Fish-inspired segment models for undulatory steady swimming
Fish-inspired segment models for undulatory steady swimming
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DOI：
10.1088/1748-3190/ac6bd6
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发表时间：
2022-07-01
影响因子：
3.4
通讯作者：
Lauder, George, V
中科院分区：
文献类型：
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作者：
Akanyeti, Otar;Di Santo, Valentina;Lauder, George, V
许多水生动物通过波动的身体运动游泳，了解这些运动的多样性可以解锁设计更好的水下机器人的潜力。在这里，我们分析了一组不同鱼类的稳定游泳运动学，以研究它们的波动运动是否可以用一系列相互关联的多段模型来表示，如果可以，则确定驱动模型段配置的关键因素。研究结果表明，用精简模型可以很好地描述鱼类的稳定游动运动学，其中83%的模型少于5个节段。在这些模型中，前节段明显长于后节段，节段构型与游泳运动学、体型和雷诺数之间存在直接联系。在高雷诺数下游动的鳗鱼状鱼类模型和其他鱼类模型相比，具有更多的节段和更小的节段长度沿体变化。这些鱼在更大程度上调动了它们的前体，在更前面启动了波动波。两个形状参数，与轴向和整体车身厚度有关，预测分段配置具有中等到高的成功率。我们发现头部形态是一个很好的预测其片段长度。虽然在头段有很大的变化，但尾段的长度在所有模型中是相似的。鉴于鱼类表现出可变的尾鳍形状，尾鳍的一致性可能是为提高推进效率而调整的进化约束的结果。本研究中提出的仿生多段模型突出了身体的关键弯曲点，可用于决定鱼仿生机器人中执行器的位置，在理论和计算研究中模拟水动力，或预测游泳过程中的肌肉激活模式。
Many aquatic animals swim by undulatory body movements and understanding the diversity of these movements could unlock the potential for designing better underwater robots. Here, we analyzed the steady swimming kinematics of a diverse group of fish species to investigate whether their undulatory movements can be represented using a series of interconnected multi-segment models, and if so, to identify the key factors driving the segment configuration of the models. Our results show that the steady swimming kinematics of fishes can be described successfully using parsimonious models, 83% of which had fewer than five segments. In these models, the anterior segments were significantly longer than the posterior segments, and there was a direct link between segment configuration and swimming kinematics, body shape, and Reynolds number. The models representing eel-like fishes with elongated bodies and fishes swimming at high Reynolds numbers had more segments and less segment length variability along the body than the models representing other fishes. These fishes recruited their anterior bodies to a greater extent, initiating the undulatory wave more anteriorly. Two shape parameters, related to axial and overall body thickness, predicted segment configuration with moderate to high success rate. We found that head morphology was a good predictor of its segment length. While there was a large variation in head segments, the length of tail segments was similar across all models. Given that fishes exhibited variable caudal fin shapes, the consistency of tail segments could be a result of an evolutionary constraint tuned for high propulsive efficiency. The bio-inspired multi-segment models presented in this study highlight the key bending points along the body and can be used to decide on the placement of actuators in fish-inspired robots, to model hydrodynamic forces in theoretical and computational studies, or for predicting muscle activation patterns during swimming.