基于水和农药流量同步控制的在线混药系统设计与试验.

To solve the problems that the existing online pesticide mixing system cannot accurately control the ratio of pesticide and water, and the amount of mixture is still excessive in agricultural operations, an online pesticide mixing system was designed based on the synchronous control of water and pesticide flow. The system was mainly composed of a decision module of mixing dosage and a control system. The input of the mixing dosage decision model was the output of the spray dosage decision model in the variable spray system, which was combined with the flow regulation control cycle in the mixing dosage decision model to calculate the water and pesticide dosage in the system in real time. After processing, the pulse width modulation (PWM) duty cycle data was transmitted to microcontroller unit (MCU) by the mixing dosage control system, and the PWM instruction was generated and sent by MCU to the dual-channel PWM driver circuit. The desired PWM duty cycle value was generated to adjust the working voltage of the conveyor pump for synchronously adjusting the flow of water and pesticide. The test results show that when the flow accuracy of peristaltic pump and diaphragm pump are in the controllable range of 0-135.5 mL and 0-18.65 L, respectively, the measured mixing error is less than 5% after specifying the mixing amount of 5.00 L. When the mixing ratios are 100, 300 and 500 with the flow regulation control periods of 300, 500 and 600 ms, the mixing ratio error can be kept within 3.24%. It can be seen that the mixed drug effect is good. [ABSTRACT FROM AUTHOR]