Abstract
A robust numerical solution to the inverse kinematics is proposed based on Levenberg-Marquardt method, where the squared norm of the residual with a small bias is used for the damping factor. A rather simple idea remarkably improves numerical stability and convergence performance even in unsolvable cases. The discussion is done through an investigation of the condition number of coefficient matrix. Comparison tests with the conventional methods show that only the proposed method succeeds in all cases. It frees operators from being careful about the target position-orientation assignment of effectors, so that it facilitates easy robot motion designs and remote operations.
