Integration of controllers with smart structural systems require the controllers to consume less power and to be small in hardware size. These requirements pose as limits on the control input and the order of the controllers. Use of reduced order model of the plant in the controller design can cause spill over problems in the closed-loop system due to possible excitation of the unmodeled dynamics. In this paper, we present a method to design output feedback robust controllers for smart structures in the presence of control input limits considering unmodeled dynamics as additive uncertainty in the design. The performance requirements for the design are specified as regional pole placement constraints on the closed-loop poles. The controller design problem requires the maximization of damping ratio in the presence of additive uncertainty and control input limits. The resulting optimization problem for the controller design is formulated as a generalized eigenvalue problem involving linear matrix inequality (LMI) constraints. The proposed controller is designed and implemented on a multiinput-multioutput 3-mass smart structural test article. The tradeoffs involved in the controller design are analyzed and the performance and robustness specifications are verified experimentally


Electrical and Computer Engineering

Keywords and Phrases

LMI Constraints; MIMO 3-Mass Smart Structural Test Article; MIMO Systems; Additive Uncertainty; Closed Loop Systems; Closed-Loop Poles; Closed-Loop System; Control Input Limits; Control System Synthesis; Damping Ratio Maximization; Eigenvalues and Eigenfunctions; Feedback; Generalized Eigenvalue Problem; Input-Limited Smart Structural Systems; Intelligent Structures; Linear Matrix Inequality Constraints; Matrix Algebra; Multivariable Control Systems; Optimal Control; Optimal Controller Design; Output Feedback Robust Controller Design; Performance Specifications; Pole Assignment; Reduced Order Model; Reduced Order Systems; Regional Pole Placement Constraints; Robust Control; Robustness Specifications; Tradeoffs; Uncertain Systems; Unmodeled Dynamics; Unmodeled Dynamics Excitation

International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version

Final Version

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© 2001 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 2001