Kinematic Calibration of 6-UPS Surgical Parallel Robot

In the applications of parallel robots, Kinematic calibration is one of the most effective methods to improve the accuracy of surgical parallel robots. In this paper, a brief kinematic calibration method which is used in the 6-UPS (Universal Prismatic Spherical) surgical parallel robot is discussed. Firstly, the primary error factors needed to be identified are proposed based on the kinematic mathematical model of the 6-UPS surgical parallel robot. Then the method of pose measurement is studied, and the definitions of the position deviation and orientation deviation which are used to evaluate the experimental results are illustrated. Lastly, an iterative least squares procedure is used to identify the error parameters, and the kinematic calibration experiment is carried out. From the statistical analysis of the experimental results, the effect of the method to improve the accuracy of the 6-UPS surgical parallel robot is demonstrated.