PSO-based time-optimal trajectory planning for space robot with dynamic constraints

It is significant to increase the efficiency of space robotic operation in on-orbital services, to plan the time-optimal trajectory becomes an important and necessary problem. As well known, any motion of space manipulator will disturb its base due to the dynamic coupling between the base and manipulator, Especially, for free-floating space robot, when robotic manipulator moves from initial point to the end point, the shorter the motion time is, the greater the disturbance to the base will be. Thus, the space robot will be damaged or uncontrolled if this disturbance is beyond the its constraints. Therefore, it is a challenging problem to plan time-optimal or suboptimal trajectory for space manipulator with dynamics constraints, such as disturbance forces and limited torques. In this paper, we proposed a Particle Swarm Optimization (PSO) to search the global time-optimal trajectory for space manipulator. For the formulation, we define the some inter-knots of joint trajectory as optimal parameters. These inter-knot parameters mainly include joint angle and joint angular velocities. Finally, we use an illustrative example to verify that PSO-based time-optimal trajectory planning method has satisfactory performance and real significance in engineering.