A Time-delayed Compensation Technique for Hybrid Force Control of Robot Manipulators

This paper presents the hybrid force control for a robot manipulator, which performs force and position control separately by a selection matrix. Decoupling position and force control axis by a selection matrix allows sub-dynamics in the Cartesian space and yields the independent axis control. In order to achieve decoupled dynamics and independent joint control of a robot manipulator, uncertain dynamics should be compensated a priori as well. Since uncertainties in robot dynamics affect poor tracking performances in both position and force control, a compensation technique of a time-delayed controller is introduced in the joint space. Simulation studies of force tracking control performance for a three-link robot manipulator are performed to verify the proposition.