Stable Tracking-in-the-Loop Control of Cable-Driven Surgical Manipulators under Erroneous Kinematic Chains

TL;DR

This paper introduces a provably stable control method for cable-driven surgical robots that compensates for kinematic errors, especially in out-of-view joints, enhancing autonomous surgical capabilities.

Contribution

It presents the first stability analysis and control scheme for handling erroneous kinematic chains in RCM surgical manipulators, including out-of-view errors.

Findings

The proposed controller is provably stable under realistic error conditions.

The method improves accuracy in simulated and real surgical scenarios.

Benchmark results demonstrate robustness against joint reading errors.

Abstract

Remote Center of Motion (RCM) robotic manipulators have revolutionized Minimally Invasive Surgery, enabling precise, dexterous surgical manipulation within the patient's body cavity without disturbing the insertion point on the patient. Accurate RCM tool control is vital for incorporating autonomous subtasks like suturing, blood suction, and tumor resection into robotic surgical procedures, reducing surgeon fatigue and improving patient outcomes. However, these cable-driven systems are subject to significant joint reading errors, corrupting the kinematics computation necessary to perform control. Although visual tracking with endoscopic cameras can correct errors on in-view joints, errors in the kinematic chain prior to the insertion point are irreparable because they remain out of view. No prior work has characterized the stability of control under these conditions. We fill this gap by designing a provably stable tracking-in-the-loop controller for the out-of-view portion of the RCM manipulator kinematic chain. We additionally incorporate this controller into a bilevel control scheme for the full kinematic chain. We rigorously benchmark our method in simulated and real world settings to verify our theoretical findings. Our work provides key insights into the next steps required for the transition from teleoperated to autonomous surgery.