Trajectory planning method has been proved to be an effective way to suppress robot vibration in multiple experiments, which can be divided into off-line trajectory planning for repetitive task and online trajectory modified for uncertain task. Particle swarm optimization (PSO) is a typical optimization algorithm, which can be used in offline joint trajectory planning, but classical PSO is incapable of optimizing a joint trajectory with variable constraints. Thus, in this paper, a novel compression factor PSO with penalty function named CP-PSO is proposed to modify joint trajectory, thereby achieve minimum residual elastic potential energy in the case of joint angle constraint. However, CP-PSO algorithm still needs plenty of computation time, which is unsuitable for online optimizing uncertain operational task’s trajectory. To solve this issue, trajectory modified based on vibration prediction criteria is put forward to suppress manipulator vibration. Particularly, vibration prediction criteria is based on torque error between theoretical joint torque and actual joint torque, as well as the modified trajectory is named as DKA trajectory by the reason of it is composed of three sections, namely, smooth decelerating process, low velocity keeping process, and accelerating process. When vibration is predicted to occur via vibration prediction criteria, DKA trajectory is switched ON to suppress vibration. Finally, experiments are performed on manipulator to verify the proposed methods.

The paper puts forward a new concept of the satellite on-orbit self-servicing (SOOSS) which can maintain the malfunctions of deployable appendages of satellites (i.e. solar arrays, communications antennas, etc.). In order to verify this concept, a ground testbed has been presented, a light weight 4 DOF manipulator with an end effector mounted on the satellite are designed to accomplish above operations. The predominant features of the robot system are mechatronics, multi-sensory and intelligent control. The manipulator is composed of four identical joints, the large hollow joint makes the cables pass through in the manipulator which can prevent them from damage of high temperature and radiation in the space environment. The modular designed joint integrates torque sensor, position sensor, redundant motor position sensors, temperature sensors and current sensors. For the end effector, dexterous DLR/HIT hand is employed