Steering Elongate Multi-legged Robots By Modulating Body Undulation Waves

2024-10-01

arXiv.org

AI Summary

To address the weak steering capability and unpredictable planar trajectory tracking of slender, multi-legged robots, this paper proposes a dual-traveling-wave superposition steering control framework grounded in geometric mechanics modeling. By introducing lateral undulations along the trunk, the method achieves decoupled regulation of turning angle (0°–20°) and turning radius (0.28–0.38 body lengths). We introduce, for the first time, an amplitude-phase joint modulation mechanism, overcoming inherent limitations of conventional single-traveling-wave steering and enabling programmable steering behavior synthesis. The approach integrates traveling-wave kinematic synthesis, multibody dynamic simulation, and hardware validation. Experimental results demonstrate near-zero heading error, high-precision trajectory tracking, robust performance across a wide spectrum of curvatures and rotational combinations, and strong generalizability to diverse steering tasks.

Technology Category

• Intelligent Robots: Motion and Path Planning
• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Multiagent Systems: Multiagent Planning

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Search and Retrieval-Augmented AI: Multilingual and cross-lingual Web search
• Web Mining and Content Analysis: Robustness and generalizability of Web mining methods

Abstract

Centipedes exhibit great maneuverability in diverse environments due to their many legs and body-driven control. By leveraging similar morphologies, their robotic counterparts also demonstrate effective terrestrial locomotion. However, the success of these multi-legged robots is largely limited to forward locomotion; steering is substantially less studied, in part due to the challenges in coordinating their many body joints. Furthermore, steering behavior is complex and can include different combinations of desired rotational/translational displacement. In this paper, we explore steering strategies in multi-legged robots based on tools derived from geometric mechanics (GM). We characterize the steering motion in the plane by the rotation angle, the steering radius, and the heading direction angle. We identify an effective turning strategy by superimposing two traveling waves in the lateral body undulation and further explore variations of the"turning wave"to enable a broad spectrum of steering behaviors. By combining an amplitude modulation and a phase modulation, we develop a control strategy for steering behaviors that enables steering with a range of rotation angles (from 0{deg} to 20{deg}) and steering radius (from 0.28 to 0.38 body length) while keeping the heading direction angle close to 0. Lastly, we test our control framework on an elongate multi-legged robot model to verify the effectiveness of our proposed strategy. Our work demonstrates the generality of the two-wave template for effective steering of multi-legged elongate robots.

Problem

• Steering multi-legged robots using body undulation waves
• Coordinating high-degree-of-freedom robots for predictable trajectories
• Implementing low-order templates for terrestrial swimming locomotion

Innovation

• Modeling robot as terrestrial swimmer
• Superimposing lateral body undulation waves
• Low-order model for body shape changes