Friction Compensation of a Mini Voice Coil Motor by Sliding Mode Control

• Main Author: 蔡慶隆
• Other Authors: 林錫寬
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/07887397028795206011

碩士 === 國立交通大學 === 電機學院碩士在職專班電機與控制組 === 97 === This thesis presents a sliding mode controller to compensate for the nonlinear friction of mini voice-coil motor (VCM), which is embedded with guide pins, for position control in compact camera module (CCM) application. With the effectiveness of compensating the nonlinear friction, the lubrication oil can be removed from the VCM, and the performance of cost and reliability then can be improved. In the VCM, the actuator’s full stroke is only 0.35mm or less, nonlinear friction force falls into mismatched condition and um-level resolution is required. With the proposed controller, arbitrarily small steady state errors can be achieved by pole placement of the sliding mode state equation. The performance is firstly simulated with a physical VCM model. The experimental results are then presented to demonstrate the proposed controller is able to avoid stick-slip oscillation that usually yields when using a classic controller, such as PI controller. The experimental results also show that the performance of settling time and repeatability is better than nominal requirement and the undesired chattering can be remedied by replacing sign function with saturation function in the proposed control law.