基于蝙蝠优化BP-PID算法的精准施肥控制系统研究

水肥一体化技术在棉花、小麦、番茄等大田农作物种植场景中的应用逐渐增多。当前能够快速有效调整大田农作物水肥一体化系统中肥料流量的控制算法研究较为有限。由于水肥一体化系统存在时变性、滞后性与非线性的特点,常见的PID与BP-PID控制算法无法获得预期的控制效果。为此设计一种基于蝙蝠算法（BA）优化的BP神经网络PID控制器。通过采用BA对BP神经网络的初始权值进行优化,加快了BP神经网络的自学习速度,实现对水肥一体化系统中肥料流量的快速精准控制,从而降低了超调量、提高了响应速度。同时,基于STM32单片机搭建了水肥一体化流量调节测试平台,并对该控制器的性能进行了试验验证。结果表明,与常规PID控制器和基于BP神经网络的PID控制器相比,所设计的控制器具有较高的控制精度和鲁棒性,降低了由时滞性、非线性等因素引起的影响。平均最大超调量为4.78%,平均调节时间为41.24s。特别是在施肥流量为0.6m3/h时,控制器表现出最佳的综合控制性能,达到了精准施肥的效果。

Precision Fertilizer Application Control System Based on BA Optimization BP-PID Algorithm

The application of water-fertilizer integration technology in cotton, wheat, tomato and other field crops planting scenarios is gradually increasing. However, the current research on control algorithms that can quickly and effectively adjust the fertilizer flow in the water-fertilizer integration system for field crops is relatively limited. The water-fertilizer integration system has the characteristics of time-varying, hysteresis and nonlinearity, and the common PID and BP-PID control algorithms cannot obtain the expected control effect. To solve these problems, a BP neural network PID controller based on bat algorithm (BA) optimization was designed. By using BA to optimize the initial weights of the BP neural network, the self-learning speed of the BP neural network was accelerated to achieve fast and accurate control of the fertilizer flow rate in the water-fertilizer integration system, which reduced the amount of overshooting and improved the response speed. At the same time, a water-fertilizer integration flow regulation test platform was built based on STM32 microcontroller, and the performance of the controller was experimentally verified. The results showed that compared with the conventional PID controller and the BP neural network-based PID controller, the designed controller had higher control accuracy and robustness, and reduced the effects caused by time lag, nonlinearity and other factors. The average maximum overshoot was 4.78% and the average regulation time was 41.24s. Especially when the fertilizer application flow rate was 0.6m3/h, the controller showed the best comprehensive control performance and achieved the effect of precise fertilizer application.