IJCAS

This paper presents the hybrid force control for a robot manipulator, which separates position and force control axes in the Cartesian space to perform force and position control separately by a selection matrix. Since the coupling dynamics with uncertainties in the Cartesian space causes poor tracking performance, decoupling and compensating for the uncertain dynamics of position and force-controlled axis are required. A time-delayed control method is combined with the hybrid force control to achieve independent axis control. Stability analysis of the combined control scheme is derived to obtain the bound of the Cartesian inertial value in terms of a joint inertia matrix and Jacobian matrix by decomposing dynamics into position and force-controlled dynamics in the Cartesian space. Force tracking control performances of a robot manipulator are simulated to validate the proposed control method.

Keywords: Hybrid force control, robot manipulators, stability in subdynamics, time-delayed control.