基于CPLD的变量施肥控制系统开发与应用

Research and application of control system for variable rate fertilizer applicator based on CPLD

为提高变量施肥系统的工作稳定性,开发了一种基于复杂可编程逻辑器件(CPLD)的变量施肥控制系统。自动模式下,系统接收GPS信号确定施肥机位置和行进速度;手动模式下,系统通过速度传感器获取速度信号。系统将施肥机的行进速度与施肥处方信息相结合,控制排肥轴转速实现变量施肥。应用该系统进行变量施肥田间作业,累计作业面积达72hm2。应用结果表明,该系统以150～600kg/hm2实施变量施肥作业时,其排肥量误差小于6%。

In order to improve the performance of the variable rate fertilizer applicator’s control system,a control system for a variable rate fertilizer applicator based on the CPLD（complex programmable logic device）was designed and applied in field.Under automatic mode,the system judged the position and the ground speed for the variable rate fertilizer applicator by means of collecting GPS signals.At manual mode,the system judged the ground speed by speed sensor.This system controlled the fertilizer output through combination of a ground speed of fertilizer applicator and prescription data which were given by the Expert System according to the nutrient levels in soil and the theory of yield goal.This system has been applied in the field covering 72 hm 2 totally in the past 4 years.The error of this system was less than 6%,when the fertilizer sowing amount was 150-600 kg/hm2.