An electrorheological spherical joint actuator for a haptic master with application to robot-assisted cutting surgery

This paper presents a spherical joint actuator using an electrorheological (ER) fluid to make a new haptic master which can be applicable to a robot-assisted cutting surgery. The proposed haptic master consists of two actuators for different motions; ER spherical joint device for 3-DOF rotational motion and ER linear device for 1-DOF translational motion. An appropriate size of the haptic master is designed based on the governing equations of the dynamic model and manufactured. The haptic master is then connected to a slave robot for the cutting surgery of a tissue. In the surgical process, the forces required to cut the tissue (a pork in this work) are obtained using a force sensor via experimets and used as the desired forces to be tracked by a slave robot controlled by a proportional-integrative-derivative (PID) controller. The desired repulsive forces are then embodied through the haptic master so that the operator can feel the forces occurred in cutting process (actual forces). In order to validate the effectiveness of the proposed haptic master, the tracking control performances between the desired force and actual force are evaluated in time domain.