Redundant Robot Task Priority Inverse Kinematics Optimization Algorithm

The typical obstacle avoidance issue for robotic arms only considers the case where an obstacle affects the motion of the arm’s end-effector along the desired trajectory, causing it to deviate from the expected path. This paper not only considers the obstacle avoidance at the end of the robotic arm but also takes into account the interference between the robotic arm itself and the obstacle. A task-priority-based trajectory planning method is proposed to enable the robotic arm to continue tracking the desired trajectory after avoiding obstacles. When the motion trajectory of the robotic arm contains obstacles, obstacle avoidance is given priority in control by finding a suitable inverse solution from the multiple inverse solutions in the kinematics of the robotic arm to circumvent the obstacles. Conversely, the set of solutions with the smallest absolute displacement of each joint in the kinematic inverse solutions is given priority. Finally, simulations and experiments were conducted on the redundant robot. The results show that when there is a conflict between obstacles and the motion trajectory of the robotic arm, the trajectory planning method based on task priority can effectively avoid obstacles at the end of the arm, and after obstacle avoidance, the robotic arm can still track the expected trajectory motion.