Active damping control of compliant base manipulators

When a robotic manipulator is mounted on a crane, boom or mobile platform, it loses its accuracy and speed due to the compliance of the base. The paper presents a simple robust control strategy that reduces mechanical vibrations and enable better tip positioning. The control algorithm uses sensory feedback of the base oscillation to modulate the manipulator actuators to induce the inertial damping forces. Previous work by the author has demonstrated the feasibility of the proposed concept using linear analysis. The work extends to a more general case of a nonlinear multiple link manipulator using acceleration feedback and one sample delayed torque. A computer simulation study shows very promising results for a test bed consisting of a two-link manipulator and a compliant base