CFD-PID方法的仿生鱼群运动控制研究

Research on Motion Control of Bio-inspired Fish Swimming Based on CFD-PID Method

摘要:

相比传统螺旋桨推进方式，水下仿生推进更具灵活性，效率更高，并且对环境干扰较小。鱼群游动可以为群体中的个体提供许多生物学优势，同样仿生鱼群中的个体也可以在运动速度和效率上获得明显益处。 串联排列的仿生鱼群中，后鱼通过主动控制身体摆动从前鱼尾流场获益。在直接求解不可压 N-S 方程并运用牛顿第二定律的基础上，嵌入 PID 控制算法，构建 CFD-PID 求解器可模拟在串联排列中后鱼通过主动控制身体摆幅下的仿生鱼群自推进运动。通过 PID 动态调节摆幅间接实现对速度的控制，寻求合适的控制参数，最终实现仿生鱼群中后鱼从静止到达到稳定速度的过程，同时对涡量场、仿生鱼群的速度变化进行分析。研究结果表明： 通过 PID 控制的仿生鱼群中，合理的控制参数可以使任意仿生鱼更加精准快速地达到预定的收敛速度。

Abstract:

Compared with traditional propeller propulsion，underwater bionic propulsion has the advantages of flexibility，high efficiency，and low environmental interference. The movement of fish schools can provide many biological advantages to individual fish. Similarly，individual fish in a bionic school can also gain significant benefits in speed and efficiency. In a tandem arranged bionic school，the rear fish can benefit from the wake field of the front fish by active body oscillation control. Based on the solution of the incompressible Navier-Stokes equations and Newton's second law，a PID control algorithm is embedded to construct a CFD-PID solver that can simulate the self-propelled movement of a bionic fish school through active body oscillation control in a tandem arranged configuration. By dynamically adjusting the oscillation angle indirectly to control the speed through PID，suitable control parameters are sought to achieve the process of the rear fish in the bionic fish school from static to a stable speed. The vorticity field and the speed changes of the bionic fish school is then analyzed. The research results show that，when using PID control method，the appropriate control parameters can enable any bionic fish in the school to reach the converged speed more accurately and quickly.