CN101936896B - Alcohol gas concentration laser telemetering device - Google Patents

Abstract

The invention discloses an alcohol gas concentration laser telemetering device comprising a laser device control and emission system and a signal receiving, analysis and display system, wherein the laser device control and emission system comprises a modulating signal generator which is connected with a laser controller, a diode laser device and a laser emission device in sequence; the signal receiving, analysis and display system comprises a phase lock amplifier, a data acquisition and analysis device, a system display and alarm device and a laser receiving device, wherein the phase lock amplifier is respectively connected with the modulating signal generator, the laser emission device, the data acquisition and analysis device and the laser receiving device; and the output end of the data acquisition and analysis device is connected with the input end of the system display and alarm device. The invention can remotely carry out predetection on alcohol content in the air in a vehicle, thereby improving the pertinence and the accuracy of drunk driving checking, improving the enforcement work efficiency and reducing the police strength application.

Description

A kind of alcohol gas concentration laser telemetry device

Technical field

The present invention relates to a kind of alcohol gas pick-up unit, be specifically related to a kind of alcohol gas concentration laser telemetry device.

Background technology

The motor vehicle of driving when intoxicated is a kind of behavior with social harm of ignoring self and other peoples' personal safety.The tragedy that causes because of driving when intoxicated is all taking place every day; Public safety traffic management department also is to have dropped into a large amount of police strength to investigate in emphasis time period and location to this and drinking drive behavior; But owing to can't judge whether vehicle driver drives when intoxicated; The investigation of the formula of can only casting net, so not only efficient is lower, has also influenced normal traffic order.

Traditional alcohol concentration detecting instrument---" expiration formula alcohol content tester " adopts electrochemical principle, accurately probe gas alcohol content.Its principle is when the oxide with N type electric conductivity is exposed in the atmosphere, can reduces its inner electron amount owing to the absorption of oxygen its resistance is increased.If there is certain specific reducibility gas thereafter in the atmosphere, it will with the oxygen reaction of absorption, thereby the electron number in the oxide is increased, cause oxide resistor to reduce.Semiconductor-oxide sensor is exactly that variation through this resistance comes analytical gas concentration.But such detection method needs equipment can directly contact tested gas, obviously is not suitable for remote detection.

Summary of the invention

To above-mentioned prior art can not long-range detection gaseous alcohol content problem, the object of the present invention is to provide a kind of alcohol gas concentration laser telemetry device, utilize spectral principle to carry out pre-detection by long-range alcoholic content to air in the vehicle.

The technical scheme that the present invention taked: a kind of alcohol gas concentration laser telemetry device, this device is made up of laser instrument control and emission coefficient and signal reception, analysis and display system; Said laser instrument control and emission coefficient comprise modulation signal generator, and said modulation signal generator is connected with laser controller, diode laser and laser beam emitting device successively; Said signal reception, analysis and display system comprise lock-in amplifier, data collection and analysis device, system's demonstration and warning device and laser receiver, and said lock-in amplifier is connected with laser receiver with said modulation signal generator, laser beam emitting device, data collection and analysis device respectively; The output terminal of said data collection and analysis device shows with said system and is connected with the input end of warning device.

, the present invention at first controls laser power when working through laser controlling and emission coefficient; Export the laser of stable specific wavelength; Launch laser through Optical Fiber Transmission to hand-held laser beam emitting device; Be mapped on the air that contains ethanol to be measured, the laser that ethanol gas is known from experience this wavelength produces an absorption spectrum, and absorbed laser is received by laser receiver through diffuse reflection; Carry out a series of signals collecting, analyzing and processing through equipment data acquisition analyzing, on liquid crystal display, show and warning.

LASER Light Source as with the laser absorption spectrum being the gas optical detection on basis should have single mode, live width will can scan characteristics such as strong absorption line through alcohol molecule much smaller than molecular spectrum live width, laser frequency; Can obtain high sensitivity detection, also necessarily require enough big laser power for remote remote measurement.

In order to realize the narrow linewidth output of diode laser, the present invention adopts low-power consumption diode laser, diode electrically stream controller and laser temperature PID controller and signal generator.Signal generator can produce sine wave and sawtooth wave simultaneously; After the totalizer stack, be injected into diode laser and utilize the diode laser current controller to carry out Laser Modulation and scanning; Modulation signal divides two parts: a part is a sawtooth signal, and another part is a sine wave signal.Sawtooth signal is superimposed upon on the direct current of laser diode current, is used for the wavelength of laser instrument is scanned, and sweep limit is relatively slow modulation variation by the amplitude decision of sawtooth wave, about tens hertz of frequency.Sine wave signal is superimposed upon on the sawtooth wave; Be used for the modulated laser frequency; And as a reference signal to absorption signal carry out once, second harmonic signal carries out demodulation, the ratio of modulation amplitude and sawtooth amplitude is relevant with the best index of modulation, this is comparatively faster modulation variation.

The output of diode laser is through optical fiber coupling output, is connected to the system's light transmitting terminal in the hand-held detector through ring flange from optical fiber again.Because the rear orientation light of scattering thing usually very a little less than, and the angle of divergence of diode laser is bigger, if directly laser is sent then the ground hot spot is too big at a distance again, the luminous energy that reflects will be too weak and be difficult to measure leakage signal.Here use the transmitting terminal of medium refraction index lens (and laser aligner) as laser; These medium refraction index lens are column type glass lenss, are about 4.8mm, and the surface is coated with the antireflection mould; And a corner cut arranged; Avoided etalon effect well, the so-called grin lens of this lens uses these lens can effectively reduce the spot size of laser.

It is that 100mm, focal length are that the lens of 18cm are used to collect scattered signal that hand-held detecting head front end is equipped with bore, and the laser that the lens scatter body reflects is collected and converged on the photodetector of along.Detector converts light signal to electric signal and sends into Circuits System; Carry out respectively once and the second harmonic signal demodulation by lock-in amplifier; Restituted signal is carried out data acquisition and is carried out real time data processing and analysis by data acquisition system (DAS) again, and its result is presented on the LCD in real time.

Beneficial effect of the present invention: " long-range alcohol gas concentration detection apparatus " then is to use handheld device to utilize the long-range alcoholic content to air in the vehicle of spectral principle to carry out pre-detection, and the traffic police can use alcohol content tester further to confirm inspection to the suspected vehicles driver according to the result that preliminary examination is measured.The result who checks out directly input system and as required the scene leave the punishment document.Can improve the specific aim accuracy of drunk driving inspection so greatly, improve law-enforcing work efficient, reduce the police strength utilization, and alleviate relation between the police and the people to a certain extent.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention is further specified.

Fig. 1 is a general structure schematic block diagram of the present invention;

Fig. 2 is laser controlling of the present invention and emission coefficient schematic block diagram;

Fig. 3 is signal reception of the present invention, analysis and display system schematic block diagram;

Fig. 4 combines the hand-held detector synoptic diagram of formation for Laser emission of the present invention and receiving trap;

Fig. 5 is medium refraction index lens and optical fiber collimator combination synoptic diagram.

Embodiment

Like Fig. 1,2,3, the present invention is made up of with signal reception, analysis and display system 2 two parts laser instrument control and emission coefficient 1; Laser instrument control and emission coefficient 1 comprise modulation signal generator 11, laser controller 12, diode laser 13 and laser beam emitting device 14.Said modulation signal generator 11 is made up ofsignal generator 111 and addition superimposer 112;Signal generator 111 is to addition superimposer 112 emission sine wave and sawtooth wave.Laser controller 12 is made up of diode laser current controller 121 and laser temperature PID controller 122; Both output terminals all are connected with the input end of diode laser 13; The output terminal of said diode laser 13 is connected with the input end of laser beam emitting device 14, and the output terminal of diode laser 13 is connected with the input end of addition superimposer 112.Sinusoidal wave and sawtooth wave is injected into diode laser 13 and utilizes the diode laser current controller to carry out Laser Modulation and scanning after 112 stacks of addition superimposer; Modulation signal is divided into two parts: a part is a sawtooth signal, and another part is a sine wave signal; Sawtooth signal is superimposed upon on the direct current of laser diode current, is used for the wavelength of laser instrument is scanned; Sine wave signal is superimposed upon on the sawtooth wave, is used for the modulated laser frequency, and as a reference signal to absorption signal carry out once, second harmonic signal carries out demodulation.The output of said diode laser 13 is through optical fiber coupling output, is connected to the Laser emission end of hand-held detector again from optical fiber.Said Laser emission end adopts medium refraction index lens and laser aligner, and said medium refraction index lens are column type glass lenss, long 4.8mm, and the surface is coated with the antireflection mould, and a corner cut is arranged.

Signal reception, analysis and display system 2 comprise that lock-in amplifier 22, data collection and analysis device 23, system show and warning device 24 and laser receiver 21, and said lock-in amplifier 22 is connected with laser receiver 21 with said modulation signal generator 11, laser beam emitting device 14, data collection and analysis device 23 respectively; The output terminal of said data collection and analysis device 23 shows with said system and is connected with the input end of warning device 24.Data collection and analysis device 23 constitutes (analog/digital converter 231 is called for short ADC, and digital signal processor is called for short DSP) by analog/digital converter 231 and digital signal processor 232.

Diode laser 13 of the present invention is controlled by diode electrically stream controller and laser temperature PID controller;Signal generator 111 produces a sawtooth wave and comes diode laser 13 injection currents are carried out laser frequency scanning and modulation with sinusoidal wave superposed signal; Realize near the frequency tuning of the laser molecule absorption peak, the sinusoidal wave while thatsignal generator 111 produces is input to lock-in amplifier 22 as demodulated reference signal.The sawtooth wave rising edge is used for the scan laser frequency, and the negative edge time is very short, is used for DSP and carries out data acquisition, analysis and processing.The frequency and the initialization outside port of dsp operation clock at first are set, are set the interrupt cycle of interrupt routine then and start interrupt routine.At first start outside ADC in the interrupt routine, obtain data converted, and data are carried out filtering, then the result is preserved in the array, the collection zone bit is set simultaneously.Main circulating program in the master routine just begins the data processing process after finding to gather flag set.After data processing finishes, judge earlier whether be used to revise the isoparametric button of threshold value is pressed, if by next processing button program and revise systematic parameter.After the button EOP (end of program), start liquid crystal and hummer control program, let data result and systematic parameter (threshold value) be presented on the liquid crystal, the while is controlled whether sounding of hummer according to logic determines.

Laser emission of the present invention shown in Figure 4 and receiving trap are combined the hand-held detector synoptic diagram of formation.Hand-held detector comprisesshell 3, establishes medium directprojection rate lens 4 at the front end ofshell 3, has a circular hole to placeoptical fiber collimator 5 in the middle of the medium directprojection rate lens 4, referring to Fig. 5.The detector rear end is that the along of lens is placedphotodetector 211, and the optical signal detection device links to each other with diode laser throughoptical fiber 7, andpilot lamp 6 is positioned at the detector lower end.The output of diode laser 13 is throughoptical fiber 7 coupling outputs, is connected to the light transmitting terminal in the hand-held detector through optical fiber again.Because the rear orientation light of scattering thing usually very a little less than, and the angle of divergence of diode laser is bigger, if directly laser is sent then the ground hot spot is too big at a distance again, the luminous energy that reflects will be too weak and be difficult to measure signal.Here use mediumrefraction index lens 4 andoptical fiber collimator 5 transmitting terminal as laser; These medium refraction index lens are the thick about 4.8mm of a glass lens; The surface is coated with the antireflection mould, and the so-called grin lens of this lens uses these lens can effectively reduce the spot size of laser.

Mediumrefraction index lens 4 bores that hand-held detecting head front end is adorned are that 100mm, focal length are 18cm, are used to collect scattered signal, and the laser that medium direct projection rate lens reflect scatterer is collected and converged on the photodetector of along.Detector converts light signal to electric signal and sends into Circuits System; Carry out respectively once and the second harmonic signal demodulation by lock-in amplifier; Restituted signal is carried out data acquisition and is carried out real time data processing and analysis by data acquisition system (DAS) again, and its result is presented on the LCD in real time.

, instrument at first controls laser power when working through laser controlling and emission coefficient; Export the laser of stable specific wavelength; Launch laser through Optical Fiber Transmission to hand-held Laser emission/receiving trap; Be mapped on the air that contains ethanol to be measured, the laser that ethanol gas is known from experience this wavelength produces an absorption spectrum, and absorbed laser is received by laser receiver through diffuse reflection; Carry out a series of signals collecting, analyzing and processing through data acquisition and analyzing subsystem, on liquid crystal display, show and warning.

Claims (4)

1. alcohol gas concentration laser telemetry device is characterized in that: this device is made up of laser instrument control and emission coefficient (1) and signal reception, analysis and display system (2); Said laser instrument control and emission coefficient (1) comprise modulation signal generator (11), and it is connected with laser controller (12), diode laser (13) and laser beam emitting device (14) successively; Said signal reception, analysis and display system (2) comprise that lock-in amplifier (22), data collection and analysis device (23), system show and warning device (24) and laser receiver (21) that said lock-in amplifier (22) is connected with said modulation signal generator (11), laser beam emitting device (14), data collection and analysis device (23) and laser receiver (21) respectively; The output terminal of said data collection and analysis device (23) shows with said system and is connected with the input end of warning device (24); The transmitting terminal of said laser beam emitting device (14) adopts the medium refraction index lens, and said medium refraction index lens are a column type glass lens, and the surface is coated with the antireflection mould, and a corner cut is arranged; Said modulation signal generator (11) is made up of signal generator (111) and addition superimposer (112); Said signal generator (111) is to addition superimposer (112) emission sine wave and sawtooth wave; Said laser controller (12) is made up of diode laser current controller (121) and laser temperature PID controller (122); Both output terminals all are connected with the input end of said diode laser (13); The output terminal of said diode laser (13) is connected with the input end of said laser beam emitting device (14), and the output terminal of said addition superimposer (112) is connected with the input end of said diode laser current controller (121).

2. alcohol gas concentration laser telemetry device according to claim 1; It is characterized in that: said sine wave and sawtooth wave are injected into diode laser (12) and utilize diode laser current controller (121) to carry out Laser Modulation and scanning after addition superimposer (112) stack; Modulation signal is divided into two parts: a part is a sawtooth signal, and another part is a sine wave signal; Sawtooth signal is superimposed upon on the direct current of diode laser electric current, is used for the wavelength of laser instrument is scanned; Sine wave signal is superimposed upon on the sawtooth wave, is used for the modulated laser frequency, and as a reference signal to absorption signal carry out once, second harmonic signal carries out demodulation.

3. alcohol gas concentration laser telemetry device according to claim 1 and 2 is characterized in that: the output of said diode laser (13) is through optical fiber coupling output, is connected to the transmitting terminal of the laser beam emitting device of hand-held detector from optical fiber.

4. alcohol gas concentration laser telemetry device according to claim 1; It is characterized in that: said laser receiver (21) is made up of photodetector (211) and prime amplifier (212), and said photodetector (211) receives laser reflection signal and is transferred to said prime amplifier (212) to signal; Said data collection and analysis device (23) comprises D/A (231) and digital signal processor (232); Said lock-in amplifier (22) is passed to said D/A (231) with amplifying signal, and carries out signal Processing through said digital signal processor (232) and report to the police through display module (241) demonstration or warning device (242).

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