Dynamic Performance Improvement of Piezoelectrically Driven Micro-Lens Actuators

Abstract

This letter presents experimental results showing significant enhancement in the dynamic performance of a novel piezoelectric micro-lens actuator using a robust feedback resonant controller. The design of the feedback controller is based on experimentally identified model of the micro-lens actuator. The stability of the closed-loop system is proven by the negative imaginary theory. The experimental results show that the resonance peak and the settling time of the actuator are reduced by 27 dB and to 2.5 ms from 119 ms, respectively. Such improvement demonstrates the capability of the piezoelectric micro-lens actuator for fast auto-focus application in miniaturized camera. The reported performance makes it the fastest micro-lens actuator compared to other previously reported micro-lens actuators.