3自由度胸鳍机器鱼动力学建模及推进性能分析

Dynamics modeling and propulsion-performance analysis of 3-DOF pectoral-fin robotic fish

为了提高仿生机器鱼在复杂水环境中的游动性能和推进效率,文中设计了一种3自由度胸鳍机器鱼推进机构,研究了鱼体在3自由度胸鳍推进和两侧胸鳍与尾鳍协同推进两种模式下的游动性能。首先,基于鱼体波传播理论分析3自由度胸鳍关节空间运动规律,采用微元法分析建立其动力学模型,并对不同推进方式下运动参数的影响程度进行了比较和仿真。仿真结果表明:当两个胸鳍相互协同时,机器鱼的平均速度为0.28 m/s,当双侧胸鳍与尾鳍共同协同时,机器鱼的平均速度为0.42 m/s,对比发现胸鳍和尾鳍协同推进时速度更高且推力更大,可实现较宽的游速范围,推进性能更好。

In this article,in order to improve the bionic robot fish’s swimming performance and propulsion efficiency in the complex water environment,a propulsion mechanism is specifically designed for the 3-DOF pectoral-fin robotic fish.Efforts are made to explore the robotic fish’s swimming performance under two modes of 3-DOF pectoral-fin propulsion as well as cooperative propulsion of bilateral pectoral fin and caudal fin.Firstly,based on the fish-body wave-propagation theory,the motion laws of the 3-DOF pectoral-fin joints are given,and the dynamics model is set up with the help of the micro-element method.Then,the influence of the motion parameters under different propulsion modes are compared and simulated.The simulation results show that the average speed of the robot fish is 0.28 m/s when the two pectoral fins cooperate with each other,while the average speed is 0.42 m/s when the bilateral pectoral fins and the caudal fin cooperate with each other.It is found that the robot fish has greater speed and thrust when the pectoral fins and the caudal fin cooperate with each other,thus ensuring a wider range of speed and better propulsion performance.