Control of multiple DOF hybrid haptic interface with active/passive actuators

This paper is aimed at developing the control method of multiple degree-of-freedom (DOF) hybrid haptic interfaces with active/passive actuators. After the mathematical description of the kinematic requirements of multiple DOF haptic interfaces with passive actuators, we outline the concept of the control method based on the passivity. The fundamental consideration of the passivity is examined by following the "power observer" (PO) approach. The "switching control" (SC) is outlined briefly and then proposed the "bridging control" (BC) comparing with SC. To evaluate the feasibility of the proposed BC/PO, the experiments were conducted via 2-DOF hybrid haptic interface which is a five-bar-linkage mechanism with two motors and two MR brakes.