The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Kevin M. Passino - One of the best experts on this subject based on the ideXlab platform.
-
Control of discrete time nonlinear systems with a time-Varying Structure
Automatica, 2003Co-Authors: Raul Ordonez, Kevin M. PassinoAbstract:In this paper, we present a control methodology for a class of discrete time nonlinear systems that depend on a possibly exogenous scheduling variable. This class of systems consists of an interpolation of nonlinear dynamic equations in strict feedback form, and it may represent systems with a time-Varying nonlinear Structure. Moreover, this class of systems is able to represent some cases of gain scheduling control, Takagi-Sugeno fuzzy systems, as well as input-output realizations of nonlinear systems which are approximated via localized linearizations. We present two control theorems, one using what we call a ''global'' approach (akin to traditional backstepping), and a ''local'' approach, our main result, where backstepping is again used but the control law is an interpolation of local control terms. An aircraft wing rock regulation problem with Varying angle of attack is used to illustrate and compare the two approaches.
-
Adaptive control for a class of nonlinear time-Varying systems
Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148), 2001Co-Authors: Yixin Diao, Kevin M. PassinoAbstract:Adaptive control for nonlinear time-Varying systems is of both theoretical and practical importance. We present an adaptive control methodology for a class of nonlinear systems with a time-Varying Structure where radial basis function neural networks are used as on-line approximators. This class of systems is composed of interpolations of nonlinear subsystems which are input-output feedback linearizable. Without assumptions on rate of change of system dynamics, a stable indirect adaptive control method is presented with analysis of stability for all signals in the closed-loop as well as asymptotic tracking. The performance of the controller is demonstrated using a jet engine control problem.
-
Adaptive control for a class of nonlinear systems with a time-Varying Structure
IEEE Transactions on Automatic Control, 2001Co-Authors: R. Ordonez, Kevin M. PassinoAbstract:We present a direct adaptive control method for a class of uncertain nonlinear systems with a time-Varying Structure. We view the nonlinear systems as composed of a finite number of "pieces," which are interpolated by functions that depend on a possibly exogenous scheduling variable. We assume that each piece is in strict-feedback form, and show that the method yields stability of all signals in the closed-loop, as well as convergence of the state vector to a residual set around the equilibrium, whose size can be set by the choice of several design parameters. The class of systems considered is a generalization of the class of strict-feedback systems traditionally considered in the backstepping literature. We also provide design guidelines based on L/sub 2/ bounds on the transient.
-
Control for a class of nonlinear systems with a time-Varying Structure
arXiv: Optimization and Control, 2000Co-Authors: Raul Ordonez, Kevin M. PassinoAbstract:In this paper we present a direct adaptive control method for a class of uncertain nonlinear systems with a time-Varying Structure. We view the nonlinear systems as composed of a finite number of ``pieces,'' which are interpolated by functions that depend on a possibly exogenous scheduling variable. We assume that each piece is in strict feedback form, and show that the method yields stability of all signals in the closed-loop, as well as convergence of the state vector to a residual set around the equilibrium, whose size can be set by the choice of several design parameters. The class of systems considered here is a generalization of the class of strict feedback systems traditionally considered in the backstepping literature. We also provide design guidelines based on L-infinity bounds on the transient.
-
Control of continuous time nonlinear systems with a time-Varying Structure
Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334), 2000Co-Authors: R. Ordonez, Kevin M. PassinoAbstract:Presents a control methodology for several classes of continuous time nonlinear systems that depend on a possibly exogenous scheduling variable. These classes of systems consist of interpolations of nonlinear dynamic equations in strict feedback form, and they may represent systems with a time-Varying nonlinear Structure. Moreover, these classes of systems are able to represent some cases of gain scheduling control, as well as input-output realizations of nonlinear systems which are approximated via localized linearizations, and a subclass of linear time-Varying systems. The results we present attempt to establish a framework for a wide variety of control applications, where stability is proved using the backstepping methodology.
R. Ordonez - One of the best experts on this subject based on the ideXlab platform.
-
Adaptive Control Scheme for Plants with Time-Varying Structure Using On-line Parameter Estimation
Proceedings of the 44th IEEE Conference on Decision and Control, 2005Co-Authors: A. Gonzalez, R. OrdonezAbstract:A Direct Adaptive Control Scheme to stabilize strict feedback plants with a time-Varying Structure is presented. Semi-global asymptotic stability is achieved with limited knowledge of the plant dynamics. Simulation of the scheme using a slender delta wing rock phenomenon model as practical example, confirming the results of the mathematical formulation of the control scheme. Various initial conditions are simulated showing the ability of the scheme to stabilize the plant over a wide range of operation.
-
Adaptive control for a class of nonlinear systems with a time-Varying Structure
IEEE Transactions on Automatic Control, 2001Co-Authors: R. Ordonez, Kevin M. PassinoAbstract:We present a direct adaptive control method for a class of uncertain nonlinear systems with a time-Varying Structure. We view the nonlinear systems as composed of a finite number of "pieces," which are interpolated by functions that depend on a possibly exogenous scheduling variable. We assume that each piece is in strict-feedback form, and show that the method yields stability of all signals in the closed-loop, as well as convergence of the state vector to a residual set around the equilibrium, whose size can be set by the choice of several design parameters. The class of systems considered is a generalization of the class of strict-feedback systems traditionally considered in the backstepping literature. We also provide design guidelines based on L/sub 2/ bounds on the transient.
-
Wing rock regulation with a time-Varying angle of attack
Proceedings of the 2000 IEEE International Symposium on Intelligent Control. Held jointly with the 8th IEEE Mediterranean Conference on Control and Au, 2000Co-Authors: R. Ordonez, K.m. PassinoAbstract:We consider the problem of aircraft wing rock regulation given that the angle of attack is allowed to change with time. This is an extension beyond the results currently available in the literature on this application, since the complex nonlinear behavior of the wing rock phenomenon, and its qualitative dependence on the angle of attack have generally forced researchers to keep the angle of attack fixed in order to develop regulators. In some cases, those regulators are tested at other angles of attack, and this serves to claim robustness of the designs. Here, we apply newly developed techniques for nonlinear systems with a time-Varying Structure to this problem, and show that regulation can be achieved even when the angle of attack changes with time over a wide range.
-
Control of continuous time nonlinear systems with a time-Varying Structure
Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334), 2000Co-Authors: R. Ordonez, Kevin M. PassinoAbstract:Presents a control methodology for several classes of continuous time nonlinear systems that depend on a possibly exogenous scheduling variable. These classes of systems consist of interpolations of nonlinear dynamic equations in strict feedback form, and they may represent systems with a time-Varying nonlinear Structure. Moreover, these classes of systems are able to represent some cases of gain scheduling control, as well as input-output realizations of nonlinear systems which are approximated via localized linearizations, and a subclass of linear time-Varying systems. The results we present attempt to establish a framework for a wide variety of control applications, where stability is proved using the backstepping methodology.
-
Control of a class of discrete time nonlinear systems with a time-Varying Structure
Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304), 1999Co-Authors: R. Ordonez, Kevin M. PassinoAbstract:We present a control methodology for a class of discrete time nonlinear systems that depend on a possibly exogenous scheduling variable. This class of systems consists of an interpolation of nonlinear dynamic equations in strict feedback form, and it may represent systems with a time-Varying nonlinear Structure. Moreover, this class of systems allows for the representation of some cases of gain-scheduling control, as well as input-output realizations of nonlinear systems which are approximated via localized linearizations. The results we present attempt to establish a framework for a wide variety of control applications that fall within the general class of systems we consider.
S D Fassois - One of the best experts on this subject based on the ideXlab platform.
-
parametric identification of a time Varying Structure based on vector vibration response measurements
Mechanical Systems and Signal Processing, 2009Co-Authors: M D Spiridonakos, S D FassoisAbstract:Abstract The problem of parametric output-only identification of a time-Varying Structure based on vector random vibration signal measurements is considered. A functional series vector time-dependent autoregressive moving average (FS-VTARMA) method is introduced and employed for the identification of a “bridge-like” laboratory Structure consisting of a beam and a moving mass. The identification is based on three simultaneously measured vibration response signals obtained during a single experiment. The method is judged against baseline modelling based on multiple “frozen-configuration” stationary experiments, and is shown to be effective and capable of accurately tracking the dynamics. Additional comparisons with a recursive pseudo-linear regression VTARMA (PLR-VTARMA) method and a short time canonical variate analysis (ST-CVA) subspace method are made and demonstrate the method's superior achievable accuracy and model parsimony.
-
output only stochastic identification of a time Varying Structure via functional series tarma models
Mechanical Systems and Signal Processing, 2009Co-Authors: Aggelos G Poulimenos, S D FassoisAbstract:Abstract The problem of output-only stochastic identification of a Time-Varying (TV) laboratory Structure is considered for the first time via a Functional Series Time-Dependent AutoRegressive Moving Average (FS-TARMA) approach. The approach is based on the modelling of a single non-stationary vibration response via a non-stationary parametric FS-TARMA model. The steps and facets of the identification procedure are presented, and the obtained model is used for structural characteristics recovery and vibration signal analysis. For purposes of comparison, multiple “frozen-configuration” stationary experiments are also carried out and a sequence of “frozen” stationary models are identified. The results of the study demonstrate the applicability, effectiveness, and high accuracy of the non-stationary FS-TARMA approach in capturing and analyzing the TV structural dynamics.
More Avraam - One of the best experts on this subject based on the ideXlab platform.
-
On Magnetorheologic Elastomers for Vibration Isolation, Damping, and Stress Reduction in Mass-Varying Structures
Journal of Intelligent Material Systems and Structures, 2010Co-Authors: Christophe Collette, Gregory Kroll, Gregory Saive, Vincent Guillemier, More AvraamAbstract:This article considers two devices based on a magnetorheological elastomer (MRE): an MRE isolator under a frequency-Varying harmonic excitation and a MRE Dynamic Vibration Absorber (DVA) mounted on a frequency-Varying Structure under a random excitation. In the first case, it is shown that the commandability of the elastomer improves the reduction of the RMS value of the body displacement by 10%. In the second case, it is shown on a simple example that a MRE DVA, while not optimal, can reduce the stress in the Structure about 50% better than a classical DVA when the mass of the Structure changes 35%. This makes them suitable to avoid high stress in mass-Varying Structures, and delay some damage mechanisms like the emergence of cracks and fatigue.
-
Isolation and damping properties of magnetorheologic elastomers
Journal of Physics: Conference Series, 2009Co-Authors: Christophe Collette, Gregory Kroll, Gregory Saive, Vincent Guillemier, More Avraam, André PreumontAbstract:This paper considers two systems based on a magnetorheological elastomer (MRE): a MRE isolator under a frequency Varying harmonic excitation and a MRE Dynamic Vibration Absorber (DVA) mounted on a frequency-Varying Structure under a random excitation. It is shown that the commandability of the elastomer improves the isolation performances in the first case, and decreases the stress level in the Structure in the second case.
Clarence W. De Silva - One of the best experts on this subject based on the ideXlab platform.
-
On Modeling and Stability Analysis of Structurally-Varying Dynamic Systems
1992 American Control Conference, 1992Co-Authors: Jie Peng, Clarence W. De SilvaAbstract:The component-mode synthesis (CMS) technique is applied in the dynamic analysis of a class of linear systems that has a time-Varying Structure. The stability analysis of such systems is carried out based on tke model established using the CMS technique. The approach adopted is to decompose a time-Varying system into a series of subsystems. The interconnections among these subsystems are modeled as time-Varying constrains. The stability analysis of the overall system is based on the subsystem models and time-Varying constrains. The objective is to eventually utilize the stability and constraint information of subsystems to establish the stability of the overall system.
