Robust Control Design for a Five-Bar Precision Positioning Mechanism

• Main Authors: Jin-Liang Chen, 陳金亮
• Other Authors: Jyh-Jong Sheen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/58522120382094768588

碩士 === 國立臺灣海洋大學 === 機械與輪機工程學系 === 92 === This research studies a robust control for a five-bar stage designed for planar positioning.The five-bar stage is formed by two actuators traveling alone a co-aix and a planar mover, which is connected to the two actuators via three bar linkages so that the movements of the two actuators constitute the planar motion of the mover.The stage is accompanied with air bearings to improve the positioning precision. In this thesis, the μ- robust control is combined with a feedforward control to solve the nonlinear control problem between the mover and the two actuators of the five-bar 2-D stage. To eliminate the nonlinear coupling effect between the mover and the two actuators, the feedforward control is calculated from the rigid-body equations of motion of the stage for the designed trajectory of the mover. The feedback control is derived from the μ- controller to compensate for the tracking errors due to the uncertainties of the system model. The uncertainties is treated by the weighting function method to account for the variations in the system model. Accordingly, a μ- controller is designed for the robustness and the position accuracy of the system.Experimental results demonstrate that the μ- controller has more robust and excellent than the LOG controller and PID controller.