Tendon-based power transmission mechanism and collocated controller with application to position tracking of autonomous surgical robots

Due to compliance and significant friction in the drive mechanism, tendon-based minimally invasive surgical robot systems exhibit highly nonlinear behavior and low position control accuracy. In this study, a novel power transmission mechanism incorporating both tendon position and tension feedback was developed. The mechanism is controlled by a corresponding collocated controller based on position sensing and a cable tension sensing method, which enables compensation for nonlinearities in the motion transmission of the tendon-based surgical robot system. The collocated controller was implemented and experimentally validated on a surgical instrument utilizing the power transmission mechanism. Experimental results demonstrate that position tracking in the motion transmission of the tendon-driven instrument can be improved by 80% using the proposed mechanism and controller. This advancement in robotic surgery holds significant potential to enhance the precision and effectiveness of surgical procedures.