OBSERVER-BASED ROBUST-H-INFINITY CONTROL LAWS FOR UNCERTAIN LINEAR-SYSTEMS

Based on the algebraic Riccati equation approach, this paper presents a simple, flexible method for designing full-order observer-based robust-H(infinity) control laws for linear systems with structured parameter uncertainty. The observer-based robust-H(infinity) output-feedback control law, obtained by solving three augmented algebraic Riccati equations, provides both robust stability and disturbance attenuation with H(infinity)-norm bound for the closed-loop uncertain linear system. Several tuning parameters are embedded into the augmented algebraic Riccati equations so that flexibility in finding the symmetric positive-definite solutions (and hence the robust-H(infinity) control laws) is significantly increased. A benchmark problem associated with a mass-spring system, which approximates the dynamics of a flexible structure, is used to illustrate the design methodologies, and simulation results are presented.