A Compliance Control based on Force Control System for a Haptic Display

In virtual reality, operators need force sensation as well as audio and video. Haptic devices provide them with the force sensation for a virtual object. In this paper, the hardness or softness of the virtual object is realized by compliance control based on force control system. When they contact the surface of an object operators feel the mechanical impedance of the object from "contact point". Moreover, they feel the mechanical impedance from some points next to "contact point". We call the former impedance "self-impedance" and the latter impedance "mutual-impedance". This paper proposes the method which realizes the two kinds of impedance by the compliance control. We consider that the two kinds of impedance provide force sensation of the virtual object near to a real object. First, in this paper the control method is stated. Then, computer simulations are performed to confirm the validity of the proposed method. Finally, experiments are performed using actuators of a haptic display.