Development of 3-DOF force feedback system using spherical arm mechanism and MR brakes

Abstract

In this research, a new 3-DOF force feedback system featuring a spherical arm mechanism and three MR brakes is proposed. One rotary MR brake is integrated in the waist joint to reflect the horizontal tangent force, another rotary MR brake integrated in the shoulder joint to reflect the elevation tangent force while a linear MR brake is integrated in the sliding joint of the arm to reflect the radial force (approach force). With this configuration, a 3-DOF desired force acting on the operator at the end-effector of the arm can be archived by independently controlling the current applied to the coils of the MR brakes. After the introduction, configuration of the proposed force feedback system is presented. After that, design and simulation of the MR brakes for the systems are conducted. A prototype of the force feedback system is then manufactured for experiment and some experimental results are obtained and presented with discussion.