Parallel force and position control with the aid of variable impedance model in robot manipulators

In this paper a new optimal approach to parallel force-position control of robot manipulator is presented. Parallel control may be needed in situation where we are interest to control end-effector position and force simultaneously. The common impedance model is modified to able the controller to track force trajectory in addition to position tracking. The impedance parameters are varied with respect to a cost function such that the sum of position and force squared error is minimized. A new feature of proposed scheme is that accuracy of force or position trajectory tracking can be determined by a weighting constant parameter in cost function. The scheme is really efficient and is able to summarize the properties of impedance control and hybrid force-motion control. Simulation study carried to verify the proposed scheme.