Transmission Backlash Compensation and Grasping Force Estimation of Surgical Instruments for the Laparoscopic Minimally Invasive Surgery Robot

It is difficult to install the sensor on the end effector of a minimally invasive surgical robot with a narrow space within which to obtain the position and grasping force; thus, the elongation effect of cable-driven surgical instruments results in low precision control, which may damage the tissues and organs of patients. A novel transmission backlash compensation and grasping force saturation limitation algorithm based on the tension and displacement transmission model of a cable-pulley system is proposed to improve the operation’s accuracy and safety. The algorithm considers the force and position transmission characteristics of each stage of the cable-pulley system including the transition stage. Experimental verifications show that the proposed algorithm can significantly improve the position tracking accuracy of surgical instruments and the safety of grasping operations.