CN216209883U - Traffic radar device - Google Patents
Traffic radar device Download PDFInfo
- Publication number
- CN216209883U CN216209883U CN202122471461.5U CN202122471461U CN216209883U CN 216209883 U CN216209883 U CN 216209883U CN 202122471461 U CN202122471461 U CN 202122471461U CN 216209883 U CN216209883 U CN 216209883U
- Authority
- CN
- China
- Prior art keywords
- frequency
- attenuator
- processing unit
- information processing
- circulator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Radar Systems Or Details Thereof (AREA)
Abstract
The utility model relates to a traffic radar device, which comprises an information processing unit, a high-frequency oscillator, a first attenuator, a directional coupler, a second attenuator, a circulator, an antenna and a mixer, wherein the high-frequency oscillator is connected with the first attenuator; the high-frequency oscillator is connected with the information processing unit; the first attenuator is respectively connected with the high-frequency oscillator and the directional coupler; the directional coupler is respectively connected with the second attenuator and the circulator, and the circulator is connected with the antenna; the mixer is respectively connected with the second attenuator and the circulator and is used for mixing the second attenuator and the output of the reflected wave from the antenna through the circulator; the frequency mixer is connected with the information processing unit through the A/D converter and the frequency analyzer in sequence; the low-frequency current measuring device measures a low-frequency current output from the mixer and inputs the low-frequency current output to the information processing unit, counts the number of passing vehicles by counting reflected waves received by the antenna, and detects and evaluates the intensity and duration of the reflected waves to identify the type of the vehicle.
Description
Technical Field
The utility model relates to the technical field of radar devices, in particular to a traffic radar device.
Background
In the existing traffic monitoring system, the traffic condition is usually monitored by adopting an optical identification mode. For example, a camera is configured, the type of passing vehicles is judged in a machine learning mode, and the passing vehicles are counted and summarized into traffic data. However, the above method is computationally intensive and is susceptible to weather influences.
SUMMERY OF THE UTILITY MODEL
In view of the disadvantages of the prior art, the present invention provides a traffic radar apparatus for counting reflected waves to count the number of passing vehicles, and detecting and evaluating the intensity and duration of the reflected waves to identify the type of vehicle.
The technical scheme adopted by the utility model is as follows:
a traffic radar apparatus includes an information processing unit, a high-frequency oscillator, a first attenuator, a directional coupler, a second attenuator, a circulator, an antenna, and a mixer;
the high-frequency oscillator is connected with the information processing unit and is used for oscillating a high-frequency signal;
the first attenuator is respectively connected with the high-frequency oscillator and the directional coupler and used for adjusting the high-frequency signal;
the directional coupler is respectively connected with the second attenuator and the circulator and is used for branching the output of the first attenuator, and the circulator is connected with the antenna;
the mixer is respectively connected with the second attenuator and the circulator and is used for mixing the second attenuator and the output of the reflected wave from the antenna through the circulator;
the device also comprises an A/D converter, a frequency analyzer and a low-frequency current measuring device; the frequency mixer is connected with the information processing unit through the A/D converter and the frequency analyzer in sequence;
the low-frequency current measuring device is used for measuring low-frequency current output from the frequency mixer and inputting the low-frequency current output to the information processing unit; the information processing unit is used for counting the reflected waves received by the antenna to calculate the number of passing vehicles, and detecting and evaluating the intensity and duration of the reflected waves to identify the type of the vehicle.
The further technical scheme is as follows:
the information processing unit comprises means for detecting a reflected wave level and a duration, and means for evaluating the duration;
the module for evaluating the duration detects a value representing a speed of the passing vehicle based on the Doppler frequency of the reflected wave, and corrects the duration based on the value representing the speed of the passing vehicle.
The information processing unit is configured to calculate the received power and create a pattern of the reflected signal of the received power corresponding to the duration, and determine the vehicle type by comparing the pattern of the reflected signal with a previously stored model pattern.
The information processing unit comprises a lane recognition module which is used for calculating the distance from the radar device to the vehicle reflecting the high-frequency signal and judging the lane of the passing vehicle according to the distance.
The data processed by the information processing unit can be output.
The utility model has the following beneficial effects:
the reflected wave count is used to count the number of passing vehicles, and the intensity and duration of the reflected wave are detected and evaluated to identify the vehicle type. Compared with the traditional optical identification mode, the method is not influenced by weather and has high detection precision.
The distance from the radar device to the vehicle reflecting the high-frequency signal is obtained through calculation, and the lane to which the passing vehicle belongs is judged according to the distance, so that the counting and the identification of the vehicle in a certain lane can be independently completed.
Drawings
FIG. 1 is a schematic structural diagram of the present invention.
Fig. 2 is a schematic view of the arrangement of the present invention in operation.
Fig. 3 is a schematic diagram of the received power of each type of vehicle obtained by the present invention.
In the figure: 1. a radar device; 2. an information processing unit; 3. a high-frequency oscillator; 4. an antenna; 5. a directional coupler; 6. a circulator; 7. a mixer; 8. an A/D converter; 9. a frequency analyzer; 10. a low frequency current measuring device; 11. a first attenuator; 12. a second attenuator.
Detailed Description
The following describes embodiments of the present invention with reference to the drawings.
The traffic radar apparatus of the present embodiment, as shown in fig. 1, includes an information processing unit 2, a high-frequency oscillator 3, a first attenuator 11, a second attenuator 12, a circulator 6, an antenna 4, and a mixer 7;
the information processing unit 2 is connected to an input of a high-frequency oscillator 3, the high-frequency oscillator 3 being for oscillating a high-frequency signal of a several tens of GHz band;
the first attenuator 11 and the second attenuator 12 are used for adjusting the attenuation factor of the high-frequency signal respectively; the input of the first attenuator 11 is connected with the output of the high-frequency oscillator 3, the output of the first attenuator 11 is connected with the input of the directional coupler 5, and the output of the directional coupler 5 is respectively connected with the input of the second attenuator 12 and the input of the circulator 6;
the directional coupler 5 is used for branching the output of the first attenuator 11, so that one part of the output is output to the second attenuator 12, the other part of the output is output to the circulator 6, and the circulator 6 is connected with the antenna 4;
the mixer 7 is connected to the second attenuator 12 and the circulator 6, respectively, and mixes the second attenuator 12 and an output signal of the circulator 6 from which the reflected wave from the antenna 4 passes;
further comprises an A/D converter 8, a frequency analyzer 9 and a low-frequency current measuring device 10;
the output of the mixer 7 is connected with the input of the information processing unit 2 through an A/D converter 8 and a frequency analyzer 9 in sequence; the output of the mixer 7 is converted from an analog signal to a digital signal by the a/D converter 8, and the output of the a/D converter 8 is input to the frequency analyzer 9 and output to the signal processing unit 2 for frequency analysis;
the low-frequency current measuring device 10 is used for measuring the output of the low-frequency current from the mixer 7 and inputting the output of the low-frequency current to the information processing unit 2;
the information processing unit 2 is used to count the reflected waves of the antenna 4 to count passing vehicles, detect and evaluate the intensity and duration of the reflected waves to identify the type of vehicle.
Specifically, the information processing unit 2 includes a module for detecting the level and duration of the reflected wave, and a module for evaluating the duration; the module for evaluating the duration detects a value representing a velocity of the passing vehicle based on the Doppler frequency of the reflected wave, and corrects the duration based on the value representing the velocity of the passing vehicle.
Specifically, the information processing unit 2 is configured to calculate the received power and create a pattern of the reflected signal of the received power corresponding to the duration, and determine the vehicle type by comparing the pattern of the reflected signal with a model pattern stored in advance.
In order to identify the vehicle type, it is necessary to previously store the intensity and duration of the reflected wave (previously stored model pattern) corresponding to each vehicle type. The pre-stored model pattern can be used as reference data to compare the intensity and duration of the reflected wave received in real time, and further judge the type of the vehicle.
As shown in fig. 2, the radar apparatus 1 is disposed on the road side, and the radar apparatus 1 should be installed at such a height that its beam range can cover the maximum height of different vehicles. A high frequency signal is emitted from the radar apparatus 1 toward the road through the antenna 4, and when the vehicle passes through the radiation band of the high frequency signal, the high frequency signal reflected by the side portion of the vehicle body is received by the antenna 4, and then the signal received by the antenna 4 is mixed with the output of the second attenuator 12 by the mixer 7, and is input to the information processing unit 2 through processing. The duration of the reflected wave and the pattern represented by its intensity level differ due to the shape and size of the side of the vehicle. For example, cars have a short duration and the reflected wave intensity level is small. Large cars last long and the intensity level of the reflected waves is large. Therefore, by comparing the pattern indicated by the intensity level and the duration of the received reflected wave with the model maps different from each other, the vehicle type of the passing vehicle can be accurately identified and recognized.
As shown in fig. 2, the radar apparatus 1 is deviated from a reference line θ degrees perpendicular to the road direction. The duration of the high frequency signal reflection from a passing vehicle can be increased and the duration of the high frequency signal reflection can be increased byThe driving speed of the vehicle is detected by the doppler effect. I.e. the Doppler frequency f of the vehicledAnd a running speed VRExpressed by a relational expression of the wavelength λ of the high-frequency signal:
fd＝(2VR/λ)cosθ·λ
the angle θ may be positive or negative, for example, illuminating the front of the vehicle (θ positive) or illuminating the rear (θ negative). The output frequency of the radar apparatus 1 is:
fb(upper) ═ fr+fd，
fb(lower) fr-fd，
Wherein f isb(upper) may represent the duration of time that the radar device 1 is located on the vehicle approach side (radar is located upstream of the vehicle in the vehicle forward direction) at the angle θ, fb(lower) may represent a duration indicating that the radar device 1 is located on the vehicle distant side (the radar is located downstream of the vehicle in the vehicle forward direction) at the angle θ; f. ofrIs a frequency with a relative velocity of 0; f. ofdIs the doppler frequency.
Therefore, the Doppler frequency f of the reflected wave can be useddAnd a running speed VRDetecting the output frequency (f) of the radar indicating the duration of the reflected waveb(upper) or fb(lower)), and passes the Doppler frequency fdAnd (6) carrying out correction.
The information processing unit 2 further includes a lane recognition module for calculating a distance d from the radar device 1 to a target reflecting object (passing vehicle) reflecting the high-frequency signal, and determining a lane to which the passing vehicle belongs based on the distance d, i.e., detecting the passing vehicles on each lane based on the distance d, respectively.
The data processed by the information processing unit 2 may be output for further processing.
The beam power P of the reflected wave received by the antenna 4r(received power) can be obtained by:
Pr＝Pt·g2·λ2·S/(4π)3·d4
in the formula, PtIn order to transmit the power, the power is,g is antenna gain, lambda is wavelength, and d is the distance from the antenna to the side face of the vehicle body; s is radar reflection sectional area, and the calculation formula is S ═ 4 pi A2·cos2α)/λ2Where a is the area of the side of the vehicle body and α is the angle of incidence of the radar beam.
As shown in fig. 3, in the case of a large-sized vehicle, the duration T is long, the reception time is long, and the level of the reflected wave is high. Fig. 3 shows a pattern of radar reflected wave levels when passing through the front of the radar apparatus at a standard speed (e.g., 40 km/h). The duration T of the small truck becomes short and the received power PrThe strength of (a) becomes small. The duration T of the car is further shortened and the power P is receivedrFurther decreases in strength.
When the radar device 1 is arranged on one side of a road, the distances d from the radar device 1 to two side surfaces (a first side surface close to the radar and a second side surface far away from the radar) of a vehicle body are respectively a first distance d1A second distance d2(d1、d2Different), the intensity distribution of the received power of the vehicle type is indicated by the solid line and the broken line in fig. 3, respectively. As can be seen, the characteristics of different vehicles at different distances are still apparent, and thus the type of vehicle can be identified by comparing the type of vehicle on the model pattern with different durations T.
Specifically, the reflected wave received by the antenna 4 is output from the circulator 6 to the mixer 7, and a phase difference signal generated between the high-frequency signal input from the directional coupler 5 and the second attenuator 12 and the reflected wave from the circulator 6 is output through the mixer 7; the difference signal is converted from an analog signal to a digital signal by the a/D converter 8, the gain is adjusted, and the frequency is analyzed by the frequency analyzer 9. The output from the frequency analyzer 9 and the measurement output of the low-frequency current value branched from the mixer 7 and measured by the low-frequency current measuring device 10 are input to the information processing unit 2. The information processing unit 2 calculates the reception power PrAnd creates a reflected signal pattern of received power corresponding to the duration T. The pattern of the reflected signal is compared to a pre-stored model pattern to determine which of a car, a small truck, a large truck, and many other vehicle types.
By adopting the traffic radar device, the vehicle type of vehicle traffic can be identified, the traffic flow information can be accurately detected further according to the vehicle type, and excessive manpower participation is not needed.
Claims (5)
1. A traffic radar apparatus is characterized by comprising an information processing unit (2), a high-frequency oscillator (3), a first attenuator (11), a directional coupler (5), a second attenuator (12), a circulator (6), an antenna (4) and a mixer (7);
the high-frequency oscillator (3) is connected with the information processing unit (2) and is used for oscillating a high-frequency signal;
the first attenuator (11) is respectively connected with the high-frequency oscillator (3) and the directional coupler (5) and is used for adjusting the high-frequency signal;
the directional coupler (5) is respectively connected with the second attenuator (12) and the circulator (6) and is used for branching the output of the first attenuator (11), and the circulator (6) is connected with the antenna (4);
the mixer (7) is respectively connected with the second attenuator (12) and the circulator (6) and is used for mixing the second attenuator (12) and the output of the reflected wave from the antenna (4) through the circulator (6);
the device also comprises an A/D converter (8), a frequency analyzer (9) and a low-frequency current measuring device (10);
the frequency mixer (7) is connected with the information processing unit (2) through an A/D converter (8) and a frequency analyzer (9) in sequence; the low-frequency current measuring device (10) is used for measuring a low-frequency current output from the mixer (7) and inputting the low-frequency current output into the information processing unit (2);
the information processing unit (2) is used for counting the reflected waves received by the antenna (4) to calculate the number of passing vehicles, and detecting and evaluating the intensity and duration of the reflected waves to identify the type of the vehicle.
2. The traffic radar apparatus according to claim 1, characterized in that the information processing unit (2) comprises means for detecting the level of reflected waves and the duration, and means for evaluating the duration;
the module for evaluating the duration detects a value representing a speed of the passing vehicle based on the Doppler frequency of the reflected wave, and corrects the duration based on the value representing the speed of the passing vehicle.
3. The traffic radar apparatus according to claim 2, wherein the information processing unit (2) is configured to calculate a received power and create a pattern of reflected signals of the received power corresponding to the duration, and to determine the vehicle type by comparing the pattern of reflected signals with a pre-stored model pattern.
4. Traffic radar apparatus according to claim 2, characterized in that the information processing unit (2) comprises a lane recognition module for calculating the distance from the radar apparatus to the vehicle reflecting the high frequency signal, and determining the lane to which the passing vehicle belongs on the basis of said distance.
5. The traffic radar apparatus according to claim 1, characterized in that data processed by the information processing unit (2) can be output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122471461.5U CN216209883U (en) | 2021-10-13 | 2021-10-13 | Traffic radar device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122471461.5U CN216209883U (en) | 2021-10-13 | 2021-10-13 | Traffic radar device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216209883U true CN216209883U (en) | 2022-04-05 |
Family
ID=80865790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122471461.5U Active CN216209883U (en) | 2021-10-13 | 2021-10-13 | Traffic radar device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216209883U (en) |
-
2021
- 2021-10-13 CN CN202122471461.5U patent/CN216209883U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6661370B2 (en) | Radar data processing apparatus and data processing method | |
| KR100645771B1 (en) | Radar | |
| US10621385B2 (en) | Device and method for determining geometry characteristic values of a wheel profile on a rolling wheel of a rail vehicle | |
| US9286796B2 (en) | Traffic flow measuring apparatus and method, and computer-readable storage medium for judging size of vehicle depending on number of times reflected wave from vehicle is detected within detection time | |
| US20030076255A1 (en) | Method for detecting stationary object on road by radar | |
| AU2014202002B2 (en) | Apparatus and Method for Determining a Vehicle Feature | |
| JPH07140245A (en) | Method for decision of visibility | |
| JP6624601B2 (en) | Radar apparatus and target object detection method | |
| CN102169180A (en) | Dual-beam three-antenna radar and method for detecting traffic information of microwave | |
| CN107807252A (en) | Vehicle Velocity Measurement Method and device | |
| CN115657007A (en) | River surface flow velocity measuring method based on millimeter wave radar | |
| KR102060286B1 (en) | Radar object detection threshold value determination method using image information and radar object information generation device using the same | |
| US6906661B2 (en) | Object-detecting system for vehicle | |
| CN216209883U (en) | Traffic radar device | |
| CN106093458B (en) | Single-transmitting-beam three-antenna microwave vehicle speed and vehicle type detection radar and detection method | |
| CN109727453A (en) | A kind of Passive Radar System and its monitoring method for freeway traffic monitoring | |
| CN107293127B (en) | Charging square congestion monitoring system based on multi-beam wide-area microwave detection | |
| CN109917371A (en) | A kind of microwave radar measurement method based on improvement microwave waveform | |
| CN109031303A (en) | Vehicle checking method and device based on radar range finding technology | |
| JPH10105878A (en) | Traffic signal controller | |
| CN112630791A (en) | Height limit measuring method for special vehicle | |
| JPH11272988A (en) | Traffic monitoring device | |
| JP2008234460A (en) | Velocity detection device and velocity detection notification system with velocity detection device | |
| CN114509281B (en) | Lane departure auxiliary system testing device and method | |
| CN117111049B (en) | ETC channel vehicle presence detection method and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |