Integrating Impedance Control and Nonlinear Disturbance Observer for Robot-Assisted Arthroscope Control in Elbow Arthroscopic Surgery

摘要

Robot-assisted arthroscopic surgery is transforming the tradition in orthopaedic surgery. Compliance and stability are essential features that a surgical robot must have for safe physical human-robot interaction ( <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</inf> HRI). Surgical tools attached at the robot end-effector and human-robot interaction will affect the robot dynamics inevitably. This could undermine the utility and stability of the robotic system if the varying robot dynamics are not identified and updated in the robot control law. In this paper, an integrated frame-work for robot impedance control and nonlinear disturbance observer (NDOB)-based compensation of uncertain dynamics is proposed, where the former ensures compliant robot behavior and the latter compensates for dynamic uncertainties when necessary. The combination of impedance controller and NDOB is analyzed theoretically in three scenarios. A complete simulation and experimental studies involving three common conditions are then conducted to evaluate the theoretical analyses. A preliminary <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$p$</tex> HRI application on arthroscopic surgery is designed to implement the proposed framework on a robotic surgeonassist system and evaluate its effectiveness experimentally. By integrating impedance controller with NDOB, the proposed framework allows an accurate impedance control when dynamic model inaccuracy and external disturbance exist.