Disturbance rejection control with H∞ optimized observer for vibration suppression of piezoelectric smart structures

Abstract

In this paper, a disturbance rejection (DR) control with H∞ optimized observer is developed for vibration suppression of smart structures considering model uncertainties and measurement noise. An electro-mechanically coupled dynamic finite element (FE) model of piezoelectric smart structures is firstly built for control design. Based on the dynamic FE model, the H∞ optimized observer is designed with a dynamic feedback gain which is calculated by H∞ mixed sensitivity optimization. Expected response speed and robustness to model uncertainties and measurement noise are obtained by configuring proper weighting functions. In the closed-loop system, estimated disturbances and state variables are fed back through a conventional DR controller to counteract disturbances and stabilize the system. In order to validate the DR control with H∞ optimized observer, vibration suppression simulations of a piezoelectric smart beam are implemented in the absence and presence of model uncertainties and measurement noise, respectively. Furthermore, DR control with generalized proportional integral observer and DR control with high-gain proportional integral observer are added for comparison. Results show that excellent vibration suppression performance and better robustness to model uncertainties and measurement noise are achieved by the DR control with H∞ optimized observer.