Development of an energy-saving PWM driving method for precision pesticide application using adjustable frequency and characterization of spray

•A frequency-adjustable solenoid valve drive method is developed which can reduce up to 92% power consumption.•The opening and closing delay, rising and falling time and flow characteristics are measured.•A model between solenoid valve delay and flow rate is proposed, which can predict the flow rate more accurately, with an RMSE of only 1.96%.