CN202153396U - Vehicle detector based on inductance variation of measuring coil - Google Patents
Vehicle detector based on inductance variation of measuring coil Download PDFInfo
- Publication number
- CN202153396U CN202153396U CN2011202355823U CN201120235582U CN202153396U CN 202153396 U CN202153396 U CN 202153396U CN 2011202355823 U CN2011202355823 U CN 2011202355823U CN 201120235582 U CN201120235582 U CN 201120235582U CN 202153396 U CN202153396 U CN 202153396U
- Authority
- CN
- China
- Prior art keywords
- inductance
- coil
- vehicle
- measuring
- central processing
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Traffic Control Systems (AREA)
Abstract
Disclosed is a vehicle detector based on the inductance variation of a measuring coil, at least comprising a circular coil, with the inductance value thereof changing according to the state and characteristics of the passing vehicles, an LC oscillator which, with the LC oscillation frequency thereof relating to the inductance changes caused by the vehicles passing the coil, is used for measuring the inductance value change of the circular coil, a channel scanning apparatus used for processing the measurement of every channel coil inductance, and a central processing apparatus which is in charge of controlling the channel scanning device, thus to finish the measuring of the inductance value of every circular circuit of each channel, calculating whether each channel has vehicles to come, leave, or exist, and outputting the result data to the exterior of the measurement detector via an output interface and/or communication interface. The circular coil, the LC oscillator, the channel scanning apparatus, and the central processing apparatus are sequentially connected. The vehicle detector of the utility model has no deadlock problem and combines the high sensitivity of an open loop system and the high stability of a closed loop system together.
Description
Technical field
The utility model relates to a kind of wagon detector, and is particularly a kind of based on measuring the wagon detector that winding inductance quantity changes.
Background technology
The employed wagon detector in intelligent transportation control field according to the different techniques principle, is divided into following several types: toroid winding, infrared, video, microwave, earth induction, ultrasound wave, optical fiber pressure induction, pressure switch etc.In these different techniques schemes, the performance of Loop Vehicle Detector is the most stable, and simple in structure, and is with low cost, and applicable surface is the widest, is the vehicle detection technology of main flow.
At present, also be not solved on " deadlock " (Lock up) problem that on the market Loop Vehicle Detector exists.This problem causes coil parameter to change during owing to the distortion of extraneous strong electromagnetic or large truck extruding road causing; This problem can make Loop Vehicle Detector cisco unity malfunction in a period of time, and this problem has some descriptions in Chinese patent document CN2258299Y.
As everyone knows, existing Loop Vehicle Detector is made up of following three parts: as the toroid winding of sensor; Connect toroid winding and the transmission feeder that detects processing unit; Detect processing unit.Referring to Fig. 1, the ultimate principle of existing Loop Vehicle Detector is: toroid winding is as a telefault, and its inductance value is relevant with the magnetoconductivity of coil surrounding space.When vehicle through or when resting on coil region, the permeability magnetic material of car body (iron etc.) can change the magnetoconductivity of surrounding space.The inductance value of coil is changed.Variation through the magnetic test coil inductance value just can detect passing through of vehicle or exist.The oscillatory circuit that more generally utilizes LC to constitute, its output frequency can change with the variation of winding inductance quantity L under the situation that inductance is fixed.Therefore, only the variation of needs detection frequencies (or cycle) just can detect passing through of vehicle or exist.Method about with measured frequency detects vehicle, in Chinese patent document CN101833862A, more detailed description is arranged.
In existing technology, the detection of Loop Vehicle Detector is divided into two kinds of open cycle system and closed-loop systems, and open cycle system does not have feedback channel; " deadlock " problem can appear; And the sensitivity of closed-loop system is relatively poor, and it is better to do " through type " detection effect, detects but can not do " having type ".
The utility model content
The utility model technical matters to be solved provides a kind of based on measuring the wagon detector that winding inductance quantity changes, and its no deadlock problem has the high sensitivity of open cycle system, possesses the high stability of closed-loop system again.
For solveing the technical problem, it is a kind of based on measuring the wagon detector that winding inductance quantity changes that the utility model provides, and it is characterized in that it comprises at least:
Toroid winding, its inductance value is according to changing through vehicle-state and characteristic;
The inductance that LC oscillator, its LC oscillation frequency cause when passing through toroid winding with vehicle changes relevant, and is used for the variation of the inductance value of measure annular coil;
The passage scanister, it is used for the measurement that each passage coil inductance is handled on timesharing ground;
Central processing unit; It is responsible for the control channel scanister so that accomplish the measurement of each passage toroid winding inductance value; Whether have vehicle get into or leave or exist, and result data connect through output interface and/or communication output to the detector for measuring outside if calculating each passage;
Toroid winding, LC oscillator, passage scanister and central processing unit are linked in sequence.
Preferably; The said wagon detector that changes based on the measurement winding inductance quantity also comprises signal regulating device, parameter setting apparatus; Signal regulating device, parameter setting apparatus all are connected with central processing unit; Signal regulating device with the analog-signal transitions of LC oscillator output be digital signal so that central processing unit is handled, parameter setting apparatus is used to be provided with the running parameter of wagon detector.
The positive progressive effect of the utility model is: the utility model does not have the deadlock problem, has the high sensitivity of open cycle system, possesses the high stability of closed-loop system again.
Description of drawings
Fig. 1 is the theory diagram of existing Loop Vehicle Detector.
Fig. 2 is the structural representation of the utility model based on the wagon detector of measuring the winding inductance quantity variation.
Fig. 3 is the synoptic diagram of absolute threshold and output time relation in the utility model.
Fig. 4 is the synoptic diagram of absolute threshold and two coil relationship in the utility model.
The theory diagram that Fig. 5 counts for the utility model.
Fig. 6 is the synoptic diagram of vehicle and toroid winding relation in the utility model.
Embodiment
Lift a preferred embodiment below, and combine accompanying drawing to come the clearer the utility model of intactly explaining.
As shown in Figure 2, the utility model comprises based on the wagon detector of measuring the winding inductance quantity variation
Toroid winding 5, its utilize its inductance value vehicle through the time character that can change, as the sensor of wagon detector, promptly its inductance value is according to changing through vehicle-state and characteristic;
The inductance that LC oscillator 3, its LC oscillation frequency cause when passing through toroid winding with vehicle changes relevant, and is used for the variation of the inductance value of measure annular coil 5;
Passage scanister 2, it is used for the measurement that each passage coil inductance is handled on timesharing ground;
Output interface 8, its analysis result with central processing unit 1 outputs to the outside, so that miscellaneous equipment uses, mainly is responsible for the conversion or the Signal Spacing output of signal driving, level.The available way of output includes but not limited to that output is isolated in the output of TTL (Transistor-Transistor Logic, transistor-transistor logic) level, optically-coupled, relay is exported.Output interface also is responsible for internal state is indicated through LED light simultaneously;
Communication interface 7, it is used for central processing unit 1 is detected data or internal state, sends to long-range host computer through communication interface.In addition, use communication interface, the running parameter of wagon detector can also be set.The communication interface of selecting for use includes but not limited to RS232/RS485/CAN bus/LIN bus/Ethernet.Select communication interface output data or internal state for use, should comprise a cover communications protocol, so that host computer correct handling communication data;
Central processing unit 1; It is responsible for control channel scanister 2 so that accomplish the measurement of each passage toroid winding inductance value; Whether calculate each passage has vehicle to get into or leaves or exist; And result data outputed to the detector for measuring outside through output interface 8 and/or communication interface 7, make things convenient for other system applies;
Parameter setting apparatus 6; The running parameter that it is used to be provided with wagon detector comprises that sensitivity, channel selecting, measurement count the mode of N, data output polarity, data output (have type, through type, postpone output time, pulse width, entering and trigger/leave triggering/entering and leave triggering) measuring period that coil frequency is used.Certainly, the running parameter of wagon detector can also be provided with through communication interface.
Wherein, toroid winding 5, LC oscillator 3, passage scanister 2 and central processing unit 1 are linked in sequence.Signal regulating device 4, parameter setting apparatus 6 all are connected with central processing unit 1.The disposal route that central processing unit uses comprises: 1) confirming based on the reference frequency of digital signal processing; 2) the vehicle-state detection method that combines based on single threshold values and relative threshold values; 3) based on the frequency measurement method of the periodicity of dynamically changeable.Adopt the digital signal processing means to confirm reference frequency, can " deadlock " problem thoroughly be eliminated so that an open cycle system becomes very stable.Based on the periodicity frequency measurement method of dynamically changeable, the system that can guarantee has high sensitivity and does not lose reliability and stability.With the vehicle-state detection method of single relative threshold values, judge that automobile storage is irrelevant with the height of sensitivity whether, this is very important for measuring the speed of a motor vehicle, to the electronic police measuring vehicle " through " also ten minutes is important with " existences ".Can not cause the output time of vehicle detection different because of the sensitivity difference.Referring to Fig. 3, if use absolute threshold, then different threshold values means different output times.When threshold values is very low, possibly, vehicle just think that vehicle " gets into " by error when also not getting into coil.Referring to Fig. 4, if use absolute threshold, then two of same track differences that coil can cause mistiming Δ t to measure because of the difference of threshold values when measuring the speed of a motor vehicle cause range rate error to increase.
In order to realize that to the judgement of vehicle system needs a reference data of judging through state.When not having vehicle through out-of-date, that establishes LC oscillator output is frequency FB, when vehicle through out-of-date, the frequency of establishing the output of LC oscillator is FO, FO is greater than FB usually.If the difference on the frequency between FO and the FB, thinks then that vehicle gets into coil greater than the Sensitirity va1ue of setting.
The output frequency of LC oscillator is not set at reference frequency FB when will have vehicle through toroid winding, and whether the frequency difference decision between LC oscillator FO and the FB has car to exist.Therefore definite vehicle detection as far as vehicle checker of FB is very important.Because the temperature variation of environment, and electric capacity is aging, and the LC oscillator is not having vehicle can change through out-of-date FB yet, and this just must adopt a kind of reference frequency to confirm that method follows the tracks of the variation of FB.
The utility model adopts the method for digital filtering, and the frequency data that collect are carried out the FIR low-pass filtering treatment, eliminates the frequency content that wherein is higher than 2Hz.The cutoff frequency of FIR LPF is 2Hz, and sampling rate is 100Hz.Through the frequency data behind the digital filtering, the bandwidth of its variation has only 2Hz, can resist very strong external disturbance; Frequency data behind the digital filtering; At a time window is in the time range of 10s～120s, also will pass through the X-11 filtering method and carry out Filtering Processing, with the trend composition of frequency data; The cycle composition and at random composition distinguish; To parse the trend composition of change of frequency, Here it is confirms that the needed data of reference frequency FB, the reference frequency FB that sets by this method can adapt to L and the temperature variation of C and the change of frequency that wears out and bring in the LC oscillator automatically.
In order to realize very wide clever lightness range, the wagon detector of the utility model invention, have one can be program control frequency measurement circuit, can select to measure the needed periodicity N of coil frequency.
With reference to figure 5, GATE (door) counter selects a Choice of data selectors according to eight, and FO counts to incoming frequency, make TGATE between the high period of GATE signal of output be incoming frequency FO signal period time T O N doubly.N gets 16,32,64,128,256,512,1024, and 2048 in one of.If the reference frequency of frequency measuring count-er is FR, count value is NC, and following relation is then arranged: N ÷ FO=NC ÷ FR; FO=N * FR ÷ NC.Because TGATE is the integral multiple of TO, do not have measuring error, but TGATE generally is not the integral multiple of the cycle T R of reference frequency, so NC is to counting existence ± 1 error of FR.This shows that N is big more, NC is big more, and the degree of accuracy of then measuring is high more.
Can find out simultaneously that when N was big, needed Measuring Time was also long more, the response of system is elongated, and reaction velocity descends.When practical applications when telling that road vehicle tests the speed, select smaller N value, such as 32 or 64; When practical applications during, select bigger N value for use, such as 256 or 512 in the control of the banister in parking lot; Very slow when the target speed that needs detect, but when needing very high clever lightness, select very large N value for use, such as 1024 or 2048.
Should be noted that the measured frequency error of less N value (such as 16 or 32) is bigger, surpass the extraneous caused change of frequency of random disturbance, do not consider extraneous random disturbance during calculating.And for the measured frequency error of bigger N value (such as more than 128) seldom, the change of frequency that extraneous random disturbance causes maybe be bigger than this measuring error, at this moment need consider the influence of external disturbance.
Single absolute threshold FTH is relevant with FB, and under different N, FB is different, and corresponding single absolute threshold FTH is also different.
Confirmed reference frequency when FB16 representes N=16, corresponding absolute threshold is FTH16;
The reference frequency of confirming when FB32 representes N=32, corresponding absolute threshold is FTH32;
Confirmed reference frequency when FB64 representes N=64, corresponding absolute threshold is FTH64;
The reference frequency of confirming when FB128 representes N=128, corresponding absolute threshold is FTH128;
Confirmed reference frequency when FB256 representes N=256, corresponding absolute threshold is FTH256;
The reference frequency of confirming when FB512 representes N=512, corresponding absolute threshold is FTH512;
Confirmed reference frequency when FB1024 representes N=1024, corresponding absolute threshold is FTH1024;
The reference frequency of confirming when FB2048 representes N=2048, corresponding absolute threshold is FTH2048;
The moment that first maximum point of the first order derivative that relative threshold values is a frequency curve occurs.For the process that the vehicle of any kind gets into coil, has only the maximal value that after headstock gets into coil region, just can obtain slope variation.Therefore, in the process that vehicle gets into, first maximum value of the first order derivative through judging FO just can judge whether vehicle gets into toroidal surveyed area (referring to Fig. 6).
Though more than described the embodiment of the utility model; But those skilled in the art is to be understood that; These only illustrate, and under the prerequisite of principle that does not deviate from the utility model and essence, can make numerous variations or modification to these embodiments.Therefore, the protection domain of the utility model is limited appended claims.
Claims (2)
1. a wagon detector that changes based on the measurement winding inductance quantity is characterized in that, comprises at least based on the wagon detector of measuring the winding inductance quantity variation:
Toroid winding, its inductance value is according to changing through vehicle-state and characteristic;
The inductance that LC oscillator, its LC oscillation frequency cause when passing through toroid winding with vehicle changes relevant, and is used for the variation of the inductance value of measure annular coil;
The passage scanister, it is used for the measurement that each passage coil inductance is handled on timesharing ground;
Central processing unit; It is responsible for the control channel scanister so that accomplish the measurement of each passage toroid winding inductance value; Whether have vehicle get into or leave or exist, and result data connect through output interface and/or communication output to the detector for measuring outside if calculating each passage;
Toroid winding, LC oscillator, passage scanister and central processing unit are linked in sequence.
2. as claimed in claim 1 based on measuring the wagon detector that winding inductance quantity changes; It is characterized in that; The said wagon detector that changes based on the measurement winding inductance quantity also comprises signal regulating device, parameter setting apparatus; Signal regulating device, parameter setting apparatus all are connected with central processing unit, signal regulating device with the analog-signal transitions of LC oscillator output be digital signal so that central processing unit is handled, parameter setting apparatus is used to be provided with the running parameter of wagon detector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202355823U CN202153396U (en) | 2011-07-06 | 2011-07-06 | Vehicle detector based on inductance variation of measuring coil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202355823U CN202153396U (en) | 2011-07-06 | 2011-07-06 | Vehicle detector based on inductance variation of measuring coil |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202153396U true CN202153396U (en) | 2012-02-29 |
Family
ID=45693891
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011202355823U Expired - Fee Related CN202153396U (en) | 2011-07-06 | 2011-07-06 | Vehicle detector based on inductance variation of measuring coil |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202153396U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103578279A (en) * | 2013-11-21 | 2014-02-12 | 北方工业大学 | Method and device for detecting annular coil vehicle |
| CN104658269A (en) * | 2013-11-22 | 2015-05-27 | 上海宝康电子控制工程有限公司 | Method for real-time base frequency updating in annular coil vehicle detector |
| CN108990233A (en) * | 2018-08-09 | 2018-12-11 | 广东工业大学 | A kind of intelligent light control system and method |
| CN111366185A (en) * | 2020-03-03 | 2020-07-03 | 上海钧正网络科技有限公司 | Lock, vehicle system and lock detection method |
-
2011
- 2011-07-06 CN CN2011202355823U patent/CN202153396U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103578279A (en) * | 2013-11-21 | 2014-02-12 | 北方工业大学 | Method and device for detecting annular coil vehicle |
| CN104658269A (en) * | 2013-11-22 | 2015-05-27 | 上海宝康电子控制工程有限公司 | Method for real-time base frequency updating in annular coil vehicle detector |
| CN108990233A (en) * | 2018-08-09 | 2018-12-11 | 广东工业大学 | A kind of intelligent light control system and method |
| CN111366185A (en) * | 2020-03-03 | 2020-07-03 | 上海钧正网络科技有限公司 | Lock, vehicle system and lock detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN202153396U (en) | Vehicle detector based on inductance variation of measuring coil | |
| CN101908250A (en) | Full RFID (Radio Frequency Identification Device) license plate based parkinglay-by intelligent monitoring system and method | |
| CN104200701B (en) | A kind of parking stall measure synthetic determination method | |
| CN102289939A (en) | Vehicle/traffic flow detection method based on three-axle magnetoresistive sensor | |
| CN101847320A (en) | Crossing traffic control system and method | |
| CN102982588A (en) | Vehicle information acquisition method based on vehicle networking technology, and vehicle-mounted terminal | |
| CN101923782A (en) | Method for acquiring transportation traffic speed based on geomagnetic sensing technology | |
| CN105761509A (en) | Traffic control system and method for pedestrians to safely cross street | |
| CN206249557U (en) | Based on the vehicle detecting system that Magnetic Sensor and ultrasonic sensor are merged | |
| CN101009047A (en) | Intelligent traffic crossing control method | |
| CN102779413B (en) | Motor vehicle characteristics data acquisition analyzer and analyzing method | |
| CN102147972A (en) | Detecting device for wireless geomagnetic vehicle and installation method of detecting device | |
| CN105298289A (en) | Intelligent car window control system and method | |
| CN106710238B (en) | Method for improving accuracy of geomagnetic vehicle detector | |
| Ng et al. | Road traffic monitoring using a wireless vehicle sensor network | |
| CN106448187B (en) | Vehicle detection system and method based on fusion of magnetic sensor and ultrasonic sensor | |
| Chen et al. | Roadside sensor based vehicle counting incomplex traffic environment | |
| CN105006151A (en) | Dynamic vehicle detection method based on weak magnetic sensor | |
| CN103903431A (en) | Vehicle detection apparatus | |
| CN100501796C (en) | Minisize buried automobile detector | |
| CN207115756U (en) | Parking position monitoring device | |
| KR101316723B1 (en) | System and method for providing traffic information using occupation-based radar | |
| CN101311982A (en) | Vehicle assorted check detection device and method | |
| CN106373407A (en) | Vehicle detector based on geomagnetic sensing | |
| CN202677617U (en) | Motor vehicle characteristic data acquisition analyzer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| DD01 | Delivery of document by public notice |
Addressee: Shanghai Quhan Industrial Co.,Ltd. Document name: Notification to Pay the Fees |
|
| DD01 | Delivery of document by public notice |
Addressee: Shanghai Quhan Industrial Co.,Ltd. Document name: Notification of Termination of Patent Right |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120229 Termination date: 20120706 |