Muscular hydrostats, such as octopus arms or elephant trunks, lack bones entirely, endowing them with exceptional dexterity and reconfigurability. Key to their unmatched ability to control nearly infinite degrees of freedom is the architecture into which muscle fibers are weaved. Their arrangement is, effectively, the instantiation of a sophisticated mechanical program that mediates, and likely facilitates, the control and realization of complex, dynamic morphological reconfigurations. Here, by combining medical imaging, biomechanical data, live behavioral experiments and numerical simulations, we synthesize a model octopus arm entailing ~200 continuous muscles groups, and begin to unravel its complexity. We show how 3D arm motions can be understood in terms of storage, transport, and conversion of topological quantities, effected by simple muscle activation templates. These, in turn, can be composed into higher-level control strategies that, compounded by the arm's compliance, are demonstrated in a range of object manipulation tasks rendered additionally challenging by the need to appropriately align suckers, to sense and grasp. Overall, our work exposes broad design and algorithmic principles pertinent to muscular hydrostats, robotics, and dynamics, while significantly advancing our ability to model muscular structures from medical imaging, with potential implications for human health and care.

翻译：肌肉水压力学结构，如八爪鱼的臂或大象的鼻子，完全缺乏骨骼，使它们具有卓越的灵巧性和可重构性。它们无与伦比地控制着近乎无限自由度，这的关键在于组成其内部的肌肉纤维的构架。它们的排列实际上是一个复杂的机械程序的实例，调节和促进了复杂的动态形态重构的控制和实现。在这里，我们通过结合医学影像、生物力学数据、实时行为实验和数值模拟，综合一条包含约200个连续肌肉组合的八爪鱼臂模型，并开始揭示其复杂性。我们展示了如何通过简单的肌肉激活模板，将3D臂的运动理解为拓扑量的存储、传输和转换。这些模板又可以组合成更高级别的控制策略，再加上臂的柔韧性，能够完成一系列物体操纵任务，这些任务由于需要适当地对齐吸盘、感知和抓取而变得更加具有挑战性。总体而言，我们的工作揭示了肌肉水压力学结构、机器人和动力学中的广泛设计和算法原则，并在极大地提高我们从医学影像建模肌肉结构的能力，具有潜在的人类健康和护理方面的影响。