Design and Control of MR Haptic Master - Slave Robot System for Minimally Invasive Surgery

In this work, magnetorheological (MR) haptic master and slave robot for minimally invasive surgery (MIS) have been designed and tested. The proposed haptic master consists of four actuators; three MR brakes featuring gimbal structure for 3-DOF rotation motion(X, Y and Z axes) and one MR linear actuator for 1-DOF translational motion. The proposed slave robot which is connected with the haptic master has vertically multi-joints, and it consists of four DC servomotors; three for positioning endoscope and one for spinning motion. We added a fixed bar with a ball joint on the base of the slave for the endoscope position at the patient's abdomen to maintain safety. A gimbal structure at the end of the slave robotic arm for the last joint rotates freely with respect to the pivot point of the fixed bar. This master-slave system runs as if a teleoperation system through TCP/IP connection, programmed by LabVIEW. In order to achieve the desired position trajectory, a proportional-integral-derivative (PID) controller is designed and implemented. It has been demonstrated that the effective tracking control performances for the desired motion are well achieved and presented in time domain. At last, an experiment in virtual environments is undertaken to investigate the effectiveness of the MR haptic master device for MIS system.