Closed Loop Control of a Continuum Surgical Manipulator for Improved Absolute Positioning Accuracy

Robotic assistance in MIS (Minimally Invasive Surgery) has attracted worldwide attention in the past decades. Even though majority of the implemented robotic surgical manipulators have articulated structures, continuum structures have been more widely applied due to their advantages of intra-abdominal dexterity and safe interaction with anatomy. However, absolute positioning accuracy of a continuum surgical manipulator can be low due to its nonlinear bending behaviors under different loads and un-modeled manufacturing clearance. This paper hence presents a proof-of-concept investigation of closed loop control scheme for improving the manipulator’s absolute positioning accuracy. System descriptions, kinematics modeling and experimental validations are reported in detail to demonstrate the effectiveness of the proposed control scheme.