Online Optimization Control With Predictive Gradient Descent for MEMS Micro-Mirrors

In this article, an online optimization control scheme is proposed for the angle control of MEMS scanning micromirror actuated via electromagnetic method. In order to avoid complicated process of building precise model of the MEMS micromirror, a control structure not relying on precise model is developed. In this structure, a simplified linear dynamic model is used to describe the basic dynamic behavior of the micromirror. Then, a model error compensation mechanism is introduced to compensate for the model uncertainty caused by unmodeled dynamics and nonlinear factors, such as hysteresis. Moreover, a predictive gradient descent based optimization mechanism is proposed to compensate the effect of time-delay and speed up the convergence of online optimization process. Then, the stability analysis of the proposed control system is implemented. Finally, the proposed control scheme is applied to the angle control of electromagnetically driven scanning micromirror and the corresponding experimental results are presented.