Modeling and robust closed loop position controllers of Piezoelectric Actuator Drive (PAD)

Abstract

This paper deals with the synthesis, design, and comparison of robust H-infinity (H ∞ ) and RST position controllers of Piezoelectric Actuator Drive (PAD). The PAD is an accurate rotary piezoelectric motor that employs the elongation of stack actuators, the micro-toothed ring and the shaft to generate rotation motion. The motor position depends on precise adjustment between motor ring and shaft and therefore demand a closed loop control to overcome the maladjustment problems. In this paper Simulink model of the PAD is firstly proposed to evaluate the motor behavior. The transfer function between the control signal and motor shaft position is experimentally identified. H ∞ and RST position controllers are then synthesized. The precision and robustness of the proposed closed loop system are also validated.