Caterpillar-Inspired Spring-Based Compressive Continuum Robot for Bristle-based Exploration

TL;DR

This paper introduces a caterpillar-inspired, spring-based continuum robot with integrated sensing for effective exploration and inspection of confined spaces, combining compliance, precise control, and contact-based perception.

Contribution

The paper presents a novel, compact, spring-based tendon-driven continuum robot with integrated bristle sensors, inspired by caterpillar locomotion, for improved confined-space exploration and inspection.

Findings

Mean position error of 4.32 mm under control model

Successful surface perception through contact interactions

Demonstrated exploration in confined environments

Abstract

Exploration of confined spaces, such as pipelines and ducts, remains challenging for conventional rigid robots due to limited space, irregular geometry, and restricted access. Inspired by caterpillar locomotion and sensing, this paper presents a compact spring-based tendon-driven continuum robot that integrates with commercial robotic arms for confined-space inspection. The system combines a mechanically compliant continuum body with a tendon actuation module, enabling coupled bending and axial length change, and uses a constant-curvature kinematic model for positional control. Experiments show a mean position error of 4.32 mm under the proposed model and control pipeline. To extend the system from motion to inspection, we integrate an artificial bristle contact sensor and demonstrate surface perception and confined-space exploration through contact interactions. This compact and compliant design offers a cost-effective upgrade for commercial robots and promises effective exploration in challenging environments.