Study Of Greenhouse Area Intelligent Monitoring System Reliability

Heilongjiang province is the important base of grain in our country, because of locating in thehigh latitudes, belongs to the temperate of continental monsoon climate, annual averagetemperature is low, getting through greenhouses to improve the production efficiency isimperative.Reliability as the measure of system whether or not it can work for a long time, it isthe problem must be considered when the greenhouses monitoring and control system beingdesigned.In this paper, taking the application of advanced reliability technology and measures to appliedto every stage of design, assembly, commissioning and practical operation of the greenhouseintelligent monitoring and control system, and according to different characteristics of differentstages using appropriate technology and methods.This paper obtained from the stage of design, finding out the affecting factors of the systemreliability, in view of the misconceptions in understanding and the loopholes in implementing ofsoftware, using the top down, structured programs, fault tolerance design method, etc.Meantimeaccording to the above affecting factors and solutions to determine the core controller and theselection of all kinds of sensors. And as well aiming at the condition of the lower computerhardware are susceptible to interference, adopted MCU watchdog circuit, PCB circuit design,data acquisition module design and the anti-interference.etc measures; Aiming at the lowercomputer of system due to the the phenomenon of the overheating to burn, electromagneticinterference, input and output channels are easy to external disturbance signal into and theenvironmental impact in the stage of assembly production, adopted respectively the thermaldesign，Emc design, ADUM1250magnetic separator and resistance to environmental design andother technical measures; Aiming at the power supply voltage, communication and databaseoperation instability of the system exposed in the stage of debugging and running, puttingforward to use switch power supply, providing voltage regulator module, differential signaltransmission, increasing the light isolation chip and after the first modular integrated databasedesign method measures, designed the control device of the system; Through the test of thesystem of field running acquisition parameters, by comparing with the actual measuredvalue(real value) analysis obtained that when the microcontroller of the lower computer of the system programming, needing to the temperature and humidity of the air for error compensate,the compensation values are respectively1.22℃and-1.42RH%, in order to improve theaccuracy of acquisition parameters of the system acquisition parameters; According to the actualsystem operation, obtaining the failure rate is0.00287, the mean time between failure MTBFis about348.43hours, mean time to repair MTTR is0.325hours, the availability A is about0.9991, thus it is concluded that the failure rate of this system is low, the mean time betweenfailure MTBF is longer, the mean time to repair MTTR is short, the availability is high, provedthe stability of the system.This system has been applied to the greenhouses area of rice seedlings production of HongHestate farm’s science and technology parks in the administration of Jiansanjiang of Heilongjiangreclamation areas.Up to the paper submitted, this system is running well and being able to meetthe needs of rice seedling production for the technology of intelligent monitoring.