One key issue in inverse kinematic modeling of lower mobility serial mechanisms

Abstract

• The D-H parameters method for establishing pose coupling equations of serial mechanisms is proposed. • The terminal pose coupling equations of two serial mechanisms are established in closed form. • The feasible positions and orientations of the end-effector for serial mechanisms are determined. The inverse kinematics of lower mobility serial mechanisms is an important problem, but it has not been well solved actually. The feasible six dimension pose of the end-effector can not be reasonably given, which leads to the defect of the inverse solution model of this kind of mechanisms. In this paper, this problem is solved based on establishing the pose coupling equations using D -H(Denavit–Hartenberg) parameters method. The complete inverse kinematics of two 5-DOF(Degree of freedom) serial mechanisms considering pose coupling equations are established to illustrate the improved inverse kinematic modeling process. The results show that the serial mechanisms always have highly coupled nonlinear pose coupling equations which can be effectively used in determining the feasible pose of the end-effector. The proposed inverse kinematics producer is applicable for other serial mechanisms.