支持种肥监测的变量施肥系统设计与试验

目前国内变量施肥控制系统与排肥监测系统集成化程度低,电动机驱动变量施肥系统动态响应研究不够深入。为此设计了基于电动机驱动、支持多路播种施肥监测的变量施肥控制系统,主要包括触摸屏、中央控制器和数据采集器。控制器以MCU为核心,读取GPS测速模块获取的机具行进速度,监测排肥电动机实时转速,与数据采集器通讯获取多路排种或施肥状态,与触摸屏通讯设置作业参数和监测作业状态。搭建试验平台,测得排肥轴转速范围为12.5~125 r/min、监测灵敏度为3 s时,系统监测可靠性为100%。进行了系统排肥量变化响应时间试验,室内试验结果表明在0~11 500 g/min的排肥量变化范围内,系统响应时间最大为0.75 s。系统整机试验中,75~450 kg/hm~2的施肥量变化区间,公差以75 kg/hm~2递增,行进速度平均为3.79 km/h时,系统响应时间平均为1.08 s;在设定施肥量450、600、750 kg/hm~2下,改变不同行进速度的过程中,排肥量准确率平均值分别为95.92%、95.24%和98.26%,方差分别为3.01%、1.39%和1.36%。田间试验表明,施肥量分别为450、600、750 kg/hm~2时,系统排肥量准确率平均值为94.69%,方差为2.23%,多路排种、排肥监测故障报警准确率为100%。

Design and Test on Variable Rate Fertilization System Supporting Seeding and Fertilizing Monitoring

The current domestic integration of a variable rate fertilization system and a fertilizer feeder fault alarming system has a low level, and there is less research on dynamic response of a motor driving fertilization system. A variable rate fertilizing control system supporting seeding and fertilizing monitoring was designed based on a motor driving method. The system mainly included a touch screen, a central controller and a data collector. The central controller was designed based on an MCU, which monitored both the vehicle speed by using a GPS module and the fertilization motor speed in real time. The touch screen was used to set or read the operation parameters by communicating with the controller. The data collector monitored the working status of the multiple seed metering or fertilizer feeder. An experimental platform was built to evaluate the monitoring accuracy. When the sowing axle speed was 12.5~125r/min and the monitoring sensitivity was set to 3s, the accuracy of the fault alarming system was 100%. A test was conducted to find the system response time with different fertilization rates, the test results showed that the maximum system response time was 0.75s when fertilization rate was from 0g/min to 11500g/min.The prototype machine test result showed that when the fertilization rate was from 75kg/hm2 to 450kg/hm2 with an increment of 75kg/hm2, the average system response time was 1.08s. When the fertilization rates were 450kg/hm2, 600kg/hm2 and 750kg/hm2 with different vehicle speeds, the average accuracies of fertilizer ejecting were 95.92%, 95.24% and 98.26%, and the variances were 3.01%, 1.39% and 1.36%, respectively. The field test results showed that when the fertilization rates were set to 450kg/hm2, 600kg/hm2 and 750kg/hm2, the average accuracies of fertilizer ejecting was 94.69% with variance of 2.23%, and the accuracy of the fault alarm for multiple feeders was 100%.