关键词: 水肥一体化控制系统, 模糊PID控制, 麻雀搜索算法, 酸碱度, 电导率

Abstract: In order to solve the problems of long steadystate time and large overshoot of Potential of Hydrogen (pH) and Electrical Conductivity (EC) in the process of fertilizer and water proportioning, the three gain parameters (proportional, integral and differential) of the controller are effectively optimized by incorporating the sparrow search algorithm on the basis of fuzzy PID control. Simulation experiments of traditional PID control of pH and EC values, simulation experiments of fuzzy PID control of pH and EC values, and simulation experiments of fuzzy PID control of pH and EC values optimized based on sparrow search algorithm are done respectively under MATLAB/Simulink, and the stabilization time of pH and EC values as well as the amount of overshooting in the three simulation experiments are compared. The experimental results show that the stabilization time of pH and conductivity are reduced by 475 s and 261 s, and the overshoot is reduced by 5.4% and 12.19%, respectively, compared with the traditional PID control by the fuzzy PID control optimized based on the sparrow search algorithm, and the stabilization time of pH and conductivity are reduced by 356 s and 95 s, respectively, and the overshoot is reduced by 1.4% and 2.34%, respectively. The control method proposed in this paper enables the system to have smaller overshoot and faster time to reach the rising steady state, which can precisely control the fertilizer and water ratios.

Key words: water and fertilizer integrated control system, fuzzy PID control, sparrow search algorithm, pH, electrical conductivity