Department of Mechanical Engineering, Drexel University, Philadelphia, PA 19104, USA.
Integr Comp Biol. 2011 Jul;51(1):176-89. doi: 10.1093/icb/icr036. Epub 2011 Jun 8.
Bony fish swim with a level of agility that is unmatched in human-developed systems. This is due, in part, to the ability of the fish to carefully control hydrodynamic forces through the active modulation of the fins' kinematics and mechanical properties. To better understand how fish produce and control forces, biorobotic models of the bluegill sunfish's (Lepomis macrochirus) caudal fin and pectoral fins were developed. The designs of these systems were based on detailed analyses of the anatomy, kinematics, and hydrodynamics of the biological fins. The fin models have been used to investigate how fin kinematics and the mechanical properties of the fin-rays influence propulsive forces and to explore kinematic patterns that were inspired by biological motions but that were not explicitly performed by the fish. Results from studies conducted with the fin models indicate that subtle changes to the kinematics and mechanical properties of fin rays can significantly impact the magnitude, direction, and time course of the 3D forces used for propulsion and maneuvers. The magnitude of the force tends to scale with the fin's stiffness, but the direction of the force is not invariant, and this causes disproportional changes in the magnitude of the thrust, lift, and lateral components of force. Results from these studies shed light on the multiple strategies that are available to the fish to modulate fin forces.
硬骨鱼在游泳时表现出的敏捷性是人类开发的系统所无法比拟的。这在一定程度上要归功于鱼类通过主动调节鳍的运动学和机械特性来精细地控制水动力的能力。为了更好地理解鱼类如何产生和控制力，人们开发了蓝鳃太阳鱼（Lepomis macrochirus）的尾鳍和胸鳍的仿生机器人模型。这些系统的设计是基于对生物鳍的解剖结构、运动学和水动力学的详细分析。这些鳍模型被用于研究鳍运动学和鳍条的机械特性如何影响推进力，并探索受生物运动启发但鱼类并未明确执行的运动模式。利用鳍模型进行的研究结果表明，对鳍条的运动学和机械特性进行细微的改变，会显著影响用于推进和机动的三维力的大小、方向和时间进程。力的大小往往与鳍的刚度成正比，但力的方向不是不变的，这会导致推力、升力和侧向力分量的大小不成比例地变化。这些研究结果揭示了鱼类可用于调节鳍力的多种策略。
