CN203881941U - Radar device for monitoring settlement of high-speed rail roadbed - Google Patents

Abstract

The utility model relates to a radar device for monitoring the settlement of a high-speed rail roadbed, the radar device is mainly composed of a DDS (digital display scope), a modulator, a power amplifier, a frequency mixer, a low-frequency amplifier, a signal processor and a communication interface circuit; the DDS generates frequency modulated continuous wave (FMCW) signals at low frequency and generates radio-frequency signals through the modulator, one path of the radio-frequency signals enters a transmitting antenna after passing through the power amplifier while the other path of the radio-frequency signals and signals received by a receiving antenna pass through the frequency mixer, and a result is sent out through the communication interface circuit. According to the utility model, a microwave radar system is adopted to measure tiny displacement, and the millimeter-wave radar technology is combined with the corner reflector fixed on a settlement plate to obtain a high-precision displacement measurement result, so that the settlement amount of the high-speed rail roadbed can be automatically monitored, the line running safety is improved, and the property loss is reduced.

Description

A kind of high ferro subgrade settlement monitoring radar installations

Technical field

The utility model relates to high ferro subgrade settlement monitoring technology, specifically a kind of subgrade settlement monitoring radar installations based on microwave radar technology.

Background technology

Railway is the main artery of national economy, is bringing into play great effect in national economy, under high-speed railway operation condition fast, carry out accurately the Real-Time Monitoring of high-speed railway subgrade sedimentation and deformation, be key subjects.

At present, the conventional sense method of high-speed railway subgrade sedimentation and deformation has total powerstation, range finder using laser, liquid sedimentation system etc., round-the-clock, full-automatic detection in real time that these methods all can not realize.

Described total powerstation, is generally used for the construction stage settling amount is observed, and is manual operation, and efficiency is low, can not realize automatic monitoring.

Patent < < adaptive scanning subgrade settlement remote monitoring device and method > >, publication number 101709968A, adopts optical system to realize settlement monitoring.Its major defect is: laser is subject to the environmental impacts such as misty rain, dust larger, and this device is containing mechanical moving element, and reliability is not high, is difficult to realize long-term, stable, all weather operations.

Patent < < roadbed settlement monitoring equipment > >, application number 201120198678.7, adopt the sedimentation of liquid processes monitoring roadbed, its reference point is provided with the container of contain fluid, at check point place, be provided with the inspection instrument of sealing suitable for reading, this inspection instrument was communicated with container by communicating pipe, and the liquid top in inspection instrument contacts with pressure transducer.This monitoring method precision is poor, once and damage or leak of liquid, be difficult to repair.

Utility model content

The purpose of this utility model is to overcome the deficiencies in the prior art, and a kind of monitoring radar installations of high ferro subgrade settlement is provided, and the high ferro roadbed subgrade settlement that this monitoring device can remote auto reads, for railway operation management decision.

The utility model is measured small displacement by microwave radar systems, adopt millimetre-wave radar technology to obtain high precision displacement measurement result in conjunction with the corner reflector being fixed on settlement plate, thereby high-speed railway subgrade settling amount is carried out to automatic monitoring, improve the security of circuit operation, reduce property loss.

The utility model is achieved in that

The subgrade settlement monitoring radar installations of the utility model, is mainly comprised of microwave radar transceiver, settlement plate, corner reflector; Settlement plate is comprised of the Metallic rod perpendicular to ground of the sheet metal Ji Ban center welding that is parallel to ground of a diameter 10cm-50cm, and corner reflector is arranged in the Metallic rod of settlement plate, and the strongest direction of the reflection of corner reflector is pointed to microwave radar antenna;

Described microwave radar transceiver, its main circuit will be comprised of emitting antenna, DDS, modulator, power amplifier, frequency mixer, reception sky money, low-frequency amplifier, signal processor, communication interface; DDS produces FMCW signal at low frequency, through modulator, produce radiofrequency signal, lead up to after power amplifier and enter emitting antenna, another road and the signal receiving from receiving antenna, pass through frequency mixer, through low-frequency amplifier, directly give signal processor again and carry out frequency spectra analysis, signal processor calculates after distance corresponding to corresponding frequencies, and result is sent by communication interface.

This microwave radar transceiver, for obtaining the displacement information between radar antenna and corner reflector; Be embedded in settlement plate under roadbed for the sedimentation situation of perception roadbed, and subgrade settlement is delivered on corner reflector by Metallic rod, be convenient to radar sedimentation information is obtained; Radar data processor is transported to Surveillance center by the data after processing by RTTY.

Described settlement plate, be embedded in underground, on the Metallic rod on settlement plate end basset.

Each monitoring section of single line high-speed railway rail, a pre-buried 1-3 settlement plate; Each monitoring section of two-wire high-speed railway rail, a pre-buried 2-6 settlement plate.

Described corner reflector, is comprised of three orthogonal equilateral right-angle triangles or three orthogonal rectangular slabs.This corner reflector is metallic conduction material.

The utility model cooperatively interacts by microwave radar, settlement plate, corner reflector and data transmission system, has realized real-time, full-automatic, high precision measurement to high ferro subgrade settlement.Be particularly useful for the unattended subgrade settlement monitoring of subgrade settlement with a varied topography, physical environment is severe.

Ultimate principle of the present utility model, essential structure and method, the sedimentation that also can be applicable to the fields such as highway, bridge detects.Obviously, in the situation that not deviating from the utility model ultimate principle and scope thereof, those skilled in the art can make multiple corresponding changes and improvements according to the utility model, but these changes and improvements all belong to protection domain of the present utility model.

Accompanying drawing explanation

Fig. 1. the organigram of the utility model monitoring device

Fig. 2. the microwave radar circuit block diagram of the utility model monitoring device

Fig. 3. the block diagram of signal flow

Fig. 4. a radar is realized the Real-Time Monitoring schematic diagram to 6 targets

Fig. 5. by coordinate diagram, show and analysis FMCW signal flow

In figure, 01 microwave radar transceiver, 02 corner reflector, 03 have the settlement plate of Metallic rod; 101DDS, 102 modulators, 103 power amplifiers, 104 emitting antennas, 105 receive day money, 106 low-frequency amplifiers, 107 signal processors, 108 communication interfaces.

Embodiment

Below in conjunction with drawings and Examples, the utility model is described further.

1 one kinds of high ferro subgrade settlement monitoring radar installationss of embodiment

As shown in Figure 1, this monitoring device is mainly by microwave radar transceiver 01, corner reflector 02, be comprised of settlement plate 03 of Metallic rod etc.Described microwave radar transceiver 01 is that operating frequency range is the FMCW transceiver of 1GHz-100GHz.

Fig. 2 shows the circuit structure of microwave radar transceiver, and this main circuit will be comprised of 105 reception sky money, DDS101, modulator 102, power amplifier 103, emitting antenna 104, frequency mixer, low-frequency amplifier 106, signal processor 107, communication interface 108.DDS101 produces FMCW signal at low frequency, through modulator 102, produces radiofrequency signal, and emitting antenna 104 is sent after giving power amplifier 103 in a road; Frequency mixer is passed through with the signal receiving from receiving antenna 105 in another road, through low-frequency amplifier 106, directly give signal processor 107 again and carry out frequency spectra analysis, signal processor 107 calculates after distance corresponding to corresponding frequencies, and result is sent by communication interface 108 circuit.

As shown in Figure 3, the signal receiving by microwave transmitting and receiving machine 01, first must convert digital signal to by AD converter to the treatment scheme of 01 pair of collection signal of microwave transmitting and receiving machine, then carries out FFT conversion.The precision detecting for improving distance is further calculated signal with Chirp transform after FFT, thereby obtains precision for the settling amount of millimeter magnitude, and this settling data is sent by communication interface.Because the settling amount accuracy of detection of high ferro roadbed is millimeter magnitude.

Corner reflector described in Fig. 1 is that aluminium or other metal are made, and it is comprised of three orthogonal equilateral modification of right-angled triangle plate, can be also three orthogonal rectangular slabs.Settlement plate described in Fig. 1 be need in building railway, bury be in advance put in high ferro without below slag track, its can perception without the settling amount of slag track solid concrete roabed below; This plate extends to without slag track top, for established angle reflecting body to the Metallic rod of 10cm by a 1cm vertical with plate face.Should be noted this Metallic rod extension rod and can not be gun iron link without slag track solid concrete roabed, can be at a protection tube of Metallic rod extension rod outside cover in concrete enforcement, the internal diameter of protection tube is greater than the external diameter of Metallic rod extension rod.

In concrete enforcement, can be configured by accompanying drawing 4, first in the railway section roadbed side a distance that need to monitor settling amount, arrange in reference cement bar or Metallic rod, cement pole or Metallic rod be apart from floor level 5-8 rice, and the distance of cement pole or Metallic rod and rail and roadbed be take reference cement bar or Metallic rod, and not receive subgrade settlement impact be principle.Microwave radar transceiver 01 and humidity temperature pickup 04, wind direction sensor 05 are all fixed on cement pole or Metallic rod upper end, the antenna surface of radar, the direction of installing to corner reflector 02 towards corner reflector 1.Pre-buried 6 settlement plates of railroad track monitoring section; 6 corner reflectors are installed on respectively on 6 metal extension rods on settlement plate 03, and the strongest direction of the reflection of corner reflector is pointed to microwave radar antenna---and with corner reflector, strengthen the signal of settlement plate, be convenient to radar and detect.

Fig. 5 is the analysis that adopts coordinate diagram to carry out FMCW signal flow

In figure, horizontal ordinate t is the time, and ordinate f is transmission frequency.

At t ₁time, if transmission frequency is f ₁, after ground return at t ₂constantly received.Mistiming Δ t=t ₂-t ₁.Δ t be exactly electric wave from radar to ground, then reflex to radar, electric wave comes and goes the time of propagating, Δ t=2H/c.

Receiving the t of reflection wave ₂constantly, present transmission frequency f ₂, therefore, within the Δ t time, transmission frequency is from f ₁change to f ₂, Δ f=f ₂-f ₁.So can carry out measuring distance with Δ f, because it has reflected mistiming Δ t, reflect the distance between radar and monitoring point.

Frequency mixer produces difference frequency fb signal, and fb signal is directly proportional to ground distance.Signal processor is first by spectrum analysis, and rough calculation current demand signal frequency, then, by signal processing technology accurate Calculation fb, finally draws corresponding distance value.

From explanation above: if transmission frequency is f ₁, when electric wave turns back to receiving antenna from ground, the time delay Δ t that relatively transmits, but receive signal frequency f _r=f ₁(constant).At this moment after the Δ t time, transmission frequency becomes

$f_r+\frac{\mathrm{df}}{\mathrm{dt}}\mathrm{\&Delta;t}$

In formula, df/dt is the frequency change rate that frequency modulation transmits, its determine the frequency displacement Δ f transmit and modulation period T _m.Concerning the millimeter wave sedimentation of Linear Triangular ripple frequency modulation detects radar:

$\frac{\mathrm{df}}{\mathrm{dt}}=\frac{\frac{1}{2}\mathrm{\&Delta;F}}{\frac{1}{4}{T}_M}=2\mathrm{\&Delta;}{\mathrm{FF}}_M$

Transmitting (being direct signal) and receiving signal is added to frequency mixer mixing, after filtering, takes out difference frequency frequency F _b:

$F_b=f_t-f_r=f_r+\frac{\mathrm{df}}{\mathrm{dt}}\mathrm{\&Delta;t}-f_r=\frac{4\mathrm{\&Delta;}{\mathrm{FF}}_M}{c}H$

Because in frequency modulation transmits, Δ F, F _mconstant, difference frequency F _bbe directly proportional to distance H.Distance is larger, and difference frequency is larger, therefore can carry out measuring distance by the size of difference frequency.

For example, the modulating frequency transmitting is 100Hz, and frequency displacement is 100MHz:

$F_b=\frac{4\&times;100\&times;{10}^6\&times;100}{3\&times;{10}^8}H=133H(\mathrm{Hz}/m)$

Be that frequency scale is 133Hz/ rice, that is to say that distance becomes 1 meter, difference frequency changes 133Hz.

Radar for triangular modulation, the time that receives background return transmits the always time delay Δ t time relatively.If radar and monitoring point distance are constant, use difference frequency formula

$F_b=\frac{4\mathrm{\&Delta;}{\mathrm{FF}}_M}{c}H$

Utilize Continuous Wave with frequency modulation (FMCW) radargrammetry target distance parameter to have many good qualities.But the resolution of this method is directly proportional to transmitted wave frequency sweep bandwidth B, be c/B (c is the light velocity in vacuum).When B=1.5GHz, precision can only reach 10cm, can not meet the requirement of high-acruracy survey.Therefore adopt Chirp z method.

The contradiction existing in order to overcome simple FFT method, the FFT/Chirp z algorithm that " from coarse to fine " determines crest frequency is proposed here, its principle is: first utilize FFT (counting relatively less) to find out roughly the interval at signal peak value point place, use again chirp Z-transform (Chirp z) this interval segmentation, accurately determine peak point.Theoretic peak point is in 2 π (kmax-1)/N～2 π (kmax+1)/N interval.In this interval, do a small amount of Chinrp z conversion, just can greatly improve the precision of crest frequency.To the sequence v (n) obtaining with speed xB sampling N point, the spectral line interval delta f=xB/N after DFT, the range resolution Δ r=Txc/4N that directly DFT calculates.After M point Chirp z conversion, range resolution becomes Δ r/M.Theoretically, along with the infinitely raising of increase range resolution of M, but true really not so, the maximum effective value of M is relevant with the time span of sampling.

Claims (5)

1. a high ferro subgrade settlement monitoring radar installations, is characterized in that: mainly microwave radar transceiver (01), settlement plate (03), corner reflector (02), consist of; Settlement plate (03) is comprised of the Metallic rod perpendicular to ground of the sheet metal Ji Ban center welding that is parallel to ground of a diameter 10cm-50cm, corner reflector (02) is arranged in the Metallic rod of settlement plate (03), and the strongest direction of reflection of corner reflector (02) is pointed to microwave radar antenna;

Described microwave radar transceiver, its main circuit will be comprised of emitting antenna (104), DDS (101), modulator (102), power amplifier (103), frequency mixer, reception sky money (105), low-frequency amplifier (106), signal processor (107), communication interface (108); DDS (101) produces FMCW signal at low frequency, through modulator (102), produce radiofrequency signal, lead up to (103) after power amplifier enter emitting antenna (104), another road and the signal receiving from receiving antenna (105), pass through frequency mixer, passing through low-frequency amplifier (106) directly gives signal processor (107) and carries out frequency spectra analysis again, signal processor (107) calculates after distance corresponding to corresponding frequencies, and result is sent by communication interface (108).

2. radar installations is monitored in a kind of high ferro subgrade settlement according to claim 1, it is characterized in that: described settlement plate (03) is embedded in underground, and on the Metallic rod on settlement plate, end bassets.

3. radar installations is monitored in high ferro subgrade settlement according to claim 1, it is characterized in that: each monitoring section of single line high-speed railway rail, a pre-buried 1-3 settlement plate (03); Each monitoring section of two-wire high-speed railway rail, a pre-buried 2-6 settlement plate (03).

4. radar installations is monitored in a kind of high ferro subgrade settlement according to claim 1, it is characterized in that: described corner reflector (02) is comprised of three orthogonal equilateral right-angle triangles or three orthogonal rectangular slabs.

5. radar installations is monitored in a kind of high ferro subgrade settlement according to claim 4, it is characterized in that: described corner reflector (02) is metallic conduction material.