Delta-type four-DOF force-feedback device composed of pneumatic artificial muscles and magnetorheological clutch and its application to lid opening

Force-feedback devices, along with virtual reality, are being studied for applications related to entertainment and rehabilitation. These devices generally comprise either direct drive motors or motors with reduction gear. However, suitable force feedback with high stiffness requires high-power and very large motors with reduction gears. Although rigidity can be increased with reduction gears, they reduce back-drivability and limit the motion freedom of the device. To address these problems, we developed a force-feedback device actuated with a magnetorheological clutch and pneumatic artificial muscles. The device can smoothly vary its stiffness and viscosity, and provides good back-drivability. In this paper, we report the development and testing of a prototype with one rotational and three translational degrees of freedom. We evaluated the effectiveness of force feedback per degree of freedom, and the prototype being used to resemble lid opening.