Development and experiment of soil disinfection injection system

A variable soil disinfection injection system was designed. The system mainly composing of controller, six-way injection units and detection unit etc. The controller generates 6-channel PWM signals, which can be adjusted independently. Detection unit can real-time detect speed of advance and spraying dose. Under the set pressure, by changing the frequency and duty cycle of the PWM signals to control solenoid valve opening and closing, realizing accurate control flow. We had a different duty ratio under different frequency of flow measurement test, spraying flow model is established. The results showed that: when the frequency is 6Hz, duty cycle of the PWM signal and flow has the best linear relationship. Controllers at this frequency can be the most accurate dosage control. We conducted a flow model validation experiments, results show that : the spray flow control error within ± 5% range.