numerical simulations using the closed-loop systems are performed to validate the controllers and to show the advantages and versatility of the proposed techniques.

Robust scheduling control of aeroelasticity.

Prime, Zebb David
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
Relevância na Pesquisa
86%
Aeroelasticity is a broad term describing the often complex interactions between structural mechanics and aerodynamics. Aeroelastic phenomena such as divergence and flutter are potentially destructive, and thus must be avoided. Passive methods to avoid undesirable aeroelastic phenomena often involve the addition of mass and/or limiting the achievable performance of the aircraft. However, active control methods allow both for the suppression of undesirable aeroelastic phenomena, and for utilisation of desirable aeroelastic phenomena using actuators, thus increasing performance without the associated weight penalty of passive systems. The work presented in this thesis involves the design, implementation and experimental validation of novel active controllers to suppress undesirable aeroelastic phenomena over a range of airspeeds. The controllers are constructed using a Linear Parameter Varying (LPV) framework, where the plant and controllers can be represented as linear systems which are functions of a parameter, in this case airspeed. The LPV controllers are constructed using Linear Matrix Inequalities (LMIs), which are convex optimisation problems that can be used to represent many linear control objectives. Using LMIs, these LPV controllers can be constructed such that they self-schedule with airspeed and provide upper performance bounds during the design process. The aeroelastic phenomena being suppressed by these controllers are Limit-Cycle Oscillations (LCOs)...

Control design for a hypersonic aircraft using a switched linear parameter-varying system approach

Lu, Q.; Zhang, L.; Shi, P.; Karimi, H.
Fonte: Professional Engineering Publishing Ltd Publicador: Professional Engineering Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 EN
Relevância na Pesquisa
95.97%
This paper is concerned with the control problem of an air-breathing hypersonic aircraft using a switched linear-parameter-varying systems approach. The rigid non-linear longitudinal model of a generic hypersonic aircraft is adopted with the aim of verifying the design methodology of the developed controller and switching logic. By linearizing the non-linear model of the hypersonic aircraft at trim points and dividing the velocity range into several parts, a switched linear parameter-varying model for the underlying system is derived. With the aid of multiple Lyapunov-like functions technique, controllers that ensure the tracking of given commands of the closed-loop system are designed under mode-independent and mode-dependent switching logic, respectively. Simulation results for the generic hypersonic aircraft show the effectiveness of the proposed method and the advantages of the mode-dependent switching logic.; Qiugang Lu, Lixian Zhang, Peng Shi and Hamid Reza Karimi

Gain-scheduled guaranteed cost control of LPV systems with time-varying state and input delays

Wang, J.; Wang, J.; Shi, P.; Yuan, W.
Fonte: ICIC International Publicador: ICIC International
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
Relevância na Pesquisa
75.93%
This paper investigates the problem of delay-dependent guaranteed cost con- trol for linear parameter-varying systems with time-varying state and input delays. At- tention is focused on the design of gain-scheduled guaranteed cost controller such that the resulting closed-loop system is asymptotically stable and a parameter-dependent cost performance is also satisfied. By parameter-dependent Lyapunov approach, a sufficient condition is proposed for designing gain-scheduled state feedback controller, in which the controller gain is dependent on the scheduling parameters. A numerical example is pro- vided to illustrate the proposed method.; Junling Wang, Junming Wang, Wei Yuan and Peng Shi

Reference tracking control of hypersonic vehicles using switched linear parameter-varying approach

Lu, Q.; Zhang, L.; Shi, P.; Karimi, H.
Fonte: IEEE; USA Publicador: IEEE; USA
Tipo: Conference paper
Publicado em //2013 EN
Relevância na Pesquisa
65.8%
This paper is concerned with the control problem of the air-breathing hypersonic vehicle using switched linear parameter-varying (LPV) systems approach. By linearizing the nonlinear model of the hypersonic vehicle at trim points and dividing the velocity scope into several partitions, a switched LPV model for the underlying systems is derived. With aid of multiple Lyapunov-like functions technique, the controllers ensuring the tracking of given commands of the closed-loop system are designed under the mode-independent and mode-dependent switching logics, respectively. Simulation results for the hypersonic vehicle show the effectiveness of the proposed method and the advantages of the mode-dependent switching logic.; Qiugang Lu, Lixian Zhang, Peng Shi, and Hamid Reza Karimi

Predictive control of convex polyhedron LPV systems with Markov jumping parameters

Yin, Y.; Liu, F.; Shi, P.; Karimi, H.
Fonte: IEEE; USA Publicador: IEEE; USA
Tipo: Conference paper
Publicado em //2012 EN
Relevância na Pesquisa
76%
The problem of receding horizon predictive control of stochastic linear parameter varying systems is discussed. First, constant coefficient matrices are obtained at each vertex in the interior of linear parameter varying system, and then, by considering semi-definite programming constraints, weight coefficients between each vertex are calculated, and the equal coefficients matrices for the time variable system are obtained. Second, in the given receding horizon, for each mode sequence of the stochastic convex polyhedron linear parameter varying systems, the optimal control input sequences are designed in order to make the states into a terminal invariant set. Outside of the receding horizon, stability of the system is guaranteed by searching a state feedback control law. Finally, receding horizon predictive controller is designed in terms of linear matrix inequality for such system. Simulation example shows the validity of this method.; Yin Yanyan, Liu Fei, Shi Peng, Karimi Hamid Reza

Seismic response control of structures using novel adaptive passive and semi-active variable stiffness and negative stiffness devices

Pasala, Dharma Theja
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
55.99%
Current seismic design practice promotes inelastic response in order to reduce the design forces. By allowing the structure to yield while increasing the ductility of the structure, the global forces can be kept within the limited bounds dictated by the yield strength. However, during severe earthquakes, the structures undergo significant inelastic deformations leading to stiffness and strength degradation, increased interstory drifts, and damage with residual drift. The research presented in this thesis has three components that seek to address these challenges. To prevent the inelastic effects observed in yielding systems, a new concept “apparent weakening” is proposed and verified through shake table studies in this thesis. “Apparent weakening” is introduced in the structural system using a complementary “adaptive negative stiffness device” (NSD) that mimics "yielding” of the global system thus attracting it away from the main structural system. Unlike the concept of weakening and damping, where the main structural system strength is reduced, the new system does not alter the original structural system, but produces effects compatible with an early yielding. Response reduction using NSD is achieved in a two step sequence. First the NSD...

Controle H 'INFINITO' não linear de robôs manipuladores subatuados; Nonlinear H'INFINITO' control of underactuated robot manipulators

Siqueira, Adriano Almeida Gonçalves
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/07/2004 PT
Relevância na Pesquisa
55.93%
Este trabalho apresenta o desenvolvimento, implementação e análise de técnicas de controle H 'INFINITO' não lineares para robôs manipuladores subatuados, sujeitos a incertezas paramétricas e distúrbios externos. Na primeira parte, duas abordagens são consideradas para robôs manipuladores individuais subatuados. A primeira abordagem consiste em representar robôs manipuladores como um sistema não linear na forma quase-linear com parâmetros variantes e utilizar técnicas de controle H 'INFINITO' para sistemas lineares a parâmetros variantes baseadas em desigualdades matriciais lineares. Na segunda abordagem, uma solução explícita do problema de controle H 'INFINITO' não linear para robôs manipuladores é encontrada via teoria dos jogos diferenciais. Com este mesmo procedimento, implementam-se também os controles misto H'IND.2'/H 'INFINITO' não linear, adaptativo H 'INFINITO' não linear e adaptativo H 'INFINITO' não linear com redes neurais para robôs manipuladores. Também é desenvolvido um sistema tolerante a falhas para robôs manipuladores baseado em sistemas Markovianos e em controladores Markovianos H'IND.2'...

Controle de sistemas dinamicos : estabilidade absoluta, saturação e bilinearidade; Control of dynamic systems : absolute stability, saturation and bilinearity

Tais Calliero Tognetti
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 06/11/2009 PT
Relevância na Pesquisa
55.83%
Esta tese apresenta contribuições para a solução de problemas de análise de estabilidade e síntese de controladores por realimentação de estados de sistemas dinâmicos que possuem elementos não-lineares, por meio de condições na forma de desigualdades matriciais lineares e funções de Lyapunov. Para sistemas chaveados sujeitos a saturação nos atuadores, são fornecidas condições convexas para o cálculo de ganhos chaveados e robustos. A saturação é modelada como uma não-linearidade de setor e uma estimativa do domínio de estabilidade é determinada. Para sistemas lineares com incertezas politópicas e não-linearidades pertencentes a setores, são fornecidas condições convexas de dimensão finita para construir funções de Lur'e com dependência polinomial homogênea nos parâmetros. Se satisfeitas, as condições garantem a estabilidade para todo o domínio de incertezas e para todas as não-linearidades pertencentes ao setor e permitem o cômputo de controladores estabilizantes robustos por realimentação linear e não-linear. Para sistemas bilineares instáveis, contínuos e discretos no tempo, é proposto um procedimento para calcular um ganho estabilizante de controle por realimentação de estados. O método baseia-se na solução alternada de dois problemas de otimização convexa descritos por desigualdades matriciais lineares...

Indirect-adaptive Model Predictive Control for Linear Systems with Polytopic Uncertainty

Di Cairano, Stefano
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 23/09/2015
Relevância na Pesquisa
55.83%
We develop an indirect-adaptive model predictive control algorithm for uncertain linear systems subject to constraints. The system is modeled as a polytopic linear parameter varying system where the convex combination vector is constant but unknown. Robust constraint satisfaction is obtained by constraints enforcing a robust control invariant. The terminal cost and set are constructed from a parameter-dependent Lyapunov function and the associated control law. The proposed design ensures robust constraint satisfaction and recursive feasibility, is input-to-state stable with respect to the parameter estimation error and it only requires the online solution of quadratic programs.

On the Fundamental Properties of Linear Parameter-Varying Dynamic Systems Under Parametrical Multi-Perturbations. Applications to Time-Delay Systems. Preliminary Results

De la Sen, M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/03/2008
Relevância na Pesquisa
65.83%
This paper deals with a unifying approach to the problems of computing the admissible sets of parametrical multi perturbations in appropriate bounded sets such that some fundamental properties of parameter-varying linear dynamic systems are maintained provided that the so-called (i.e. perturbation-free) nominal system possesses such properties. The sets of parametrical multi perturbations include any combinations of parametrical multi perturbations in the matrix of dynamics as well as in the control, output and input-output interconnection matrices which belong to some prescribed bounded domain in the complex space. The various properties which are investigated are controllability, observability, output controllability and existence of minimal state-space realizations together with the associate existence or not of associate decoupling, transmission and invariant zeros. All the matrices of parameters including the nominal and the disturbed ones which parameterize the dynamic system may be real or complex. The radii of the multi- parametrical perturbations are calculated in a simple way. The obtained results are then applied to systems subject to a finite number of point internal delays and parametrical multi perturbations by comparing the state- space descriptions of such systems with the general descriptions previously investigated. In particular...

An Overview of Integral Quadratic Constraints for Delayed Nonlinear and Parameter-Varying Systems

Pfifer, Harald; Seiler, Peter
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/04/2015
Relevância na Pesquisa
65.79%
A general framework is presented for analyzing the stability and performance of nonlinear and linear parameter varying (LPV) time delayed systems. First, the input/output behavior of the time delay operator is bounded in the frequency domain by integral quadratic constraints (IQCs). A constant delay is a linear, time-invariant system and this leads to a simple, intuitive interpretation for these frequency domain constraints. This simple interpretation is used to derive new IQCs for both constant and varying delays. Second, the performance of nonlinear and LPV delayed systems is bounded using dissipation inequalities that incorporate IQCs. This step makes use of recent results that show, under mild technical conditions, that an IQC has an equivalent representation as a finite-horizon time-domain constraint. Numerical examples are provided to demonstrate the effectiveness of the method for both class of systems.

A Polynomial Chaos Framework for Designing Linear Parameter Varying Control Systems

Bhattacharya, Raktim
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
85.86%
Here we use polynomial chaos framework to design controllers for linear parameter varying (LPV) dynamical systems. We assume the scheduling variable to be random and use polynomial chaos approach to synthesize the controller for the resulting linear stochastic dynamical system. The stability of the LPV system is formulated as an exponential mean-square (EMS) stability problem. Two algorithms are presented that guarantee EMS stability of the stochastic system and correspond to parameter dependent and independent Lyapunov functions, respectively. LPV controllers from the polynomial chaos based framework is shown to outperform LPV controller from classical design for an example nonlinear system.; Comment: Published in ACC 2015

Optimal Linear Parameter-Varying Control Design for a Pressurized Water Reactors

Bodenheimer, Bobby; Bendotti, Pascale
Fonte: California Institute of Technology Publicador: California Institute of Technology
Tipo: Report or Paper; PeerReviewed Formato: application/pdf; application/postscript
Publicado em /01/1995
Relevância na Pesquisa
65.89%
The applicability of employing parameter-dependent control to a nuclear pressurized water reactor is investigated. The synthesis techque produces a controller which achieves specified performance against the worst-case time variation of a measurable parameter which enters the plant in a linear fractional manner. The plant can thus have widely varying dynamics over the operating range. The results indicate this control technique is comparable to linear control when small operating ranges are considered.

Linear Parameter-Varying Control of a Ducted Fan Engine

Bodenheimer, Bobby; Bendotti, Pascale; Kantner, Michael
Fonte: California Institute of Technology Publicador: California Institute of Technology
Tipo: Report or Paper; PeerReviewed Formato: application/pdf; application/postscript
Publicado em 16/01/1995
Relevância na Pesquisa
65.82%
Parameter-dependent control techniques are applied to a vectored thrust, ducted fan engine. The synthesis technique is based on the solution of Linear Matrix Inequalities and produces a controller which achieves specified performance against the worst-case time variation of measurable parameters entering the plant in a linear fractional manner. Thus the plant can have widely varying dynamics over the operating range. The controller designed performs extremely well, and is compared to an ℋ∞ controller.

Optimal economic planning and control for the management of ecosystems

Macksamie, Kevin
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
85.86%
In recent years the interest on sustainable systems has increased significantly. Among the many interested problems, creating and restoring sustainable ecosystems is a challenging and complex problem. One of the fundamental problems within this area is the imbalance between species that have a predator-prey relationship. Solutions involving management have become an integral player in many environments. Management systems typically use ad hoc methods to develop harvesting policies to control the populations of species to desired numbers. In order to amalgamate intelligence and structure, ecological systems require a diverse research effort from three primary fields: ecology, economics, and control theory. In this thesis, all three primary fields aforementioned are researched to develop a theoretical framework that includes an optimal trajectory planning system that exploits an ecosystem to maximize profits for the supporting community, and a robust control system design to track the optimal trajectories subjected to exogenous disturbances. Population ecology is used to select a model that identifies the key characteristics a management system needs to understand the behavior of the natural environment. A bioeconomic model is developed to relate the species populations to revenue. The nonlinear ecosystem is transformed into a linear parameter-varying (LPV) system that is then controlled using hinf synthesis and the gain scheduling methodology. The consequences of the results in this thesis are that optimal trajectories of an ecosystem can be obtained by constructing and solving a nonlinear programming problem (NLP)...