Trajectory Planning to Optimize Base Disturbance of 7-DOF Free-Floating Space Manipulator Based on QPSO

Abstract

Because of the movement of space manipulator is in accordance with the law of conservation of momentum. All the motions will pose interference on the position and posture of the base. So the interference on the base generated by the motions of manipulator must be reduced. In this paper, the nonholonomic redundancy features of the free-floating space manipulator system are used. The position and posture of 7-DOF space manipulator are planned at the same time. Firstly, the kinematics equations of manipulator are established. Secondly, the angles of joints are parameterized by the sine polynomial function, and then objective function is designed according to the precision index of the position and posture. Finally, quantum-behaved particle swarm optimization (QPSO) is applied to optimize the base disturbance. The model of space manipulator system is set up, which is composed of a free- floating base and a 7-DOF manipulator. It can be seen from the experimental results, the proposed method could find the global optimal value quickly. Moreover, this method has less correlation parameters. And the planned joint path is smooth and it meets the ranges of angle of joints, angular velocity and angular acceleration. The theoretical analysis and simulation results show that the proposed method is feasible and suitable to optimize the base disturbance.