Koizumi Sakito, Nakata Toshiyuki, Liu Hao
Graduate School of Science and Engineering, Chiba University, Chiba, Japan.
Graduate School of Engineering, Chiba University, Chiba, Japan.
Front Bioeng Biotechnol. 2021 Apr 22;9:612183. doi: 10.3389/fbioe.2021.612183. eCollection 2021.
Flying animals such as insects display great flight performances with high stability and maneuverability even under unpredictable disturbances in natural and man-made environments. Unlike man-made mechanical systems like a drone, insects can achieve various flapping motions through their flexible musculoskeletal systems. However, it remains poorly understood whether flexibility affects flight performances or not. Here, we conducted an experimental study on the effects of the flexibility associated with the flapping mechanisms on aerodynamic performance with a flexible flapping mechanism (FFM) inspired by the flexible musculoskeletal system of insects. Based on wing kinematic and force measurements, we found an appropriate combination of the flexible components could improve the aerodynamic efficiency by increasing the wingbeat amplitude. Results of the wind tunnel experiments suggested that, through some passive adjustment of the wing kinematics in concert with the flexible mechanism, the disturbance-induced effects could be suppressed. Therefore, the flight stability under the disturbances is improved. While the FFM with the most rigid spring was least efficient in the static experiments, the model was most robust against the wind within the range of the study. Our results, particularly regarding the trade-off between the efficiency and the robustness, point out the importance of the passive response of the flapping mechanisms, which may provide a functional biomimetic design for the flapping micro air vehicles (MAVs) capable of achieving high efficiency and stability.
像昆虫这样的飞行生物，即使在自然和人造环境中不可预测的干扰下，也能展现出具有高稳定性和机动性的出色飞行性能。与无人机等人造机械系统不同，昆虫能够通过其灵活的肌肉骨骼系统实现各种扑翼运动。然而，灵活性是否会影响飞行性能仍知之甚少。在此，我们进行了一项实验研究，以昆虫灵活的肌肉骨骼系统为灵感，采用灵活扑翼机构（FFM）来研究与扑翼机制相关的灵活性对空气动力学性能的影响。基于翅膀运动学和力的测量，我们发现灵活部件的适当组合可以通过增加拍翅幅度来提高空气动力学效率。风洞实验结果表明，通过与灵活机制协同对翅膀运动学进行一些被动调整，可以抑制干扰引起的影响。因此，干扰下的飞行稳定性得到了提高。虽然在静态实验中，弹簧最刚性的FFM效率最低，但在研究范围内，该模型对风的耐受性最强。我们的研究结果，特别是关于效率和鲁棒性之间的权衡，指出了扑翼机制被动响应的重要性，这可能为能够实现高效率和稳定性的扑翼微型飞行器（MAV）提供一种功能性仿生设计。
