Robotic Forceps without Position Sensors using Visual SLAM

In this study, a robotic forceps with a wrist joint using visual SLAM for joint angle sensing was developed. The forceps has a flexible joint connected to the wrist joint at its rear end and the motion of the rear joint is driven by a parallel linkage. A monocular camera attached on the rear of the parallel linkage is in charge of position sensing, and the joint angles are estimated from the pose of the camera. The pose of the camera is obtained by a visual SLAM. The visual servo system realizes a simple attaching mechanism. The static and dynamic positioning experiments are conducted. We confirmed that the visual servoing system controls the forceps tip within the error of 3 deg in the motion range of 50 deg.