A Hermetic, Transparent Soft Growing Vine Robot System for Pipe Inspection

TL;DR

This work tackles in-pipe condition assessment for aging, non-branching pipes by introducing a hermetic, transparent soft growing vine robot that encloses all subsystems to enable internal visual sensing. A passively adapting enclosed tip mount keeps sensors at the moving tip while minimizing propulsion losses, and a canister-style base station simplifies deployment without active length control. The system is modeled and validated through lab tests and a real wastewater pipe deployment, demonstrating robust growth, sensing, and 3D pipe mapping capabilities with minimal external hardware. The approach reduces environmental interference, improves reliability in challenging pipe interiors, and provides a practical platform for future integration of advanced sensing and localization methods.

Abstract

Rehabilitation of aging pipes requires accurate condition assessment and mapping far into the pipe interiors. Soft growing vine robot systems are particularly promising for navigating confined, sinuous paths such as in pipes, but are currently limited by complex subsystems and a lack of validation in real-world industrial settings. In this paper, we introduce the concept and implementation of a hermetic and transparent vine robot system for visual condition assessment and mapping within non-branching pipes. This design encloses all mechanical and electrical components within the vine robot's soft, airtight, and transparent body, protecting them from environmental interference while enabling visual sensing. Because this approach requires an enclosed mechanism for transporting sensors, we developed, modeled, and tested a passively adapting enclosed tip mount. Finally, we validated the hermetic and transparent vine robot system concept through a real-world condition assessment and mapping task in a wastewater pipe. This work advances the use of soft-growing vine robots in pipe inspection by developing and demonstrating a robust, streamlined, field-validated system suitable for continued development and deployment.

Figures (7)

• Figure 1: A visualization of the hermetic, transparent soft growing vine robot system being used to inspect a buried pipe. The vine robot enters the pipe from the top left, and the inset image shows the electronics and mechanical equipment enclosed and hermetically sealed at the tip of the robot.
• Figure 2: Enclosed vine robot system. (A) Schematic of the entire system; the middle of the vine robot body is hidden. The relative locations of the subsystems B and C are also shown. (B) The canister-style base station and key features. (C) The distal end of the enclosed vine robot, with the internal electrical and mechanical elements housed within the vine robot body.
• Figure 3: Working principle of the passively adapting enclosed tip mount. (A) The tip mount is offset from the tip of the vine robot, and clamps to the vine robot tail. As the vine robot grows to the right, tail material and attached tip mount are pulled to the tip. (B) When the tip mount reaches the tip of the vine robot, its clamp is forced open to allow the vine robot's tail material to slide through.
• Figure 4: (A) A free-body diagram of a constant force enclosed tip mount design. (B) A free-body diagram of a passively adapting enclosed tip mount design.
• Figure 5: The pressure required for a vine robot to begin growing with various loads attached, with and without tip mounts. (A) Growth with the load directly attached to the vine robot's tail. This method requires the least pressure to grow for a given load. The experimental setup used for this and all other tests is diagrammed in the top left of the subfigure. (B) A comparison of the growth pressure required when using the constant force tip mount and passively adjusting the enclosed tip mount as attachment points. In these tests, the tip mount clamps were tuned to slip at loads above 12 N. (C) The same tests as in subfigure B, but with the tip mount maximum friction force tuned to 24 N.