Toward Extending Concentric Tube Robot Kinematics for Large Clearance and Impulse Curvature

TL;DR

This paper extends the kinematic modeling of Concentric Tube Robots to better handle scenarios with large clearances and curvatures, improving accuracy for minimally invasive surgical applications and industrial pipe navigation.

Contribution

The authors develop a generalized CTR kinematic model that accounts for large tube-to-tube clearance and high curvature, validated through simulations and experiments.

Findings

Achieved 1.53 mm tip error in 2D experiments

Achieved 4.36 mm tip error in 3D experiments

Model outperforms existing models by over 66% in accuracy

Abstract

Concentric Tube Robots (CTRs) have been proposed to operate within the unstructured environment for minimally invasive surgeries. In this letter, we consider the operation scenario where the tubes travel inside the channels with a large clearance or large curvature, such as aortas or industrial pipes. Accurate kinematic modeling of CTRs is required for the development of advanced control and sensing algorithms. To this end, we extended the conventional CTR kinematics model to a more general case with large tube-to-tube clearance and large centerline curvature. Numerical simulations and experimental validations are conducted to compare our model with respect to the conventional CTR kinematic model. In the physical experiments, our proposed model achieved a tip position error of 1.53 mm in the 2D planer case and 4.36 mm in 3D case, outperforming the state-of-the-art model by 71% and 66%, respectively.