Online Iterative Optimization for Angle Tracking of Electromagnetic Scanning Micro-Mirror With Unmatched Interference and Hysteresis

Abstract

In this paper, a precise angle tracking control strategy of electromagnetic driven scanning micro-mirror (EDSM) using online iterative optimization control (OIOC) scheme is addressed. Considering modeling difficulty caused by nonlinear hysteresis and complex dynamic characteristics, a simplified model (SM) is applied to describe the essential motion trait of EDSM approximately, more than that, the predictive model (PM) is developed based on the SM to improve the accuracy of the model. As for the omitted section caused by unmolded nonlinear and dynamic factor with unmatched interference (e.g., oscillation, nonlinear hysteresis and stochastic noise), that’s all being introduced into the angular deviation compensator (ADC) once again. Subsequently, a compensating structure SM+ADC is acquired to describe the dynamic performance and to design angular tracking control. Due to the nonlinear performance of multi-valued mapping, the generalized gradient is applied to optimize the control variables located in the nonlinear interval aiming to suppress the model deviation and eliminate unmatched interference. Then, a new iterative optimization control OIOC+ADC is obtained on the basis of compensation structure and generalized gradient. Besides, by designing Lyapunov function, the proposed control design incorporated by the relationship between optimized step-size and optimization gradient that needs to be satisfied guarantees the high accuracy positioning and stability. Conducted quantitative experiment results are provided to validate the effectiveness of the proposed control strategy in precise angle tracking to the fast dynamic system.