[Paper Review] A Tip Mount for Carrying Payloads using Soft Growing Robots.

Ok Hwa Jeon, Margaret M. Coad+6 more|arXiv (Cornell University)|Dec 17, 2019

Modular Robots and Swarm Intelligence4 citations

TL;DR

This paper presents a novel tip mount for soft growing robots that enables reliable payload attachment at the robot's tip during extension, retraction, and steering. The mount allows the robot to carry active devices and exert significant tensile loads without buckling, demonstrated by successful object retrieval and delivery in experimental validation.

ABSTRACT

Pneumatically operated soft growing robots that lengthen through tip eversion can be used for inspection and manipulation tasks in confined spaces such as caves, animal habitats, or disaster environments. Because new material is continually emitted from the robot tip, it is challenging to mount sensors, grippers, or other useful payloads at the tip of the robot. Here, we present a tip mount for soft growing robots that can be reliably used and remain attached to the tip during growing, retraction, and steering, while carrying a variety of payloads, including active devices. Our tip mount enables two new soft growing robot capabilities: retracting without buckling while carrying a payload at the tip, and exerting a significant tensile load on the environment during inversion. In this paper, we review previous research on soft growing robot tip mounts, and we discuss the important features of a successful tip mount. We present the design of our tip mount and results for the minimum pressure to grow and the maximum payload in tension. We also demonstrate a soft growing robot equipped with our tip mount retrieving an object and delivering it to a different location.

Motivation & Objective

• Address the challenge of mounting sensors and grippers on soft growing robots due to continuous tip extension via tip eversion.
• Enable reliable payload attachment that remains secure during dynamic robot motions including growing, retracting, and steering.
• Allow the robot to retract without buckling while carrying a payload at the tip.
• Enable the robot to exert significant tensile loads on the environment during inversion.
• Demonstrate practical application through object retrieval and delivery using the mounted payload.

Proposed method

• Design a mechanical tip mount that integrates with the soft growing robot’s tip and securely holds payloads during actuation.
• Use pneumatic actuation to drive robot extension through tip eversion, with the mount attached to the advancing tip.
• Ensure structural integrity of the mount under tensile loads during retraction and environmental interaction.
• Optimize the mount’s geometry and material interface to maintain attachment during dynamic motion and payload loading.
• Test the mount’s performance under varying internal pressures to determine minimum pressure for successful growth.
• Evaluate maximum payload capacity in tension to quantify load-bearing capability.

Experimental results

Research questions

• RQ1 How can a tip mount be designed to remain securely attached to a soft growing robot during extension, retraction, and steering?
• RQ2 What is the minimum internal pressure required for the robot to grow while carrying a payload via the new tip mount?
• RQ3 What is the maximum tensile load the robot can exert on the environment while carrying a payload at the tip?
• RQ4 Can the robot successfully retrieve and deliver an object using the mounted payload?
• RQ5 How does the tip mount prevent buckling during retraction when carrying a payload?

Key findings

• The tip mount enables stable payload attachment during all phases of robot motion, including growing, retracting, and steering.
• The robot achieved successful object retrieval and delivery using the mounted payload, demonstrating practical applicability.
• The minimum pressure required to grow the robot while carrying a payload was experimentally determined, though the exact value is not specified in the provided text.
• The mount allowed the robot to exert a significant tensile load on the environment during inversion, indicating enhanced mechanical capability.
• The robot did not buckle during retraction when carrying a payload, confirming the structural robustness of the mount design.
• The tip mount supports a variety of payloads, including active devices, expanding the robot’s functional versatility.