Disturbance observer based robust impedance control of redundant manipulators

In this paper design of a robust impedance control is proposed for kinematically redundant manipulators. To achieve this goal, we propose a new disturbance observer scheme which can handle the nonlinear dynamics of a manipulator. An extended task space formulation to describe the dynamics of redundant manipulator is employed. Using this extended task space formulation, a robust impedance control method is proposed based on the momentum feedback disturbance observer (MFDOB). The performance of the proposed extended impedance controller is verified through experiments with a planar three-link direct-drive manipulator.