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

2026-03-10

AI Summary

This work proposes a spring-based tendon-driven continuum robot inspired by the locomotion and sensing mechanisms of caterpillars to address the challenge of effective exploration in confined and irregularly shaped pipelines, where conventional rigid robots struggle. The design integrates a bioinspired compressible structure with artificial setae-based tactile sensors and is compatible with commercial robotic arms, enabling coupled bending and axial elongation/contraction. Position control is achieved through a constant-curvature kinematic model. Experimental results demonstrate an average positioning error of 4.32 mm, confirming the system’s capability for compliant, contact-based exploration and surface perception within constrained environments. The robot offers a compelling combination of compactness, compliance, and low cost, making it well-suited for delicate inspection tasks in complex spaces.

Technology Category

• Intelligent Robots: Manipulation
• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Mixed Discrete/Continuous Planning

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work

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.

Problem

• confined-space exploration
• pipeline inspection
• continuum robot
• bristle-based sensing
• caterpillar-inspired locomotion

Innovation

• continuum robot
• tendon-driven
• bristle sensor
• confined-space exploration
• constant-curvature kinematics