Experimental validation of internal model approach for tracking control of a MEMS micromirror without angular velocity measurement

Abstract

This paper addresses the angular tracking control for an electromagnetic MEMS micromirror. The problem is formulated in the output regulation framework for output feedback systems. An extended internal model-based output feedback controller is developed, which can achieve excellent angular tracking and allow large parameter uncertainties ranging within any compact set. In addition, the simplified robust controller features itself in the aspect of having a very simple tuning procedure with only one adjusting parameter. The control scheme is based on sensing the angular position and incorporates only tracking error to adjust the desired output angular of micromirror. As a result, it is independent of the angular velocity and removes the noise amplification problem of the first-order backward difference method in state-feedback design. It also relaxes the extra measurement hardware, which reduces the complexity of tracking controller. In general, the proposed control scheme is beneficial for the integrated packaging of micromirror devices. Experimental validation is provided to verify the effectiveness of the proposed controller, which is programmed by LabVIEW and implemented with a field programmable gate array platform. The sinusoidal waves with different frequencies are utilized as the reference signals. It is shown that the controller offers improved steady-state performance over the existing schemes.