Research On Signal Acquisition And Processing System Of Mini Laser Spectrometer

Laser fluorescence spectrometer,with the advantages of instant,fast and non-destructive measurement,has a wide range of application in food safety,environmental monitoring,medical aviation and national defense technology and other fields.In recent years,in order to overcome the shortcomings of traditional spectrometers,such as large volume,high power consumption and high cost,laser fluorescence spectrometers have gradually developed towards miniaturization.Miniature spectrometers have the advantages of short development cycle,low cost,portability and secondary development.Based on the spectrometer developed by the research team,this paper improves the detection system and software,and redesigns a miniature laser fluorescence spectrometer under the premise of unchanged working principle.The main research contents of the paper are as follows:(1)The front-end signal pre-processing circuit is designed for the micro laser fluorescence spectrometer that collects the PAL spectral video signal.The timing of the signal is analyzed,and the filter amplifier circuit is designed and simulated using the Multisim platform.The experiment verifies that the signal front-end filter circuit can effectively improve the signal-to-noise ratio.(2)The spectrometer hardware system is designed,which mainly includes optical system and signal acquisition and processing system.The optical system includes collimating prism,dispersion prism,focusing prism,etc.;the signal acquisition and processing system includes detector,filter amplification circuit,decoding circuit and MCU circuit.After the analog video signal is amplified by the filter circuit,it outputs a stable PAL standard signal,which is collected by a data acquisition circuit composed of a decoding chip and an ARM controller,and performs digital decoding and high-speed calculation on the input analog signal;the communication between the Bluetooth module and the mobile terminal app or the direct communication with the computer USB can realize the bidirectional control between the mobile terminal and the computer terminal;the power system is built with several integrated IC chips with small ripple coefficient and high voltage output accuracy;the laser intensity and brightness are controlled by digital positioner and laser control circuit.(3)The algorithm of spectrometer data processing is designed,and various working measurement modes of the spectrometer are added to realize the functions of collection,calculation,communication,display and storage of spectral data.(4)Finally,the miniaturized system integration of the spectrometer is completed and debugging is completed.The designed spectrometer is used to carry out spectrum detection experiments for different kinds of substances.A variety of test modes can be selected for the experiment,such as laser measurement mode,background subtraction mode,etc.Experiments show that the micro laser fluorescence spectrometer designed in this paper can detect a variety of substances,which is significantly improved in signal processing,software algorithms and system stability compared to the prototype spectrometer.The spectrometer designed in this paper has the advantages of small size,low cost and low power consumption,stable system,and easy secondary development.It achieves dual-platform communication of spectral data.Today,with the continuous development of Internet of Things technology,it provides a new idea for the civilian use of spectrometer.