设施栽培营养液自动调控装置设计与试验

Design and Test of Nutrient Solution Automatic Control Device in Protected Cultivation

针对设施栽培中营养液调控缺少监测管理、自动化程度低、稳定性难以保证等问题,设计了一种设施栽培营养液自动调控装置。通过传感器对营养液指标值的实时检测、控制器对检测数据的处理、执行部件对营养液指标值的调整,实现设施栽培营养液的自动调控。同时,设计了各关键部件结构参数及传感器检测子系统、数据融合与智能决策子系统和协同调控子系统的硬件和软件结构。采用响应曲面法试验,研究了均匀混合机构的纵向安装位置、横向安装位置、作业速度对营养液均匀混合时间的影响,并进行验证试验。响应曲面试验结果显示:试验因素的显著性主次顺序为作业速度、纵向安装位置、横向安装位置,最优组合参数为作业速度110r/min、纵向安装位置50mm、横向安装位置150mm。验证试验表明:营养液自动调控装置完成1次营养液调控所需时间约为135s,完成调控后营养液指标值pH值、EC、K^(+)浓度、Ca^(2+)浓度和NO_(3)^(-)浓度的误差分别为4.73%、3.28%、4.44%、4.15%、3.54%%。所设计的营养液自动调控装置具有结构简单、调控误差小的优点,可为提高设施栽培作业自动化程度提供参考。

In order to solve the problems of nutrient solution control in protected cultivation,such as lack of monitoring and management,low degree of automation,and difficult to guarantee the stability,an automatic nutrient solution control device for protected cultivation was designed.Through the real-time detection of nutrient solution index value by sensor,the processing of detection data by controller and the adjustment of nutrient solution index value by executive component,the automatic regulation of nutrient solution in protected cultivation was realized.The structural parameters of key components were designed.The hardware and software structure of sensor detection subsystem,data fusion and intelligent decision subsystem and cooperative control subsystem were designed.Response surface method was used to study the effects of the longitudinal installation position,transverse installation position and operation speed of the uniform mixing mechanism on the uniform mixing time of nutrient solution,and the verification test was carried out.Response surface test results show that the order of significance of test factors was operation speed,longitudinal installation position and transverse installation position.The optimal combination parameters were working speed 110r/min,longitudinal installation position 50mm,transverse installation position of 150 mm.The results show that the time required for the automatic control device to complete the first nutrient solution regulation was about 110s.The error of pH value,EC,K^(+)concentration,Ca^(2+)concentration and NO_(3)^(-)concentration of nutrient solution after the control was 4.73%,3.28%,4.44%,4.15%,3.54%.The automatic control device of nutrient solution designed in this paper has the advantages of simple structure and small control error,which can provide reference for improving the automation of facility cultivation.