Inverse Kinematics Solution Algorithm of a 6R Robot with Non-spherical Wrist

doi:10.3901/JME.2022.19.068

Abstract

Abstract: The 6R spray painting robot with non-spherical wrist has been widely used. However, structure of this kind of robot does not satisfy Pieper-Criterion, leading to the inverse kinematics of this robot a very difficult problem. Then, an inverse kinematic algorithm for the 6R robot with non-spherical wrist is proposed by combining the approximate analytical solution and the numerical iterative method. Firstly, according to structure characteristics, the 6R robot with non-spherical wrist is transformed to a 6R robot with spherical wrist. By taking analytical solutions of the spherical wrist robot as approximate solutions, the Jacobian based iterative method is employed to derive the exact solutions of the 6R robot with non-spherical wrist. Secondly, failure of the proposed method caused by the reduction of the workspace due to structure transformation is analyzed. A target end configuration offsetting method is presented to improve the robustness of the proposed inverse kinematics algorithm. Finally, numerical simulations are carried out to prove the effectiveness and efficiency of the proposed inverse kinematic method for the 6R robot with non-spherical wrist.

Key words: 6R robot, non-spherical wrist, spray painting robot, inverse kinematics

CLC Number:

TP242

LUO Renfeng, WANG Xuhao, ZHANG Dawei, ZHANG Peilun, ZHAO Chen. Inverse Kinematics Solution Algorithm of a 6R Robot with Non-spherical Wrist[J]. Journal of Mechanical Engineering, 2022, 58(19): 68-76.

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