Humanoid robotic arm design with S-R-S configuration, redundant swivel angles analysis, and collision-free trajectory planning

Abstract

In recent years, high-DOFs robotic arms have been investigated for various labor force shortage applications, such as welding and assembling, because of the brought flexibility. High-DOFs configuration can reduce the occurrence of the singularity and bring the possibility of optimization. However, it becomes more unintuitive for neophytes to operate. To compensate for this drawback, transferring human arm movements directly to the robot is more intuitional. For this purpose, the mechanical design of the humanoid robotic arm to meet the simplified kinematic model of the human is presented first in this research. Furthermore, the redundant characteristics of the 7-DOF humanoid robotic arm were analyzed to optimize the end-effector’s manipulability by adjusting swivel angles without changing the position and the orientation of the end-effector. Last, obstacle avoidance was also considered and achieved by using the oriented bounding box, which can decrease the computation time and provides the closest collision point with obstacles. The result shows that the mechanism can mimic human-like motions, and the algorithm can optimize the manipulability and the obstacle-free trajectory.