仿生机器鱼胸尾鳍联动水动力学性能分析

Hydrodynamic performance analysis of linkage by pectoral and caudal fins of bionic robot fish

针对尾鳍摆动仿生机器鱼游动迟缓、姿态不稳定的问题,文中提出一种胸尾鳍联动的仿生机器鱼,实现了仿生机器鱼外部轮廓、内部布局设计,提出了仿生机器鱼运动控制系统,为仿真和实验提供硬件基础;改进了仿生机器鱼运动学模型,提出了水动力学仿真中鱼体轮廓改变的运动函数;基于仿生机器鱼游动水动力学仿真分析,得到最优运动参数以及最优运动参数下的应力、流速、涡情况;采用仿真最优胸尾鳍运动幅度结果,改变胸尾鳍运动频率,设计实验研究了仿生机器鱼游动水动力学性能。仿真结果表明,以尾鳍摆动幅度72 mm、胸鳍转动角度水平正负45°、胸尾鳍运动频率均为3 Hz等运动参数进行仿真,无胸鳍辅助游动的推进力为2 N,有胸鳍辅助游动的推进力为2.6 N;实验分析结果表明,以最佳运动参数实验,无胸鳍辅助游动的推进力为1.57 N,有胸鳍辅助游动的推进力为2.57 N。仿真和实验均说明,有胸鳍辅助鱼体游动的推进力更大。

Considering the problems of slow swimming and unstable posture of bionic robot fish with swinging tail fin,a bionic robot fish with linkage by pectoral and caudal fins was proposed,the external contour and internal layout design of bionic robot fish were realized,and the motion control system of bionic robot fish was proposed,which provides hardware basis for simulation and experiment.The kinematics model of bionic robot fish was improved,and the motion function of fish contour change in hydrodynamic simulation was put forward.Based on the hydrodynamic simulation analysis of bionic robot fish swimming,the optimal motion parameters and the stress,velocity and vortex under the optimal motion parameters were obtained;according to the simulation results of the optimal motion amplitude of the pectoral and caudal fins,the motion frequency of the pectoral and caudal fins was changed,and experiments were designed to study the hydrodynamic performance of the bionic robot fish when swimming.Simulation was carried out with motion parameters,including the swing amplitude of the caudal fin of 72 mm,the horizontal rotation angle of the pectoral fin of±45 degrees,and the motion frequency of the pectoral fin of 3 Hz.The simulation results show that the propulsion force without pectoral fin was 2 N,and that of swimming with pectoral fin was 2.6 N;the experimental analysis results show that the propulsive force without pectoral fin was 1.57 N and that with pectoral fin was 2.57 N.Both the simulation and experimental results show that the propulsive force with pectoral fin is greater.