An Iterative Calculation Method for Solve the Inverse Kinematics of a 7-DOF Robot with Link Offset.

This paper presents an inverse kinematics solution method for a 7-degrees-of-freedom (DOF) redundant robot with offset shoulder and wrist joints. Aiming at the plan-points of the 7-DOF redundant robot, we propose an iterative method to solve the inverse kinematics for a specific application scenario, that is, the orientation matrices and arm angle keep the same values during the movement of robot which can be found in some specific operations, like painting on a plane. The position, orientation and arm angle of current plan-point are used to calculate the corresponding values of next plan-point. Through iterative calculation, the inverse kinematics solutions can be obtained with the characteristic that the orientation matrices and arm angle maintain the same values for all plan-points. The comparison and analytical results show this iterative solving method is effective.