PWM变量喷雾喷头流量模型

Nozzle Flow Model of PWM Variable-rate Spraying

基于脉宽调制(PWM)的变量喷雾控制中,尤其对喷头进行独立控制时,喷头流量模型不可或缺。设计了能够精确控制喷雾压力,便捷设定PWM参数的试验平台,并使用该平台进行了二次回归正交试验,针对TEEJET AITXA 8002型、8003型和8004型喷头分别建立了喷头流量模型。参数检验和失拟检验表明喷头流量模型合适。模型普适性试验表明,8002型喷头模型最大相对误差为7.05%,最小相对误差为0.14%;8003型喷头模型最大相对误差为7.27%,最小相对误差为0.31%;8004型喷头模型最大相对误差为7.94%,最小相对误差为0.71%;模型计算流量和实际测量流量具有很好的一致性。

Nozzle flow model is indispensable in variable-rate spraying control based on pulse width modulation(PWM) technology,especially when nozzles are controlled independently.A variable-rate test platform which could control spraying pressure precisely and was easy to set PWM parameters was designed.The central composite orthogonal regression tests were completed by using the test platform,and the flow models of TEEJET AITXA nozzles of type 8002,8003 and 8004 were obtained.The results of equation hypothesis test and test for lack of fit of flow models showed that the three flow models were agreeable.The maximum relative error of the TEEJET AITXA nozzle model of type 8002 was 7.05%,while the minimum relative error was 0.14%.For the type 8003,the maximum and minimum relative errors were 7.27% and 0.31%.And for the type 8004,the maximum and minimum relative errors were 7.94% and 0.71%.Nozzle flow model validation trials showed that the relative errors between model flow and actual flow were small.