Vibration controllability of flexible robot-payload systems

The system tackled in the paper consists of a rigid robotic manipulator and a flexible shear metal payload being grasped at several points by the robot gripper. The dynamic model is first developed using the component mode synthesis method, and the vibration controllability of the flexible payload is discussed. It is concluded that some flexible states may become uncontrollable if the grasping points are located in the subspace of the payload modal nodes. In addition, given proper grasping of the payload and sufficient degrees of freedom of the robot, the flexible states are locally controllable in almost all of the robot workspace with the exception of some singular configurations. This result implies that vibration suppression control can be achieved by properly selecting the grasping points and robot moving path