Online Jacobian Estimation and Tracking Control of a Two-Section Tendon-Driven Continuum Robot

Abstract

This paper proposes a control framework for a two-section, concentrically tendon-driven continuum robot. The tracking control is formulated based on a Jacobian approach using zeroing dynamics. The Jacobian is estimated online from input–output data, using applied tendon force as inputs and measured tip positions as outputs, without requiring an explicit model. Tendon force is employed as the control input to better account for the deformation under external loads. The proposed framework is experimentally validated on a real-scale continuum robot, with tip-position feedback from a stereo-vision system. Experimental results demonstrate that the robot tip follows the desired trajectory with an RMSE of about 1.18 mm, while maintaining good performance under unknown external loads.