Research On Liquid Micro-spray Control Strategy In Facility Agriculture

With the improvement of agricultural technology and economic level,facility agriculture has become an important part of modern agriculture.As an important agricultural facility,the greenhouse has developed rapidly.The proportion of traditional simple control or manual control to regulated facilities has increased year by year.The demand for the transformation of facility agriculture into modern refined facilities agriculture is increasingly urgent.In this paper,the Feijoa seedling greenhouse was taken as the research object.Because of the high requirements on air humidity during the process of seedling cutting,it is important to study the fine control of greenhouse air humidity.On the basis of extensive review of relevant literatures at home and abroad,the greenhouse micro-spray control system was designed,and the sensor data anomaly detection processing algorithm,air humidity sensor deployment algorithm and micro-injection control strategy were studied to make research on greenhouse fine control.For meaningful exploration,the main research work has the following aspects:Firstly,aiming at the outliers and loss phenomena of data collected in the greenhouse,a new method of eliminating the inaccuracy of data using the density anomaly detection algorithm improved by multi-attribute correlation between data is proposed;Secondly,aiming at the spatial variability of greenhouse air,a sensor deployment algorithm using stepwise accumulation and discrete particle swarm optimization is proposed.The humidity distribution characteristics of the greenhouse are determined by a small number of humidity sensors,while ensuring the perception accuracy and the representativeness of the collected data.,reducing deployment costs and data redundancy;Thirdly,the greenhouse mechanism modeling and experimental modeling methods were studied.The greenhouse humidity model was established by step modeling.The rationality of the greenhouse humidity model was verified by a large number of greenhouse simulation experiments.Based on the greenhouse humidity model,the control effects of PID control,fuzzy control and fuzzy PID control method are compared.For the time lag problem of greenhouse control,the fuzzy PID control method based on dynamic matrix control feedback adjustment is adopted to improve the accuracy of greenhouse control.The fourth is to design the hardware framework and system functions of the embedded greenhouse monitoring system based on wireless sensor network and WIFI;Finally,the software and hardware platform of the greenhouse air humidity control system were tested.The results show that the system can effectively control the greenhouse humidity between the preset thresholds,which is helpful to the survival rate of the fruit cutting seedlings.