A Tip Mount for Transporting Sensors and Tools using Soft Growing Robots (1912.08297v3)

Abstract: Pneumatically operated soft growing robots that extend via tip eversion are well-suited for navigation in confined spaces. Adding the ability to interact with the environment using sensors and tools attached to the robot tip would greatly enhance the usefulness of these robots for exploration in the field. However, because the material at the tip of the robot body continually changes as the robot grows and retracts, it is challenging to keep sensors and tools attached to the robot tip during actuation and environment interaction. In this paper, we analyze previous designs for mounting to the tip of soft growing robots, and we present a novel device that successfully remains attached to the robot tip while providing a mounting point for sensors and tools. Our tip mount incorporates and builds on our previous work on a device to retract the robot without undesired buckling of its body. Using our tip mount, we demonstrate two new soft growing robot capabilities: (1) pulling on the environment while retracting, and (2) retrieving and delivering objects. Finally, we discuss the limitations of our design and opportunities for improvement in future soft growing robot tip mounts.

• The paper presents a tip mount that maintains reliable sensor and tool attachment during both growth and retraction.
• The design successfully transmits pulling forces up to 2.5 kg while mitigating buckling through a retractable mechanism.
• The retractable, arbitrary-length mount enhances soft robot manipulation in constrained environments, paving the way for advanced applications.

Overview of "A Tip Mount for Transporting Sensors and Tools using Soft Growing Robots"

The paper "A Tip Mount for Transporting Sensors and Tools using Soft Growing Robots" explores the advancement of a novel tip mount designed for pneumatically actuated soft growing robots. These robots, characterized by their tip eversion growth mechanism, show promise for applications in restricted environments. However, a significant challenge arises in mounting sensors and tools at the robot tip due to the changing nature of the material at the tip during growth and retraction. The research presented addresses this challenge through an innovative design that maintains attachment at the robot tip while facilitating the transport of sensors and tools, allowing for environmental interaction.

Key Contributions

The authors introduce a tip mount that overcomes several shortcomings of previous designs:

1. Reliable Attachment: The proposed tip mount consistently remains at the robot tip during both growth and retraction. This is a notable improvement over prior solutions that often failed to remain attached during retraction.
2. Force Transmission Capability: The design successfully transmits pulling forces from the robot body to the environment, enhancing the robot's manipulation capabilities.
3. Retractable Design: The tip mount incorporates a retraction device to prevent undesired buckling of the robot body during retraction, ensuring stability and control that previous designs lacked.
4. Arbitrary Length Functionality: The tip mount operates effectively at arbitrary robot body lengths, a vital feature for navigating extensive and variable terrains.

Technical Details

The mechanics of the design are underpinned by a combination of features from earlier models including the outer cap and the magnetic rollers. The integration of a rolling interlock system leverages passive rollers to minimize friction, allowing material to pass smoothly while maintaining a secure attachment. Additionally, this design does not depend on a physical connection back to the base, unlike some previous models, meanwhile managing to transmit substantial forces.

Experimental Validation

Through rigorous experiments, the researchers have quantified the impact of the tip mount on operational parameters. The minimum pressure required for growth increased by 1.4 kPa with the addition of the outer cap and retraction components, yet remained within a range that maintains functionality below the burst pressure of the robot body. More impressively, the new design allows the soft growing robot to exert a pulling force of up to 2.5 kg, clearly demonstrating enhanced capabilities over existing models.

Discussion and Implications

While the new design effectively addresses several persistent challenges in soft growing robot tip mount technology, some limitations persist, such as significant additional weight and reduced ability to shrink through apertures. These challenges indicate clear avenues for future research, particularly in reducing the weight of the mount and improving its adaptability in varied environments.

The implications of this advancement extend into practical applications, such as in exploratory and rescue operations within constrained environments where the effective transportation of sensors and tools can greatly enhance mission outcomes. Theoretically, this work contributes to the broader understanding of soft continuum robotics, offering insights into managing the dynamic interaction between a soft structure and its environment throughout variable motion states.

Conclusion

In summary, the paper proposes a significant evolution in the design of tip mounts for soft growing robots. By enhancing force transmission, maintaining reliable attachment, and preventing buckling, this work paves the way for more capable and dependable robotic systems. Future developments might improve its weight efficiency and environmental adaptability, potentially transforming the utility of soft robotics in complex and confined scenarios.