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

2026-04-16

AI Summary

This work addresses the challenge of diminished controllability and safety risks in continuum robots operating within highly constrained environments, where distinguishing between beneficial and harmful contacts remains difficult. The authors propose a contact-aware motion planning framework that, for the first time, integrates contact quality assessment of the distal segment directly into trajectory optimization. By penalizing hazardous contacts while preserving benign ones, the method generates kinematically feasible trajectories and constructs a contact-aware Jacobian matrix for closed-loop control. Evaluated in three experimental setups based on real anatomical structures, the approach achieves 100% target reachability without any dangerous tip contacts and demonstrates high tracking accuracy, with average errors of 1.9 ± 0.5 mm, 1.2 ± 0.1 mm, and 1.7 ± 0.2 mm, respectively, significantly enhancing manipulability while preventing hardware failure.

Technology Category

• Intelligent Robots: Manipulation
• Humans and AI: Human-Aware Planning and Behavior Prediction
• Natural Language Processing: Safety and Robustness

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

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.

Problem

• continuum robots
• constrained environments
• contact-aware planning
• kinematic singularities
• safety risks

Innovation

• contact-aware planning
• continuum robots
• constrained environments
• contact quality evaluation
• closed-loop control