A Decapod Robot with Rotary Bellows-Enclosed Soft Transmissions

2025-03-10

AI Summary

This work addresses the challenges of complex pneumatic valve control and low locomotion efficiency in soft robots. We propose a valveless rotary bellows-based enclosed soft transmission system (R-BESTS), which directly converts servo motor rotation into leg swing motion to achieve alternating tripod gait and in-place turning. Key innovations include: (1) a novel structured-output bellows design enabling passive, time-sequenced bending—replacing active pneumatic supply regulation; (2) synchronous counter-phase belt transmission ensuring precise inter-leg coordination; and (3) fully tetherless autonomous operation. Experimental results demonstrate a forward speed of 1.75 cm/s (0.07 body-lengths/s), 90-minute endurance, a minimum turning radius of 15 cm (0.6 body-lengths), a payload capacity of 200 g, and robust locomotion on unstructured terrains including sand and inclined surfaces.

Technology Category

• Intelligent Robots: Manipulation
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Multiagent Systems: Distributed Problem Solving

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Search and Retrieval-Augmented AI: Agentic search

Abstract

Soft crawling robots exhibit efficient locomotion across various terrains and demonstrate robustness to diverse environmental conditions. Here, we propose a valveless soft-legged robot that integrates a pair of rotary bellows-enclosed soft transmission systems (R-BESTS). The proposed R-BESTS can directly transmit the servo rotation into leg swing motion. A timing belt controls the pair of R-BESTS to maintain synchronous rotation in opposite phases, realizing alternating tripod gaits of walking and turning. We explored several designs to understand the role of a reinforcement skeleton in twisting the R-BESTS' input bellows units. The bending sequences of the robot legs are controlled through structural design for the output bellows units. Finally, we demonstrate untethered locomotion with the soft robotic decapod. Experimental results show that our robot can walk at 1.75 centimeters per second (0.07 body length per second) for 90 min, turn with a 15-centimeter (0.6 BL) radius, carry a payload of 200 g, and adapt to different terrains.

Problem

• Develops a soft-legged robot with rotary bellows-enclosed transmissions.
• Explores designs for reinforcement skeletons in soft transmission systems.
• Demonstrates untethered locomotion and adaptability to various terrains.

Innovation

• Rotary bellows-enclosed soft transmission systems
• Valveless soft-legged robot design
• Untethered locomotion with structural control