Wang Zhouyi, Feng Yiping, Wang Bingcheng, Yuan Jiwei, Zhang Baowen, Song Yi, Wu Xuan, Li Lei, Li Weipeng, Dai Zhendong
College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Nanjing University of Aeronautics and Astronautics Shenzhen Research Institute, Shenzhen 518063, China.
Biomimetics (Basel). 2024 Feb 26;9(3):141. doi: 10.3390/biomimetics9030141.
A precise measurement of animal behavior and reaction forces from their surroundings can help elucidate the fundamental principle of animal locomotion, such as landing and takeoff. Compared with stiff substrates, compliant substrates, like leaves, readily yield to loads, presenting grand challenges in measuring the reaction forces on the substrates involving compliance. To gain insight into the kinematic mechanisms and structural-functional evolution associated with arboreal animal locomotion, this study introduces an innovative device that facilitates the quantification of the reaction forces on compliant substrates, like leaves. By utilizing the stiffness-damping characteristics of servomotors and the adjustable length of a cantilever structure, the substrate compliance of the device can be accurately controlled. The substrate was further connected to a force sensor and an acceleration sensor. With the cooperation of these sensors, the measured interaction force between the animal and the compliant substrate prevented the effects of inertial force coupling. The device was calibrated under preset conditions, and its force measurement accuracy was validated, with the error between the actual measured and theoretical values being no greater than 10%. Force curves were measured, and frictional adhesion coefficients were calculated from comparative experiments on the landing/takeoff of adherent animals (tree frogs and geckos) on this device. Analysis revealed that the adhesion force limits were significantly lower than previously reported values (0.2~0.4 times those estimated in previous research). This apparatus provides mechanical evidence for elucidating structural-functional relationships exhibited by animals during locomotion and can serve as an experimental platform for optimizing the locomotion of bioinspired robots on compliant substrates.
精确测量动物行为及其周围环境的反作用力，有助于阐明动物运动的基本原理，如着陆和起飞。与坚硬的基质相比，像树叶这样的柔性基质很容易在负载下变形，这给测量涉及柔性的基质上的反作用力带来了巨大挑战。为了深入了解与树栖动物运动相关的运动机制和结构 - 功能进化，本研究引入了一种创新装置，该装置有助于量化在像树叶这样的柔性基质上的反作用力。通过利用伺服电机的刚度 - 阻尼特性和悬臂结构的可调节长度，可以精确控制该装置的基质柔性。该基质进一步连接到力传感器和加速度传感器。在这些传感器的协同作用下，测量到的动物与柔性基质之间的相互作用力消除了惯性力耦合的影响。该装置在预设条件下进行了校准，并验证了其力测量精度，实际测量值与理论值之间的误差不超过10%。测量了力曲线，并通过对附着动物（树蛙和壁虎）在该装置上着陆/起飞的对比实验计算了摩擦粘附系数。分析表明，粘附力极限明显低于先前报道的值（是先前研究估计值的0.2至0.4倍）。该装置为阐明动物在运动过程中表现出的结构 - 功能关系提供了力学证据，并可作为优化仿生机器人在柔性基质上运动的实验平台。
