Design Of Smart Greenhouse For Pot-plant Control System Based On PLC

Our national economy highly depends on agriculture and large amount of people living in rural. The rice production is able to feed 1.4 billion people, thus agricultural economy plays an indispensable role in our national economy. With the development of life quality, demands on rice, vegetable and fruits are gradually increasing. To grow vegetable and fruits with higher quality, it is necessary and must to develop smart greenhouse. In the smart greenhouse, operators are able to adjust environmental elements to the desired values and keep crops away from effects of outside environment. In this way, the smart greenhouse supports the task of seed selecting and growing.This thesis designs a scenario of greenhouse and accurately samples physiological indexes and growing environmental elements of individual plants with high frequency. In general, the samples have characteristics of large number and long data acquisition cycle. In order to improve the automation level of breeding, this thesis uses micro homebound transport cart, implements techniques of PLC programming, sensor and wireless communication, and designs a data acquisition system working on greenhouse pot plants. This device can measure temperature, humidity, illumination intensity and carbon dioxide concentration.The main controller is FX2N-48MR-001 type of PLC from Mitsubishi company. The mechanism includes manual and automatic controls. Operators are able to adjust environmental elements in the greenhouse by pushing the corresponding buttons. They can also manage these elements in software in upper computers. This is the former part. The greenhouse can collect data by the micro cart and send it back to the main PLC via Zig Bee wireless communication technique. Then PLC will take average of all environmental elements, compare it with the desired range, and decide how to adjust the environmental elements in the future. This is the latter part.The main PLC and homebound transport cart communicate upper computers via 3G wireless communication, realizing remote control of smart greenhouse. The upper computers install Delphi 11.0, which displays not only Automated Guided Vehicle collected individual environmental temperature, humidity, illumination intensity and carbon dioxide concentration, but also average value processed by PLC. Besides, this upper software can control all executors and demonstrate their operating statuses.