The explanatory power of the lift equation in the wingbeat kinematics, motor control, and evolution of animal flight

我的研究计划的最终目标是回答两个相互交织的问题：1)鸟类如何整合来自头部、身体和翅膀的感觉信息，并产生运动指令来控制翅膀的拍打运动和动态形状，以应对空气动力学挑战？2)飞行控制机制如何影响鸟类飞行的进化和飞行性能的多样性？飞行的鸟类必须极其精确地调节和平衡力，以执行不同的行为，但鸟类如何做到这一点还没有被很好地理解。空气动力由空气密度(ρ)、机翼速度(V)、机翼大小(特别是面积A)和力系数(Cf)决定，该力系数说明了机翼在遇到迎面而来的空气时的形状和外观。总力等于1/2ρV2ACF，这个简单的方程在流体力学中广泛适用。以前关于动物如何调节力的研究只考虑了力的各个组成部分，但随着最近的进展，我们现在可以应用更具挑战性的方法来同时检查这些元素。力方程可以分为两种基本的力产生策略：调整机翼速度(V)和改变机翼大小和形状(A和Cf)。我的研究小组是鸟类飞行的领先实验室之一，最近提出，力方程的这种物理划分反映在鸟类飞行控制的多个层面上，包括解剖学、肌肉生理学和翼拍运动学。我们的最终假设是，通过翼速和变形来调节力的生理和生物力学机制决定了个体的表现，并塑造了主要鸟类支系的进化。这个Discovery Grant应用的目标是确定鸟类如何同时控制翅膀的速度和翅膀的变形，以调节力量的产生。我们将研究力方程在生物组织的三个水平上的表示：1)悬停蜂鸟的力调制的进化比较。2)为了调节气动力，在机翼速度和机翼变形方面进行了种内和种内的权衡。3)翼速和翼形的神经肌肉控制。这项研究将大大加深我们对飞行动物如何调节空气动力的理解。这种方法将通过揭示空气动力方程是如何在生物组织的多个层面上表达出来的，从而改变动物飞行领域。这项综合研究利用了不同的方法，并将为HQP提供一系列的培训机会。这些发现有可能改变教科书上对肌肉生理学、动物飞行力学和鸟类学的理解，也将为飞机和机器人的生物启发工程提供指南。

The ultimate goal of my research program is to answer two intertwined questions: 1) How do birds incorporate sensory information from the head, body, and wings, and generate motor commands for controlling the flapping motion and dynamic shape of wings in response to aerodynamic challenges? 2) How do mechanisms of flight control shape the evolution of flight and diversity of flight performance in birds? Flying birds must modulate and balance force with extreme precision to perform different behaviours, but how birds do this is not well understood. Aerodynamic force is determined by air density (ρ), wing velocity (V), wing size (specifically area A), and a force coefficient (CF) that accounts for the wing's shape and presentation as it encounters the oncoming air. Total force is equal to ½ρV2ACF, and this simple equation is broadly applicable in fluid mechanics. Previous studies of how animals modulate force considered only individual components of the force equation, but, through recent advances, we can now apply more challenging methods to examine these elements in concert. The force equation can be divided into two fundamental strategies for force generation: modulation of wing velocity (V), and morphing of wing size and shape (A and CF). My research group, one of the leading laboratories in avian flight, has recently proposed that this physical division of the force equation is reflected at multiple levels of avian flight control including anatomy, muscle physiology, and wingbeat kinematics. Our ultimate hypothesis is that the physiological and biomechanical mechanisms for modulating force through wing velocity and morphing determine individual performance and shape the evolution of major avian clades. The goal of this Discovery Grant application is to determine how birds simultaneously control wing velocity and wing morphing to modulate force production. We will investigate the representation of the force equation at three levels of biological organisation: 1) Evolutionary comparisons of force modulation in hovering hummingbirds. 2) Inter- and intra-specific trade-offs in wing velocity and wing morphing for modulating aerodynamic forces. 3) Neuromuscular control of wing velocity and wing morphing. This research will add significantly to our understanding of how flying animals modulate aerodynamic force. This approach will transform the field of animal flight by revealing how the aerodynamic force equation is expressed at multiple levels of biological organisation. This integrative research makes use of diverse approaches, and will provide a range of training opportunities for HQP. The discoveries have the potential to alter textbook understanding of muscle physiology, animal flight mechanics, and ornithology, and will also provide a guidepost for bioinspired engineering of aircraft and in robotics.