Variable universe adaptive fuzzy PID control of spray flow valve

To solve the control problem of micro-flow or low flow on real-time mixing of pesticides in the course of variable rate spraying, an electromechanical flow control valve was developed with a miniature pin valve, a direct current (DC) motor, and a gear set. Mathematical model of Electromechanical flow control valve was constructed, and variable universe adaptive fuzzy PID control algorithm was designed. The simulations with software MATLAB for the variable universe adaptive fuzzy PID controller and a PID controller of the electromechanical flow control valve were carried out. Results showed that the response time of PID control was 3.5 s, the maximum overshoot was about 39.0%, and the response time of variable universe adaptive fuzzy PID was 0.93 s, and the maximum overshoot didn’t exceed 2.9%. The system is of good stability, accuracy and rapidity and able to satisfy the agriculture technical requirements