Gripper´s rotation of five DoF surgical robot by using coordinate transformation

This paper presents a control method of gripper´s rotation angle using the five degrees of freedom (DoF) surgical robot. Minimally invasive surgery has advantages for patients, but skills are required for surgeons and the demand to support by engineering is increasing. Therefore, surgical robots teleoperated by surgeons and operate patients are studied and developed. However, conventional surgical robots are not able to transmit force sense to operator adequately. Besides, there are mechanical problems caused by driving method and increased DoF. In order to overcome these problems, the five DoF surgical robot with z-translation, grasping, roll motion, pitch motion and yaw motion is developed. The rotation axes of roll, pitch and yaw motion cross a point and it is similar to human hand which can manage complex tasks. However, the roll motion of the five DoF surgical robot is different from the one of human hand because the all part inserted into human body is rotated by the roll motion. In this paper, a method to control the gripper´s rotation angle by using coordinate transformation and control on workspace is proposed. The validity of the proposed method is verified by experiments.