Trajectory planning of space robot system for reorientation after capturing target

A typical servicing operation in space mainly includes three phases: capturing the target, re-orientating of the whole system with the target, and repairing the target. The attitude of a satellite usually changes after the capturing, because the control system is turned off during this phase for safety reasons. In this paper, a method is proposed to achieve re-orientating the space robot system, planning the manipulator configuration and spacecraft orientation at the same time. Firstly, angular momentum preloaded in the manipulator will provide a favorable condition for the capturing and reorientation after capturing, so the manipulator moves with some initial velocity after capturing. The constraints on the manipulator and the objective function are defined according to the planning problem. Then the joint trajectory is parameterized by sinusoidal function, whose argument is the polynomial. Finally, particle swarm optimization (PSO) is used to search for the global optimal resolution of the parameters. When the parameters are found, each joint trajectory can be determined. This planned trajectory is smooth and more applicable for the control of the free-floating robotic system.