Configuration dependent vibration controllability of flexible base mounted robot manipulators

This paper addresses the issues of base vibration control of flexible base mounted robot systems. The system is considered as that the flexible base is not equipped with actuators, whereas the manipulator is fully actuated. The only way to suppress vibration of the base is by using the actuators of the manipulator. In order to evaluate controllability and further investigate the easiness and hardness for the control of base vibration, a controllability matrix is defined using a nominal state equation of the system, and controllability measure is proposed based on the controllability Gramian and state equation. Case studies are presented to demonstrate configuration dependent controllability. Uncontrollable configurations in the joint space are identified. Base vibration control simulations are carried out on a system consisting of a two-link robot manipulator mounted on a 2 DOF flexible base to illustrate different control performances of the system at different configurations of the manipulator.