CN102798862B

CN102798862B - A kind of traffic speed-measuring method and device

Info

Publication number: CN102798862B
Application number: CN201110133721.6A
Authority: CN
Inventors: 王钟鸣; 杜劲
Original assignee: SHENZHEN HUARU TECHNOLOGY Co Ltd
Current assignee: SHENZHEN HUARU TECHNOLOGY Co Ltd
Priority date: 2011-05-23
Filing date: 2011-05-23
Publication date: 2015-12-09
Anticipated expiration: 2031-05-23
Also published as: CN102798862A

Abstract

The embodiment of the invention discloses a kind of traffic speed-measuring method, comprising: the echo signal processing of vehicles all in the scope of testing the speed is intermediate-freuqncy signal by traffic speed measuring device in real time; Described traffic speed measuring device processes described intermediate-freuqncy signal, obtains the frequency spectrum in the default time; Described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.The embodiment of the invention also discloses a kind of traffic speed measuring device.The present invention can record the maximum speed value of the vehicle in the scope of testing the speed, and the mode that tests the speed accuracy that is quick and easy, the result that tests the speed is higher.

Description

A kind of traffic speed-measuring method and device

Technical field

The present invention relates to traffic velocity measuring technique field, particularly relate to a kind of traffic speed-measuring method and device.

Background technology

Along with improving constantly of socioeconomic development and people's living standard, urban automobile operation amount increases rapidly, and the car owning amount of ordinary people is also doubled year by year.While urban transportation fast development, the traffic hazard that the behaviors such as urban automobile is illegal, drive against traffic regulations cause, has had a strong impact on normal traffic order, has caused a large amount of traffic safety management crises.

In order to ensure the safety of people; the sections such as the current section of school's periphery, road construction section, traffic control section, hospital and district entrance usually can be set to speed limit region by traffic control center (traffic control center); and warning sign is set; warning sign indicates the maximum travelling speed allowed in this speed limit region; when vehicle is sailed into speed limit region by driver; controlled the current vehicle speed of vehicle by the maximum travelling speed that warning sign indicates in real time, avoid the generation of hypervelocity phenomenon in violation of rules and regulations.In order to the dynamics tightened traffic management, vehicle in speed limit region generally needs the velocity measuring accepting traffic control center, traffic control center is by the velocity measuring to the vehicle in speed limit region, guarantee that the maximum speed value of all vehicles in speed limit region remains within the scope of allowed maximum travelling speed, to avoid the generation of traffic accidents.

The existing traffic scheme that tests the speed is main following several, and one is: induction velocimetry.Inductive coil is buried underground in speed limit region, when vehicle sails in speed limit region, the velocity amplitude of the real-time sense vehicle of inductive coil, and the toy vehicle velocity value sensed is sent to traffic control center, choose maximum speed value by traffic control center, judge whether to exist in speed limit region the phenomenon that exceeds the speed limit in violation of rules and regulations.This kind test the speed scheme to bury engineering underground comparatively huge, and when (such as: pavement recondition etc.) is changed on the road surface in speed limit region, also comparatively difficult to the maintenance work of coil; It two is: video frequency speed-measuring method.At speed limit region erection camera, the vehicle in speed limit region to be made a video recording continuously, and by the analysis of video image, judge whether to exist in speed limit region violation and to exceed the speed limit phenomenon.This requirement of scheme to camera and analysis software of testing the speed is higher, and is subject to the impact of the factor such as weather, light, reduces precision of analysis.

Summary of the invention

Embodiment of the present invention technical matters to be solved is, provides a kind of traffic speed-measuring method and device, can record the maximum speed value of the vehicle in the scope of testing the speed, and the mode that tests the speed accuracy that is quick and easy, the result that tests the speed is higher.

In order to solve the problems of the technologies described above, embodiments provide a kind of traffic speed-measuring method, comprising:

The echo signal processing of vehicles all in the scope of testing the speed is intermediate-freuqncy signal by traffic speed measuring device in real time;

Described traffic speed measuring device processes described intermediate-freuqncy signal, obtains the frequency spectrum in the default time;

Described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

Wherein, the echo signal processing of vehicles all in the scope of testing the speed is intermediate-freuqncy signal by described traffic speed measuring device in real time, comprising:

Described traffic speed measuring device real time emission radar signal forms the scope that tests the speed, and receive sail into described in the echoed signal that reflects in real time of all vehicles tested the speed in scope;

Each echoed signal received is carried out mixing with corresponding radar signal of launching by described traffic speed measuring device successively, and generate intermediate-freuqncy signal, each intermediate-freuqncy signal includes: in-phase signal I and orthogonal signal Q two paths of signals;

Wherein, the scope that tests the speed described in is scope that the radar signal that described traffic speed measuring device is launched covers.

Wherein, described traffic speed measuring device processes described intermediate-freuqncy signal, obtains the frequency spectrum in the default time, comprising:

Described traffic speed measuring device carries out filter amplifying processing to described intermediate-freuqncy signal;

Described traffic speed measuring device, according to the time of presetting, carries out AD(Analog-to-Digital to the intermediate-freuqncy signal after filter and amplification, modulus) sampling, form the digital medium-frequency signal in the described default time and store;

Described traffic speed measuring device carries out FFT(FastFourierTransformation to the digital medium-frequency signal in the described default time stored, fast Fourier transform), digital medium-frequency signal in the described default time is converted in frequency domain, forms the frequency spectrum in the described default time.

Wherein, after described traffic speed measuring device obtains the frequency spectrum in the described default time, to calculate in time of presetting, described in test the speed in scope before the maximum speed value of all vehicles on the direction of measurement preset, also comprise:

The relevant information of the digital medium-frequency signal that each bar frequency spectrum is corresponding in frequency spectrum in the time of presetting described in described traffic speed measuring device sequential storage;

Wherein, the corresponding digital medium-frequency signal of each frequency spectrum in the frequency spectrum in the described default time; The relevant information of described digital medium-frequency signal comprises: frequency, real part information i, imaginary part information j and amplitude.

Wherein, described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope, comprising:

Described traffic speed measuring device extracts the relevant information of the maximum digital medium-frequency signal of its frequency stored, and judge whether the amplitude of described digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal, if judged result is no, described traffic speed measuring device extracts the relevant information of the maximum digital medium-frequency signal of its frequency stored again, and repeats above-mentioned steps;

If the determination result is YES, described traffic speed measuring device, according to the real part information i of described digital medium-frequency signal and imaginary part information j, determines the direction of motion of the vehicle that described digital medium-frequency signal is corresponding;

If the direction of motion of the described vehicle determined is identical with the direction of measurement preset, described traffic speed measuring device is according to the maximum frequency f of described digital medium-frequency signal _d, according to formula to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope;

If the direction of motion of the described vehicle determined is different from the direction of measurement preset, described traffic speed measuring device extracts the relevant information of the maximum digital medium-frequency signal of its frequency stored again, and repeats above-mentioned steps;

Wherein, when extracting the relevant information of the maximum digital medium-frequency signal of frequency, described traffic speed measuring device correspondence removes the relevant information of the digital medium-frequency signal be extracted in its storage space;

Wherein, when the amplitude of digital medium-frequency signal is positioned at described preset amplitude range, the vehicle tested the speed described in described digital medium-frequency signal corresponds in scope;

Wherein, f ₀for described traffic speed measuring device launches the transmission frequency of radar signal, c ₀for the light velocity, α is the angle that the line between vehicle that described traffic speed measuring device is corresponding with described digital medium-frequency signal is formed in the direction of motion of described vehicle.

Wherein, described traffic speed measuring device, according to the real part information i of described digital medium-frequency signal and imaginary part information j, is determined the direction of motion of the vehicle that described digital medium-frequency signal is corresponding, being comprised:

Described traffic speed measuring device, according to the real part information i of the in-phase signal I of described digital medium-frequency signal and imaginary part information j, calculates the phase information φ obtaining described in-phase signal I according to formula φ=arctan (j/i) ₁;

Described traffic speed measuring device, according to the real part information i of the orthogonal signal Q of described digital medium-frequency signal and imaginary part information j, calculates the phase information φ obtaining described orthogonal signal Q according to formula φ=arctan (j/i) ₂;

Described traffic speed measuring device is according to φ ₁and φ ₂, calculate described in-phase signal I and the phase difference φ of described orthogonal signal Q in same period;

Described traffic speed measuring device, according to the value of Δ φ, is determined the direction of motion of the vehicle that described digital medium-frequency signal is corresponding, being comprised: if the value of Δ φ is positioned at preset phase range, determines that the direction of motion of described vehicle is for close described traffic speed measuring device; If the value of Δ φ exceeds preset phase range, determine that the direction of motion of described vehicle is away from described traffic speed measuring device.

Wherein, described traffic speed measuring device calculated in the described default time, described in test the speed in scope after the maximum speed value of all vehicles on the direction of measurement preset, also comprise:

Described traffic speed measuring device records in time of presetting described at least twice continuously, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope;

Described traffic speed measuring device according to continuous recording maximum speed value, to calculate in time of presetting, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope;

Described traffic speed measuring device exports described final speed value, comprising: described traffic speed measuring device shows described final speed value, and/or described final speed value is uploaded to traffic control center by described traffic speed measuring device.

Correspondingly, the embodiment of the present invention additionally provides a kind of traffic speed measuring device, comprising:

Echo Processing module is intermediate-freuqncy signal for the real-time echo signal processing by vehicles all in the scope of testing the speed;

Signal processing module, processes for the intermediate-freuqncy signal obtained described Echo Processing resume module, obtains the frequency spectrum in the default time;

Speed measuring module, for the frequency spectrum in time of presetting of obtaining according to described signal processing module, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

Wherein, described Echo Processing module comprises:

Transmitter unit, formed for real time emission radar signal and to test the speed scope, described in test the speed scope for the scope that the radar signal that described transmitter unit is launched covers;

Receiving element, for receive sail into described in the echoed signal that reflects in real time of all vehicles tested the speed in scope;

Signal generation unit, the radar signal of launching corresponding to described transmitter unit of each echoed signal for being received by described receiving element carries out mixing, and generate intermediate-freuqncy signal, each intermediate-freuqncy signal includes: in-phase signal I and orthogonal signal Q two paths of signals.

Wherein, described signal processing module comprises:

Filter and amplification unit, for carrying out filter amplifying processing to described intermediate-freuqncy signal;

AD sampling unit, for according to the time of presetting, carries out AD sampling to the intermediate-freuqncy signal after described filter and amplification unit filtering amplifies, forms the digital medium-frequency signal in the described default time;

Storage unit, for storing the digital medium-frequency signal in the described default time of described AD sampling unit acquisition;

FFT unit, for carrying out FFT to the digital medium-frequency signal in the described Preset Time of described cell stores, being converted in frequency domain by the digital medium-frequency signal in the described default time, forming the frequency spectrum in the described default time.

Wherein, described traffic speed measuring device also comprises:

Sequential storage module, for the relevant information of digital medium-frequency signal corresponding to each bar frequency spectrum in the frequency spectrum in time of presetting described in sequential storage;

Wherein, described speed measuring module comprises:

Amplitude judging unit, for extracting the relevant information of the maximum digital medium-frequency signal of frequency from described sequential storage module, and judge whether the amplitude of described digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal, if judged result is no, then the relevant information again extracting the maximum digital medium-frequency signal of frequency from described sequent modular carries out amplitude judgement;

Direction-determining unit, for when the judged result of described amplitude judging unit is for being, according to real part information i and the imaginary part information j of described digital medium-frequency signal, determines the direction of motion of the vehicle that described digital medium-frequency signal is corresponding;

Computing unit, when the direction for the described vehicle determined when described direction-determining unit is identical with the direction of measurement preset, according to the maximum frequency f of described digital medium-frequency signal _d, according to formula to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope;

When the direction of described vehicle of described amplitude judging unit also for determining when described direction-determining unit is different from the direction of measurement preset, the relevant information again extracting the maximum digital medium-frequency signal of frequency from described sequential storage module carries out amplitude judgement;

Wherein, when extracting the relevant information of the maximum digital medium-frequency signal of frequency, described sequential storage module correspondence removes the relevant information of the digital medium-frequency signal be extracted in its storage space;

Wherein, described direction-determining unit comprises:

First computing unit, for real part information i and the imaginary part information j of the in-phase signal I according to described digital medium-frequency signal, calculates the phase information φ obtaining described in-phase signal I according to formula φ=arctan (j/i) ₁;

Second computing unit, for real part information i and the imaginary part information j of the orthogonal signal Q according to described digital medium-frequency signal, calculates the phase information φ obtaining described orthogonal signal Q according to formula φ=arctan (j/i) ₂;

Phase difference calculating unit, for the φ obtained according to described first computing unit ₁with the φ that described second computing unit obtains ₂, calculate described in-phase signal I and the phase difference φ of described orthogonal signal Q in same period;

Determining unit, for the value of Δ φ calculated according to described phase difference calculating unit, determine the direction of motion of the vehicle that described digital medium-frequency signal is corresponding, comprising: if the value of Δ φ is positioned at preset phase range, determine that the direction of motion of described vehicle is for close described traffic speed measuring device; If the value of Δ φ exceeds preset phase range, determine that the direction of motion of described vehicle is away from described traffic speed measuring device.

Wherein, described traffic speed measuring device also comprises:

Logging modle, for record continuously in the time of presetting that speed measuring module described at least twice records, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope;

Speed calculation module, for according to the continuous recording maximum speed value of described logging modle, to calculate in time of presetting, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope;

Output module, for exporting the final speed value that described speed calculation module calculates;

The way of output of described output module comprises: show described final speed value, and/or, described final speed value is uploaded to traffic control center.

Implement the embodiment of the present invention, there is following beneficial effect:

The embodiment of the present invention is processed by the echoed signal of traffic speed measuring device to vehicles all in the scope of testing the speed and is calculated, record the maximum speed value of all vehicles in the scope of testing the speed, its mode that tests the speed is quick and easy, and only needing the region (as speed limit region) of testing the speed at needs to install traffic speed measuring device can realize; Preferably, traffic speed measuring device forms by launching radar signal the scope that tests the speed, and because radar signal is comparatively stable, be not subject to the impact of the factor such as weather, light, its echoed signal is also comparatively stable, and the result precision recorded thus is higher.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is the structural representation of the first embodiment of traffic speed measuring device of the present invention;

Fig. 2 is the structural representation of the second embodiment of traffic speed measuring device of the present invention;

Fig. 3 is the structural representation of the embodiment of Echo Processing module of the present invention;

Fig. 4 is the schematic diagram of the installation embodiment of radar sensor of the present invention;

Fig. 5 is the structural representation of the embodiment of signal processing module of the present invention;

Fig. 6 is the structural representation of the embodiment of speed measuring module of the present invention;

Fig. 7 is the structural representation of the embodiment of the direction-determining unit shown in Fig. 6;

Fig. 8 is the process flow diagram of the first embodiment of traffic speed-measuring method of the present invention;

Fig. 9 is the particular flow sheet of the step S101 shown in Fig. 8;

Figure 10 is the particular flow sheet of the step S102 shown in Fig. 8;

Figure 11 is the particular flow sheet of the step S103 shown in Fig. 8;

Figure 12 is the process flow diagram of the second embodiment of traffic speed-measuring method of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

Referring to Fig. 1, is the structural representation of the first embodiment of traffic speed measuring device of the present invention; Described traffic speed measuring device comprises:

Echo Processing module 10 is intermediate-freuqncy signal for the real-time echo signal processing by vehicles all in the scope of testing the speed.

Described Echo Processing module 10 is preferably a radar sensor, and this radar sensor sends radar signal in real time, and the scope that this radar signal covers forms the scope that tests the speed, and the vehicle sailing this scope that tests the speed into needs to accept velocity measuring.Sail into when testing the speed scope when there being vehicle, this radar sensor receives the echoed signal of sailing these all vehicles reflections in scope of testing the speed into, and each echoed signal is treated to intermediate-freuqncy signal successively.It should be noted that, due to radar sensor real time emission radar signal, when only there being a vehicle to sail in the scope of testing the speed, the echoed signal of this this vehicle multiple reflections of radar sensor real-time reception, and be treated to intermediate-freuqncy signal successively; When sailing many vehicles in the scope of testing the speed into, the echoed signal of these many vehicles difference multiple reflections of this radar sensor real-time reception, and be treated to intermediate-freuqncy signal successively.Be understandable that, described Echo Processing module 10 can also be infrared sensor, now needs to consider that the factor such as illumination, weather is on ultrared impact; Described Echo Processing module 10 can also be laser sensor, now needs to consider cost factor; Described Echo Processing module 10 can also be other similar devices, can similar analysis in above-mentioned various situation, is not repeated herein.

Signal processing module 20, processes for processing to described Echo Processing module 10 intermediate-freuqncy signal obtained, and obtains the frequency spectrum in the default time.

Described signal processing module 20 can adopt high-speed dsp (DigitalSignalProcessor, digital signal processing device) chip, and this high-speed dsp chip can carry out the process such as AD sampling, FFT to the intermediate-freuqncy signal that described Echo Processing module 10 obtains.It should be noted that, high-speed dsp chip carries out AD sampling according to the time of presetting to intermediate-freuqncy signal, the described default time can be set according to actual needs by user, such as: the time needed for traffic speed measuring device one secondary response sets, or the time needed for traffic control centre management sets, etc., and the process preset is same as the prior art, is not repeated herein.

Speed measuring module 30, for the frequency spectrum in time of presetting of obtaining according to described signal processing module 20, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

Described default direction of measurement comprises: near the direction of traffic speed measuring device or the direction away from traffic speed measuring device, in order to ensure the accuracy of measuring, the traffic speed measuring device of the embodiment of the present invention carries out unidirectional testing the speed to the vehicle in the scope of testing the speed, certainly, in order to ensure traffic administration dynamics, in traffic speed limit region, can install the traffic speed measuring device of the embodiment of the present invention respectively in the position of different directions, then can realize two-way range rate measurement, the situation of two-way range rate measurement can similar analysis.Described signal processing module 20 processes each a frequency spectrum i.e. corresponding intermediate-freuqncy signal in the frequency spectrum in the time of presetting of acquisition, described speed measuring module 30 according to the exchangeable formulas of frequency and speed, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.In specific implementation, described speed measuring module 30 also can adopt high-speed dsp chip, completes by this dsp chip the process of testing the speed.In practical application, described signal processing module 20 and described speed measuring module 30 can merge into same module, and the module of this merging can directly adopt high-speed dsp chip, realize sampling to the AD of intermediate-freuqncy signal, FFT and the process such as to test the speed.

Referring to Fig. 2, is the structural representation of the second embodiment of traffic speed measuring device of the present invention; Identical with a upper embodiment, described traffic speed measuring device comprises: Echo Processing module 10, signal processing module 20 and speed measuring module 30.In the present embodiment, described traffic speed measuring device also comprises:

Sequential storage module 40, for the relevant information of digital medium-frequency signal corresponding to each bar frequency spectrum in the frequency spectrum in time of presetting described in sequential storage.

After a series of process such as the 20 pairs of intermediate-freuqncy signal AD samplings of described signal processing module and FFT, obtain the frequency spectrum in time of presetting, the all corresponding digital medium-frequency signal of every bar frequency spectrum in this frequency spectrum, each digital medium-frequency signal includes real part information i and imaginary part information j; Every bar frequency spectrum peak on the vertical scale represents the amplitude of digital medium-frequency signal corresponding to this frequency spectrum, and this amplitude also can be calculated by real part information i and imaginary part information j; The point that every bar frequency spectrum is corresponding on the horizontal scale represents the frequency values of digital medium-frequency signal corresponding to this frequency spectrum; Described sequential storage module 40, according to the distributing order of each bar frequency spectrum on the frequency spectrum in the time of presetting, stores the relevant information of digital medium-frequency signal corresponding to each bar frequency spectrum successively, comprising: frequency, real part information i, imaginary part information j and amplitude.

Logging modle 50, for record continuously in the time of presetting that speed measuring module 30 described at least twice records, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

In specific implementation, such as: in described logging modle 50 time of presetting that continuously record three described speed measuring modules 30 record, described in test the speed the maximum speed value ν of all vehicles on the direction of measurement preset in scope ₁, ν ₂, ν ₃.

Speed calculation module 60, for according to the continuous recording maximum speed value of described logging modle 50, to calculate in time of presetting, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope.

According to above-mentioned example, described speed calculation module 60 pre-sets an empirical value scope (as: ± 10 kilometers/time), and this empirical value obtains according to practical experience, for judging whether the maximum speed value that speed measuring module 30 records is stablized, and whether undergos mutation.First described speed calculation module 60 calculates ν ₁with ν ₂difference, whether the difference of both judgements within this empirical value scope, if within this empirical value scope, then represent that the maximum speed value that described speed measuring module 30 records is comparatively stable, described speed calculation module 60 calculates ν ₁with ν ₂mean value, this mean value then in the described default time, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope; If ν ₁with ν ₂difference exceed empirical value scope, described speed calculation module 60 calculates ν again ₁with ν ₃difference, whether the difference of both judgements within the scope of this empirical value, if within the scope of this empirical value, described speed calculation module 60 calculates ν ₁with ν ₃mean value, this mean value then in the described default time, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope; If ν ₁with ν ₃difference exceed empirical value scope, described speed calculation module 60 calculates ν again ₂with ν ₃difference, whether the difference of both judgements within the scope of this empirical value, if within the scope of this empirical value, described speed calculation module 60 calculates ν ₂with ν ₃mean value, this mean value then in the described default time, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope; If ν ₂with ν ₃difference exceed empirical value scope, described speed calculation module 60 judges that the maximum speed value that described speed measuring module 30 records is undergone mutation, stable not, data are not accurate enough, then described speed calculation module 60 to determine in time of presetting, described in the final speed value of all vehicles on the direction of measurement preset in scope that test the speed be 0.

In specific implementation, described speed calculation module 60 is by performing one section of program code to realize above-mentioned velocity computation process, and code is as follows:

It should be noted that, above-mentioned velocity computation process is only citing, and when described logging modle 50 records multiple maximum speed value, the velocity computation process of described speed calculation module 60 can similar analysis, is not repeated herein.

Output module 70, for exporting the final speed value that described speed calculation module 60 calculates.

The way of output of described output module 70 comprises: show described final speed value, and/or, described final speed value is uploaded to traffic control center.When described speed calculation module 60 to calculate in the default time, described in test the speed final speed value on the direction of measurement preset of all vehicles in scope time, this final speed value can show by described output module 70, particularly, described output module 70 is by RS-232 or RS-422 communication interface, show on the warning sign in the speed limit region residing for final speed value transmit to traffic speed measuring device, with the speed of reminding driver to note vehicle; In addition, described output module 70 also by GPRS(GeneralPacketRadioService, general packet radio service technology) etc. wireless mode this final speed value is uploaded to traffic control center, facilitate the traffic administration at traffic control center.

In order to be illustrated more clearly in the present invention, describe in detail to each module in traffic speed measuring device of the present invention below.

Referring to Fig. 3, is the structural representation of the embodiment of Echo Processing module of the present invention; Described Echo Processing module 10 comprises:

Transmitter unit 101, formed for real time emission radar signal and to test the speed scope, described in test the speed scope for the scope that the radar signal that described transmitter unit 101 is launched covers.

Receiving element 102, for receive sail into described in the echoed signal that reflects in real time of all vehicles tested the speed in scope.

Signal generation unit 03, the radar signal of launching corresponding to described transmitter unit 101 of each echoed signal for being received by described receiving element 102 carries out mixing, generates intermediate-freuqncy signal.

Each intermediate-freuqncy signal includes: in-phase signal I and orthogonal signal Q two paths of signals.In specific implementation, described transmitter unit 101, receiving element 102 and signal generation unit 103 can merge into same unit, this unit can be a radar sensor, preferably, this radar sensor is planar microstrip radar sensor, adopt the transmission frequency of 24GHz to launch radar signal, form the scope that tests the speed; Receive the echoed signal that all vehicles tested the speed in scope reflect in real time, echoed signal and the mixing that transmits are generated the intermediate-freuqncy signal comprising I, Q two paths of signals.In practical application, described radar sensor can be installed in the region (as: traffic speed limit region) needing to carry out velocity measuring, specifically refers to Fig. 4, is the schematic diagram of the installation embodiment of radar sensor of the present invention; In traffic speed limit region, radar sensor is installed on the position of high about 2m, the horizontal range that the radar signal that radar sensor is launched covers can reach 100m, and the vehicle sailed within the scope of this 100m then accepts velocity measuring.Be understandable that, the installation process of Fig. 4 is only citing, and the scope of the setting height(from bottom) of its radar sensor, position, horizontal range that radar signal arrives and covering all can set according to actual needs, can similar analysis in other situations, is not repeated herein.

Referring to Fig. 5, is the structural representation of the embodiment of signal processing module of the present invention; Described signal processing module 20 comprises:

Filter and amplification unit 201, for carrying out filter amplifying processing to described intermediate-freuqncy signal.

Described filter and amplification unit 201 can be a low-pass filtering amplifying circuit, and it processes to described Echo Processing module 10 all intermediate-freuqncy signals obtained and carries out filter amplifying processing respectively, with undesired signals such as filtering noises.

AD sampling unit 202, for according to the time of presetting, carries out AD sampling to all intermediate-freuqncy signals after described filter and amplification unit 201 filter and amplification, forms the digital medium-frequency signal in the described default time.

In specific implementation, described AD sampling unit 202 adopts the time of presetting to carry out AD sampling to all intermediate-freuqncy signals, forms the digital medium-frequency signal in the described default time.The described default time, can be set according to actual needs by user, such as: the time needed for traffic speed measuring device one secondary response sets, or the time needed for traffic control centre management sets, etc., and the process preset is same as the prior art, is not repeated herein.Be understandable that, after the time of presetting is determined, that samples as required counts, then can determine the sample frequency that AD samples.

Storage unit 203, for storing the digital medium-frequency signal in the described default time of described AD sampling unit 202 acquisition.In specific implementation, described storage unit 203 can be the built-in storer of described traffic speed measuring device.

FFT unit 204, carries out FFT for the digital medium-frequency signal in the described Preset Time to described storage unit 203 storage, is converted in frequency domain, forms the frequency spectrum in the described default time by the digital medium-frequency signal in the described default time.

Digital medium-frequency signal in the described default time that described storage unit 203 stores by DMA(DirectMemoryAccess, direct memory access) be passed in FFT unit 204 and process.Digital medium-frequency signal in the described default time is after described FFT unit 204 converts, obtain the frequency spectrum in time of presetting, the all corresponding digital medium-frequency signal of every bar frequency spectrum in this frequency spectrum, each digital medium-frequency signal includes real part information i and imaginary part information j; Every bar frequency spectrum peak on the vertical scale represents the amplitude of digital medium-frequency signal corresponding to this frequency spectrum, and this amplitude also can be calculated by real part information i and imaginary part information j; The point that every bar frequency spectrum is corresponding on the horizontal scale represents the frequency values of digital medium-frequency signal corresponding to this frequency spectrum.

Referring to Fig. 6, is the structural representation of the embodiment of speed measuring module of the present invention; Described speed measuring module 30 comprises:

Amplitude judging unit 301, for extracting the relevant information of the maximum digital medium-frequency signal of frequency from described sequential storage module 40, and judge whether the amplitude of described digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal, if judged result is no, then the relevant information again extracting the maximum digital medium-frequency signal of frequency from described sequent modular 40 carries out amplitude judgement.

Due to other objects of the people or motion that also may there is walking in the scope of testing the speed, these people or object also can produce corresponding echoed signal and be treated to corresponding intermediate-freuqncy signal by described Echo Processing module 10, and this intermediate-freuqncy signal belongs to invalid signals, should filtering.This intermediate-freuqncy signal obtains corresponding frequency spectrum in the frequency spectrum in the described default time through described signal processing module 20 process, the amplitude of the digital medium-frequency signal that this frequency spectrum is corresponding is stored in described sequential storage module 40, because this intermediate-freuqncy signal is invalid signals, therefore the amplitude of this intermediate-freuqncy signal should not meet the amplitude range of effective intermediate-freuqncy signal, described amplitude judging unit 301 extracts the relevant information of the maximum digital medium-frequency signal of frequency from sequential storage module 40, and judge whether the amplitude of this digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal, if judged result is no, then shows that this digital medium-frequency signal extracted is invalid signals, need filtering, need the relevant information again extracting the maximum digital medium-frequency signal of new frequency from sequential storage module 40 to carry out amplitude judgement simultaneously, if the determination result is YES, then show that this digital medium-frequency signal extracted is useful signal, can subsequent operation be carried out.It should be noted that, because sequential storage module 40 pairs of digital medium-frequency signals are sequential storage, therefore described amplitude judging unit 301 is when carrying out amplitude and judging, directly can judge whether the amplitude of described digital medium-frequency signal is greater than the amplitude of its last digit intermediate-freuqncy signal and the amplitude of a digital medium-frequency signal thereafter.In addition, described amplitude range carries out preset according to actual needs, and particularly, can arrange according to the distance of the vehicle in the scope of testing the speed and described traffic speed measuring device, this setting up procedure is same as the prior art, is not repeated herein.

It should be noted that, when described amplitude judging unit 301 extracts the relevant information of the maximum digital medium-frequency signal of frequency, described sequential storage module 40 correspondence removes the relevant information of the digital medium-frequency signal be extracted in its storage space, to facilitate the extraction of the relevant information of the follow-up digital medium-frequency signal maximum to new frequency.Wherein, when the frequency amplitude of digital medium-frequency signal is positioned at described preset amplitude range, the vehicle tested the speed described in described digital medium-frequency signal corresponds in scope, shows that this digital medium-frequency signal is the useful signal that certain vehicle movement tested the speed in scope in default time produces.

Direction-determining unit 302, for when the judged result of described amplitude judging unit 301 is for being, extracts f from described sequential storage module 40 _dthe real part information i of corresponding digital medium-frequency signal and imaginary part information j, determines f _dthe direction of motion of the vehicle that corresponding digital medium-frequency signal is corresponding.

In specific implementation, please also refer to Fig. 7, it is the structural representation of the embodiment of the direction-determining unit shown in Fig. 6; Described direction-determining unit 302 comprises:

First computing unit 211, for real part information i and the imaginary part information j of the in-phase signal I according to described digital medium-frequency signal, calculates the phase information φ obtaining described in-phase signal I according to formula φ=arctan (j/i) ₁.Wherein, φ ₁phase range be-pi/2 to+pi/2 between.

Second computing unit 212, for real part information i and the imaginary part information j of the orthogonal signal Q according to described digital medium-frequency signal, calculates the phase information φ obtaining described orthogonal signal Q according to formula φ=arctan (j/i) ₂.Wherein, φ ₂phase range be-pi/2 to+pi/2 between.

Phase difference calculating unit 213, for the φ obtained according to described first computing unit 211 ₁with the φ that described second computing unit 212 obtains ₂, calculate described in-phase signal I and the phase difference φ of described orthogonal signal Q in same period.

First, described phase difference calculating unit 213 is by φ ₁and φ ₂be converted in same period, detailed process is as follows: (1) is if φ ₁be greater than 0, the imaginary values of in-phase signal I is less than 0, then by φ ₁do and subtract π process; (2) if φ ₁be greater than 0, the imaginary values of in-phase signal I is greater than 0, then by φ ₁do and add π process; (3) if φ ₂be greater than 0, the imaginary values of orthogonal signal Q is less than 0, then by φ ₂do and subtract π process; (4) if φ ₂be greater than 0, the imaginary values of orthogonal signal Q is 0, then by φ ₂do and add π process.Secondly, described phase difference calculating unit 213 calculates the φ in same period ₁and φ ₂difference, and the difference of the two added 2 π obtain Δ φ, remain Δ φ on the occasion of.Described phase difference calculating unit 213 can by performing follow procedure codes implement phase difference calculating, and code is as follows:

Determining unit 214, for the value of Δ φ calculated according to described phase difference calculating unit 213, determine the direction of motion of the vehicle that described digital medium-frequency signal is corresponding, comprise: if the value of Δ φ is positioned at preset phase range, determine that the direction of motion of described vehicle is for close described traffic speed measuring device; If the value of Δ φ exceeds preset phase range, determine that the direction of motion of described vehicle is away from described traffic speed measuring device.It should be noted that, described preset phase range can set according to actual needs, is not repeated herein.

Refer to Fig. 6 again, described speed measuring module 30 also comprises:

Computing unit 303, for when the direction of the described vehicle that described direction-determining unit 302 is determined is identical with the direction of measurement preset, according to the maximum frequency f of described digital medium-frequency signal _d, according to formula to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

Wherein, f ₀for described traffic speed measuring device launches the transmission frequency of radar signal, c ₀for the light velocity, α is the angle that the line between vehicle that described traffic speed measuring device is corresponding with described digital medium-frequency signal is formed in the direction of motion of described vehicle.As in the aforementioned embodiment of the present invention, f ₀for 24GHz, α are about 0(installation embodiment shown in Figure 4), described computing unit 304 is by frequency-rate conversion formula can to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

Described amplitude judging unit 301 is also for when the direction of the described vehicle that described direction-determining unit 302 is determined is different from the direction of measurement preset, and the relevant information again extracting the maximum digital medium-frequency signal of frequency from described sequential storage module 40 carries out amplitude judgement.

As aforementioned, the traffic speed measuring device of the embodiment of the present invention only carries out unidirectional testing the speed, therefore when the direction of the described vehicle that described direction-determining unit 302 is determined is different from the direction of measurement preset, described amplitude judging unit 301 needs the relevant information again extracting the maximum digital medium-frequency signal of frequency from described sequential storage module 40, re-starts subsequent treatment.Be understandable that, through above-mentioned process, when the amplitude of all digital medium-frequency signals that described sequential storage module 40 stores all does not meet the requirement that amplitude judges, in this described default time recorded, described in the maximum speed value of all vehicles on the direction of measurement preset in scope that test the speed be 0; When the direction of motion of vehicle corresponding to all digital medium-frequency signals that described sequential storage module 40 stores all meets the direction of measurement preset, in this described default time recorded, described in the maximum speed value of all vehicles on the direction of measurement preset in scope that test the speed also be 0.

In order to be illustrated more clearly in the present invention, will describe in detail to traffic speed-measuring method of the present invention below.

Referring to Fig. 8, is the process flow diagram of the first embodiment of traffic speed-measuring method of the present invention; Described method comprises:

S101, the echo signal processing of vehicles all in the scope of testing the speed is intermediate-freuqncy signal by traffic speed measuring device in real time.

Please also refer to Fig. 9, it is the particular flow sheet of the step S101 shown in Fig. 8; Described step S101 comprises:

S11, described traffic speed measuring device real time emission radar signal forms the scope that tests the speed, and receive sail into described in the echoed signal that reflects in real time of all vehicles tested the speed in scope.

In specific implementation, described in test the speed scope for scope that the radar signal that described traffic speed measuring device is launched covers.

S12, each echoed signal received is carried out mixing with corresponding radar signal of launching by described traffic speed measuring device successively, generates intermediate-freuqncy signal.

Each intermediate-freuqncy signal includes: in-phase signal I and orthogonal signal Q two paths of signals.In specific implementation, described S11 and S12 all can adopt radar sensor, and preferably, this radar sensor is planar microstrip radar sensor, adopts the transmission frequency of 24GHz to launch radar signal, forms the scope that tests the speed; Receive the echoed signal that all vehicles tested the speed in scope reflect in real time, echoed signal and the mixing that transmits are generated the intermediate-freuqncy signal comprising I, Q two paths of signals.In practical application, described radar sensor can be installed in the region (as: traffic speed limit region) needing to carry out velocity measuring, specifically refer to Fig. 4, in traffic speed limit region, radar sensor is installed on the position of high about 2m, the horizontal range that the radar signal that radar sensor is launched covers can reach 100m, and the vehicle sailed within the scope of this 100m then accepts velocity measuring.Be understandable that, the installation process of Fig. 4 is only citing, and the scope of the setting height(from bottom) of its radar sensor, position, horizontal range that radar signal arrives and covering all can set according to actual needs, can similar analysis in other situations, is not repeated herein.

S102, described traffic speed measuring device processes described intermediate-freuqncy signal, obtains the frequency spectrum in the default time.

Described S102 can adopt high-speed dsp chip, and the intermediate-freuqncy signal that this high-speed dsp chip can obtain described S101 carries out the process such as AD sampling, FFT.Please also refer to Figure 10, it is the particular flow sheet of the step S102 shown in Fig. 8; Described step S102 comprises:

S21, described traffic speed measuring device carries out filter amplifying processing to described intermediate-freuqncy signal.

Described S21 can adopt a low-pass filtering amplifying circuit, and it carries out filter amplifying processing, with undesired signals such as filtering noises respectively to all intermediate-freuqncy signals that described S101 process obtains.

S22, described traffic speed measuring device, according to the time of presetting, carries out AD sampling to the intermediate-freuqncy signal after filter and amplification, forms the digital medium-frequency signal in the described default time and store.

In specific implementation, described S22 adopts the time of presetting to carry out AD sampling to all intermediate-freuqncy signals, forms the digital medium-frequency signal in the described default time and stores.The described default time, can be set according to actual needs by user, such as: the time needed for traffic speed measuring device one secondary response sets, or the time needed for traffic control centre management sets, etc., and the process preset is same as the prior art, is not repeated herein.Digital medium-frequency signal in the described default time can be stored in the built-in storer of described traffic speed measuring device by described S22.Be understandable that, after the time of presetting is determined, that samples as required counts, then can determine the sample frequency that AD samples.

S23, described traffic speed measuring device carries out FFT to the digital medium-frequency signal in the described default time stored, and is converted in frequency domain, forms the frequency spectrum in the described default time by the digital medium-frequency signal in the described default time.

Digital medium-frequency signal in the described default time that described S22 stores is passed to described S23 process by DMA.Digital medium-frequency signal in the described default time carries out after FFT conversion through described S23, obtain the frequency spectrum in time of presetting, the all corresponding digital medium-frequency signal of every bar frequency spectrum in this frequency spectrum, each digital medium-frequency signal includes real part information i and imaginary part information j; Every bar frequency spectrum peak on the vertical scale represents the amplitude of digital medium-frequency signal corresponding to this frequency spectrum, and this amplitude also can be calculated by real part information i and imaginary part information j; The point that every bar frequency spectrum is corresponding on the horizontal scale represents the frequency values of digital medium-frequency signal corresponding to this frequency spectrum.

S103, described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

In specific implementation, described S103 also can adopt high-speed dsp chip, completes by this dsp chip the computation process that tests the speed.Please also refer to Figure 11, it is the particular flow sheet of the step S103 shown in Fig. 8; Described step S103 comprises:

S31, described traffic speed measuring device extracts the relevant information of the maximum digital medium-frequency signal of its frequency stored.The relevant information of described digital medium-frequency signal comprises: comprising: frequency, real part information i, imaginary part information j and amplitude.

S32, described traffic speed measuring device judges whether the amplitude of described digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal, if the determination result is YES, proceeds to S33; Otherwise, proceed to S31.

Due to other objects of the people or motion that also may there is walking in the scope of testing the speed, these people or object also can produce corresponding echoed signal and be treated to corresponding intermediate-freuqncy signal by described S101, and this intermediate-freuqncy signal belongs to invalid signals, should filtering.This intermediate-freuqncy signal obtains corresponding frequency spectrum in the frequency spectrum in the described default time through described S102 process, the amplitude of the digital medium-frequency signal that this frequency spectrum is corresponding is stored in described traffic speed measuring device, because this intermediate-freuqncy signal is invalid signals, therefore the amplitude of this intermediate-freuqncy signal should not meet the amplitude range of effective intermediate-freuqncy signal, after described S31 extracts the relevant information of the maximum digital medium-frequency signal of frequency, described S32 then judges whether the amplitude of this digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal, if judged result is no, then shows that this digital medium-frequency signal extracted is invalid signals, need filtering, need the relevant information again extracting the maximum digital medium-frequency signal of new frequency to carry out amplitude judgement simultaneously, therefore proceed to S31, if the determination result is YES, then show that this digital medium-frequency signal extracted is useful signal, can subsequent operation be carried out, therefore proceed to S33.It should be noted that, because described traffic speed measuring device is sequential storage to digital medium-frequency signal, therefore described S32 is when carrying out amplitude and judging, directly can judge whether the amplitude of described digital medium-frequency signal is greater than the amplitude of its last digit intermediate-freuqncy signal and the amplitude of a digital medium-frequency signal thereafter.In addition, described amplitude range carries out preset according to actual needs, and particularly, can arrange according to the distance of the vehicle in the scope of testing the speed and described traffic speed measuring device, this setting up procedure is same as the prior art, is not repeated herein.

It should be noted that, when described S31 extracts the relevant information of the maximum digital medium-frequency signal of frequency, described traffic speed measuring device is the corresponding relevant information removing the digital medium-frequency signal be extracted in its storage space then, to facilitate the extraction of the relevant information of the follow-up digital medium-frequency signal maximum to new frequency.Wherein, when the frequency amplitude of digital medium-frequency signal is positioned at described preset amplitude range, the vehicle tested the speed described in described digital medium-frequency signal corresponds in scope, shows that this digital medium-frequency signal is the useful signal that certain vehicle movement tested the speed in scope in default time produces.When described S32 judges that the amplitude of all digital medium-frequency signals that described traffic speed measuring device stores all does not meet the requirement that amplitude judges, in this described default time recorded, described in the maximum speed value of all vehicles on the direction of measurement preset in scope that test the speed be 0.

S33, described traffic speed measuring device, according to the real part information i of described digital medium-frequency signal and imaginary part information j, determines the direction of motion of the vehicle that described digital medium-frequency signal is corresponding.

In specific implementation, described S32 specifically comprises the steps:

A1, described traffic speed measuring device, according to the real part information i of the in-phase signal I of described digital medium-frequency signal and imaginary part information j, calculate the phase information φ obtaining described in-phase signal I according to formula φ=arctan (j/i) ₁.Wherein, φ ₁phase range be-pi/2 to+pi/2 between.

A2, described traffic speed measuring device, according to the real part information i of the orthogonal signal Q of described digital medium-frequency signal and imaginary part information j, calculate the phase information φ obtaining described orthogonal signal Q according to formula φ=arctan (j/i) ₂.Wherein, φ ₂phase range be-pi/2 to+pi/2 between.

A3, described traffic speed measuring device are according to φ ₁and φ ₂, calculate described in-phase signal I and the phase difference φ of described orthogonal signal Q in same period.

In this step, described traffic speed measuring device is by φ ₁and φ ₂be converted in same period, detailed process is as follows: (1) is if φ ₁be greater than 0, the imaginary values of in-phase signal I is less than 0, then by φ ₁do and subtract π process; (2) if φ ₁be greater than 0, the imaginary values of in-phase signal I is greater than 0, then by φ ₁do and add π process; (3) if φ ₂be greater than 0, the imaginary values of orthogonal signal Q is less than 0, then by φ ₂do and subtract π process; (4) if φ ₂be greater than 0, the imaginary values of orthogonal signal Q is 0, then by φ ₂do and add π process.Secondly, described traffic speed measuring device calculates the φ in same period ₁and φ ₂difference, and the difference of the two added 2 π obtain Δ φ, remain Δ φ on the occasion of.In specific implementation, described traffic speed measuring device is by performing follow procedure codes implement phase difference calculating, and code is as follows:

A4, described traffic speed measuring device, according to the value of Δ φ, are determined the direction of motion of the vehicle that described digital medium-frequency signal is corresponding, being comprised: if the value of Δ φ is positioned at preset phase range, then determine that the direction of motion of described vehicle is for close described traffic speed measuring device; If the value of Δ φ exceeds preset phase range, then determine that the direction of motion of described vehicle is away from described traffic speed measuring device.

S34, described traffic speed measuring device judges that whether the direction of motion of described vehicle is identical with the direction of measurement preset, and if the determination result is YES, proceeds to S34; Otherwise, proceed to S31.

Be understandable that, when described S34 judges that the direction of motion of the vehicle that all digital medium-frequency signals that described traffic speed measuring device stores are corresponding all meets the direction of measurement preset, in this described default time recorded, described in the maximum speed value of all vehicles on the direction of measurement preset in scope that test the speed also be 0.

S35, described traffic speed measuring device is according to the maximum frequency f of described digital medium-frequency signal _d, according to formula to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

Wherein, f ₀for described traffic speed measuring device launches the transmission frequency of radar signal, c ₀for the light velocity, α is the angle that the line between vehicle that described traffic speed measuring device is corresponding with described digital medium-frequency signal is formed in the direction of motion of described vehicle.As in the aforementioned embodiment of the present invention, f ₀for 24GHz, α are about 0(installation embodiment shown in Figure 4), described S35 is by frequency-rate conversion formula can to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

Refer to Figure 12, be the process flow diagram of the second embodiment of traffic speed-measuring method of the present invention, described method comprises:

S201, the echo signal processing of vehicles all in the scope of testing the speed is intermediate-freuqncy signal by traffic speed measuring device in real time.

S202, described traffic speed measuring device processes described intermediate-freuqncy signal, obtains the frequency spectrum in the default time.

In the present embodiment, described S201-S202 is identical with the S101-S102 step in a upper embodiment, is not repeated herein.

S203, the relevant information of the digital medium-frequency signal that each bar frequency spectrum is corresponding in the frequency spectrum in the time of presetting described in described traffic speed measuring device sequential storage.

Through described S202 to after a series of process such as intermediate-freuqncy signal AD sampling and FFT, obtain the frequency spectrum in time of presetting, the all corresponding digital medium-frequency signal of every bar frequency spectrum in this frequency spectrum, each digital medium-frequency signal includes real part information i and imaginary part information j; Every bar frequency spectrum peak on the vertical scale represents the amplitude of digital medium-frequency signal corresponding to this frequency spectrum, and this amplitude also can be calculated by real part information i and imaginary part information j; The point that every bar frequency spectrum is corresponding on the horizontal scale represents the frequency values of digital medium-frequency signal corresponding to this frequency spectrum; Described S203, according to the distributing order of each bar frequency spectrum on the frequency spectrum in the time of presetting, stores the relevant information of digital medium-frequency signal corresponding to each bar frequency spectrum successively, comprising: frequency, real part information i, imaginary part information j and amplitude.

S204, described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

In the present embodiment, described S204 is identical with the S103 step of a upper embodiment, is not repeated herein.

S205, described traffic speed measuring device records in time of presetting described at least twice continuously, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope.

In specific implementation, such as: described S205 records in time of presetting that three described S204 record continuously, described in test the speed the maximum speed value ν of all vehicles on the direction of measurement preset in scope ₁, ν ₂, ν ₃.

S206, described traffic speed measuring device according to continuous recording maximum speed value, to calculate in time of presetting, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope.

According to above-mentioned example, described S206 pre-sets an empirical value scope (as: ± 10 kilometers/time), and this empirical value obtains according to practical experience, for judging whether the maximum speed value that S204 records is stablized, and whether undergos mutation.First described S206 calculates ν ₁with ν ₂difference, whether the difference of both judgements within this empirical value scope, if within this empirical value scope, then represent that the maximum speed value that described S204 records is comparatively stable, described S206 calculates ν ₁with ν ₂mean value, this mean value then in the described default time, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope; If ν ₁with ν ₂difference exceed empirical value scope, described S206 calculates ν again ₁with ν ₃difference, whether the difference of both judgements within the scope of this empirical value, if within the scope of this empirical value, described S206 calculates ν ₁with ν ₃mean value, this mean value then in the described default time, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope; If ν ₁with ν ₃difference exceed empirical value scope, described S206 calculates ν again ₂with ν ₃difference, whether the difference of both judgements within the scope of this empirical value, if within the scope of this empirical value, described S206 calculates ν ₂with ν ₃mean value, this mean value then in the described default time, described in test the speed the final speed value of all vehicles on the direction of measurement preset in scope; If ν ₂with ν ₃difference exceed empirical value scope, described S206 judges that the maximum speed value that described S204 records is undergone mutation, stable not, data are not accurate enough, then described S206 to determine in time of presetting, described in the final speed value of all vehicles on the direction of measurement preset in scope that test the speed be 0.In specific implementation, described S206 is by performing one section of program code to realize above-mentioned velocity computation process, and code is as follows:

It should be noted that, above-mentioned velocity computation process is only citing, and when described S205 records multiple maximum speed value, the velocity computation process of described S206 can similar analysis, is not repeated herein.

S207, described traffic speed measuring device exports described final speed value.

The way of output of described S207 comprises: show described final speed value, and/or, described final speed value is uploaded to traffic control center.When described S206 to calculate in the default time, described in test the speed final speed value on the direction of measurement preset of all vehicles in scope time, this final speed value can show by described S207, particularly, described S208 is by RS-232 or RS-422 communication interface, show on the warning sign in the speed limit region residing for final speed value transmit to traffic speed measuring device, with the speed of reminding driver to note vehicle; In addition, this final speed value is also uploaded to traffic control center by wireless modes such as GPRS by described S207, facilitates the traffic administration at traffic control center.

Above disclosedly be only present pre-ferred embodiments, certainly the interest field of the present invention can not be limited with this, one of ordinary skill in the art will appreciate that all or part of flow process realizing above-described embodiment, and according to the equivalent variations that the claims in the present invention are done, still belong to the scope that invention is contained.

Claims

1. a traffic speed-measuring method, is characterized in that, comprising:

The relevant information of the digital medium-frequency signal that each bar frequency spectrum is corresponding in frequency spectrum in the time of presetting described in described traffic speed measuring device sequential storage, wherein, the corresponding digital medium-frequency signal of each frequency spectrum in frequency spectrum in the described default time, the relevant information of described digital medium-frequency signal comprises: frequency, real part information i, imaginary part information j and amplitude;

Described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope;

Wherein, described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in the maximum speed value of all vehicles on the direction of measurement preset in scope that test the speed comprise:

The relevant information of the digital medium-frequency signal that the digital medium-frequency signal medium frequency that the frequency spectrum in the described traffic speed measuring device extraction described default time is corresponding is maximum, and judge whether the amplitude of the digital medium-frequency signal of described extraction is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal, if judged result is no, then show that this digital medium-frequency signal extracted is invalid signals, the described digital medium-frequency signal extracted described in filtering, repeat this step, if the determination result is YES, described traffic speed measuring device is according to the real part information i of described digital medium-frequency signal and imaginary part information j, determine the direction of motion of the vehicle that described digital medium-frequency signal is corresponding, if the direction of motion of the described vehicle determined is identical with the direction of measurement preset, described traffic speed measuring device is according to the maximum frequency f of described digital medium-frequency signal _d, according to formula to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope, wherein, f ₀for described traffic speed measuring device launches the transmission frequency of radar signal, c ₀for the light velocity, α is the angle that the line between vehicle that described traffic speed measuring device is corresponding with described digital medium-frequency signal is formed in the direction of motion of described vehicle,

2. the method for claim 1, is characterized in that, the echo signal processing of vehicles all in the scope of testing the speed is intermediate-freuqncy signal by described traffic speed measuring device in real time, comprising:

3. the method for claim 1, is characterized in that, described traffic speed measuring device processes described intermediate-freuqncy signal, obtains the frequency spectrum in the default time, comprising:

Described traffic speed measuring device, according to the time of presetting, carries out modulus AD sampling to the intermediate-freuqncy signal after filter and amplification, forms the digital medium-frequency signal in the described default time and store;

Described traffic speed measuring device carries out fast Fourier transform FFT to the digital medium-frequency signal in the described default time stored, and is converted in frequency domain, forms the frequency spectrum in the described default time by the digital medium-frequency signal in the described default time.

4. the method for claim 1, it is characterized in that, described traffic speed measuring device according to the frequency spectrum in the described default time, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope, comprising:

If when the direction of motion of the described vehicle determined is different from the direction of measurement preset, repeat the relevant information that described traffic speed measuring device extracts the maximum digital medium-frequency signal of its frequency stored, and judge whether the amplitude of described digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude step of adjacent digital medium-frequency signal;

Wherein, when the amplitude of digital medium-frequency signal is positioned at described preset amplitude range, the vehicle tested the speed described in described digital medium-frequency signal corresponds in scope.

5. the method as described in any one of claim 1-4, is characterized in that, described traffic speed measuring device calculated in the described default time, described in test the speed in scope after the maximum speed value of all vehicles on the direction of measurement preset, also comprise:

6. a traffic speed measuring device, is characterized in that, comprising:

Sequential storage module, for the relevant information of digital medium-frequency signal corresponding to each bar frequency spectrum in the frequency spectrum in time of presetting described in sequential storage, wherein, the corresponding digital medium-frequency signal of each frequency spectrum in frequency spectrum in the described default time, the relevant information of described digital medium-frequency signal comprises: frequency, real part information i, imaginary part information j and amplitude;

Speed measuring module, for the frequency spectrum in time of presetting of obtaining according to described signal processing module, to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope;

Wherein, described speed measuring module comprises:

Amplitude judging unit, for extracting the relevant information of the maximum digital medium-frequency signal of frequency from described sequential storage module, and judges whether the amplitude of described digital medium-frequency signal is positioned at preset amplitude range and is greater than the amplitude of adjacent digital medium-frequency signal;

Computing unit, during for determining that when described direction-determining unit the direction of described vehicle is identical with the direction of measurement preset, according to the maximum frequency f of described digital medium-frequency signal _d, according to formula to calculate in the described default time, described in test the speed the maximum speed value of all vehicles on the direction of measurement preset in scope, wherein, f ₀for described traffic speed measuring device launches the transmission frequency of radar signal, c ₀for the light velocity, α is the angle that the line between vehicle that described traffic speed measuring device is corresponding with described digital medium-frequency signal is formed in the direction of motion of described vehicle;

When amplitude judging unit is no, show that this digital medium-frequency signal extracted is invalid signals, the described digital medium-frequency signal extracted described in the filtering of described amplitude judging unit;

Described direction-determining unit comprises:

7. traffic speed measuring device as claimed in claim 6, it is characterized in that, described Echo Processing module comprises:

8. traffic speed measuring device as claimed in claim 7, it is characterized in that, described signal processing module comprises:

9. traffic speed measuring device as claimed in claim 8, it is characterized in that, described speed measuring module comprises:

10. the traffic speed measuring device as described in any one of claim 6-9, is characterized in that, also comprise: