Kinematics Accuracy Analysis and Error Compensation for Stewart Platform

摘要

In designing and controlling a Stewart platform, accuracy is one of the most important factors to be considered. In order to improve the accuracy of Stewart platforms an effective method for the kinematical calibration is presented to enable the full set of geometric errors to be identified by measuring poses of the mobile platform. The calibration model between poses and kinematical parameters of a Stewart platform is derived from the inverse kinematics solution, which indicates that the length errors of the 6 actuators and the position errors of the passive joints on the base and the mobile platform play an important role in accuracy reducing. The kinematical parameters of the platform are measured and identified by three-dimension coordinate measuring machine and iterative least square method. The kinematical calibration experiments are carried out with the Stewart platform developed in Harbin Institute of Technology. And the results show that the method can improve the accuracy of Stewart platform.