Tracking Control of a Piezoelectric Actuator using a Disturbance Observer and a Hysteresis Model

• Main Authors: Chien-Fu Chen, 陳皆福
• Other Authors: Jiann-Lih Hwang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/3wedqz

碩士 === 逢甲大學 === 自動控制工程所 === 91 === This thesis is intended to investigate the tracking control of a nano-positioner driving by a piezo-actuator. It is well known that piezo-electric actuators exhibit significant nonlinear hysteresis effects. The hysteresis effects have to be compensated in the control loop for achieving better performance. The traditional ZPETC (zero phase error tracking controller) with disturbance observer control scheme has been shown to be robust to disturbances of low frequencies in the precision motion control applications. In this study, it is observed that most of the energy of the hysteresis effect is at low frequency regions, however, there are still some portions of energy at high frequency regions. The above-mentioned control scheme is effective for compensating the lower frequency components of the hysteresis, while the higher frequency components of the hysteresis effect will degrade the performance when tracking high frequency input signals. The aim of this study is to improve the tracking performance for high frequency reference signals. A hysteresis observer is designed which is robust to model uncertainties of the hysteresis model. By using the hysteresis observer, hysteresis effects may be estimated more accurately. The estimated hysteresis is then used in the disturbance observer to compensate for the high frequency components of hysteresis. The proposed controller is verified through simulations and experiments.