Trajectory control of a dual-arm planar space robot with little attitude disturbance

This work presents a trajectory planning strategy for a dual-arm planar space robot in workspace that is intended to minimize vehicle attitude disturbance that may occur due to dynamic coupling between the arms and the vehicle of the space robot. The strategy is based on the principle of dynamic coupling between the tip motion and the vehicle motion of the space robot. The strategy uses the two arms of manipulator. One arm, called the mission arm, achieves the trajectory control task while the other arm, called the balance arm, moves in such a way as to reduce the attitude of the vehicle. A robust overwhelming controller is used for trajectory control of the tip of the mission arm. The balance arm first-joint rotation is based on the mission arm first-joint rotation, whereas the balance arm second-joint rotation is carried out such that a small attitude disturbance of the vehicle takes place. An example of the two degrees of freedom planar space robot is considered to illustrate the methodology. A bond graph has been adopted as the modeling tool, as it facilitates the system modeling from the physical paradigm itself and it is easy to develop various control strategies by modifying the physical paradigm.