Authors

Abstract

The aim of this research is to address the issues of low precision in variable spraying within the existing farmland application system, whereby nozzles cannot be controlled independently and low pesticide utilisation is observed. A variable spraying system based on PTO protocol has been designed. The system comprises an STM32 microcontroller as the control core, including the host computer, multi-channel controller, electronic switch, and electromagnetic spray nozzle. The master control unit receives the spray amount set by the user and calculates the duty cycle of the corresponding nozzle, which is then sent to the multiplex controller in real time through CAN communication. The multiplex controller adjusts the on-off frequency and duty cycle of each electromagnetic nozzle in real time according to the duty cycle of the corresponding nozzle it receives, thus enabling the nozzles to be controlled independently. This study offers theoretical and technical support for the independent control of spray nozzles and the optimisation of pesticide utilisation for variable spray systems based on PTO protocols.

Abstract in Chinese

针对现有农田施药系统变量喷雾精准化程度低、喷头不能独立控制及农药利用率低等问题，该研究设计了一种基于PTO协议的变量喷雾系统。系统以STM32单片机为控制核心，包括上位机、多路控制器、电子开关、电磁喷头等。主控接收用户设置的喷药量并计算对应喷头的占空比，通过CAN通讯实时发送到多路控制器；多路控制器根据接收的对应喷头的占空比，实时调节各个电磁喷头的通断频率与占空比，从而实现喷头的独立控制。该研究为基于PTO协议的变量喷雾系统提供了实现喷头独立控制和提高农药利用率的理论和技术支持。