Design And Implementation Of Crop Growth Information Monitoring Instrument Based On Active Light Source

Precision agriculture is a modern agricultural management technology based on information technology and data knowledge,which combines crop information collection,information data processing and management regulation technology,can produce the maximum use of resources,realize the agriculture production efficiency,high yield and low pollution,played an important role in the development of world agriculture technology the.Crop information collection is the basis for the implementation of precision agriculture,how to realize the crop information fast,accurate access,is a key problem to be solved urgently in the current precision agriculture.In order to realize the urgent need of precision agriculture growing information acquisition of field crops,the research on the design of crop growth information monitor based on active source,and designing the corresponding experimentation to test the performance for the monitor.First,the paper expounds the problems faced by traditional agriculture in our country,the importance of digital precision agriculture development,and analysis the crop growth information acquisition for realizing the important role of digital precision agriculture,comparison of domestic and overseas in recent years in non-destructive crop growth based on spectral information monitoring equipment research,development of information and the existing problems,putting forward the research the purpose and meaning of this paper,and planning the research contents and technical route of the paper.According to the content of this paper analyzed the nondestructive monitoring based on the characteristics and superiority,introduced the mechanism of near infrared spectroscopy based on non-destructive monitoring of crop,the description method of spectracteristics of crop canopy reflectance and define various spectral vegetation index,and design the overall scheme of crop growth information monitor based on active light source.Secondly,in this paper,according to the distribution features of the crop canopy and crop sensitivity spectral bands of 730nm,810nm,designed a kind of crop canopy reflectance spectra of 730nm and 810nm in crop growth information sensor.The crop growth information sensor mainly comprises a data acquisition system of circuit and dual exact laser ranging system light source system,optical spectrum signal acquisition unit and the weak signal conditioning driving circuit of light source and an optical path of the light source unit.The light source system using LED constant current modulation and filter combination,prevent the influence of external optical signal of test results,light source modulation frequency is 1KHz,the central wavelength of the filter for 730nm and 810nm,bandwidth is 10nm.The light source driving circuit is composed of a square wave signal generator,a level switching circuit,a constant current driving circuit;weak signal conditioning circuit by the former class I-V amplifier circuit,passive band-pass filter circuit,after the class with to amplifying circuit,signal detection circuit.Crop growth information sensor light source system sends out constant light intensity 730nm,810nm modulation spectrum signal radiation crop canopy,spectrum signal acquisition system to accept the modulation spectrum signal crop canopy reflectance,realize the acquisition of crop canopy reflectance spectrum intensity.The optical path of the light source unit and condensing LED collimated light from the light source,optical spectrum signal acquisition unit realizes do crop canopy reflectance spectra of condensing and filtering function.Thirdly,in this paper,according to the crop canopy spectral reflectance sensor output signal and field testing needs,using the internal integrated ADC module ATmega32 as the control chip with perseverance,hardware circuit of the control part of the temperature and humidity sensor,keyboard input,LCD display,sound and light to remind,SD card storage and power management etc.;design using C language embedded control software,the realization of crop growth the information acquisition,display and storage,SolidWorks was used to design the structure diagram of instrument,and according to the structure diagram of machining monitor.Finally,in order to test the performance of inspection and monitor,respectively,the function test and field test of the monitor.Function test by the stability test,anti light interference test,test,the return error calibration test,temperature performance test etc.;field test by reflectance verification test,crop growth information verification test,leaf area index verification test etc..Through the function test and field test results show that the performance of the designed monitor crop growth information is good,can use the field crop growth information fast,accurate access to required.