An earthworm-inspired friction-controlled soft robot capable of bidirectional locomotion
An earthworm-inspired friction-controlled soft robot capable of bidirectional locomotion
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DOI：
10.1088/1748-3190/aae7bb
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发表时间：
2019-05-01
影响因子：
3.4
通讯作者：
Perez-Arancibia, Nestor O.
中科院分区：
文献类型：
--
作者：
Ge, Joey Z.;Calderon, Ariel A.;Perez-Arancibia, Nestor O.
我们提出的设计，制造，建模和反馈控制的蚯蚓启发的软机器人能够双向运动的水平和倾斜的平板平台。在这种方法中，通过主动改变机器人和支撑平台的接触表面之间的摩擦系数来控制运动模式，从而在概念层面上模仿蚯蚓的无肢运动。蚯蚓的特征在于分段的身体结构，称为变粒，由纵向和环形肌肉组成，在运动期间，这些肌肉周期性地收缩和放松，以便产生相对于蠕虫的行进方向向后传播的蠕动波;同时，每个后节上的微小刚毛状结构（刚毛）协调地伸出或缩回以提供与地面的不同牵引力，从而使蠕虫能够挖洞或爬行。所提出的软机器人复制了蚯蚓的肌肉功能和刚毛机制，采用机械驱动的致动器和3D打印的外壳。使用可控子空间的概念，我们表明，摩擦在这种类型的机器人的运动的生成和控制中起着不可或缺的作用。基于这种分析，我们介绍了一种基于仿真的方法，用于合成和实施反馈控制方案，使机器人产生向前和向后的运动。从一组可行的控制策略在仿真研究中，我们采用了frictionmodulation为基础的反馈控制算法，这是可实施的真实的时间和兼容的机器人系统的硬件限制。通过实验，证明了机器人能够在不同纹理和倾斜度的表面上进行双向爬行。
We present the design, fabrication, modeling and feedback control of an earthworm-inspired soft robot capable of bidirectional locomotion on both horizontal and inclined flat platforms. In this approach, the locomotion patterns are controlled by actively varying the coefficients of friction between the contacting surfaces of the robot and the supporting platform, thus emulating the limbless locomotion of earthworms at a conceptual level. Earthworms are characterized by segmented body structures, known as metameres, composed of longitudinal and circular muscles which during locomotion are contracted and relaxed periodically in order to generate a peristaltic wave that propagates backwards with respect to the worm's traveling direction; simultaneously, microscopic bristle-like structures (setae) on each metamere coordinately protrude or retract to provide varying traction with the ground, thus enabling the worm to burrow or crawl. The proposed soft robot replicates the muscle functionalities and setae mechanisms of earthworms employing pneumatically-driven actuators and 3D-printed casings. Using the notion of controllable subspace, we show that friction plays an indispensable role in the generation and control of locomotion in robots of this type. Based on this analysis, we introduce a simulation-based method for synthesizing and implementing feedback control schemes that enable the robot to generate forward and backward locomotion. From the set of feasible control strategies studied in simulation, we adopt a frictionmodulation-based feedback control algorithm which is implementable in real time and compatible with the hardware limitations of the robotic system. Through experiments, the robot is demonstrated to be capable of bidirectional crawling on surfaces with different textures and inclinations.