Inverse kinematics analysis for the arm of a mobile humanoid robot based on the closed-loop algorithm

This paper presents a kind of method for the inverse kinematics of a seven degrees of freedom (DoF) arm installed on a mobile humanoid robot. Due to the redundancy of 7-DoF open-chain arm, the closed-loop inverse kinematics via pseudoinverse method is used to solve the corresponding joint trajectories if the end-effector trajectory is given. Because of the existence of the null space in the kinematically redundant arm, the constraints of joint limits are applied here to optimize the redundancy in order to get some desired solutions of inverse kinematics. Computer simulations are made respectively with and without considering the joint limits and simulation results verify the effectiveness of the proposed algorithm.