The Tracking Control of Piezoceramic Actuator for Atomic Force Microscopy

• Main Authors: Chen Yil, 陳毅
• Other Authors: Mu-Tian Yan
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/19319141807134240842

碩士 === 華梵大學 === 機電工程研究所 === 93 === Atomic Force Microscope (AFM) can achieve the nanometer scale of precise image acquisitions with the aids of piezoceramic actuators. However, the tracking control accuracy of piezoceramic actuators is limited due to their inherent hysteresis nonlinearity. A conventional digital controller may not suffice to provide a high tracking accuracy as well as adequate hysteresis compensation and parameter variation robustness. In this paper, a self-tuning regulator combined with feedforward control is proposed to improve the tracking accuracy of the piezoceramic actuators. The adaptive controller is designed to stabilize the control system based on an approximate linear model identified by using recursive least square method. The feedforward controller is designed to compensate the tracking error due to the hysteresis effect based on a simple static model. Experimental results on tracking several types of reference inputs demonstrate that the maximum tracking error can be greatly reduced by utilizing the proposed control method.