仿牛鼻鲼机器鱼胸鳍的时间非对称摆动研究

Research on Pectoral Fins Oscillating Asymmetrically in Time of a Cownose-like Robotic Fish

针对以胸鳍升力模式推进的牛鼻鲼在胸鳍扇动时存在时间上的非对称摆动问题,分析了牛鼻鲼这一泳动特征的力学含义,并通过仿牛鼻鲼机器鱼开展了时间非对称摆动的研究。首先建立了时间非对称摆动的数学模型;然后在一系列的不对称系数下进行了机器鱼的泳动实验,发现存在一个不对称系数的较佳范围,并且当不对称系数为0.56时,机器鱼的泳动速度最大;最后通过机器鱼的水动力实验研究,讨论了不对称系数对水动力的影响规律。结果表明,牛鼻鲼在实际游动过程中通过上挥急回的方式拍动,特别是经常以不对称系数0.56工况方式扇动,可以获得更好的推进性能。

Before the asymmetrical oscillation in time of Cownose-like robotic fish was discussed,the mechanic hint behind the swimming behavior was analysed.Firstly,a mathematic model of the fin rays oscillating asymmetrically in time was set up;secondly,the swimming experiments of the robotic fish with a series of asymmetric coefficients were made,and the results show that it exits a better range of asymmetric coefficients,and while asymmetric coefficients is 0.56,the robotic fish attains the best forward velocity.Finally,the hydrodynamic force of the robotic fish with these asymmetric coefficients was tested,and the relations among each other were discussed.These results will reveal that the attention of the swimming behavior of Cownose ray may improve the propulsive,especially in the case of oscillating with the 0.56 of asymmetric coefficient.