Redundant Manipulator Orientation Control Scheme Based on Gradient Projection Algorithm

Aiming to solve the problem of the redundant manipulator, it is necessary to complete the trajectory-tracking with a fixed orientation in tasks. Therefore, we propose a manipulator end orientation control scheme based on a gradient projection algorithm. Firstly, according to the property of the redundant manipulator that realizes self-motion, the orientation control problem is transformed into the self-motion problem of the manipulator. The angle between the end-effector of the manipulator and each coordinate axis of the base coordinate system is optimized as the objective. Secondly, according to the expected orientation required by the task, the corresponding objective optimization function is designed and its gradient vector is calculated. Then, the expected orientation is taken as the target criteria, and a reasonable joint velocity adjustment function is designed. Finally, the scheme uses MATLAB simulation software to simulate the four-link manipulator and the six-degree-of-freedom manipulator, respectively. The experimental results show that the scheme is effective and feasible.