Research On Greenhouse Monitoring System Based On Wireless Sensor Network

Traditional greenhouses usually adopt artificial acquisition to collect the environmental parameters of crop growth such as temperature and humidity, the efficiency is very low as relying on artificial experience for thermal insulation, moisture, etc. That not only consumes a large amount of manpower and material resources, also cannot assure the real time of data, which greatly restricted the development of greenhouses technology in China. This paper Introduces the wireless sensor network technology to greenhouse monitoring and control, can not only improve the efficiency of information collection and gather the results more precise, but also avoids the problem of that the wiring of cable transmission is complex.This system mainly divides into two sections to design, one is the lower computer design. At first, this paper analyzes the several popular wireless communication techniques at present, with the overall considerations of the transmission distance, networking capability, power dissipation, costing and transmission rate and so on, chooses ZigBee technology as the wireless communication technique of this system at last, which puts the needed monitor node in the different monitor areas. ZigBee Network transmits the collected real-time environment factors through the router nodes forward eventually into the Coordinator Node. Node hardware design adopt the on-chip system scheme which combines the main control chip and Coordinator Node, reducing the design complexity and meeting the greenhouse actual demand of low-costing, low-power consumption, high stability. The software design is mainly based on the Z-Stack, digging into deeply the composition and framework of the Z-Stack, designs the relevant software about the Sensor Node and Coordinator Node. The whole system constitutes flexible forms of all kinds of network topology which based on the distribution difference of the Sensor Node, at the same time, it also can realize the Ad-Hoc Network of the Node, the dynamic addition or the delete function.The other part is the upper computer design which needs to reveal and storage the greenhouses parameters collected by the lower computer and mainly use the fuzzy expert system to judge the control strategy. The greenhouse is a complex environment, with the feature of coupling, nonlinear and so on, which is hard to establish a accurate model for control. This paper make the greenhouses in the winter as the background, the crop in tomatoes, for instance, combines the fuzzy system into the expert system and designs the fuzzy expert system which fits the need of the tomato in every growing stage. At the same time, this paper tells the constitution of this system, operating principle, and the development process of every module. This fuzzy expect control system fuzzily processes the real-time data which collected and transited by the lower computer and outputs the final corresponding executive strategy using the fuzzy reasoning rule. This system adjusts the greenhouse condition into the best grow environment of the tomato, making sure of the output and the quality of tomato.This greenhouse monitoring system has the ability to multi-point monitoring and data transmission, which has the characteristic of the low-costing, easy-install and reliable-operation, etc. This system can make the use of the fuzzy expert system to give the corresponding environment control strategy based on the specific crop, guaranteeing the crops grow in the most comfortable environment. This system also applies to the other fields in the agriculture, having the certain reference value in the personalized control development of the future greenhouse.