CN2768106Y

CN2768106Y - Device for detecting traffic flow speed

Info

Publication number: CN2768106Y
Application number: CN 200420103428
Authority: CN
Inventors: 徐建闽; 林培群; 梁俊斌; 饶建炜
Original assignee: GUANGZHOU YUNXING TECHNOLOGY Co Ltd; South China University of Technology SCUT
Current assignee: GUANGZHOU YUNXING TECHNOLOGY Co Ltd; South China University of Technology SCUT
Priority date: 2004-12-31
Filing date: 2004-12-31
Publication date: 2006-03-29
Anticipated expiration: 2014-12-31

Abstract

The utility model provides a device for detecting traffic flow speed which is characterized in that it consists of a detecting device and a processing system. The detecting device is connected with the processing system through a communication apparatus, and said detecting device includes an LC oscillating circuit and at least one electromagnetic coil connected with the LC oscillating circuit. The device for detecting traffic flow speed is connected with the LC oscillating circuit through the electromagnetic coil and detects the traffic flow speed on the highway matching with a computer, so the structure is simple. In addition, it uses the classical electromagnetic theory as a tutorial, and the detecting result is exact and reliable. The device for detecting traffic flow speed is suitable for popularization and application.

Description

A kind of device that detects traffic flow speed

Technical field

The utility model relates to traffic flow speed detection technique field, specifically is meant a kind of method and apparatus that utilizes a coil checker to detect traffic flow speed.

Background technology

Traffic data collection is the basic work of serving traffic programme, design, maintenance and management.It is the important component part of carrying out traffic data collection that road traffic flow speed detects.In fields such as traffic controls, it also is unusual important problem that traffic flow speed is detected.The research of relevant traffic flow speed detection technique, many colleges and universities and enterprise are all carrying out.

In the middle of existing product and the document, more advanced technology is to utilize coil checker to carry out car speed to measure, major part need be buried two coils underground on each track, sail the travel speed of determining vehicle through the mistiming of two coils by vehicle, and utilize a coil can finish also not having of car speed detection well, and detect car speed by two coils, not only waste coil method, and on highway is buried underground, take time and effort more, so be badly in need of to improve.

According to the electromagnetic theory of classics as can be known: when metal object during by coil, the frequency of the inductance value of coil and LC oscillatory circuit also can change.Sample with certain sample frequency, the frequency departure value (departing from reference value) of sampling instant is depicted, the frequency variation curve that produces in the time of can obtaining vehicle through coil.The curve quite stable that same car produces when passing through same coil with same speed; Different types of motor vehicle is owing to the difference of size, structure, material, and also different to the influence that coil checker produces, therefore can produce different frequency variation curves, particularly crest value has very big discrimination.This is to carry out the basis that traffic flow speed detects.

Summary of the invention

The purpose of this utility model is to overcome the deficiencies in the prior art, and a kind of device that utilizes a coil just can detect road traffic flow speed is provided.

The technical solution adopted in the utility model is as follows:

A kind of device that detects traffic flow speed is made up of pick-up unit and disposal system, and pick-up unit is connected with disposal system by communication facilities, and described pick-up unit comprises LC oscillatory circuit and at least one solenoid that is connected with the LC oscillatory circuit.

In the technique scheme, the frequency departure value the when device of described detection traffic flow speed detects vehicle through solenoid by the LC oscillatory circuit.

The LC oscillatory circuit is made up of inductance L 1, capacitor C 10, C11, resistance R 23, R24, R25, R26, R27, R28 and triode P5, P6.

Disposal system of the present utility model adopts common computer, and preferred LC oscillatory circuit is connected with computing machine by the RS232 serial ports.

Pick-up unit of the present utility model also can comprise single-chip microcomputer, and described LC oscillatory circuit is connected with single-chip microcomputer, and described single-chip microcomputer is connected with computing machine by the RS232 serial ports.

Principle of work of the present utility model is: by the RS232 serial ports frequency variation curve that the LC oscillatory circuit produces is sent in the computing machine, and adopt following method to carry out traffic flow speed and detect: carry out sample collection earlier, set up the waveform library of traffic flow, from waveform library, extract the crest value characteristic parameter then, this parameter is only relevant with size, the structure and material of vehicle, and is irrelevant with speed.Characteristic parameter extraction finishes, can parameter range be set by manual setting or two kinds of parallel modes of machine learning, with the machine learning is example: for the some samples that collect, according to ascending regularly arranged its crest value, select certain scope in the crest value arrangement to represent a kind of vehicle to be called with reference to vehicle, for example the representative of 95% to 100% waveform values is a kind of with reference to vehicle, if vehicle in the crest value scope of out-of-date crest value in the reference vehicle, can think that then the vehicle of process belongs to reference to vehicle.Various lengths of wagon with reference to vehicle are general to be changed not quite, can manually set length of wagon with reference to vehicle, to add the detection length of coil with reference to the length of wagon of vehicle, in the time interval of the waveform representative that produces during then divided by vehicle process coil, then can obtain this with reference to the average velocity of vehicle on this track.Can with more than obtain multiple with reference to vehicle at the average velocity of this road average velocity as this traffic flow.

The utility model connects the LC oscillatory circuit by solenoid, and coupled computer carries out speed to the wagon flow of travelling on the highway and detects, thus simple in structure, and be guidance with the electromagnetic theory of classics, testing result is fit to promote the use of accurately and reliably.

Description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is testing process figure of the present utility model;

Fig. 3 is a parameter configuration block diagram of the present utility model;

Fig. 4 is a LC oscillatory circuit schematic diagram of the present utility model;

Accompanying drawing 5 is the circuit theory diagrams of single-chip microcomputer of the present utility model.

Embodiment

Below in conjunction with accompanying drawing the utility model is further described.

Structural representation of the present utility model as shown in Figure 1, its pick-up unit comprises the solenoid that is embedded under the highway pavement, the LC oscillatory circuit that connects with solenoid, the single-chip microcomputer composition that is connected with the LC oscillatory circuit, single-chip microcomputer is connected with the computing machine of background process by the RS232 interface again, and present embodiment also is provided with the parameter that is connected with single-chip microcomputer interface circuit is set.

Testing process figure of the present utility model as shown in Figure 2, the parameter of the electromagnetic frequency off-set value that motor vehicle produced that the solenoid handle crosses from above is by slave computer, be that single-chip microcomputer is sent to host computer by the RS232 network interface, be on the computing machine, host computer filters to the received signal, make signal parameter meet the requirements of scope, judge the pairing vehicle of signal then, again the length of wagon of the vehicle judged is added the detection length of coil, in the time interval of the waveform representative that produces during then divided by vehicle process coil, then can obtain this with reference to the average velocity of vehicle on this track.

The utility model can be provided with parameter range by manual setting, two kinds of parallel modes of machine learning, as shown in Figure 3.

The schematic diagram of LC oscillatory circuit of the present utility model and the circuit theory diagrams of single-chip microcomputer are shown in accompanying drawing 4, accompanying drawing 5, form LOOP1 and LOOP2 port among the outside inductive coil two termination circuit figure by inductance L 1, capacitor C 10, C11, resistance R 23, R24, R25, R26, R27, R28 and triode P5, P6.In the LC oscillatory circuit, add self-bias on the one hand, bias voltage strengthens in reaching the process of sustained vibration, thereby make transistor produce non-linear action and come the restriction set electrode current, the resonant circuit that L, C form is set on feedback circuit on the other hand, make it and the tuning generation sine voltage of the first-harmonic of output current, its part is feedbacked, take out as output simultaneously.Because the mutual inductance effect, when vehicle passed through the coil checker top, the variation of coil oscillation frequency made the oscillation frequency of LC oscillatory circuit also change thereupon, and the sinusoidal signal of generation outputs to single-chip microcomputer the 25th pin (P2.1) by triode P6.

Claims

1, a kind of device that detects traffic flow speed, it is characterized in that forming by pick-up unit and disposal system, pick-up unit is connected with disposal system by communication facilities, and described pick-up unit comprises LC oscillatory circuit and at least one solenoid that is connected with the LC oscillatory circuit.

2, the device of detection traffic flow speed according to claim 1 is characterized in that the frequency departure value when described device detects vehicle through solenoid by the LC oscillatory circuit.

3, the device of detection traffic flow speed according to claim 1 and 2 is characterized in that described LC oscillatory circuit is made up of inductance L 1, capacitor C 10, C11, resistance R 23, R24, R25, R26, R27, R28 and triode P5, P6.

4, the device of detection traffic flow speed according to claim 3 is characterized in that described disposal system adopts common computer.

5, the device of detection traffic flow speed according to claim 4 is characterized in that described LC oscillatory circuit is connected with computing machine by the RS232 serial ports.

6, the device of detection traffic flow speed according to claim 4 is characterized in that described pick-up unit also comprises single-chip microcomputer, and described LC oscillatory circuit is connected with single-chip microcomputer, and described single-chip microcomputer is connected with computing machine by the RS232 serial ports.