Dynamic Modeling and Robust Gait Optimization of a Compliant Worm Robot

2026-04-13

AI Summary

This work addresses the challenges in modeling locomotion and achieving reliable gait optimization for soft worm-like robots operating in corrugated pipes, where deformable anchoring mechanisms exhibit strong coupling with the environment. To overcome these difficulties, the authors propose a hybrid dynamic model that integrates continuous body dynamics with discrete anchoring transitions. This framework incorporates a slack-aware actuation mapping and a physics-based energy consumption model to enable multi-objective gait optimization that balances speed and energy efficiency. A key innovation is the introduction of a kinematic robustness margin during anchoring transitions, which enhances deployment stability in real-world scenarios. Experimental results validate the model’s accuracy in capturing both locomotion performance and energy usage, demonstrating its capability to generate gaits that are simultaneously efficient and robust across diverse operating conditions.

Technology Category

• Intelligent Robots: Motion and Path Planning
• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Mixed Discrete/Continuous Planning

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Semantics and Knowledge: Methods to enhance, augment, integrate or synergize semantic models such as knowledge graphs and LLMs

Abstract

Worm-inspired robots provide an effective locomotion strategy for constrained environments by combining cyclic body deformation with alternating anchoring. For compliant robots, however, the interaction between deformable anchoring structures and the environment makes predictive modeling and deployable gait optimization challenging. This paper presents an experimentally grounded modeling and optimization framework for a compliant worm robot capable of traversing corrugated pipes. First, a hybrid dynamic locomotion model is derived, in which the robot motion is represented by continuous dynamics within a corrugation groove and discrete switching of anchoring positions between adjacent grooves. A slack-aware actuation model is further introduced to map the commanded gait input to the realized body-length change, and an energy model is developed based on physics and calibrated with empirical power measurement. Based on these models, a multi-objective gait optimization problem is formulated to maximize average speed while minimizing average power. To reduce the fragility of nominal boundary-seeking solutions, a kinematic robustness margin is introduced into the anchoring-transition conditions, leading to a margin-based robust gait optimization framework. Experimental results show that the proposed framework captures the dominant locomotion and energy-consumption behavior of the robot over the tested conditions, and enables robust gait optimization for achieving speed-power trade-off.

Problem

• compliant worm robot
• dynamic modeling
• gait optimization
• anchoring interaction
• robust locomotion

Innovation

• compliant worm robot
• hybrid dynamic locomotion model
• slack-aware actuation
• energy modeling
• robust gait optimization