CN106383097A - Tunable-laser-based motor vehicle exhaust gas remote sensing detection system and method - Google Patents

Abstract

The invention relates to a tunable-laser-based motor vehicle exhaust gas remote sensing detection system and method. A laser control module controls each laser in a laser module to emit detection light within a desired wavelength range; the multiple beams of detection light emitted by the laser module pass through a light path collimating array unit to be collimated to form parallel light beams, and the parallel light beams are emitted to an optical reflector unit; under the condition of an open-type light path, the optical reflector unit reflects the laser detection light beams passing through the exhaust gas of a motor vehicle to a light path focusing and filtering array unit for focusing and filtering processing; the detection beams emitted by the focusing and filtering array unit are detected and received by a semiconductor photoelectric detector group and are sent to a computer by a signal collecting and processing device; and the computer computes concentration of each component in the exhaust gas of the motor vehicle under the condition of the open-type light path. The system and the method disclosed by the invention can be widely used in remote sensing detection of the exhaust gas of the motor vehicle.

Description

Motor-vehicle tail-gas remote sensing detection system and method based on tunable laser

Technical field

The present invention is with regard to a kind of motor-vehicle tail-gas remote sensing detection system and method based on tunable laser, is related to machine Motor-car emission detections technical field.

Background technology

Tail gas pollution of motor-driven vehicle has become as the key factor of impact China urban air-quality, and Chinese Ministry of Environmental Protection is to 9, China The source resolution result that big city is carried out shows the PM having 4 cities_2.5Primary pollution source is motor vehicles, the PM in 1 city_2.5First Pollution source is wanted to be the moving source dominated by motor vehicles.With vehicle guaranteeding organic quantity continue to increase and 6 years inner exhaust gas of new car are exempted from The issue of annual test policy, motor-vehicle tail-gas remote sensing monitoring technology become lifting emission from vehicles ability to supervise and efficiency important Means.《The Law of the People's Republic of China on the Prevention and Control of Atmospheric Pollution》Clear stipulaties, from January 1 in 2016, can not affect traffic In the case of satisfy the need upper traveling motor vehicles implement remote exhaust emission detection.With being phased out of the high pollution vehicles such as yellow mark car, " yellow Change green, green change green " strict control, state five discharge standard progressively implement and state six standard draft formulation, China road is up The automotive emission level sailed will necessarily significantly reduce, and this just carries to the power of test of motor-vehicle tail-gas remote sensing monitoring equipment Go out higher requirement.Due to motor-vehicle tail-gas complicated components, motor-vehicle tail-gas remote sensing monitoring equipment typically requires infrared light supply (include infrared lamp or near infrared laser) and ultraviolet source (ultraviolet deuterium lamp) combine use.

Prior art discloses one kind using infrared lamp as continuous light source, using NDIR (non-dispersive Infrared) commercial measurement CO, CO₂, HC, using uviol lamp as light source adopt DUV technology for detection NOx.Also report in prior art Road adopts CO, CO in TDLAS technology for detection tail gas with Near-infrared Tunable laser diode for light source₂, with uviol lamp it is The light source method of DOAS technology for detection HC, NO.Further, uviol lamp can be combined with the other technologies such as DOAS as light source NO in detection tail gas₂, SO₂, NH₃Deng.For the particulate matter in motor-vehicle tail-gas, prior art reports with ultraviolet laser For light source measurement exhaust particulate thing concentration or using ultraviolet light known to wavelength and infrared photo measure exhaust particulate thing concentration Method.But, motor-vehicle tail-gas remote sensing technology is as a kind of open light path detection, each group in the tail gas in actual measurement Can be affected by ambient temperature and humidity during point concentration, and NDIR, DOAS and DUV commercial measurement gas concentration with humiture close phase Close, frequently must be demarcated according to physical condition when leading to using these technology.In addition, some motor-vehicle tail-gas remote sensing monitorings The corresponding wavelength of Near-infrared Tunable laser diode that equipment uses belongs to CO and CO₂Absorption in over-frequency band, in this wave band CO And CO₂Very weak to the absorbability of detection light, lead to not lift instrument detection precision further.

Prior art also discloses a kind of remote vehicle emissions measurement system utilizing based on QCL and side Method.QCL is as a kind of preferable middle-infrared band light source of high sensitivity Trace gas detection, light-source monochromaticity Good, live width is much smaller than the absorption line width of tested gas；Light source has very high spectral power density simultaneously, can be in room temperature work The high-resolution to many trace gas, highly sensitive detection is realized under making.But as emerging technology, single quantum stage at present The wavelength tuning speed of connection laser instrument is very restricted, generally no greater than 100cm^-1/ the second.Due to remote exhaust emission testing equipment Use under the conditions of open light path, and motor-vehicle tail-gas can be at a terrific speed to surrounding after emitting from offgas duct Environmental diffusion, concentration change is very greatly so that remote exhaust emission testing equipment (as 10ms) must complete to each within the extremely short time The measurement of individual species；Different Trace Species generally have stronger absorption in different wave-length coverages, beyond single amount simultaneously The wavelength tuning range of son metering laser instrument；Lead to QCL currently with middle infrared wavelength in high velocity conditions Under traces various in motor-vehicle tail-gas are carried out with accurate remote sensing survey single quanta cascade must be used to swash for each species Light device, and the cost being directed to each species QCL is very high.Secondly, according to Lambert-Beer law, gas The factor such as temperature and pressure by surrounding simultaneously is understood in absorption under certain wavelength for the body species to be affected, and therefore instructs in advance The artificial neural network practiced and use must consider the impact of temperature and pressure simultaneously, and the measurement of multiple species is blended in one Cause bigger complexity in individual neutral net, affect measurement effect.

Content of the invention

For the problems referred to above, one of goal of the invention of the present invention is that offer one kind can be in synchronization to motor vehicles The motor-vehicle tail-gas remote sensing detection system based on tunable laser that in exhaust gas composition, different plant species are detected.

Another goal of the invention of the present invention be provide one kind can in synchronization is to motor-vehicle tail-gas component not jljl Plant the motor-vehicle tail-gas remote sensing detection method based on tunable laser being detected

For realizing above-mentioned one of goal of the invention, the present invention takes technical scheme below：One kind is based on tunable laser The motor-vehicle tail-gas remote sensing detection system of device, this system for remote exhaust emission measurement includes laser instrument module, laser control module, light Road collimating array unit, light path focusing and filter array unit, semiconductor photo detector group, signals collecting and processing meanss, Optical reflection mirror unit and computer；Described laser control module controls each laser instrument in described laser instrument module to send out respectively Go out the detection light of required wave-length coverage；The multi beam detection light that described laser instrument module sends is through described beam path alignment array element Collimation forms collimated light beam and is transmitted into described optical reflection mirror unit；Under the conditions of open light path, described optical mirror Unit by the laser detection light beam through motor-vehicle tail-gas reflex to described light path focus on and filter array unit be focused and Filtering Processing, the detection light beam through described focusing and filter array unit outgoing detects through described semiconductor photo detector group and connects Receive and be sent to described computer, under the conditions of described computer calculates open light path through described signals collecting and processing meanss Each concentration of component in motor-vehicle tail-gas.

Further, in described beam path alignment array element, the number of collimating lens, light path focus on and filter array unit In the number of middle condenser lenses and optical filter, semiconductor photo detector group, the number of semiconductor photo detector is all swashed with described The number of the laser instrument of light device module is corresponding.

Further, this motor-vehicle tail-gas remote sensing detection system also includes the automatic mark for light path is carried out with automatic Calibration Determine device, described automatic calibration device is arranged on outside described focusing and filter array unit, described in described computer controls certainly Dynamic caliberating device operates at set intervals and to the focusing of described light path and filter unit, each species passage is demarcated.

Further, this motor-vehicle tail-gas remote sensing detection system also includes motor vehicle speed/acceleration analysis module and machine Motor-car Car license recognition module, motor vehicle speed described in described computer controls/acceleration analysis module measurement motor vehicles are in tail gas The speed of monitoring point and acceleration information, control described automobile license plate identification module to shoot motor vehicles simultaneously and monitor through tail gas Headstock or the photo of the tailstock carry out Car license recognition during point.

Further, described laser instrument module is by several Near-infrared Tunable laser instrument, mid-infrared tunable laser With ultraviolet light/visible laser composition, it is detected type and the number of option of species laser instrument for motor-vehicle tail-gas, each Detected species correspond to a laser instrument.

Further, described semiconductor photo detector adopts the semiconductor photo detector of TEC refrigeration.

Further, described laser control module includes temperature-control circuit and current control circuit, described temperature control Circuit processed controls in described laser instrument module each laser to keep stabilized operating temperature, institute in the range of -30～60 DEG C of ambient temperature State current control circuit and produce sinusoidal current and sawtooth current simultaneously, sinusoidal current and sawtooth current are superimposed composition laser instrument respectively Driving current, drives each laser instrument in laser instrument module to send the detection light of required wave-length coverage.

Further, described beam path alignment array element adopts collimator lens array, and the light of each laser instrument output is all logical Cross corresponding collimating lens to be collimated, every collimating lens are respectively adopted AR plated film non-spherical lens；Described light path focus on and Filter array unit includes focusing lens array and bandpass filter chip arrays, and the condenser lenses in described focusing lens array are all adopted With AR plated film aspheric surface focus lamp, it is respectively provided with the light direction of corresponding collimating lens, the band in described bandpass filter chip arrays What pass filter was separately positioned on corresponding semiconductor photodetector enters light direction, will after described bandpass filter filtering interfering light Detection light focuses on and carries out spectral measurement on corresponding semiconductor photo detector.

Further, described signals collecting and processing meanss gather the detection data of described semiconductor photo detector group simultaneously Carry out signal to amplify and mean filter process, then enter horizontal lock and amplify and second harmonic demodulation or first harmonic demodulation, same When collection road environment in temperature and pressure data, and by the direct absorption spectra data finally giving, species of gases secondary Harmonic spectrum, the first harmonic spectrum of particulate matter species and temperature, pressure data is activation are to described computer.

For realizing above-mentioned another goal of the invention, the present invention takes technical scheme below：A kind of tunable laser motor-driven Tail gas remote sensing detection method, including herein below：1) obtain Theoretical gas infrared second harmonic absworption peak amplitude curve；2) obtain The infrared second harmonic of Theoretical gas is taken to absorb the ambient pressure calibration trace of peak amplitude；3) adopt motor-vehicle tail-gas remote sensing detection system System detects to motor-vehicle tail-gas, detailed process is：3.1) demarcated using automatic calibration device, obtain each species and lead to The calibrating parameters in road；3.2) measurement motor vehicles each species second harmonic in air background value before absorbs peak amplitude；3.3) Obtain each species of gases second harmonic in motor vehicles light path in setting time and absorb peak amplitude and particulate matter light obscuration； 3.4) obtain motor vehicles each species of gases cigarette in setting time inner exhaust gas and roll into a ball value changes trend；3.5) according to each gaseous state cigarette group Value changes trend obtains concentration proportion between each gaseous species using least square fitting, further according to burning equation in computer Middle inverse obtains each gaseous species concentration and particle emission factor in motor-vehicle tail-gas；3.6) computer controls motor vehicles speed Degree/acceleration analysis module, automobile license plate identification module obtain motor vehicles respectively through out-of-date automobile license plate number and speed Degree/acceleration information；4) computer export motor-vehicle tail-gas remote sensing detection data, wherein, motor-vehicle tail-gas remote sensing detection data For gaseous species concentration each in motor-vehicle tail-gas and particle emission factor, automobile license plate number and speed/acceleration information.

Due to taking above technical scheme, it has advantages below to the present invention：1st, the present invention is directed to each species using near Infrared, mid-infrared tunable laser, ultraviolet/visible light laser instrument, simultaneously each laser instrument have corresponding semiconductor optoelectronic Detector, therefore, it is possible to detect to different plant species in synchronization simultaneously.2nd, the present invention can adopt quanta cascade laser Device is detected, because QCL can send the infrared light of different wave length, the present invention can be by increasing laser The number of device and detector is formed to CO, CO₂、NO、NO₂、HC、SO₂、NH₃、N₂Detect while pollutant in the tail gas such as O, HC, And it can be avoided that the disadvantage such as short, short life of optical path length being led to using ultraviolet deuterium lamp is so that equipment can be longer Life-time service under light path.3 present invention uses TEC refrigeration semi-conductor photodetector and TEC refrigeration laser instrument, due to Increase the working range of TEC refrigeration and ability so that system can between -30～60 DEG C steady operation it is ensured that equipment energy Enough normally use under road environment high temperature and low temperature.4th, the present invention is due to using automatic calibration device every 20～30 days automatically Demarcate once it is ensured that in system operation measurement data accuracy.5th, the tunable laser of the present invention has at a high speed Tuning performance, can adopt 100Hz frequency motor vehicles are scanned through tail gas later, can greatly improve sampling rate and Tail gas concentration proportion matching accuracy rate.6th, NO, CO, CO of the present invention₂, the species such as HC detection laser centre wavelength corresponding Fundamental frequency absworption peak, compares the long detection sensitivity of absorption in over-frequency spike and greatly improves.7th, the present invention obtains not for Theoretical Calculation Gas second harmonic under synthermal and pressure absorbs peak amplitude and has carried out pressure correction, and by the gas second harmonic after correction Absworption peak amplitude curve is used for calculating, due to very accurate for the correction of temperature in gas INFRARED ABSORPTION theory, therefore It is used for during actual measurement can adapt to different pressure and temperature environment using the curve after pressure correction, significantly improve The accuracy of measurement data.The present invention can be widely applied in motor-vehicle tail-gas remote sensing detection.

Brief description

Fig. 1 is the structural representation of the motor-vehicle tail-gas remote sensing detection system of the present invention；

Fig. 2 is the light path principle schematic diagram of the laser instrument module of the present invention；

Fig. 3 is the light path principle schematic diagram of the beam path alignment array element of the present invention；

Fig. 4 is the focusing of the present invention and the light path principle schematic diagram of filter array unit；

Fig. 5 is the motor-vehicle tail-gas remote sensing detection method flow schematic diagram of the present invention.

Specific embodiment

With reference to the accompanying drawings and examples the present invention is described in detail.It should be appreciated, however, that the offer of accompanying drawing Only for more fully understanding the present invention, they should not be interpreted as limitation of the present invention.

As shown in figure 1, the motor-vehicle tail-gas remote sensing detection system based on tunable laser that the present invention provides, including sharp Light device module 101, laser control module 102, beam path alignment array element 103, light path focusing and filter array unit 104, Semiconductor photo detector group 105, signals collecting and processing meanss 106, automatic calibration device 107, optical reflection mirror unit 108th, motor vehicle speed/acceleration analysis module 109, automobile license plate identification module 110 and computer 111, wherein, light path is accurate The number of collimating lens in straight array element 103, light path focus on and filter array unit 104 in condenser lenses and optical filter In number, semiconductor photo detector group 105, the number of semiconductor photo detector is all individual with the laser instrument of laser instrument module 101 Number is corresponding.

Laser control module 102 controls each laser instrument in laser instrument module 101 to send required wave-length coverage respectively Detection light；The multi beam detection light that laser instrument module 101 sends collimates through beam path alignment array element 103 and forms collimated light beam simultaneously It is transmitted into optical reflection mirror unit 108, under the conditions of open light path, laser detection light beam is worn by optical reflection mirror unit 108 Cross motor-vehicle tail-gas and reflex to that light path focuses on and filter array unit 104 is focused and Filtering Processing respectively, line focus and filter The detection light beam of optical arrays unit 104 outgoing through semiconductor photo detector group 105 detect receive and be sent to signals collecting and The signal of reception is processed by processing meanss 106, signals collecting and processing meanss 106, and the data is activation that process is obtained To computer 111, computer 111 calculates each component in motor vehicle exhaust under the conditions of open light path according to burning equation Concentration.

Automatic calibration device 107 is used for carrying out automatic Calibration to light path, during use, is arranged on focusing and filter array unit 108 outsides (initial position is placed on outside detection light path), computer 111 controlled automatic calibration device 107 every 20～30 days Operate and to light path focusing and filter unit 104, each species passage is demarcated, automatic calibration device 107 is specifically calibrated Journey is prior art, will not be described here.

Motor vehicle speed/acceleration analysis module 109 is used for measuring the speed in tail gas monitoring point for the motor vehicles and acceleration And the data is activation obtaining will be measured to computer 111.

Automobile license plate identification module 110 is used for shooting the photo of motor vehicles headstock or tailstock when tail gas monitoring point And carry out Car license recognition, and license plate recognition result is sent to computer 111.

In a preferred embodiment, the Near-infrared Tunable laser that laser instrument module 101 is freezed by several TEC Device, mid-infrared tunable laser and ultraviolet light/visible laser composition, can be for detected option of species laser instrument Type and number, each detected species corresponds to a laser instrument.For example：For near infrared band have the relatively strong CO absorbing, CO₂、NH₃And O₂Near infrared laser (0.76～2.3um) can be adopted；For HC, SO₂、NO_xInhale near infrared band Deng other Receipts are weaker and the larger species of ambient interferences can adopt mid-infrared QCL；Wherein CO, CO₂, HC, NO laser instrument Corresponding wavelength is respectively 2326.8nm, 2004.0nm, 3370nm and 5362.93nm, has corresponded to the fundamental frequency of each species respectively Absorption band.Detection for particulate matter in tail gas can adopt ultraviolet 250nm laser instrument or visible 550nm laser instrument.This Bright to detect CO, CO simultaneously₂、NH₃、O₂, the composition of laser instrument module 101 is described as a example HC and NO.As shown in Fig. 2 laser instrument control Molding block 102 includes temperature-control circuit 201 and current control circuit, and temperature-control circuit 201 controls in laser instrument module 101 6 laser instrument 204～209 keep stabilized operating temperature in the range of -30～60 DEG C of ambient temperature, and current control circuit produces simultaneously Raw 100KHz sinusoidal current 202 and 1KHz sawtooth current 203,6 road sinusoidal current and 6 road 1KHz sawtooth currents are superimposed composition respectively 6 tunnel laser drive current, drive 6 laser instrument 204～209 in laser instrument module 101 to send the detection of required wave-length coverage Light.

In a preferred embodiment, beam path alignment array element 103 adopts collimator lens array, and each laser instrument is defeated The light going out all is collimated by corresponding collimating lens, and every collimating lens are respectively adopted AR plated film non-spherical lens.This Invention is to detect CO, CO simultaneously₂、NH₃、O₂, the composition of beam path alignment array element 103 is described as a example HC and NO.As shown in figure 3, The collimating lens of the present invention are correspondingly arranged at corresponding laser light path exit direction, 6 laser instrument 204 in laser instrument module 101 ～209 6 misconvergence of beams light 301～306 sending are respectively by 6 AR plated film non-spherical lenses in beam path alignment array element 103 307～312 collimations, form the collimated light 313～318 being parallel to each other, obtain the light beam of a diameter of 5～7cm.

In a preferred embodiment, light path focuses on and filter array unit 104 includes focusing lens array and band logical Filter arrays, the condenser lenses in focusing lens array, all using AR plated film aspheric surface focus lamp, are respectively provided with corresponding collimation The light direction of lens, the bandpass filter in bandpass filter chip arrays is separately positioned on entering of corresponding semiconductor photodetector Light direction, prevents semiconductor photo detector from being affected by veiling glare, after bandpass filter filtering interfering light focuses on detection light Spectral measurement is carried out on corresponding semiconductor photo detector.The present invention is to detect CO, CO simultaneously₂、NH₃、O₂, as a example HC and NO Light path focusing and the composition of filter unit are described.As shown in figure 4,313～318 points of the collimated beam through beam path alignment unit outgoing Do not focused on by AR plated film aspheric surface focus lamp 401～406, the light beam 407～412 after focusing is entering semiconductor photo detector Respectively optical filtering process is carried out by band pass filter 413～418 before semiconductor photo detector 419～424 in group 105.

In a preferred embodiment, semiconductor photo detector group 105 comprises the semiconductor light of several TEC refrigeration Electric explorer.The corresponding detection light detecting that each laser instrument sends of each semiconductor photo detector.Semiconductor photosensor In TEC element ensure that photodetector keeps steady operation in the range of -30～60 DEG C of ambient temperature.

In a preferred embodiment, signals collecting and processing meanss 106 gather semiconductor photo detector group 105 Detection data simultaneously carries out signal amplification and mean filter process, then enters horizontal lock amplification and second harmonic demodulates or once humorous Ripple demodulates, simultaneously temperature and pressure data in collection road environment, and by the direct absorption spectra data finally giving, gas thing Second harmonic spectrum, the first harmonic spectrum of particulate matter species and the temperature, pressure data is activation planted are to computer 111.

As shown in figure 5, being based on above-mentioned motor-vehicle tail-gas remote sensing detection system, the machine based on tunable laser of the present invention Motor-car remote exhaust emission detection method, including herein below：

1st, obtain Theoretical gas infrared second harmonic absworption peak amplitude curve.

Hypothesis Theoretical Calibration species of gases concentration is σ_calMeasure the 80% about of concentration maxima for actual, optical path length For L_cal, to each species of gases in the laser cardiac wave strong point Fu Yite (Voigt) linear function -50～100 DEG C and 50～ It is simulated in the range of 120Kpa and integrates, calculate each species theory second harmonic and absorb peak amplitude H_2,calValue：

$H_{2,cal}=\frac{{\mathrm{\σ}}_{cal}*L_{cal}*S}{\mathrm{\π}*v_d}*0.46971*{\∫}_{-\mathrm{\π}}^{\mathrm{\π}}V(x,y)*cos\left(2\mathrm{\Θ}\right)*d\mathrm{\Θ}$

$\begin{array}{ccc}V(x,y)=\frac{y}{\mathrm{\π}}*{\∫}_{-\mathrm{\π}}^{\mathrm{\π}}\frac{e^{-t^2}}{y^2+{(x-t)}^2}dt& x=\frac{(v-v_0)}{v_d}*{\left(ln2\right)}^{0.5}& y=\frac{v_L}{v_d}*{\left(ln2\right)}^{0.5}\end{array}$

In formula, S is the gas long ν of cardiac wave in the laser₀The line absorption intensity at place, v_dFor gas, cardiac wave is long in the laser The doppler linewidth at place, V (x, y) are Fu Yite (Voigt) linear function, v_LLong-range navigation for gas cardiac wave strong point in the laser Hereby live width, these parameters above-mentioned can directly be inquired about in Hitran data base and be learnt, for simplifying amount of calculation, V (x, y) adopts Humlicek simulation formula is described.

2nd, obtain the ambient pressure calibration trace that the infrared second harmonic of Theoretical gas absorbs peak amplitude.

The temperature of control targe gas keeps constant, and actual measurement concentration is σ under conditions of differential pressure_calGas Second harmonic absorption peak, to the gas second harmonic absworption peak measured value H obtaining_2,obsWith theoretical amplitude H_2,calCarrying out many Item formula matching, obtains pressure correction curve：

f_(P)=a+b*P+c*P²+d*P³+e*P⁴

In formula, a, b, c, d, e are coefficient of polynomial fitting, and P is real gas gross pressure.

3rd, using motor-vehicle tail-gas remote sense monitoring system, motor-vehicle tail-gas are detected, detailed process is：

1) system calibrating

Demarcated using automatic calibration device 107, obtained the calibrating parameters of each species passage.Between the automatic Calibration time Every being set as 20～30 days, due to being affected by open atmospheric temperature pressure change and the atmospheric background value, mainly pass through The mixing gas being passed through concentration known, to automatic calibration device, is then detected actually measured signal value, is compared with standard value, Each corridorbarrier function deviation cannot be greater than 5%, is specifically demarcated as prior art, will not be described here.

2) background value measurement

Measurement motor vehicles (refer to front truck and pass through afterwards, rear car records before passing through remote sensing detection through air background value before Atmospheric environment reference background concentration) in each species second harmonic absorb peak amplitude H_2,bak.

3) obtain motor vehicles and absorb peak amplitude H through species of gases second harmonic each in light path in later 1～2 second time_2,obs With particulate matter light obscuration.

Motor vehicles within afterwards 1～2 second time with 100Hz frequency measurement light path in each species gases second harmonic absorb Peak amplitude H_2,ob, and calculate particulate matter light obscuration T in air background_PM：

$T_{PM}=1-\frac{H_{1,obs}-H_{1,zero}}{H_{1,bak}-H_{1,zero}}$

In formula, H_1,obsFor motor vehicles through particulate matter passage first harmonic absorption peak, H in the range of later 1～2 second_1,zeroFor Particulate matter passage first harmonic absorption peak when motor vehicles are in the light, H_1,bakIt is the granule not having motor vehicles through out-of-date background air Thing passage first harmonic absorption peak.

4) motor vehicles are obtained through each species of gases cigarette group value N in later 1～2 second time inner exhaust gas_obsVariation tendency.

Signals collecting and processing meanss 106 gather the ambient temperature and pressure during measurement simultaneously, according to corresponding in step 2 H under temperature and pressure_2,calWith pressure correction curve f in step 3_(P)Calculate vehicle through in later 1～2 second time inner exhaust gas Each species concentration value N_obsVariation tendency：

$N_{obs}={\mathrm{\σ}}_{obs}*L_{obs}=\mathrm{\σ}\left(cal\right)*\frac{H_{2,obs}-H_{2,bak}}{H_{2,cal}*f\left(P\right)}*L_{obs}$

Wherein, σ_obsFor gaseous contaminant concentration each in light path, L_obsFor actual measurement light path；H_2,obsPass through it for motor vehicles The corresponding second harmonic absorption peak of each passage, H in the light path that in 1～2 second, actual measurement obtains afterwards_2,bakIt is not have motor vehicles warp Each passage second harmonic absorption peak in out-of-date background air.

5) obtain each species concentration

Value changes trend is rolled into a ball according to each gaseous state cigarette and obtains concentration proportion between each gaseous species using least square fitting, Each gaseous species and CO is calculated in the present embodiment₂Cigarette group is worth ratio, and further according to burning equation, in computer 111, inverse obtains machine Each gaseous species concentration and particle emission factor in motor-car offgas duct, burning equation is：

$C_{{\mathrm{CO}}_2}=\frac{100}{6.499+4.62Q_{CO}+Q_{HC}+2.38Q_{NO}+4.76Q_{O_2}}---\left(5\right)$

$C_{CO}=\frac{100Q_{CO}}{6.499+4.62Q_{CO}+Q_{HC}+2.38Q_{NO}+4.76Q_{O_2}}---\left(6\right)$

$C_{HC}=\frac{100Q_{HC}}{6.499+4.62Q_{CO}+Q_{HC}+2.38Q_{NO}+4.76Q_{O_2}}---\left(7\right)$

$C_{NO}=\frac{100Q_{NO}}{6.499+4.62Q_{CO}+Q_{HC}+2.38Q_{NO}+4.76Q_{O_2}}---\left(8\right)$

$C_{{\mathrm{NH}}_3}=\frac{100Q_{{\mathrm{NH}}_3}}{6.499+4.62Q_{CO}+Q_{HC}+2.38Q_{NO}+4.76Q_{O_2}}---\left(9\right)$

${\mathrm{EF}}_{PM}=\frac{-ln(1-\frac{T_{PM}}{100})}{\mathrm{\γ}*(N_{{\mathrm{CO}}_2}+N_{CO}+N_{HC})}*17670---\left(10\right)$

In formula,C_CO、C_HC、C_NO、Represent CO in petrol and diesel oil tail gas respectively₂、CO、HC、NO、NH₃Concentration, single Position is %；EF_PMFor the emission factor of exhaust particulate thing, represent the particulate matter quality g number that the 1Kg fuel oil that often burns discharges； Q_CO、Q_HC、Q_NO、Represent CO, HC, NO, O in tail gas respectively₂Cigarette group's value and CO₂Cigarette group is worth ratio, dimensionless；N_CO、N_HC Represent CO in tail gas respectively₂, CO and HC cigarette group value, unit be %*cm；γ is particulate matter delustring system at different wavelengths Number, unit is m²/ g, directly can inquire about from document.

3) acquisition of automobile license plate number and speed/acceleration information

Motor vehicle speed/acceleration analysis module 109, automobile license plate identification module 110 obtain motor vehicles respectively and pass through When automobile license plate number and speed/acceleration information, and send such information to computer 111.

4th, computer 111 output motor-vehicle tail-gas remote sensing detection data, wherein, motor-vehicle tail-gas remote sensing detection data is machine Each gaseous species concentration and particle emission factor, automobile license plate number and speed/acceleration information in motor-car offgas duct.

The various embodiments described above are merely to illustrate the present invention, and the structure of wherein each part, connected mode and processing technology etc. are all Can be varied from, every equivalents carrying out on the basis of technical solution of the present invention and improvement, all should not exclude Outside protection scope of the present invention.

Claims (10)

1. a kind of motor-vehicle tail-gas remote sensing detection system based on tunable laser is it is characterised in that this remote exhaust emission detects System includes laser instrument module, laser control module, beam path alignment array element, light path focuses on and filter array unit, half Conductor photodetector group, signals collecting and processing meanss, optical reflection mirror unit and computer；Described laser control module The each laser instrument in described laser instrument module is controlled to send the detection light of required wave-length coverage respectively；Described laser instrument module sends Multi beam detection light collimate through described beam path alignment array element and form collimated light beam be transmitted into described optical mirror list Unit；Under the conditions of open light path, the laser detection light beam through motor-vehicle tail-gas is reflexed to by described optical reflection mirror unit Described light path focuses on and filter array unit is focused and Filtering Processing, the inspection through described focusing and filter array unit outgoing Semiconductor photo detector group described in light-metering Shu Jing detects and receives and be sent to described meter through described signals collecting and processing meanss Calculation machine, described computer calculates each concentration of component in motor-vehicle tail-gas under the conditions of open light path.

2. a kind of motor-vehicle tail-gas remote sensing detection system based on tunable laser as claimed in claim 1, its feature exists In condenser lenses and filter in the number of collimating lens, light path focusing and filter array unit in described beam path alignment array element The laser all with described laser instrument module for the number of semiconductor photo detector in the number of mating plate, semiconductor photo detector group The number of device is corresponding.

3. the motor-vehicle tail-gas remote sensing detection system based on tunable laser as claimed in claim 1 is it is characterised in that be somebody's turn to do Motor-vehicle tail-gas remote sensing detection system also includes the automatic calibration device for light path is carried out with automatic Calibration, described automatic Calibration Device is arranged on outside described focusing and filter array unit, and automatic calibration device described in described computer controls is when one section Between operate to described light path focus on and filter unit before each species passage is demarcated.

4. the motor-vehicle tail-gas remote sensing detection system based on tunable laser as claimed in claim 1 is it is characterised in that be somebody's turn to do Motor-vehicle tail-gas remote sensing detection system also includes motor vehicle speed/acceleration analysis module and automobile license plate identification module, institute State motor vehicle speed described in computer controls/acceleration analysis module and measure the speed in tail gas monitoring point for the motor vehicles and acceleration Data, controls described automobile license plate identification module to shoot the photograph of motor vehicles headstock or tailstock when tail gas monitoring point simultaneously Piece simultaneously carries out Car license recognition.

5. the motor-vehicle tail-gas remote sensing detection system based on tunable laser as claimed in claim 1 is it is characterised in that institute State laser instrument module by several Near-infrared Tunable laser instrument, mid-infrared tunable laser and ultraviolet light/visible light lasers Device forms, and is detected type and the number of option of species laser instrument for motor-vehicle tail-gas, corresponding one of each detected species Laser instrument.

6. the motor-vehicle tail-gas remote sensing detection system based on tunable laser as claimed in claim 2 is it is characterised in that institute State the semiconductor photo detector that semiconductor photo detector adopts TEC refrigeration.

7. the motor-vehicle tail-gas remote sensing detection system based on tunable laser as described in any one of claim 1～6, it is special Levy and be, described laser control module includes temperature-control circuit and current control circuit, described temperature-control circuit controls In described laser instrument module, each laser keeps stabilized operating temperature, described current control in the range of -30～60 DEG C of ambient temperature Circuit produces sinusoidal current and sawtooth current simultaneously, and sinusoidal current and sawtooth current are superimposed composition laser drive current respectively, Each laser instrument in laser instrument module is driven to send the detection light of required wave-length coverage.

8. the motor-vehicle tail-gas remote sensing detection system based on tunable laser as described in any one of claim 1～6, it is special Levy and be, described beam path alignment array element adopts collimator lens array, and the light of each laser instrument output is all by accurate accordingly Straight lens are collimated, and every collimating lens are respectively adopted AR plated film non-spherical lens；Described light path focuses on and filter array list Unit includes focusing lens array and bandpass filter chip arrays, and the condenser lenses in described focusing lens array are all non-using AR plated film Spherical surface focusing mirror, is respectively provided with the light direction of corresponding collimating lens, and the bandpass filter in described bandpass filter chip arrays divides Be not arranged on corresponding semiconductor photodetector enters light direction, after described bandpass filter filtering interfering light focuses on detection light Spectral measurement is carried out on corresponding semiconductor photo detector.

9. the motor-vehicle tail-gas remote sensing detection system based on tunable laser as described in any one of claim 1～6, it is special Levy and be, described signals collecting and processing meanss gather the detection data of described semiconductor photo detector group and carry out signal and put Big and mean filter is processed, and then enters horizontal lock and amplifies and second harmonic demodulation or first harmonic demodulation, gathers road simultaneously Temperature and pressure data in environment, and by the second harmonic of the direct absorption spectra data finally giving, species of gases spectrum, granule The first harmonic spectrum of thing species and temperature, pressure data is activation are to described computer.

10. a kind of motor-vehicle tail-gas remote sensing detection system based on the tunable laser as described in any one of claim 1～9 Detection method it is characterised in that include herein below：

1) obtain Theoretical gas infrared second harmonic absworption peak amplitude curve；

2) obtain the ambient pressure calibration trace that the infrared second harmonic of Theoretical gas absorbs peak amplitude；

3) using motor-vehicle tail-gas remote sensing detection system, motor-vehicle tail-gas are detected, with detailed process is：

3.1) demarcated using automatic calibration device, obtained the calibrating parameters of each species passage；

3.2) measurement motor vehicles each species second harmonic in air background value before absorbs peak amplitude；

3.3) obtain each species of gases second harmonic in motor vehicles light path in setting time and absorb peak amplitude and particulate matter not Transmittance；

3.4) obtain motor vehicles each species of gases cigarette in setting time inner exhaust gas and roll into a ball value changes trend；

3.5) value changes trend is rolled into a ball according to each gaseous state cigarette and obtains concentration proportion between each gaseous species using least square fitting, Further according to burning equation, inverse obtains each gaseous species concentration and particle emission factor in motor-vehicle tail-gas in a computer；

3.6) computer controls motor vehicles speed/acceleration measurement module, automobile license plate identification module obtain motor vehicles respectively Through out-of-date automobile license plate number and speed/acceleration information；

4) computer export motor-vehicle tail-gas remote sensing detection data, wherein, motor-vehicle tail-gas remote sensing detection data is motor-driven vehicle Each gaseous species concentration and particle emission factor, automobile license plate number and speed/acceleration information in gas.