Soft robotic snakes made of compliant materials can continuously deform their bodies and, therefore, mimic the biological snakes' flexible and agile locomotion gaits better than their rigid-bodied counterparts. Without wheel support, to date, soft robotic snakes are limited to emulating planar locomotion gaits, which are derived via kinematic modeling and tested on robotic prototypes. Given that the snake locomotion results from the reaction forces due to the distributed contact between their skin and the ground, it is essential to investigate the locomotion gaits through efficient dynamic models capable of accommodating distributed contact forces. We present a complete spatial dynamic model that utilizes a floating-base kinematic model with distributed contact dynamics for a pneumatically powered soft robotic snake. We numerically evaluate the feasibility of the planar and spatial rolling gaits utilizing the proposed model and experimentally validate the corresponding locomotion gait trajectories on a soft robotic snake prototype. We qualitatively and quantitatively compare the numerical and experimental results which confirm the validity of the proposed dynamic model.

翻译：由柔性材料制成的软体机器蛇能够持续变形其身体，因此相比刚性体同类能更好地模仿生物蛇灵活敏捷的运动步态。由于缺乏轮式支撑，目前软体机器蛇仅限于模拟平面运动步态，这些步态通过运动学建模推导并在机器人样机上得到测试。考虑到蛇类运动源于其皮肤与地面间分布式接触产生的反作用力，因此有必要通过能够适应分布式接触力的高效动力学模型来研究运动步态。我们提出了一种完整空间动力学模型，该模型采用浮动基座运动学模型与分布式接触动力学相结合，适用于气动软体机器蛇。我们利用所提模型数值评估了平面与空间滚动步态的可行性，并在软体机器蛇样机上实验验证了相应运动步态轨迹。通过定性与定量对比数值与实验结果，证实了所提动力学模型的有效性。