【摘要】 PWM变量喷雾是国内外精准农业领域的研究热点，但PWM变量喷雾过程中电磁阀的快速启闭在管路内易形成压力脉冲，致使喷头喷雾压力发生变化，导致喷雾质量下降。为了降低压力脉冲，设计了一种相邻电磁阀异步启闭的PWM喷雾系统，由移动底盘、药箱、隔膜泵、稳压罐、PWM控制器、电磁阀及压力表等组成，通过延时控制，实现电磁阀异步启闭。在室内无风环境条件下，探究了喷雾系统电磁阀前管路内压力波动特性和沉积量分布均匀性。试验表明：与电磁阀同步启闭的PWM喷雾系统相比，电磁阀异步启闭可有效降低管路内压力峰值，不同PWM频率工况条件下，50%占空比时降幅最大，降幅最高为14%;20Hz频率条件下，异步启闭PWM喷雾的沉积量分布均匀性变异系数略高于常规连续喷雾，但均小于15%。上述结果符合喷杆喷雾机技术性能国家标准。更多还原

【Abstract】 PWM variable spraying is a research hotspot in the field of precision agriculture, but in the process of PWM variable spraying, the rapid opening and closing of the solenoid valve is likely to form pressure pulses in the pipeline, resulting in changes in the spray pressure of the nozzle, resulting in a decrease in spray quality. In order to reduce the pressure pulse, a PWM spray system with asynchronous opening and closing of adjacent solenoid valves is designed. The solenoid valve can be opened and closed asynchronouslybydelay control. Under the condition of indoor windless environment, we explored the pressure fluctuation characteristicsin the pipeline before the solenoid valve and the distribution uniformity of spray deposition. The test results show that compared with the PWM spray system in which the solenoid valve opens and closes synchronously, the asynchronous opening and closing of the solenoid valve can effectively reduce the pressure in the pipeline; under different PWM frequency conditions, the maximum decrease is 14% when the duty cycle is 50%.Under the condition of 20Hz frequency, the coefficient of variation of deposition distribution uniformity of asynchronous opening and closing PWM spray is slightly higher than that of conventional continuous spray, but both are less than 15%, which is in line with the national standard of technical performance of boom sprayer.更多还原