Mirror Angle Tuning of Electromagnetic Micro-Mirrors With Oscillation Compensation

摘要

Underdamped feature and hysteresis existing in electromagnetic scanning micro-mirrors (EMSMs) often lead to oscillation and undesired positioning error of deflection angle. In this paper, a model-based robust scheme is proposed for the angle tuning of mirror plate of the EMSM. To build a proper model for describing the behavior of EMSM, which is also convenient for the design of tuning strategy, a data-driven model composed of linear dynamic submodel as well as hysteresis submodel is developed. In the data-driven model, the deflection mechanism is described by a linear dynamic submodel while the hysteresis in EMSM is depicted by a nonsmooth hysteresis basis function submodel. Then, in order to compensate for the internal oscillation caused by both underdamping factor and hysteresis, a pseudo-feedforward oscillation compensator (PFOC) not relying on the inverse model is proposed. Then, the design procedure of the angle tuning strategy with the PFOC is presented. Afterward, the robust design of the angle tuning scheme is also studied to overcome the effect of compensation residual. Subsequently, the proposed scheme is applied to the angle tuning of EMSM.