Continuous gain scheduling control for a micro-positioning system: simple,robust and no overshoot response

Continuous gain scheduling control is proposed for a micro-positioning syst em. Controllers should be adapted according to the task. In fine positionin g regions, the controller gain should be large enough to reject the disturb ance and to maintain high-precision positioning. In coarse positioning regi ons, since the reference input is large, the controller gain should be smal l in order to avoid the controller saturation. The simple continuous functi on of gain versus displacement error is derived based on the robust control ler. From the simulation and experimental results, continuous gain scheduli ng control provides a better response than fixed gain control in disturbanc e rejection and settling time. It also brings robustness to system uncertai nty and prevents overshoot responses. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.