The Research On Automatic Control System Of Small Seedling Greenhouse

Small seedling greenhouse is an environment system that for precious seedling culturing, at present, the comprehensive consideration of impact factor to seedling survival environment in the design of the artificial incubator for nursery stock survival environment is not comprehensive.This topic use the small seedling greenhouse’s cultivation environment as the research object, mainly do the following work:1)According to the requirements of the precious seedling cultivation, use Siemens S7-200 CPU224XP as control unit, and design the overall structure and the size of small greenhouse; 2) Use the software of ANSYS CFX to build the space model and analyses the coupling relationship of the internal temperature, humidity of greenhouse and the finite element analysis, get the gradient distribution of internal temperature, humidity in steady state, and accord to its results to adjust the sampling points of sensors; In addition, with the help of Simulink toolbox of MATLAB to achieve briefly simulation model, concluded its characteristic response curve; 3)Use the software of STEP7 Micro WIN V4.0 SP6 compiling monitoring program, realize the control of the small internal parameters of greenhouse, at the same time through PC monitoring software of KINGVIEW 6.53, text display to real-time monitor the conditions inside the greenhouse environmental factors, through monitoring and analysis the corresponding data of processing to feedback the situation of internal control; 4) In the process of control, use history database to store the internal environment parameters of process data in real time, by data processing to get the analysis of changes in a single environment factor’s influence on other environmental factors, coupling relationship between the greenhouse internal temperature and humidity and other relationships with the environmental factors, and then draw the related curve of various environmental factors. In the control system debugging process, use the built-in PID setting function of programming software to set the environmental factor, and get stable control effect.After the test, the developed system effectively realizes the control of environment parameter. Its simple operation, strong stability, high reliability and strong practicability, cooperates with KINGVIEW monitoring interface and real-time monitoring meets the need of modern precious seedling cultivation, has good economic efficiency.