Kinematic accuracy analysis of robot based on Local POE

Linear kinematics model based on POE formula has been widely applied to the error compensation of robot. In this paper, we employed a calibration model in the Local POE frame where all the joint axes are repressed in their respective local frames. The major advantage of this formula is that the local coordinate frames can be arbitrarily assigned onto their corresponding links. For analyzing the applicability of linear model, this paper builds envelope model of error distribution using linear and second-order error model. Meanwhile, this paper analyzes Kuka Youbot robot's error distribution through the established model. The results show that the second-order model could be neglected in comparison with first-order model, when nominal error values of the joint angles are less than 0.1 degree. Hence, linear error model is enough precise in most real applicable environments.