Deciphering how quadrupeds coordinate their legs and other body parts, such as the trunk, head, and tail (i.e., body--limb coordination), can provide informative insights to improve legged robot mobility. In this study, we focused on sprawling locomotion of the salamander and aimed to understand the body--limb coordination mechanisms through mathematical modeling and simulations. The salamander is an amphibian that moves on the ground by coordinating the four legs with lateral body bending. It uses standing and traveling waves of lateral bending that depend on the velocity and stepping gait. However, the body--limb coordination mechanisms responsible for this flexible gait transition remain elusive. This paper presents a central-pattern-generator-based model to reproduce spontaneous gait transitions, including changes in bending patterns. The proposed model implements four feedback rules (feedback from limb-to-limb, limb-to-body, body-to-limb, and body-to-body) without assuming any inter-oscillator coupling. The interplay of the feedback rules establishes a self-organized body--limb coordination that enables the reproduction of the speed-dependent gait transitions of salamanders, as well as various gait patterns observed in sprawling quadruped animals. This suggests that sensory feedback plays an essential role in flexible body--limb coordination during sprawling quadruped locomotion.

中文翻译：

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通过感官驱动的身体 - 肢体协调机制进行四足运动的自发步态转换

解读四足动物如何协调他们的腿和其他身体部位，如躯干、头部和尾部（即身体 - 肢体协调），可以提供信息洞察力，以提高有腿机器人的移动性。在这项研究中，我们专注于蝾螈的蔓延运动，旨在通过数学建模和模拟来了解身体 - 四肢协调机制。蝾螈是一种两栖动物，通过协调四足与身体横向弯曲在地面上移动。它使用取决于速度和步态的横向弯曲的驻波和行波。然而，负责这种灵活步态转换的身体 - 肢体协调机制仍然难以捉摸。本文提出了一种基于中央模式生成器的模型来重现自发的步态转变，包括弯曲模式的变化。所提出的模型实现了四种反馈规则（从肢体到肢体、肢体对身体、身体对肢体和身体对身体的反馈），而无需假设任何振荡器间耦合。反馈规则的相互作用建立了一种自组织的身体 - 肢体协调，使蝾螈的速度依赖步态转变以及在四足动物中观察到的各种步态模式得以再现。这表明感觉反馈在四足动物伸展运动过程中灵活的身体 - 肢体协调中起着至关重要的作用。反馈规则的相互作用建立了一种自组织的身体 - 肢体协调，使蝾螈的速度依赖步态转变以及在四足动物中观察到的各种步态模式得以再现。这表明感觉反馈在四足动物伸展运动过程中灵活的身体 - 肢体协调中起着至关重要的作用。反馈规则的相互作用建立了一种自组织的身体 - 肢体协调，使蝾螈的速度依赖步态转变以及在四足动物中观察到的各种步态模式得以再现。这表明感觉反馈在四足动物伸展运动过程中灵活的身体 - 肢体协调中起着至关重要的作用。