Kinematic analysis of a class of multi-DOF tendon-driven minimally invasive surgical instruments

Each servo motor was installed on the base and servo motor torque was transmitted to each joint through a tendon-and-pulley system to reduce volume and to get compact surgical instruments in robot-assisted minimally invasive surgery. In this paper, a class of multi-DOF tendon-driven minimally invasive surgical instrument was designed and corresponding forward kinematic and inverse kinematic were analyzed based on the product of exponentials formula, and Paden and Kahan subproblems. Due to the tendon-driven surgical instrument existing motion coupling, the relationships of the tendon-driven multi-DOF surgical instrument between actuator space and joint space were derived to achieve joint motion decoupling. The analysis method can be useful for motion analysis and control for tendon-driven robotic mechanisms with open&close function.