LQG/LTR-Based Robust Control of Composite Beams with Piezoelectric Devices

Abstract

The performance of an LQG/LTR-based multi-input multi-output robust vibration control system for a laminated composite beam is investigated. A finite element model based on a higher order shear defor mation theory and accounting for piezoelectric effects is developed. The model is thus applicable to both thick and thin laminated composite beams. The lateral strain is also incorporated in the model by a systematic re duction of two-dimensional plate constitutive equations. The mode superposition method is used to transform the coupled finite element equations of motion in the physical coordinates into a set of reduced uncoupled equations in the modal coordinates. The state space model of the system is obtained in the reduced-order modal coordinates. An LQG/LTR-based robust controller is designed using the reduced-order state space model of the structure. The performance of the controller is verified for various arbitrary initial conditions of the beam. The effect of structural parameter variation on the closed-loop system performance is also investi gated. The performance robustness of the linear quadratic Gaussian with loop transfer recovery (LQG/LTR) controller is compared with that of the proportional feedback controller.-