外文翻译---基于新的温室环境参数监测和控制系统(编辑修改稿)

外文翻译---基于新的温室环境参数监测和控制系统(编辑修改稿)内容摘要：

sture is measured by standing wave radio method in this system. Based on the theory of Engineering Electromagic Field,for lossy medium,the electromagic wave impedance as follows: Z0=√μ/ε(1+jλ/(ωε)) Where μ is medium permeability,and μ of soil is μ≈μ0 is the vacuum permeability。 ε is medium dielectric constant。 λ is medium conductivity。 ω is electromagic wave frequency. In the very low audio(2020Hz),the loss tangent of dry soil dielectric is λ/ωε≈,if you choose the frequency of the signal source at above ,ε≈ε∞,the imaginary part of the soil wave impedance is neglect,only the real part,which amounts to a pure resistance. Soil moisture sensor consists of 100MHz signal source,a coaxial transmission line and a 4pin stainless electromagic waves of signal transmit to the probe along the the probe impedance and line impedance are different,the superimposition of incident waves and reflected waves forms a standing waves. Taking the coaxial transmission line as a lossless uniform line,wave impedance is Z0,Zl is the load impedance. Then the reflected coefficient of voltage wave at the probe is: Γ= （ ZLZ0） /(ZL+Z0) Choosing the length of transmission line is l=λ/4,the maximum and minimum of both ends of the line are Umax and Umin,Then the standing wave radio in the line can be expressed as: S=Umax /Umin =(1|Γ|)/(1+|Γ|) In the way,the soil moisture radio can be measured by measuring the standing wave rate of transmission line. 外文翻译 6 As shown in .,soil moisture module consists of sensors and controllers,the sensors are subordinated to controllers,controllers can be omitted without the need of irrigation in greenhouse. To simplify the control,irrigation technology of nodetype in partition is adopted in the control soil moisture in this a certain extent,the parameters of upper and lower the ground can be decoupled by adopting this technology. IV CONTROL SYSTEM PROGRAMMING The software of PC is developed by KingView of Beijingcontrolled configuration software has high reliability,shorter development cycle,perfect capability of graphical interface generation,and friendly humanputer interaction。 and can create dynamic images and charts in accordance with the layout of equipment in the scene。 can visually display the changes of parameters,control status,and can give an alarm when overlimited。 and can achieve fuzzy control of greenhouse parameters by using the history curve of environment parameters stored in the specific database and adopting the agricultural expert system. The software of SCM of the slave is developed by Keil C51 to achieve realtime collecting,processing,uploading of the parameters and accept the fuzzy control instructions from the host puter and plete local control of the device. A. Program design of the control module The software of the subslave machine of soil moisture module,that include the main function,subroutines of data acquisition and processing,interrupt handling and 外文翻译 7 municating etc,read the value of standing wave voltage through the parallel data port and obtained the value of soil moisture content by function calculating. The software of the slave machine of monitoring and control of soil moisture mainly plete data munication with the subslave machine,uploading measurement data and current control state to the host puter,accepting the fuzzy control instructions from the host puter and output the implementation instructions. The software of the slave machine of temperature and humidity,and CO2 mainly plete reading data of CO2 concentrations and temperature and humidity through the I2C concentration,uploading measurement data and current control state to the host puter,accepting the fuzzy control instructions from the host puter and output the implementation structure of the main program and interrupt subroutine of temperature and humidity module ar。