A feed-forward friction compensation motion controller for a tendon-sheath-driven flexible robotic gripper

The flexible endoscope has great potential to reach a diseased organ through a natural opening of the human body to perform surgeries without leaving a scar on the body surface. Despite such advances in reaching the diseased organ, using the conventional flexible endoscope to complete surgical procedure is still largely constrained by the limited degree-of-freedoms (DOFs) of endoscopic instruments. A 3-DOFs robotic gripper, which is designed to work through the channel of a flexible endoscope and driven by tendon-and-sheath system (TSS), has therefore been developed. In order to perform precise trajectory tracking for complex surgical procedures, this paper aims to analyze the friction loss of the flexible robotic gripper inherent to TSS and generate compensation methods for developing an intelligent motion controller for this robotic gripper. The experiment results showed improvement in the trajectory tracking performance after applying the designed compensation techniques.