Kinematic Calibration of UVW Direct Drive Platform Through Microscopic Vision
Aiming at the fast and precise alignment requirements of multi-degree of freedom correction align-ment system for high-end manufacturing equipment,a UVW direct drive motion platform is designed,and a kinematic calibration method based on microscopic vision measurement is proposed to realize the calibration and compensation of platform structural parameter errors and verticality errors. In this paper,the mapping re-lationship between the platform base coordinate system and the end coordinate system is derived,the end dis-placement coupling caused by the vertical error of the moving pair is analyzed by graphical method,and the forward and inverse kinematics are established. A microscopic vision measurement system based on absolute coding pattern is constructed for the orientation measurement of the end of the platform. The platform coordi-nates under different orientation are obtained by aligning the measurement coordinate system with the plat-form base coordinate system. The UVW motion platform and its vision measurement system were built,and the kinematic calibration experiments of the proposed method were carried out. The experimental results show that the RMSE of X,Y and C axes after platform calibration decreases from 0.2177 mm,0.2298 mm and 0.0057° to 0.0043 mm,0.0083 mm and 0.0019°,which is further reduced by 93.97％,19.41％ and 56.81％ compared with the conventional method. The validity of the calibration method in this paper is veri-fied,and it also lays a foundation for the precision correction and positioning of UVW platform.
万方数据
维普
