Torque Control of a New Haptic Master for Surgical Robot System Featuring Electrorheological Fluid Based Spherical Joint

This study presents the configuration and modeling of haptic mater device for minimally invasive surgery (MIS) using ER fluid. The haptic device has 3-DOF rotational motion which is realized by the ER spherical joint. The electrorheologcial (ER) spherical joint is designed based on Bingham model. The haptic master device that consists of spherical joint as an inner electrode and sphere housing as an outer electrode is manufactured. Generated torque of the manufactured haptic master device is then experimentally evaluated with respect to applied electric field. In order to achieve the desired torque trajectories, a sliding mode controller (SMC) which is robust to uncertainty and disturbance is designed and experimentally implemented. Torque tracking control performances featured by sinusoidal trajectory are presented in the time domain.