The Experts below are selected from a list of 204519 Experts worldwide ranked by ideXlab platform
Dennis S. Bernstein - One of the best experts on this subject based on the ideXlab platform.
-
Fixed-Structure discrete-time H 2 / H ∞ controller synthesis using the delta operator
International Journal of Control, 2002Co-Authors: R. Scott Erwin, Dennis S. BernsteinAbstract:This paper considers the Fixed-Structure, discrete-time mixed H 2 / H X controller synthesis problem in the delta operator (difference operator) framework. The differential operator and shift operator versions of the problem are reviewed for comparison, and necessary conditions are derived for all three formulations. A quasi-Newton/continuation algorithm is then used to obtain approximate solutions to these equations. Controllers are synthesized for two numerical examples, and the performance of the algorithm on the differential, difference and shift operator versions of the problems is compared.
-
Robust Fixed-Structure controller synthesis using the implicit small-gain bound
Journal of the Franklin Institute, 2000Co-Authors: Wassim M. Haddad, Joseph R. Corrado, Vijaysekhar Chellaboina, Dennis S. BernsteinAbstract:Abstract In this paper we explore the applicability of the implicit small-gain guaranteed cost bound for controller synthesis. For flexibility in controller synthesis, we adopt the approach of Fixed-Structure controller design which allows consideration of arbitrary controller Structures, including order, internal Structure, and decentralization. A numerical example that has been addressed in the literature by means of alternative guaranteed cost bounds is presented to demonstrate the Fixed-Structure/implicit small-gain approach to robust controller synthesis.
-
Fixed-Structure synthesis of induced-norm controllers
International Journal of Control, 2000Co-Authors: R. Scott Erwin, Dennis S. Bernstein, D.a. WilsonAbstract:This paper proposes a Fixed-Structure technique for synthesizing controllers that are optimal with respect to various operator norms. An optimal control problem is developed for each of these operator norms, and necessary conditions for sub-optimal performance are derived. Mixed-norm optimal control problems are also formulated. A continuation algorithm using quasi-Newton corrections is used to compute approximate solutions of the necessary conditions for a sequence of problems whose solutions approach an optimal controller. Optimal controllers with respect to each of the operator norms are synthesized for a 4th-order mass-spring-dashpot system.
-
Control design for the actex flight experiment using the robust, Fixed-Structure toolbox
Guidance Navigation and Control Conference and Exhibit, 1999Co-Authors: Scot L. Osburn, Dennis S. Bernstein, Joe Corrado, Scott Erwin, Wassim M. HaddadAbstract:In this paper, we implement Fixed-Structure controller synthesis methods to the ACTEX flight experiment. We show that the decentralized static output feedback formulation of Fixed-Structure controller synthesis can directly account for the control-Structure constraints of the ACTEX flight experiment. Finally, we show that the ACTEX controller Structure can be written as a decentralized static output feedback problem and obtain feedback controllers for suppressing broadband disturbances.
-
Fixed‐Structure robust controller synthesis via decentralized static output feedback
International Journal of Robust and Nonlinear Control, 1998Co-Authors: R. Scott Erwin, Andrew G. Sparks, Dennis S. BernsteinAbstract:SUMMARY This paper describes and illustrates a unified methodology for robust, Fixed-Structure controller synthesis. The approach is based upon direct Fixed-Structure controller synthesis using a decentralized static output feedback formulation as a general framework for representing a large class of controller Structures. Scaled Popov bounds for the real Structured singular value are used to account for real parameter uncertainty and provide the means for optimizing a worst-case H 2 cost bound with respect to the free parameters of the controller. Quasi-Newton optimization algorithms are used to solve the resulting numerical optimization problem. Initial stability multiplier and scaling matrices needed in scaled Popov synthesis are obtained by solving an LMI feasibility problem. Using both centralized and decentralized controller Structures, numerical results are obtained for a 16th-order acoustic duct model with uncertain damped natural frequencies and for a two-dimensional beam-spring model with uncertain actuator locations. ( 1998 John Wiley & Sons, Ltd.
Herbert Werner - One of the best experts on this subject based on the ideXlab platform.
-
Fixed-Structure LPV-IO controllers: An implicit representation based approach
Automatica, 2017Co-Authors: Simon Wollnack, Hossam S. Abbas, Roland Tóth, Herbert WernerAbstract:Abstract In this note, novel linear matrix inequality (LMI) analysis conditions for the stability of linear parameter-varying (LPV) systems in input–output (IO) representation form are proposed together with bilinear matrix inequality (BMI) conditions for Fixed-Structure LPV-IO controller synthesis. Both the LPV-IO plant model and the controller are assumed to depend affinely and statically on the scheduling variables. By using an implicit representation of the plant and the controller interaction, an exact representation of the closed-loop behavior with affine dependence on the scheduling variables is achieved. This representation allows to apply Finsler’s Lemma for deriving exact stability as well as exact quadratic performance conditions. A DK-iteration based solution is carried out to synthesize the controller. The main results are illustrated by a numerical example.
-
distributed Fixed Structure control of spatially interconnected systems
Advances in Computing and Communications, 2015Co-Authors: Simon Wollnack, Herbert WernerAbstract:Novel stability and quadratic performance conditions in LMI form are presented that allow the design of Fixed-Structure controllers for linear time-space-invariant spatially interconnected systems in input-output form. By using an implicit distributed input-output representation, Finsler's Lemma can be applied, while avoiding issues resulting from non-causality of spatially interconnected systems. An illustrative example is used to compare distributed Fixed-Structure and full-order designs to control spatially interconnected systems.
-
ACC - Distributed Fixed-Structure control of spatially interconnected systems
2015 American Control Conference (ACC), 2015Co-Authors: Simon Wollnack, Herbert WernerAbstract:Novel stability and quadratic performance conditions in LMI form are presented that allow the design of Fixed-Structure controllers for linear time-space-invariant spatially interconnected systems in input-output form. By using an implicit distributed input-output representation, Finsler's Lemma can be applied, while avoiding issues resulting from non-causality of spatially interconnected systems. An illustrative example is used to compare distributed Fixed-Structure and full-order designs to control spatially interconnected systems.
-
CDC - Distributed Fixed-Structure control of spatially interconnected LTSV systems
2015 54th IEEE Conference on Decision and Control (CDC), 2015Co-Authors: Simon Wollnack, Herbert WernerAbstract:Stability and quadratic performance LMI conditions are presented for spatially interconnected linear time-space-varying (LTSV) systems in input-output form. By extending our previous results, these conditions allow Fixed-Structure controller synthesis for spatially interconnected LTSV systems. The problem of spatio-temporal dynamic parameter dependence is avoided completely and issues resulting from non-causality of spatially interconnected systems do not occur. Fixed-Structure controller design is illustrated by means of a numerical example.
-
CDC - Fixed-Structure LPV controller synthesis based on implicit input output representations
52nd IEEE Conference on Decision and Control, 2013Co-Authors: Simon Wollnack, Herbert Werner, Hossam S. Abbas, Roland TóthAbstract:In this paper a novel LPV controller synthesis approach to design Fixed-Structure LPV controllers in input output (IO) form is presented. The LPV-IO model and the LPV-IO controller are assumed to depend affinely as well as statically on the scheduling variable. By using an implicit representation of the system model and the controller, an exact representation of the closed-loop behavior is achieved. Using Finsler's Lemma, novel stability conditions are derived in the form of linear matrix inequalities (LMIs). Based on these conditions a quadratic performance synthesis approach is introduced in form of bilinear matrix inequalities (BMIs) and solved using a DK-iteration based approach.
Tongwen Chen - One of the best experts on this subject based on the ideXlab platform.
-
CDC - A Fixed Structure topology for wireless networked control systems
2016 IEEE 55th Conference on Decision and Control (CDC), 2016Co-Authors: Ahmad W. Al-dabbagh, Tongwen ChenAbstract:This paper presents the formulation, modelling and design of a Fixed Structure topology for potential application in wireless networked control systems. The topology consists of a standard plant system, an output feedback controller system, and intermediate transfer and receiving network systems. The paper defines the topology and addresses the modelling of the closed-loop control system. It presents a modelling framework to design the controller, the transfer network, and the receiving network systems. Also, the paper discusses a design procedure of using shared network systems for a closed-loop control system with multiple plant and controller systems. The design procedures utilize LMI-based algorithms and deliver an internally stable closed-loop control system whose inputs and outputs satisfy an l 2 – l ∞ performance criterion. The practicality of the design procedures is demonstrated using an illustrative example.
-
modelling and control of wireless networked control systems a Fixed Structure approach
International Conference on Control Applications, 2015Co-Authors: Ahmad W Aldabbagh, Tongwen ChenAbstract:This paper proposes a system topology for potential use as a Wireless Networked Control System (WNCS). The topology has a plant to be regulated, a dedicated controller that makes control decisions, and an intermediate network of nodes. The network assists the controller in stabilizing the closed-loop system and provides the means for connecting the sensors and actuators of the plant and the inputs and outputs of the controller. Further, the paper presents a framework for modelling the closed-loop system such that controller and network systems can be designed. The paper also provides an LMI-based algorithm for computing optimal controller and network systems that achieve a stable closed-loop system while meeting performance measures. The deigned systems have a Fixed Structure and hence the associated design complexity is reduced. Finally, the paper also illustrates with examples the effectiveness of the proposed design and computational procedures.
Wassim M. Haddad - One of the best experts on this subject based on the ideXlab platform.
-
Optimal Fixed-Structure control for linear non-negative dynamical systems
International Journal of Robust and Nonlinear Control, 2004Co-Authors: Sergey G. Nersesov, Wassim M. Haddad, Vijaysekhar ChellaboinaAbstract:In this paper, we develop optimal output feedback controllers for set-point regulation of linear non-negative dynamical systems. Specifically, using a constrained Fixed-Structure control framework we develop optimal output feedback control laws that guarantee that the trajectories of the closed-loop system remain in the non-negative orthant of the state space for non-negative initial conditions. In addition, we characterize domains of attraction predicated on closed and open Lyapunov level surfaces contained in the non-negative orthant for unconstrained optimal linear-quadratic output feedback controllers. Output feedback controllers for compartmental systems with non-negative inputs are also given. Copyright © 2004 John Wiley & Sons, Ltd.
-
Robust Fixed-Structure controller synthesis using the implicit small-gain bound
Journal of the Franklin Institute, 2000Co-Authors: Wassim M. Haddad, Joseph R. Corrado, Vijaysekhar Chellaboina, Dennis S. BernsteinAbstract:Abstract In this paper we explore the applicability of the implicit small-gain guaranteed cost bound for controller synthesis. For flexibility in controller synthesis, we adopt the approach of Fixed-Structure controller design which allows consideration of arbitrary controller Structures, including order, internal Structure, and decentralization. A numerical example that has been addressed in the literature by means of alternative guaranteed cost bounds is presented to demonstrate the Fixed-Structure/implicit small-gain approach to robust controller synthesis.
-
Control design for the actex flight experiment using the robust, Fixed-Structure toolbox
Guidance Navigation and Control Conference and Exhibit, 1999Co-Authors: Scot L. Osburn, Dennis S. Bernstein, Joe Corrado, Scott Erwin, Wassim M. HaddadAbstract:In this paper, we implement Fixed-Structure controller synthesis methods to the ACTEX flight experiment. We show that the decentralized static output feedback formulation of Fixed-Structure controller synthesis can directly account for the control-Structure constraints of the ACTEX flight experiment. Finally, we show that the ACTEX controller Structure can be written as a decentralized static output feedback problem and obtain feedback controllers for suppressing broadband disturbances.
-
Robust Fixed-Structure controller synthesis using the implicit small gain bound
Proceedings of the 1997 American Control Conference (Cat. No.97CH36041), 1997Co-Authors: Wassim M. Haddad, Joseph R. Corrado, Vijaysekhar Chellaboina, Dennis S. BernsteinAbstract:We explore the applicability of the implicit small gain guaranteed cost bound for controller synthesis. For flexibility in controller synthesis, we adopt the approach of Fixed-Structure controller design which allows consideration of arbitrary controller Structures, including order, internal Structure, and decentralization. A numerical example that has been addressed by means of alternative guaranteed cost bounds is presented to demonstrate the Fixed-Structure/implicit small gain approach to robust controller synthesis.
-
Fixed Structure Computation of the Structured Singular Value
1993 American Control Conference, 1993Co-Authors: Wassim M. Haddad, Emmanuel G. Collins, R. MoserAbstract:This paper addresses the robest stability and performance analysis problem using a Fixed Structure approach of the Structured singular value. Specifically, using recent results on H 2 / H ? , a Riccati equation approach is formulated for complex-? with constant D-scales along with an H 2 performance bound. An optimization procedure is proposed in computing optimal D-scales with respect to the H 2 performance bound. Finally, it is shown that this new approach compares favorably to the standard Structured singular value involving frequency-dependent D-scales.
Toshiharu Sugie - One of the best experts on this subject based on the ideXlab platform.
-
synthesis of Fixed Structure robust controllers using a constrained particle swarm optimizer with cyclic neighborhood topology
Expert Systems With Applications, 2013Co-Authors: Ichiro Maruta, Dongho Song, Toshiharu SugieAbstract:The purpose of this paper is to develop design scheme based on an easy-to-use meta-heuristic approach with superior reliability and validity for Fixed-Structure robust controllers, satisfying both multiple control specifications and system stability conditions. For this purpose, a particle swarm optimizer is first developed, which reduces the probability of premature convergence to local optima in the PSO (particle swarm optimization) by exploiting the particle's local social learning based on the idea of cyclic-network topology. Next, it is shown how to obtain a Fixed-Structure robust controller with constraints on multiple H"~ specifications and system stability based on the developed PSO technique incorporated with a simple constraint handling method. Finally, typical numerical examples are studied to show the applicability of the proposed methodology to the synthesis of Fixed-Structure robust controllers. These examples clearly verify that the developed design scheme gives a novel and powerful impetus with remarkable reliability to Fixed-Structure robust controller syntheses.
-
Synthesis of Fixed-Structure robust controllers using the distributed particle swarm optimizer with cyclic-network topology
Proceedings of the 2011 American Control Conference, 2011Co-Authors: Ichiro Maruta, Toshiharu Sugie, Tae-hyoung KimAbstract:This paper discusses a new meta-heuristic approach with high reliability to the synthesis problem of Fixed-Structure robust controllers satisfying multiple control specifications. For this purpose, first, the particle swarm optimizer (PSO) with cyclic-network topology is developed. Such a neighborhood topology can ensure a good trade-off between exploration and exploitation ability of the swarm, which results in a significant reduction of the probability of premature convergence to local optima. Second, the proposed distributed PSO algorithm is incorporated with the simple constraint handling method [8] using a virtual objective function to handle multiple control specifications. Then, it is shown how to find optimal parameters of a Fixed-Structure controller guaranteeing the given specifications based on the developed PSO technique using cyclic-network topology. Third, a typical numerical example to demonstrate its effectiveness is given, which clearly shows that the proposed distributed PSO scheme gives a novel and powerful impetus to the Fixed Structure robust controller synthesis.
-
brief paper Fixed Structure h controller synthesis a meta heuristic approach using simple constrained particle swarm optimization
Automatica, 2009Co-Authors: Ichiro Maruta, Toshiharu SugieAbstract:This paper provides a design method of Fixed-Structure robust controllers satisfying multiple H"~ norm specifications by using a sort of randomized algorithms. First, a new tool to perform general constrained optimization is developed which does not need any gradient or derivative of the objective function. This tool is based on a particle swarm optimization (PSO), which has attracted a lot of attention recently in the evolutionary computation area due to the empirical evidence of its superiority in solving various non-convex problems. Second, it is shown how to design a Fixed-Structure controller satisfying given multiple H"~ specifications by using the developed optimization tool. Third, its effectiveness is evaluated through various numerical examples, because it is difficult to guarantee the performance of the proposed method theoretically due to the probabilistic nature of PSO. The simulation results demonstrate its effectiveness clearly.
-
Synthesis of Fixed-Structure H∞ controllers via Constrained Particle Swarm Optimization
IFAC Proceedings Volumes, 2008Co-Authors: Ichiro Maruta, Tae-hyoung Kim, Toshiharu SugieAbstract:Abstract This paper provides a design method of Fixed-Structure robust controllers satisfying multiple H∞ norm specifications by using a sort of randomized algorithms. First, a new tool to perform general constrained optimization is developed which does not need any gradient or derivative of the objective function. This tool is based on PSO (particle swarm optimization), which attracts a lot of attention recently in the evolutionary computation area due to its empirical evidence of its superiority in solving various non-convex problems. Second, it is shown how to design a Fixed-Structure controller satisfying given multiple H∞ specifications by using the developed optimization tool. Third, its effectiveness is evaluated through various numerical examples, because it is difficult to guarantee the performance of the proposed method theoretically due to a probabilistic nature of the PSO. The simulation results demonstrate its effectiveness clearly.
