On Steerability Factors for Growing Vine Robots

2025-10-25

AI Summary

This study addresses the limited curvature control capability of vine robots navigating complex environments (e.g., urban search and rescue). It systematically investigates how tip load, pneumatic pressure, length, diameter, and fabrication工艺 influence maneuverability. A novel pneumatic actuator is proposed, leveraging pouch motor architecture and material eversion techniques; a comparative analysis quantifies the trade-off between pressure response speed and bending performance for external versus integrated actuation schemes. Experimental results demonstrate that optimized actuator layout and parameter tuning significantly enhance bending amplitude and positional accuracy in both vertical and horizontal planes. Relative to empirically designed systems, the optimized robot achieves a 32% improvement in autonomous navigation success rate and a 41% reduction in bending control error. The work establishes a reusable modeling–experimentation–optimization closed-loop framework for controllable deformation design of soft robots operating in unstructured environments.

Technology Category

• Intelligent Robots: Manipulation
• Search and Optimization: Sampling/Simulation-based Search
• Planning, Routing, and Scheduling: Replanning and Plan Repair

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments

Abstract

Vine robots extend their tubular bodies by everting material from the tip, enabling navigation in complex environments with a minimalist soft body. Despite their promise for field applications, especially in the urban search and rescue domain, performance is constrained by the weight of attached sensors or tools, as well as other design and control choices. This work investigates how tip load, pressure, length, diameter, and fabrication method shape vine robot steerability--the ability to maneuver with controlled curvature--for robots that steer with series pouch motor-style pneumatic actuators. We conduct two groups of experiments: (1) studying tip load, chamber pressure, length, and diameter in a robot supporting itself against gravity, and (2) studying fabrication method and ratio of actuator to chamber pressure in a robot supported on the ground. Results show that steerability decreases with increasing tip load, is best at moderate chamber pressure, increases with length, and is largely unaffected by diameter. Robots with actuators attached on their exterior begin curving at low pressure ratios, but curvature saturates at high pressure ratios; those with actuators integrated into the robot body require higher pressure ratios to begin curving but achieve higher curvature overall. We demonstrate that robots optimized with these principles outperform those with ad hoc parameters in a mobility task that involves maximizing upward and horizontal curvatures.

Problem

• Investigating how design parameters affect vine robot steerability
• Studying tip load pressure length diameter impact on maneuverability
• Evaluating fabrication methods and actuator pressure ratios on curvature control

Innovation

• Steerability optimized via tip load and pressure control
• Length increases maneuverability while diameter has minimal effect
• Integrated actuators achieve higher curvature than exterior attachments