An effective and unified method to derive the inverse kinematics formulas of general six-DOF manipulator with simple geometry

For decades, although the inverse kinematics (IK) problem of six degrees of freedom (DOF) manipulator with general geometry has been solved, there is still needed an efficient and unified method to derive the IK formulas for the six-DOF manipulator with simple geometry. In this paper, we propose an improved method of disconnection and re-connection to achieve this purpose. Firstly, we determined the position selection of the two cutting points and the attitude setting at the first cutting point. Next, we gave the new conditions for the re-connection of the two sub-chains and the corresponding equations. Then, we summarized five methods of cutting the manipulator into two three-DOF sub-chains and corresponding equation deformations, as well as the selection principles of equation deformations. Finally, we used three examples to demonstrate the effectiveness of the method. The results show that the expressions of six joint variables can be derived from only six equations. The solutions of the wrist joint variables are not affected by the singularity. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

We proposed an improved method of disconnection and re-connection for solving the inverse kinematics of a six-DOF manipulator with simple geometry. By determining the position selection of cutting points, attitude setting, re-connection conditions, and equations, we simplified the process of deriving the IK formulas efficiently.