Vibration Control of Flexible-link Manipulators

In this paper, vibration control of flexible-link manipulators is considered. A nonlinear partial differential equation describing the dynamics of a two-link planar manipulator with a flexible forearm is derived. The zero-dynamics of a rigid/flex (hybrid) manipulator are given. Thereafter, different controllers are synthesized. The controller design strategies are based upon an inner-loop controller which corresponds to the rigid body motion of the manipulator taking into consideration the vibrations of the manipulator and an outer-loop controller for further vibration damping and robustness enhancement of the closed-loop dynamics to parameter variations in the system. The measurements used in the outer-loop controller are obtained through accelerometer and strain gages mounted on the flexible forearm. The control methodologies advocated in this paper are applicable to the multi-link flexible manipulators.