Research Of Greenhouse Temperature And Humidity Measure & Control System Based On Arm Microprocessor

With China's agricultural production and industrial technology development and progress, kinds of greenhouse has been widely used at home and abroad.At present,greenhouse measurement and control technology as an important part of greenhouse production has become the focus of research at home and abroad.With the appearance of the 32-bit high-performance microprocessors that to the ARM as the core, control technology development and mature application of sensor technology,developing a new greenhouse measure-control system becomes possible in these technical background.In the research,we first comprehensively analysed domestic and international greenhouse development situation of technology and embedded technology. Aimed at small and medium greenhouse,we set up a good human-machine interaction properties of the greenhouse temperature and humidity control system,which was researched by embedded company based on the demo board of S3C2440A microprocessor. Choosing the two main greenhouse environment affecting factors temperature and humidity as control object,control system could adjust the temperature and humidity of greenhouse automatically according to different growth stages of crop in the different requirements of temperature and humidity so as to achieve the best growth crops needs.The main research contents are as follows:(1)In the hardware, controller hardware circuit design included micro processor core circuit, environmental factors data acquisition circuit,actuators drive circuit,acousto-optic alarm circuit etc.Processor core circuit module was the core of the system module,which was composed of embedded processor S3C2440A, storage systems,JTAG interface circuit,system reset circuit, clock and power circuit.Their main functions were to execute the driver of the whole system's hardware part,process data gotten from environmental factors acquisition module,operate system control software,save data,control environment regulating equipment etc. Data acquisition circuit module collected at various points in greenhouse on greenhouse environment factor of sensor,then put collected data into processors for processing. Because each sensor output signal is different,part of the analog signal need to input sensor adc, converts digital signal processor after the input processors can handle.Main function of actuators circuit module by processor was to control relay output high level and the corresponding environment regulating equipment work in order to adjust for greenhouse environment. Acousto-optic alarm module's main function was when greenhouse environment temperature and humidity above or below the system's settings of the reference, lower limit, the system will sound alarm and show the corresponding light.(2)In the software, constructing embedded Linux system was the development foundation of controller application software and sensor driver. According to the specific development board hardware configuration and parameters,we successful transplanted embedded Linux operating system,including U-boot on the transplant, Linux kernel transplantation, root file system production,realizeing the real-time processing of multiple tasks.So the system had a good stability and reliability, maintainability,which lay the foundation for future application program updated.Under Linux built,we wrote the controller application software with three modules:The data acquisition module, actuators driver module and the acousto-optic alarm module.What's more,developing hardware driver according to the temperature and humidity sensor used in this pape, and loaded into the kernel successfully.(3)Greenhouse control system was a multivariable and nonlinear time-varying, lagging behind system.And the variables of the coupling relationship between was strong,so it was hard to establish accurate mathematical model. In the comprehensive analysis that based on the characteristics of greenhouse temperature and humidity, design many factors greenhouse control algorithm based on a RBF nerve network and FALCON network.In conclusion,the embedded technology, automatic control technology and sensor technology were used in the paper.Aimed at small and medium greenhouse, a control system with good stability, high reliability and easy to operate greenhouse temperature and humidity measurement was designed.