Online Jacobian Estimation and Tracking Control of a Two-Section Tendon-Driven Continuum Robot
Ivan Adi Kuncara, Ayoung Hong
AI summary
Problem
Model uncertainties from tendon friction, inter-section interactions, and strong coupling hinder accurate Jacobian derivation and degrade tracking control performance in multi-section continuum robots.
Approach
The framework estimates the robot's Jacobian matrix online using real-time tendon force inputs and vision-based tip position outputs, updating it iteratively via a zeroing-dynamics controller without an explicit forward model.
Key results
- Online Jacobian estimation updates iteratively from input-output data without an explicit model
- Tip position tracks a circular trajectory with an overall RMSE of approximately 1.18 mm
- Controller maintains robust tracking performance under unknown external loads
- Experimental validation on a real-scale two-section concentric tendon-driven continuum robot
Why it matters
Provides a practical, model-free control strategy for complex continuum robots, advancing their reliability for minimally invasive medical procedures.
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.