Contact-Aware Planning and Control of Continuum Robots in Highly Constrained Environments

TL;DR

This paper introduces a contact-aware planning method for continuum robots that evaluates and penalizes hazardous contact, enabling safe navigation in highly constrained environments with successful hardware validation.

Contribution

The authors develop a novel planning approach that accounts for contact quality, producing feasible trajectories and Jacobians for improved control in complex environments.

Findings

The planner successfully generated safe, effective trajectories in three anatomical models.

Hardware trials achieved 100% success in reaching targets while avoiding dangerous contact.

Penalizing end-of-continuum-segment contact improved manipulability and prevented failures.

Abstract

Continuum robots are well suited for navigating confined and fragile environments, such as vascular or endoluminal anatomy, where contact with surrounding structures is often unavoidable. While controlled contact can assist motion, unfavorable contact can degrade controllability, induce kinematic singularities, or introduce safety risks. We present a contact-aware planning approach that evaluates contact quality, penalizing hazardous interactions, while permitting benign contact. The planner produces kinematically feasible trajectories and contact-aware Jacobians which can be used for closed-loop control in hardware experiments. We validate the approach by testing the integrated system (planning, control, and mechanical design) on anatomical models from patient scans. The planner generates effective plans for three common anatomical environments, and, in all hardware trials, the continuum robot was able to reach the target while avoiding dangerous tip contact (100% success). Mean tracking errors were 1.9 +/- 0.5 mm, 1.2 +/- 0.1 mm, and 1.7 +/- 0.2 mm across the three different environments. Ablation studies showed that penalizing end-of-continuum-segment (ECS) contact improved manipulability and prevented hardware failures. Overall, this work enables reliable, contact-aware navigation in highly constrained environments.