Manipulator Task Space Trajectory Tracking with Kinematics and Dynamics Uncertainties

The paper develops a control scheme for task-space trajectory tracking of robot manipulators in the face of unknown kinematic and dynamic parameters of both the manipulator and picked object/tool, and in the presence of time varying disturbances/noise and certain unmodelled dynamics. The proposed scheme consists of an outer task-space control loop and an inner joint space control loop. The two control loops in combination ensure that the errors tend to zero asymptotically and thus achieve precise task-space tracking. Other features of the proposed method are simple control structure that do not require decomposition of the dynamics into the regressor matrix-parameter vector. Simulation results are provided for a full 6-DOF manipulator performing complex tasks while carrying a tool with unknown kinematics and dynamics parameters.