ZHANG Ji-cheng,MENG Fan-feng,ZHENG Ping,et al.Variable Rate Control and Fertilization System of Liquid Fertilizer Applicator Based on Electronic Control Unit[J].Soybean Science,2019,38(01):111-117.[doi:10.11861/j.issn.1000-9841.2019.01.0111]
基于电子控制单元的大豆液肥施肥机变量施控系统
- Title:
- Variable Rate Control and Fertilization System of Liquid Fertilizer Applicator Based on Electronic Control Unit
- Keywords:
- Liquid fertilizer; Control and fertilization system; Electronic control unit; Variable rate fertilization
- 文献标志码:
- A
- 摘要:
- 针对我国农业生产中肥料利用率相对较低的现状，以实现减肥增效为目标，设计基于电子控制单元（electronic control unit，ECU）的大豆液肥施肥机精确变量施控系统。该系统包括电子控制单元ECU、信号采集系统和变量施肥系统，以Raspberry Pi 微型计算机作为电子控制单元，采用北斗+GPS双重定位技术。系统依据作业区域内处方施肥数据、作业机具行进速度等信息，并通过实时监测施肥量数据和作业状态数据，建立闭环反馈环节；依据变量施控系统的作业流程，生成施控指令，向基于压力调节阀的液肥施肥系统下达作业指令，施肥装置根据作业指令调整压力调节阀的开度，实现液肥按需变量施入的目的。结果表明：基于ECU的施控系统，各组成部分工作状态稳定可靠，工作流程设计合理，响应速度快，系统从开启到施入流速稳定所需时间一般在7 s以内，试验台和田间试验的施肥精度不低于97.3%，各喷药口实际流速的平均差较小，均分器效果显著。该变量施控系统可行性强，能满足变量施肥作业精度需求，适合当前农业生产中的农艺需求，为我国农业精确生产和实现减肥增效提供一种实现手段。
- Abstract:
- Fertilization is an important process of agricultural production, which directly affects the yield of crops, and reasonable and effective use of chemical fertilizer can not only improve the yield of crops, but also reduce water and soil contamination. At present, the mechanization level of fertilization according to needs is very low in China, and the utilization rate of fertilizer has to be raised up. Variable rate fertilization (VRF) for crop is an effective way to outperform uniform rate fertilization (URF). A control and fertilization system of fertilizer applicator based on electronic control unit (ECU) was designed and experimented in this paper. It included ECU as the control system, signal collection system and fertilization system. ECU used the Raspberry Pi microcomputer to improve the response and steady performance of system. BeiDou/GPS dual-mode point positioning module was applied in the system to insure the positioning and velocity measurement of applicator and query accuracy of prescription map. ECU was responsible for collecting the signals of theoretical fertilization data from prescription map, the applicator speed, the input rate of fertilization measured and operation state data, and for generating fertilization instructions for fertilization system. The fertilization mechanism adjusted the openness of the pressure valve to response these instructions from ECU. This work flow fulfilled VRF based on the agronomic requirements and quantitatively. The experiment data showed that the control and fertilization system based on ECU could provide a reasonable and real-time control of every component. It generally took no more than 7 s from system open to steady flow. The fertilization precision were more than 97.3% both in experimental bench test and field test. The mean difference of flow rate of every fertilization sprayer was low that benefited from liquid separating and sharing device. The control and fertilization system was feasible and can meet the requirement of variable fertilization precision, and it was suitable for agricultural production in current agricultural production, and provided a means for agricultural precision production and reducing fertilization while increasing efficiency in agriculture in our country.
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收稿日期：2018-08-29