基于电容法的施肥量检测系统设计与试验

发布时间：2019-04-18 19:46

【摘要】：为了实现施肥机施肥量的在线检测,根据肥料与空气介电特性差异,设计了一种基于电容法的施肥量在线检测系统。采用电容转换芯片PCAP01和单片机STM32F103C8T6搭建电容检测电路,实现了差分电容传感器微电容信号输出的有效获取。研究了环境温度变化对流量传感器的影响规律,建立了氮磷钾肥料质量流量与电容输出的关系模型,并对模型进行了验证。试验结果表明,差分型肥料流量传感器对环境温度变化有很好的适应性,系统能够准确的对肥料质量进行在线检测,最大测量误差为3.75%。另外系统能够准确识别管路堵塞故障,识别准确率达到100%,最大识别响应时间为1.22 s。电容式施肥量在线检测系统为施肥机肥料流量的在线获取提供了有效途径,对于高精度变量施肥作业的实施具有重要的意义。
[Abstract]:According to the difference of dielectric properties between fertilizer and air, an on-line measurement system based on capacitive method was designed in order to realize on-line measurement of the amount of fertilizer applied on-line. The capacitance detection circuit is built by using capacitance conversion chip PCAP01 and single-chip microcomputer STM32F103C8T6, and the output of micro-capacitance signal of differential capacitance sensor is obtained effectively. The influence of ambient temperature on flow sensor was studied, and the relationship model between mass flow rate of N, P and K fertilizer and capacitance output was established, and the model was verified. The experimental results show that the differential fertilizer flow sensor has good adaptability to the environmental temperature change and the system can accurately detect the fertilizer quality on-line with a maximum measurement error of 3.75%. In addition, the system can accurately identify the pipeline blocking fault, the recognition accuracy is 100%, and the maximum recognition response time is 1.22 s. The capacitive on-line measurement system provides an effective way for the on-line acquisition of fertilizer flow and is of great significance to the implementation of variable-rate fertilization with high precision.
【作者单位】：中国农业机械化科学研究院;吉林省农业机械化管理中心;
【基金】：国家重点研发计划项目(2016YFD0700103) 北京市科技新星计划项目(Z1511000003150116) 河南省科技开放合作项目(152152106000036)
【分类号】：S224.2

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