CN110514862B - A method for estimating running speed of high-speed rail using speed scanning - Google Patents

Abstract

The invention discloses a method for estimating the running speed of a high-speed railway by using speed scanning. The amplitude spectrum template function is designed according to the running speed and the typical parameters of high-speed railway trains in China; the signal excited when the high-speed railway passes by is intercepted in the seismic data of a single detector; Fourier transform the signal to obtain its amplitude spectrum; calculate the cumulative function of the energy spectrum of this signal to determine the frequency range where most of its energy is located; cross-correlate the template function of the amplitude spectrum with the actual amplitude spectrum; Find the largest cross-correlation coefficient and its corresponding speed in the data; take this speed as the base point, narrow the speed change interval, and re-establish the amplitude spectrum template function; perform the cross-correlation calculation between the amplitude spectrum template function and the actual amplitude spectrum again; find the maximum The speed corresponding to the cross-correlation coefficient of , and the speed is recorded as the final estimated speed v _final of the train running.

Description

A method for estimating running speed of high-speed rail using speed scanning

technical field

The invention belongs to the technical field of exploration geophysics, and in particular relates to a method for estimating the running speed of a high-speed rail using speed scanning.

Background technique

In 1964, the commercial operation of Japan's Shinkansen opened a new era of high-speed rail development in the world. Subsequently, countries such as France, Germany, Canada, Italy, Sweden and South Korea scrambled to build high-speed railways and put them into commercial operation. On August 1, 2008, China opened its first commercial high-speed rail line, the Beijing-Tianjin Intercity Railway. Up to now, the operating mileage of high-speed railways in China has reached 31,000 kilometers, which is close to 70% of the total operating mileage of high-speed railways in the world. Starting from 0:00 on July 10, 2019, the national railways implemented a new train operation map, with 3,310 pairs of mobile trains operating every day. With such a large number of trains running at high speed on high-speed railway lines, obtaining the running speed of high-speed railway trains is one of the important means to monitor the safety of train operation, and it is also the key to the subsequent use of high-speed railway trains to cause vibration signals. At present, the existing methods to obtain the running speed of high-speed trains mainly include:

Prior art 1: Obtaining the running speed of the train by using on-board equipment: The running speed of the train can be obtained directly by using the tachometer on the train, but the speed of the train when passing a certain position cannot be determined. In addition, GPS devices carried by high-speed trains can provide train speed and real-time train location. The required equipment is installed on the train and therefore requires permission from the HSR department.

Existing technology 2: Install video, optical and radar equipment in the high-speed rail line isolation area: Commonly used external speed measurement systems and methods include a camera-based speed estimation system, a train speed estimation method based on an optical sensor or two vibration sensors, and a Radar speed measurement method based on Doppler effect and speed estimation method based on wheel count, etc. The above method needs to be installed in a position where the rails can be seen, and requires permission to enter the isolation area and install equipment in the isolation area.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method for estimating the running speed of a high-speed rail by using velocity scanning, using seismic data collected by a single geophone outside the high-speed rail line isolation area, and using the method for velocity scanning It can estimate the running speed of the train and provide data for the subsequent judgment of the running state of the train.

The present invention adopts following technical scheme:

A method for estimating the running speed of a high-speed rail using speed scanning, comprising the following steps:

S1. Design the amplitude spectrum template function |F(ω,v)| according to the running speed and the typical parameters of the high-speed train;

S2. Intercept the signal excited by the passing of the high-speed rail from the single-geophone seismic data, and the time range corresponding to the valid signal obtained by the detector is [t ₁ , t ₂ ];

S3. Perform Fourier transform on the intercepted signal to obtain its amplitude spectrum;

S4, calculate the energy spectrum accumulation function of the signal intercepted in step S3, and determine the energy frequency interval;

S5, perform cross-correlation calculation between the amplitude spectrum template function and the actual amplitude spectrum;

S6, find the largest cross-correlation coefficient among all the cross-correlation coefficients in step S5, and its corresponding speed v _r ;

S7, take the speed determined in step S6 as a base point, reduce the speed variation interval, re-establish the amplitude spectrum template function;

S8, perform the cross-correlation calculation between the amplitude spectrum template function and the actual amplitude spectrum again;

S9. Find the speed corresponding to the largest cross-correlation coefficient, and record the speed as the final estimated speed v _final of the train running.

Specifically, in step S1, the amplitude spectrum template function |F(ω,v)| is:

v=v _initial +mΔv ₁

Among them, D is the length of each car body, v is the preset train speed, v _initial is the initial scanning speed, m is the index of the scanning speed, and Δv ₁ is the initial speed scanning interval.

Further, set the number of carriages N to be 16, the length of each car body D to be 25 meters, v _initial to be set to 30 km/h, the value range of m to be [0,370], Δv ₁ to be 1 km/h, A series of amplitude spectrum template functions contains a total of 371 functions.

Specifically, in step S3, it is assumed that the intercepted signal caused by the operation of the high-speed rail is y(t), and Fourier transform is performed on the signal to obtain its amplitude spectrum |Y(ω)| as:

Among them, [t ₁ , t ₂ ] is the time range corresponding to the effective signal obtained by the detector, y(t) is the signal caused by the operation of the high-speed rail, j is the imaginary unit ω is the frequency, and t is the speed.

Specifically, in step S4, the total energy E _y of the signal is firstly obtained, then the upper bound of the frequency of the signal is calculated, and the square of the amplitude is accumulated from the zero value of the frequency until the ratio of the accumulated value to the total energy E _y is high At the set retention rate η ₁ , the corresponding frequency is the desired upper frequency bound ω _max ; when obtaining the lower frequency bound, start accumulating from the upper frequency bound until the ratio of the accumulated value to the total energy E _y is higher than the set The retention rate η ₂ of , the corresponding frequency at this time is the required frequency lower bound ω _min , and the frequency range where 95% of the energy is determined is [ω _min , ω _max ].

Further, the total energy E _y of the intercepted signal:

Frequency upper bound ω _max :

Frequency lower bound ω _min :

Specifically, in step S5, the existing amplitude spectrum template function and the data amplitude spectrum actually received are cross-correlated, and the normalized cross-correlation coefficient Corr(v) corresponding to it is obtained as:

Among them, |Y(ω)| is the amplitude spectrum of the vibration signal caused by the high-speed rail, dω is the frequency element, and the value range of the cross-correlation coefficient is between [0, 1].

Specifically, in step S6, the corresponding speed v _r is:

v _r = argmax _v Corr(v)

where v _r is a rough estimate of the velocity v.

Specifically, in step S7, within the range of [v _r -Δv ₁ , v _r +Δv ₁ ], the speed search interval is reduced to Δv ₂ , and reconstructed according to the amplitude spectrum template function |F(ω,v)| Amplitude spectral template function |F(ω,v)|, where v=v _r -Δv ₁ +mΔv ₂ ,

Specifically, in step S9, within the range of [v _r -Δv ₁ , v _r +Δv ₁ ], according to the corresponding velocity v _r determined in step S6 to find the velocity corresponding to the maximum cross-correlation coefficient, then the velocity is recorded as is the final estimated speed v _final for the train to run.

Compared with the prior art, the present invention at least has the following beneficial effects:

The present invention is a method for estimating the running speed of a high-speed railway by using a speed scan, which can realize the running speed estimation of a high-speed railway by only using the data of a geophone outside the isolation area. The present invention firstly generates a series of force function amplitude spectra for the structural parameters of the high-speed train and the preset train running speed, and then calculates the cross-correlation function between the force function amplitude spectra at various speeds and the signal amplitude spectrum received by a single detector, Finally, the speed corresponding to the maximum value of the cross-correlation function is selected as the estimated value of the train running speed. Compared with the conventional high-speed train speed estimation method, the present invention can obtain the running speed of the high-speed train only by relying on the data of one geophone outside the isolation area.

Further, the amplitude spectrum template function is designed according to the running speed and the typical parameters of the high-speed train, which is beneficial to the subsequent calculation of the cross-correlation function between the amplitude spectrum template function and the actual signal.

Further, intercepting the signal excited by the high-speed train passing through the single-geophone seismic data is helpful for estimating the speed of each train passing by the geophone, and at the same time, it is helpful for reducing the computational complexity of the subsequent calculation of the amplitude spectrum.

Further, the energy spectrum accumulation function of the intercepted signal and the determination of the energy frequency range are beneficial to reduce the frequency range involved in the calculation of the cross-correlation function, and at the same time, it is beneficial to improve the noise resistance of the method.

Further, the cross-correlation calculation between the amplitude spectrum template function and the actual amplitude spectrum provides a data basis for the subsequent finding of the maximum correlation coefficient.

Further, searching for the largest cross-correlation coefficient and its corresponding speed among all the cross-correlation coefficients in step S5 can provide a relatively rough speed estimation, which is beneficial to improve the accuracy of subsequent speed estimation.

Further, taking the speed determined in step S6 as the base point, narrowing the speed change interval, re-establishing the amplitude spectrum template function and performing the cross-correlation calculation between the amplitude spectrum template function and the actual amplitude spectrum again, it is beneficial to improve the accuracy of subsequent speed estimation.

Further, finding the speed corresponding to the largest cross-correlation coefficient and recording the speed as the final estimated speed of the train operation is beneficial to obtain a higher-precision train speed estimate.

To sum up, the present invention can effectively and quickly realize the estimation of the running speed of a high-speed train using only one geophone data. A method that is independent of on-board/isolated devices.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the flow chart of the present invention;

Figure 2 is a seismic signal of a high-speed rail source received by a single geophone when train 1 passes by;

Fig. 3 is the amplitude spectrum of a high-speed rail source seismic signal received by a single detector when the train 1 passes by;

Fig. 4 is the amplitude spectrum template function generated according to 300km/h;

Figure 5 shows the cross-correlation function of a series of amplitude spectrum template functions and the actual signal amplitude spectrum.

Detailed ways

The present invention provides a method for estimating the running speed of a high-speed railway by using speed scanning, which can realize the running speed of a high-speed railway by only using the data of a geophone outside the isolation area. The invention firstly generates a series of force function amplitude spectra for the structural parameters of the high-speed train and the preset train running speed, and then calculates the cross-correlation function between the force function amplitude spectra at various speeds and the signal amplitude spectrum received by a single detector, Finally, the speed corresponding to the maximum value of the cross-correlation function is selected as the estimated value of the train running speed.

Please refer to Fig. 1, a kind of high-speed rail running speed estimation method utilizing speed scanning of the present invention, comprises the following steps:

S1. Design the amplitude spectrum template function according to the running speed and the typical parameters of the high-speed train;

The parameters of high-speed rail trains are relatively fixed, and the typical train parameters are selected as follows: the number of carriages N is 16, and the length of each car body D is 25 meters. Constantly changing the preset train speed v at certain speed intervals Δv ₁ (e.g. can vary from 30 km/h to 400 km/h in 1 km/h intervals), resulting in a series of speed-dependent amplitudes Spectral template function |F(ω,v)|:

v=v _initial +mΔv ₁ (2)

If the value of v _initial is set to 30 km/h, the value range of m is limited to [0,370], and Δv ₁ is 1 km/h, then this series of amplitude spectrum template functions contains a total of 371 functions.

S2. Intercept the signal excited by the passing of the high-speed rail from the single-geophone seismic data;

Embed a detector outside the isolation area of the high-speed rail line, intercept the signal excited by the high-speed rail from the signal received by the detector when the high-speed rail passes, and the time range corresponding to the obtained valid signal is [t ₁ , t ₂ ].

S3. Perform Fourier transform on the intercepted signal to obtain its amplitude spectrum;

Assuming that the intercepted signal caused by the operation of the high-speed rail is y(t), perform Fourier transform on the signal to obtain its amplitude spectrum |Y(ω)| as:

S4. Calculate the cumulative function of the energy spectrum of the signal, and determine the frequency range where most of its energy is located;

First get the total energy E _y of the signal:

Then calculate the upper bound of the frequency of the signal, and start to accumulate the square of the amplitude from the zero value of the frequency until the ratio of the accumulated value to the total energy E _y is higher than the set retention rate η ₁ , and the corresponding frequency is the Find the upper frequency bound ω _max :

In the same way, when obtaining the lower bound of frequency, the accumulation can be started from the upper bound of frequency until the ratio of the accumulated value to the total energy E _y is higher than the set retention rate η ₂ , and the corresponding frequency at this time is the lower bound of frequency ω. _min :

By setting η ₁ and η ₂ to be 0.975 and 0.95, respectively, the frequency interval in which 95% of the energy is located is determined as [ω _min , ω _max ].

S5, cross-correlate the amplitude spectrum template function with the actual amplitude spectrum;

In the frequency interval [ω _min , ω _max ], cross-correlate the existing series of amplitude spectrum template functions with the actual received data amplitude spectrum, and obtain the corresponding normalized cross-correlation coefficient Corr(v )for:

The value range of the cross-correlation coefficient is between [0, 1], and the closer it is to 1, the stronger the correlation between the amplitude spectrum template function at the current speed v and the actual data amplitude spectrum.

S6. Find the largest cross-correlation coefficient among all the cross-correlation coefficients, and its corresponding speed;

Find the largest cross-correlation coefficient among all the cross-correlation coefficients, and find the corresponding velocity v _r as:

v _r = argmax _v Corr(v) (8)

where v _r is a rough estimate of the velocity v.

S7, take the speed determined in step S6 as a base point, reduce the speed variation interval, re-establish the amplitude spectrum template function;

After the speed v _r is determined, within the range of [v _r -Δv ₁ , v _r +Δv ₁ ], reduce the speed search interval to Δv ₂ (the value can be 0.01 km/h), according to formula (1 ) reconstructs the amplitude spectrum template function |F(ω,v)|, where

v=v _r -Δv ₁ +mΔv ₂ (9)

in,

S8, perform the cross-correlation calculation between the amplitude spectrum template function and the actual amplitude spectrum again;

Use formula (7) to calculate the cross-correlation coefficient Corr(v) between the new template function and the actual signal.

S9. Find the speed corresponding to the largest cross-correlation coefficient, and record the speed as the final estimated speed v _final of the train running.

Within the range of [v _r -Δv ₁ , v _r +Δv ₁ ], use the formula (8) to find the speed corresponding to the maximum cross-correlation coefficient, and record the speed as the final estimated speed v _final of the train operation.

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather to represent only selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

The present invention is a method for estimating the running speed of a high-speed rail by using speed scanning, taking the signal received by a single low-frequency detector 75m away from the high-speed rail line when the high-speed rail passes as an example.

Table 1 shows the running speed of high-speed trains estimated by this method when 8 trains pass by

Please refer to Figure 2. Figure 2 shows the vibration signal caused by the high-speed rail source received by a single detector when the train 1 passes by. The sampling interval is 5ms, and there are 3001 sampling points in total. Please refer to Figure 3, Figure 4 and Figure 5, Figure 3 is the amplitude spectrum of the vibration signal caused by the passing of the train 1, Figure 4 is the amplitude spectrum template function generated according to 300km/h, Figure 5 is a series of amplitude spectrum template functions and Cross-correlation function of the actual signal amplitude spectrum. From Fig. 5, it can be obtained that the velocity corresponding to the maximum value of the cross-correlation coefficient is 83.58 m/s (ie, 300.89 km/h). The data received by a single detector when 8 trains pass by are analyzed by the method of this patent, and the estimated speed of the 8 trains obtained is shown in Table 1, which is consistent with the commercial operation speed of my country's high-speed rail.

The above content is only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention all fall within the scope of the claims of the present invention. within the scope of protection.

Claims (6)

1. A high-speed rail running speed estimation method utilizing speed scanning is characterized by comprising the following steps:

s1, designing an amplitude spectrum template function | F (omega, v) | according to the running speed and typical parameters of the high-speed train, wherein the amplitude spectrum template function | F (omega, v) | is as follows:

v＝v_initial+mΔv₁

wherein D is the length of each car body, v is the preset train speed, v_initialIs the initial scanning speed, m is an index of the scanning speed, Δ v₁Scanning the interval for an initial velocity;

s2, intercepting the signal excited by the passing of the high-speed rail in the seismic data of the single detector, wherein the time range corresponding to the effective signal acquired by the detector is [ t [ ]₁,t₂]；

S3, performing Fourier transform on the intercepted signal to obtain an amplitude spectrum of the signal, assuming that the intercepted signal caused by the operation of the high-speed rail is Y (t), performing Fourier transform on the signal to obtain an amplitude spectrum | Y (omega) | of the signal:

wherein, [ t ]₁,t₂]The time range corresponding to the effective signal acquired by the detector, y (t) is the intercepted signal caused by the running of the high-speed rail, j is an imaginary unit, omega is frequency, and t is speed;

s4, calculating an energy spectrum accumulation function of the signal intercepted in the step S3, and determining an energy frequency interval;

s5, performing cross-correlation calculation on the amplitude spectrum template function and the actual amplitude spectrum, performing cross-correlation on the existing amplitude spectrum template function and the actually received data amplitude spectrum, and obtaining a corresponding normalized cross-correlation coefficient corr (v) as follows:

wherein, Y (omega) is the amplitude spectrum of the vibration signal caused by the high-speed rail, d omega is the frequency infinitesimal, and the value range of the cross correlation coefficient is between [0,1 ];

s6, finding the largest cross correlation coefficient in all the cross correlation coefficients of the step S5 and the corresponding speed v_r；

S7, taking the speed determined in the step S6 as a base point, reducing the speed change interval, and reestablishing an amplitude spectrum template function;

s8, performing cross-correlation calculation of the amplitude spectrum template function and the actual amplitude spectrum again;

s9, finding the speed corresponding to the maximum cross correlation coefficient, and recording the speed as the final estimated speed v of the train operation_final。

2. The method according to claim 1, wherein in step S1, the number of cars N is set to 16, the length of car body D per car is set to 25 m, and v is set to v_initialSet to 30 km/hWhen m is in the range of [0,370 ]]，Δv₁At 1 km/h, a total of 371 functions were included in a series of amplitude spectra template functions.

3. The method of claim 1, wherein the total energy E of the intercepted signal is obtained first in step S4_yThen, the upper frequency bound of the signal is calculated, and the square of the amplitude is accumulated from zero value of the frequency until the accumulated value is equal to the total energy E_yIs higher than the set retention η₁The corresponding frequency is the upper frequency bound omega_max(ii) a When acquiring the lower frequency bound, the accumulation is started from the upper frequency bound until the accumulated value and the total energy E_yIs higher than the set retention η₂When the corresponding frequency is the lower frequency bound omega_minDetermining that 95% of energy is in a frequency interval [ omega ]_min,ω_max]。

4. Method for estimating the speed of operation of a high-speed railway according to claim 3, characterized in that the total energy E of the intercepted signal_y：

Upper frequency bound omega_max：

Lower frequency bound omega_min：

5. The method of claim 1, wherein the corresponding speed v is determined in step S6_rComprises the following steps:

v_r＝argmax_vCorr(v)

wherein v is_rIs a rough estimate of the velocity v.

6. The method of estimating a speed of operation of a high speed railway using a speed sweep as claimed in claim 1, wherein in step S7, [ v ] v_r-Δv₁,v_r+Δv₁]Within range, the velocity search interval is reduced to Δ v₂Reconstructing the amplitude spectrum template function | F (ω, v) | from the amplitude spectrum template function | F (ω, v) |, where v ═ v |_r-Δv₁+mΔv₂，

Images