Inverse kinematics robot calibration by spline functions

Inverse kinematics calibration is a technique used to improve the accuracy of robot manipulators when they are programmed off-line. This technique requires an approximation of position deviations of the end-effector of the robot. In this paper three-variate splines are used as approximating functions; a stable and efficient algorithm for their computation is presented. Many experimental tests are performed to evaluate the merits of the approximation. The improvements in the accuracy of the robot, obtained after calibration, demonstrate the validity of the method.