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

Abstract

Precise pesticide application is mainly to control the solenoid valve by pulse width modulation (PWM). However, as the number of solenoid valves increases, power consumption and heat generation become significant challenges that impact values the efficiency and lifetime. In this study, an automated pressure monitoring system was constructed and an energy-saving PWM driving method was developed that uses different frequency drive signals during different stages of the solenoid valve operation. The parameters such as power consumption, coil surface temperature rise, opening and closing delays, rise and fall times, activation time, and spray flow characteristics were tested and evaluated. The results showed that this method can significantly reduce the holding current of the solenoid valves, resulting in energy savings of up to 92% and effectively reducing the surface temperature rise. Furthermore, the pattern between flowrate and opening/closing delays was established, with an RMSE of 1.96% in flowrate prediction based on activation time. The developed energy-saving driving method enhances the application potential while the established flowrate model provides valuable insights for precise pesticide application based on PWM technology.