A Scaled Bilateral Teleoperation System for Robotic-Assisted Surgery with Time Delay

The master-slave teleoperated robotic systems have advanced the surgeries in the past decades. Time delay is usually caused due to the data transmission between communication channel connecting the master and slave in bilateral teleoperation, which is crucial because even small time delay could destabilize the whole teleoperation system. Motivated to solve the instability caused by time delay in bilateral teleoperation, wave variable transformation (WVT) structure has been proposed to passivate the delayed communication channel. However, conventional WVT structure provides poor velocity, position and force tracking performances which are not sufficient for surgical applications. In this paper, a new wave variable compensation (WVC) structure is proposed to improve the tracking performances with less conservative condition and comprehensive analysis to keep stable and improved tracking performance is also provided. In order to better facilitate certain surgical procedures with special requirements, e.g. robotic-assisted neurosurgery, velocity/position and force scalings are designed in the proposed structure with guaranteed system passivity, and transparency of the scaled WVC structure is also analyzed. Simulation and experimental studies were carried out to verify the performance of the proposed structure with time delay. System performance comparisons with several existing wave based bilateral teleoperation structures are also provided through simulation studies to show the improvements brought by the proposed teleoperation structure.