Hybrid Continuum-Eversion Robot: Precise Navigation and Decontamination in Nuclear Environments using Vine Robot

TL;DR

The paper addresses the challenge of safely navigating and decontaminating complex pipe networks and enclosed vessels in nuclear facilities while enabling payload delivery (sensors, liquids, aerosols). It proposes a hybrid continuum-eversion robot that combines a soft, inflatable eversion body with a rigid, tip-mounted continuum module actuated by servos for selective steering, enabling precise navigation in constrained spaces. Key contributions include the design and construction of a 3-DOF hybrid robot, CAD-based modelling of tip angles, force and motor-selection analyses, and experimental demonstration achieving over 95% spray precision in controlled tests. The work offers a promising remote-decontamination solution for hazardous nuclear environments and identifies avenues for sealing improvements, footprint reduction, AI-assisted guidance, and radiation-tolerance validation to advance toward practical deployments.

Abstract

Soft growing vine robots show great potential for navigation and decontamination tasks in the nuclear industry. This paper introduces a novel hybrid continuum-eversion robot designed to address certain challenges in relation to navigating and operating within pipe networks and enclosed remote vessels. The hybrid robot combines the flexibility of a soft eversion robot with the precision of a continuum robot at its tip, allowing for controlled steering and movement in hard to access and/or complex environments. The design enables the delivery of sensors, liquids, and aerosols to remote areas, supporting remote decontamination activities. This paper outlines the design and construction of the robot and the methods by which it achieves selective steering. We also include a comprehensive review of current related work in eversion robotics, as well as other steering devices and actuators currently under research, which underpin this novel active steering approach. This is followed by an experimental evaluation that demonstrates the robot's real-world capabilities in delivering liquids and aerosols to remote locations. The experiments reveal successful outcomes, with over 95% success in precision spraying tests. The paper concludes by discussing future work alongside limitations in the current design, ultimately showcasing its potential as a solution for remote decontamination operations in the nuclear industry.

Figures (8)

• Figure 1: Innovative Hybrid Continuum-Eversion Robot: Selective tip steering enabled by a rigid-component robotic structure, demonstrated by a) and b). Subfigure c) shows the tip design without the nylon sleeve covering.
• Figure 2: Front view of the hybrid robot showing its sprayer and camera integrated in a hard cap.
• Figure 3: Illustration depicting the eversion robot in action in figure a), showcasing its operational mechanism and dynamic expansion process. Figure b) illustrates the operation of how tail extrusion causes no shift in the outer lining of the robot.
• Figure 4: 60 mm Nylon ripstop material folded in half and stitched 5 mm from the edge. The dotted line shows where the seam should be.
• Figure 5: Detailed view of the tip structure: Illustrating how the robot turns when the servos are not actuated a) and actuated b).