Remote Center of Motion Based on Null Space and Virtual Joints in a Surgical Robotics Research Platform

Abstract

We propose an approach for Remote Center of Motion (RCM) control in a Robot-assisted Minimally Invasive Surgery (RMIS) setting. We define Remote Center of Motion constraint as a primary task. Its control includes an implementation of a virtual joint. Task tracking of the surgical tool’s end-effector is treated as a secondary task and controlled by exploiting the redundancy of our system. To evaluate the approach, a RMIS research platform including two 7-DOF robot arms and a surgical tool was used. The platform is based on a modular and open platform for surgical robotics research [8]. A pick and place task is learned through teleoperation, via kinesthetic guidance of one of the robot arms. The results show applicability of our proposed approach, as the RCM constraint is ensured with high precision, while there is no drastic rise in the tracking error of desired pose of the surgical tool’s end-effector.