Prediction and real time control system of change of soil mositure in a greenhouse

本研究的目的是开发能够预测温室内土壤水分(PP值)变化的实时控制系统，并对PP值进行适当控制。1996年和1997年，建立了土壤水分调控系统和环境监测系统。通过多元回归分析，确定以PF值的变化为因变量，以温度、湿度和太阳辐射量为自变量。1998年，采用两种控制方式建设了自动灌溉系统。一种是上述的多元回归控制，另一种是模糊控制。将这些栽培结果与农民手工灌溉的结果(风俗法)进行了比较。以需灌溉次数较多的黄瓜为研究对象，试验期总灌水量，关区为I，330 L，多元回归控制区为641L，模糊控制区为917L。整个试验期间关区优质率为47%，多元回归控制区为43%，模糊控制区为47%。试验期黄瓜单株产量关区为2,006克，多元回归控制区和模糊控制区分别为2,067克和2,338克。每股收益分别为847日元、885日元和1,026日元，从上述结果来看，这两种控制方法被证明是适用于温室自动灌溉控制的。

The objective of this study is to develop the real time control system which can predict the changes of soil moisture (pP value) in a greenhouse and appropriately control pF value. In 1996 and 1997, the soil moisture control system and the environmental supervisory system were constructed. Using the multiple regression analysis, changes of pF values were determined to be the dependent variable, and the temperature, the moisture and the amount of solar radiation were used for independent variables. In 1998, the automatic irrigation systems were constructed using two kinds of control methods. One is the multiple regression control mentioned above, and the other is the fuzzy control. These cultivation results were compared with those of farmer's manual irrigation work (the custom method). Cucumber, which frequently requires irrigation work, was chosen in this study.Regarding the total amount of irrigation in the experimental periods, that of the custom area was I , 330 L, while that of the multiple regression control area was 641 L, and that of the fuzzy control area was 917 L.The ratios of A-quality during the whole experimental period showed 47% in the custom area, 43% in the multiple regression control area, and 47% in -the fuzzy control area. The yield of cucumbers per stock during the experimental period showed 2,006g in the custom area, white those in the multiple regression control area and in the fuzzy control area showed 2,067g and 2,338g. The earnings per stock are 847 yen, 885 yen and 1,026 yen, respectively, From the results mentioned above, these two control methods were proven to be useful for automatic irrigation control in the greenhouse.