Inchworms have been one of the most widely used bionic templates for designing soft robotic devices. Bioresearch has shown that muscles of inchworms exhibit nonlinear hysteresis and their body structures are with hydrostatic skeleton. But effects of these properties on their dynamic movements have not been studied yet. In this work, a dynamic model based on the principle of virtual power of an inchworm is established to examine the problem. A spring-damper model with time-varying stiffness and damping coefficients is used to model controllable nonlinear properties of the inchworm muscles. The hydrostatic skeleton is applied to the model as a constant volume constraint for each segment. Based on this, simulations of three typical movements including omega-shaped arching motion, cantilevered probing motion and surprising fast looping motion are presented. The effects of the nonlinear properties including variable stiffness and damping properties of muscles on these dynamic behaviors of inchworms are illustrated. Some inspiration for designing bio-inspired crawling robots and soft slender robotic devices is obtained. And we think this work will hopefully provide better understanding and guidance for design and control of these robotic devices.

中文翻译：

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蠕虫运动向生物启发式软机器人设计的动态建模和仿真。

蠕虫一直是设计软机器人设备中使用最广泛的仿生模板之一。生物研究表明，尺虫的肌肉表现出非线性滞后现象，其身体结构具有静水骨架。但是，尚未研究这些特性对其动态运动的影响。在这项工作中，建立了基于足蠕虫虚拟力量原理的动态模型来研究该问题。具有随时间变化的刚度和阻尼系数的弹簧-阻尼器模型用于对尺inch肌肉的可控制非线性特性进行建模。静液压骨架作为每个段的恒定体积约束应用于模型。在此基础上，模拟了三种典型运动，包括欧米茄形的弓形运动，悬臂式探测运动和令人惊讶的快速循环运动。说明了非线性特性（包括可变的刚度和肌肉的阻尼特性）对on蠕虫的这些动态行为的影响。获得了一些设计灵感来自生物的爬行机器人和细长的机器人设备的灵感。而且我们认为这项工作有望为这些机器人设备的设计和控制提供更好的理解和指导。