A model reference adaptive PID control for electromagnetic actuated micro-positioning stage

This paper presents a model reference adaptive PID controller for controlling a novel compliant flexures-based XY micro-positioning stage driven by electromagnetic actuators. The stage is specially designed by employing double four-bar parallelogram flexures and four non-contact electromagnetic force actuators to realize the kinematic decoupling and force decoupling respectively. Based on preliminary open loop experiments and simple PID controller based close-loop experiments, we found that the system is with typical hysteresis and nonlinear characteristics. As model reference adaptive control techniques possess great advantages to tackle robustness issues of nonlinear and model uncertainty systems, it is designed and adopted to control the micro-manipulator system. At first, a model reference adaptive PID controller design process is introduced. Then control parameters are systematically tuned based on intuitive desired performance and robustness. At last, experimental results verify the process for controlling the micro-positioning stage, which shows that the adopted controller can drive the mobile stage to track the desired reference path exactly.