CN102501886A - Method and system for detecting states of steel rail welding joints of high-speed railway - Google Patents

Abstract

The invention discloses a method and system for detecting the states of steel rail welding joints of a high-speed railway. The method comprises the following steps of: sampling the time of the vertical acceleration of an axle box to obtain a time sampling signal of the vertical acceleration of the axle box; carrying out band-pass filtration on the time sampling signal of the vertical acceleration of the axle box; calculating an effective value of the filtered vertical acceleration of the axle box; determining the positions of the welding joints according to the effective value of the vertical acceleration of the axle box, and extracting the effective value of the vertical acceleration of the axle box at each welding joint; and if the effective value of the vertical acceleration of the axle box at each welding joint is larger than a threshold value, judging that the welding joint is in a poor state. The states of the welding joints on the whole railway are detected according to data of the vertical acceleration of the axle box in the technical scheme of the embodiment of the invention, therefore, the current using states of the welding joints of the high-speed railway can be effectively detected, and a powerful theoretical basis is provided for reasonably and economically guiding the maintenance and the repair of the welding joints.

Description

Rail in high speed railway welded joint status detection method and system

Technical field

The present invention relates to high speed railway safe operation technical field, particularly a kind of rail in high speed railway welded joint status detection method and system.

Background technology

Steel rail weld joint is the weak link of high speed railway, has become the key equipment of restriction road speed and decision maintenance quality.Judge to steel rail weld joint comprises static judge and dynamically passes judgment on two kinds, mainly adopts static judge the, dynamically judge disappearance at present.

Static judge operation is fairly simple, at first utilizes the straight appearance of electronics to measure the flatness of steel rail weld joint, passes judgment on its state according to certain criterion then.As, be in the 1m scope at center with the weld seam, if flatness height fluctuation difference in any 200mm section is not more than 0.2mm, thinks that then state is qualified, otherwise need repairing.Fig. 1 is the static measurement scheme drawing as a result of the flatness of steel rail weld joint, and wherein upper and lower bound constitutes optimum waveform, and the ultimate range between them is called optimum peak value, usually value 0.2.

Static optimum waveform and the optimum peak value of passing judgment on rule of thumb decided, and lacks theoretical foundation.In addition, the flatness of welded joint is to the influence of vehicle-rail system dynamic characteristics, and is except relevant with its optimum peak value, closely related with the suspension parameter of the contact condition of wheel track, vehicle simultaneously.Therefore,, instruct maintenance, be necessary very much to carry out the dynamic judge of welded joint in order dynamically to grasp the state of steel rail weld joint.

According to wavelength division; The steel rail weld joint irregularity belongs to the shortwave irregularity; Wavelength is generally between 0.1～1m; And the detection wavelength of track geometry checking system is difficult to pass judgment on the safety and the influence of traveling comfort of the shortwave irregularity of steel rail weld joint to high speed railway track-Vehicular system operation usually between 3～120m, needs to study other auxiliary judge means.

Axle box directly with wheel to linking to each other, track irregularity is through taking turns being directly delivered on the axle box.Suppose that then the axle box vertical acceleration can directly reflect the influence of the excitation power in the caused external world of track shortwave irregularity to vehicle dynamics with taking turns pairing approximation regarding rigid construction as.Therefore, select to adopt the auxiliary track shortwave irregularity of passing judgment on of axle box vertical acceleration to vehicle dynamics Effect on Performance [list of references 1-7] both at home and abroad.Fig. 2 is the axle box vertical acceleration signal schematic representation of on ripple abrasion rail, surveying, and Fig. 3 is the axle box vertical acceleration signal schematic representation on normal rail.

Though both at home and abroad carried out number of research projects [list of references 8-10] aspect the axle box vertical acceleration diagnosis rail wear utilizing; Also do not see pertinent literature report and patent description but how to utilize the axle box vertical acceleration to pass judgment on the welded joint state, and the state of welded joint is significant for transporting safely of high speed railway.

Summary of the invention

To the defective of prior art, the embodiment of the invention provides a kind of high speed railway welded joint status detection method and system, and this scheme utilizes the axle box vertical acceleration to detect the state of welded joint, has filled up domestic and international technological gap in this area.

To achieve these goals, the embodiment of the invention provides a kind of rail in high speed railway welded joint status detection method, and said method comprises: the axle box vertical acceleration is carried out time sampling, obtain the time sampling signal of axle box vertical acceleration; Time sampling signal to said axle box vertical acceleration carries out bandpass filtering; The effective value of the axle box vertical acceleration after the calculation of filtered; Confirm the position of welded joint according to the effective value of said axle box vertical acceleration, and extract the effective value of the axle box vertical acceleration at each welded joint place; Whether the axle box vertical acceleration effective value of judging the welded joint place greater than threshold value, if greater than threshold value then judge that this welded joint state is bad.

Before the time sampling signal to said axle box vertical acceleration carried out bandpass filtering, said method also comprised: the lower-frequency limit F that preestablishes bandpass filtering _L, and the upper cut-off frequency F that dynamically confirms bandpass filtering _HWherein, dynamically confirm the upper cut-off frequency F of bandpass filtering _HSpecifically comprise: in the cooresponding frequency limit of the power spectrum of axle box vertical acceleration, the axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency; Calculate the percentum that the first dominant frequency energy in each power envelope spectrum accounts for this power envelope spectrum gross energy, draw the relation curve of said percentum and its corresponding frequency; The peak value frequency points corresponding of percentum in the said relation curve is confirmed as the upper cut-off frequency of bandpass filtering.

In the cooresponding frequency limit of said power spectrum in the axle box vertical acceleration; The axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency comprise: the energy of supposing the axle box vertical acceleration mainly is distributed in [F _a-F _b] between the Hz, to frequency from F _aHz is to F _bHz scans, and supposes that frequency increment is F _cHz, then the j time sweep rate is F _j=Fa+ (j-1) * FcHz; Repeat the following step A-step C, up to accomplishing [F _a-F _b] scanning of Hz frequency limit; A, the axle box vertical acceleration is carried out [F _L, F _j] the Hz bandpass filtering, generate filtered signal x _j(t); F wherein _LBe lower-frequency limit; B, utilize the Hilbert conversion to extract x _j(t) envelope obtains a _j(t); C, to a _j(t) carrying out the refinement Fourier analysis obtains and F _jThe power envelope spectrum of cooresponding axle box vertical acceleration.

The effective value of the axle box vertical acceleration after the said calculation of filtered comprises: suppose that the axle box vertical acceleration signal behind the bandpass filtering is { x _i, i=1,2 ... N}, N representes sampling number, the window width of supposing effective value is K; The sum of squares of K point before calculating

Obtain the 1st effective value:

To the j circulation, j=2,3 ... N-K+1, calculate all the other effective values: ${\mathrm{RMS}}_j=\sqrt{(S+x_{j+K-1}^2-x_{j-1}^2)/K}.$

Confirm the position of welded joint according to the effective value of said axle box vertical acceleration; And the effective value that extracts the axle box vertical acceleration at each welded joint place comprises: a plurality of effective values are divided into one group; Calculate the aviation value m and the variances sigma of every group of effective value, draw the reference value R of axle box vertical acceleration effective value according to said aviation value m and variances sigma _TWith axle box vertical acceleration effective value greater than reference value R _TThe transfinite position at a place of big value confirm as the big value welded joint that transfinites; According to the welded joint periodic spacings, confirm the transfinite position of all welded joints of welded joint centre of big value; Get near a plurality of big values same welded joint and transfinite the maxim of an effective value as the effective value of the axle box vertical acceleration at this welded joint place.

Before whether the axle box vertical acceleration effective value of judging the welded joint place is greater than threshold value; Said method also comprises: according to the effective value of the axle box vertical acceleration at said welded joint place, draw the distribution curve of the axle box vertical acceleration effective value at welded joint place; In the distribution curve with the axle box vertical acceleration effective value at welded joint place, corresponding probability greater than the effective value of setting threshold value as the threshold value that detects the welded joint state.

To achieve these goals; The embodiment of the invention also provides a kind of rail in high speed railway welded joint status detection system; Said system comprises: the acceleration/accel sampling setup, be used for the axle box vertical acceleration is carried out time sampling, and obtain the time sampling signal of axle box vertical acceleration; Band pass filter means is used for the time sampling signal of said axle box vertical acceleration is carried out bandpass filtering; The effective value computer device is used for the effective value of the axle box vertical acceleration after the calculation of filtered; The welded joint registration device is used for confirming according to the effective value of said axle box vertical acceleration the position of welded joint, and extracts the effective value of the axle box vertical acceleration at each welded joint place; Whether connector status detecting device, the axle box vertical acceleration effective value that is used to judge the welded joint place greater than threshold value, if greater than threshold value then judge that this welded joint state is bad.

Said system also comprises the logical upper cut-off frequency generating apparatus of band; The logical upper cut-off frequency generating apparatus of said band comprises: the resonance and demodulation unit; Be used in the cooresponding frequency limit of the power spectrum of axle box vertical acceleration; The axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency; Percentum curve drawing unit, the first dominant frequency energy that is used for calculating each power envelope spectrum accounts for the percentum of this power envelope spectrum gross energy, draws the relation curve of said percentum and its corresponding frequency; Upper cut-off frequency is confirmed the unit, is used for the peak value frequency points corresponding of said relation curve percentum is confirmed as the upper cut-off frequency of bandpass filtering.

Said welded joint registration device comprises: the reference value generation unit, be used for a plurality of effective values are divided into one group, and calculate the aviation value m and the variances sigma of every group of effective value, draw the reference value R of axle box vertical acceleration effective value according to said aviation value m and variances sigma _TFirst welded joint is confirmed the unit, is used for axle box vertical acceleration effective value greater than reference value R _TThe transfinite position at a place of big value confirm as the big value welded joint that transfinites; Second welded joint is confirmed the unit, is used for according to the welded joint periodic spacings, confirms the transfinite position of all welded joints of welded joint centre of big value; The welded joint effective value is confirmed the unit, and being used to get near the same welded joint a plurality of big value transfinites the maxim of an effective value as the effective value of the axle box vertical acceleration at this welded joint place.

Said system also comprises the threshold process unit; Said threshold process unit specifically comprises: the distribution curve drawing unit; Be used for effective value, draw the distribution curve of the axle box vertical acceleration effective value at welded joint place according to the axle box vertical acceleration at said welded joint place; Threshold value is confirmed the unit, is used for the distribution curve with the axle box vertical acceleration effective value at welded joint place, and corresponding probability is greater than the threshold value of the effective value of setting threshold value as detection welded joint state.

The technical scheme of the embodiment of the invention detects welded joint state completely according to the data of axle box vertical acceleration; Can effectively detect the current running condition of high speed railway welded joint, for reasonable economy instructs the maintenance of welded joint that strong theoretical foundation is provided.

Description of drawings

Fig. 1 is the static measurement scheme drawing as a result of the flatness of prior art steel rail weld joint;

Fig. 2 is the axle box vertical acceleration signal schematic representation of on ripple abrasion rail, surveying;

Fig. 3 is the axle box vertical acceleration signal schematic representation on normal rail;

Fig. 4 is the detailed schematic diagram of embodiment of the invention high speed railway welded joint status detection method;

Fig. 4 a is the diagram of circuit of the high speed railway welded joint state-evaluation method of the embodiment of the invention;

Fig. 5 is the power envelope spectrum scheme drawing of the pairing axle box vertical acceleration of certain frequency of the embodiment of the invention;

Fig. 6 is that the embodiment of the invention first dominant frequency power percentum is with the frequency filtering change curve;

Fig. 7 is the axle box acceleration/accel waveform scheme drawing of embodiment of the invention actual measurement;

Fig. 8 a is one of effective value scheme drawing of the axle box vertical acceleration that calculates of the embodiment of the invention;

Fig. 8 b be the axle box vertical acceleration that calculates of the embodiment of the invention the effective value scheme drawing two;

Fig. 8 c be the axle box vertical acceleration that calculates of the embodiment of the invention the effective value scheme drawing three;

Fig. 9 is the distribution curve scheme drawing of embodiment of the invention actual measurement axle box vertical acceleration effective value;

Figure 10 is an embodiment of the invention high speed railway welded joint state final detection result scheme drawing;

Figure 11 is the schematic diagram of embodiment of the invention rail in high speed railway welded joint status detection system;

Figure 11 a is the refinement functional block diagram of the logical upper cut-off frequency generating apparatus 115 of band among Figure 11;

Figure 11 b is the refinement functional block diagram of welded joint registration device 113 among Figure 11;

Figure 11 c is the refinement functional block diagram of threshold process device 116 among Figure 11.

The specific embodiment

The embodiment of the invention provides a kind of high speed railway welded joint status detection method and system.Compare with irregular wear, wave and ripple abrasion, the shortwave irregularity at welded joint place had both had the high-frequency percussion characteristic, had the low-frequency cycle characteristic simultaneously.Utilize the axle box vertical acceleration to pass judgment on the problem that steel rail weld joint will run into two keys, the i.e. location of the selection of bandpass filtering frequency and welded joint.With different in undulatory wear concentrates on narrower high-frequency range, the high-frequency percussion ripple that welded joint causes is distributed in the very wide frequency band, and changes.

According to the Fourier transform principle; The steel rail weld joint momentary impulse is an infinite bandwidth signal from frequency domain; There are all frequency contents in theory, and are uniformly distributed with, thereby must contain the right-axle box system eigentone composition of wheel along whole frequency axis energy; Also just must cause the characteristic oscillation of system, produce generalized resonance.The embodiment of the invention utilizes resonance and demodulation to propose new high speed railway welded joint condition detection method and system based on above-mentioned principle.

The groundwork of the axle box vertical acceleration being carried out resonance and demodulation is following:

1, axle box vertical acceleration signal is carried out bandpass filtering, remember that filtered axle box vertical acceleration continuous signal is x (t), t is sampling instant.

2, utilize the Hilbert conversion to extract the envelope of x (t), obtain a (t).

3, a (t) is carried out the refinement Fourier analysis, obtain the refinement power envelope spectrum of axle box vertical acceleration.

The dynamic testing method of embodiment of the invention steel rail weld joint mainly comprises following algorithm: the fast algorithm that moves effective value based on the axle box vertical acceleration of resonance and demodulation; Axle box vertical acceleration bandpass filtering upper cut-off frequency self adaptation based on resonance and demodulation is chosen algorithm; And based on the accurate location and the state-detection algorithm of the welded joint of resonance and demodulation.

For the purpose, technical scheme and the advantage that make the embodiment of the invention clearer; To combine the accompanying drawing in the embodiment of the invention below; Technical scheme in the embodiment of the invention is carried out clear, intactly description; Obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of claim protection of the present invention.

Fig. 4 is the detailed schematic diagram of embodiment of the invention high speed railway welded joint status detection method; As shown in Figure 4; This method comprised for two steps: the 1st step (left-half of Fig. 4) was utilized the effective value at a large amount of actual measurement axle box vertical acceleration data computation welded joint places; And, calculate threshold value according to the effective value distribution character; Particularly, Fig. 7 is the axle box acceleration/accel waveform scheme drawing of actual measurement; Wherein left-half is an axle box vertical acceleration signal, and right half part is the axle box transverse acceleration signal, can find out, when transverse acceleration variable was big, also the phase strain was big for vertical acceleration; Fig. 8 a-Fig. 8 c is the effective value scheme drawing of the axle box vertical acceleration that calculates; Fig. 9 is the distribution curve scheme drawing of axle box vertical acceleration effective value; The 2nd step (right half part of Fig. 4) is according to the vertical acceleration effective value and the threshold value at welded joint place, the state of online detection welded joint.

The key algorithm in the 1st step and the 2nd step is identical.Key algorithm comprises: the axle box vertical acceleration moves the fast algorithm of effective value, the accurate location algorithm that axle box vertical acceleration bandpass filtering upper cut-off frequency self adaptation is chosen algorithm, welded joint.In addition; The 1st step also comprised the algorithm of the axle box vertical acceleration effective value distribution of calculating the welded joint place; The embodiment of the invention adopts histogram to represent the probability distribution function of effective value, then it is carried out normalization method and handles the distribution function that obtains effective value, and specifically divided for 3 steps accomplished: the 1st step calculated the axle box vertical acceleration effective value at welded joint place; The 2nd step calculated the axle box vertical acceleration effective value histogram at welded joint place, i.e. probability distribution function; The 3rd step, normalization method obtained its distribution function to histogram.

Fig. 4 a is the diagram of circuit of the high speed railway welded joint state-evaluation method of the embodiment of the invention, and shown in Fig. 4 a, this method comprises:

S401, the axle box vertical acceleration is carried out time sampling, obtain the time sampling signal of axle box vertical acceleration.

Therefore the collecting device of axle box vertical acceleration is installed on the axle box of comprehensive detection train, and train is gathered the axle box vertical acceleration of a plurality of positions on the rail in operational process, and the sampling to the vertical acceleration of axle box is a time sampling.

S402, the time sampling signal of axle box vertical acceleration is carried out bandpass filtering.

The frequency limit upper limit of bandpass filtering will be chosen algorithm through the described bandpass filtering upper cut-off frequency of hereinafter self adaptation and obtain; Because the axle box vertical acceleration mainly is a radio-frequency component; The low-frequency component proportion seldom; Therefore the selection of lower limit influences seldom the result of filtering, can preestablish a lower frequency limit F according to actual needs _L, like 20Hz.

Suppose that the embodiment of the invention adopts bandpass filtering upper cut-off frequency self adaptation to choose the upper cut-off frequency F that algorithm obtains _HBe 450Hz, with F _L=20HZ is an example, and then the frequency limit of bandpass filtering is [20,450] Hz.Need to prove; This concrete frequency limit only is used for the embodiment of the invention explanation that makes an explanation; And the protection domain that is not used in claim limits, and what this case claim needed protection is the method that how to obtain this frequency limit, but not concrete frequency limit numerical value.

The axle box vertical acceleration bandpass filtering upper cut-off frequency self adaptation that the embodiment of the invention adopted is chosen algorithm and is comprised: at first; In the cooresponding frequency limit of the power spectrum of axle box vertical acceleration; The axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency; Then, calculate the percentum that the first dominant frequency energy in each power envelope spectrum accounts for this power envelope spectrum gross energy, draw the relation curve of said percentum and its corresponding frequency; At last, the peak value frequency points corresponding of percentum in the said relation curve is confirmed as the bandpass filtering cutoff frequency.

Concrete algorithm is following:

(1) in the cooresponding frequency limit of the power spectrum of axle box vertical acceleration, the axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency.

The energy of supposing the axle box vertical acceleration mainly is distributed in [F _a-F _b] between the Hz, to frequency from F _aHz is to F _bHz scans, and supposes that frequency increment is F _cHz, then the j time sweep rate is F _j=Fa+ (j-1) * FcHz; Repeat the following step A-step C, up to accomplishing [F _a-F _b] scanning of Hz frequency limit.

A, the axle box vertical acceleration is carried out [F _L, F _j] the Hz bandpass filtering, generate filtered signal x _j(t); F wherein _LBe lower-frequency limit, like 20Hz;

B, utilize the Hilbert conversion to extract x _j(t) envelope obtains a _j(t);

C, to a _j(t) carry out the refinement Fourier analysis, obtain and F _jThe power envelope spectrum of the cooresponding axle box vertical acceleration of Hz.

In the present embodiment; Power spectral analysis through to the axle box vertical acceleration can know that the energy of axle box vertical acceleration mainly is distributed between [100-600] Hz, therefore frequency is scanned from 100Hz to 600Hz; Suppose that frequency increment is 10Hz, then the j time sweep rate is F _j=100+ (j-1) * 10Hz; This frequency increment can also change according to the realistic accuracy demand.

Steps A, B, C are referred to as the process of resonance and demodulation; Through this resonance and demodulation process just can access and frequency limit [100-600] Hz of the power spectrum of axle box vertical acceleration between the pairing a plurality of power envelopes spectrums of each frequency, Fig. 5 be that the power envelope of the pairing axle box vertical acceleration of certain frequency is composed scheme drawing.

(2) calculate the percentum that the first dominant frequency energy in each power envelope spectrum accounts for this power envelope spectrum gross energy, draw the relation curve of said percentum and its corresponding frequency.

D, from Fig. 5, therefore the energy of preceding 5Hz can be represented gross energy, calculates energy E 1 and the energy E in the preceding 5Hz of first dominant frequency of envelope spectrum respectively;

E, the calculating first dominant frequency energy account for gross energy percentum

Step D, E also are on-cycle processes, need the pairing power envelope of each frequency spectrum all be carried out one time, draw the percentum of each power envelope spectrum, draw the relation curve of said percentum and corresponding frequency, and be as shown in Figure 6.

(3) the peak value frequency points corresponding of percentum in the said relation curve is confirmed as the bandpass filtering upper cut-off frequency.

Peak value among Fig. 6 is 450HZ, is 450Hz so obtain the upper limit of frequency filtering scope.

The effective value of the axle box vertical acceleration after S403, the calculation of filtered.

When the embodiment of the invention moves effective value in calculating axle box vertical acceleration, by the time sampling.Suppose that the axle box vertical acceleration signal behind the bandpass filtering is { x _i, i=1,2 ... N}, wherein N representes sampling number, and the window width of supposing effective value is K, and then the algorithm of the mobile effective value of axle box vertical acceleration is following:

(1) calculate preceding K the sum of squares of putting

and obtain the 1st effective value:

${\mathrm{<figure-callout\; id="1"\; label="RMS"\; filenames="HDA0000105546700000011.png,HDA0000105546700000043.png"\; state="\{\{state\}\}">RMS</figure-callout>}}_1=\sqrt{S/K}---\left(1\right)$

(2) to the j circulation, j=2,3 ... N-K+1, calculate all the other effective values:

${\mathrm{RMS}}_j=\sqrt{(S+x_{j+K-1}^2-x_{j-1}^2)/K}---\left(2\right)$

Casehistory is following: suppose sampling number N=11, and the long K=7 of window, the axle box vertical acceleration signal behind the bandpass filtering is { x _i, i=1,2 ... 11}, then the definition of the 1st to N-K+1=5 effective value and calculating are as follows:

${\mathrm{<figure-callout\; id="1"\; label="RMS"\; filenames="HDA0000105546700000011.png,HDA0000105546700000043.png"\; state="\{\{state\}\}">RMS</figure-callout>}}_1=\sqrt{\frac{1}{7}\underset{i=1}{\overset{7}{\mathrm{\&Sigma;}}}{x}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA0000105546700000043.png,HDA0000105546700000051.png"\; state="\{\{state\}\}">i</figure-callout>}}^2}$

${\mathrm{<figure-callout\; id="2"\; label="RMS"\; filenames="HDA0000105546700000043.png,HDA0000105546700000051.png"\; state="\{\{state\}\}">RMS</figure-callout>}}_2=\sqrt{\frac{1}{7}\underset{i=2}{\overset{8}{\mathrm{\&Sigma;}}}{x}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA0000105546700000043.png,HDA0000105546700000051.png"\; state="\{\{state\}\}">i</figure-callout>}}^2}$

${\mathrm{<figure-callout\; id="3"\; label="RMS"\; filenames="HDA0000105546700000043.png"\; state="\{\{state\}\}">RMS</figure-callout>}}_3=\sqrt{\frac{1}{7}\underset{i=3}{\overset{9}{\mathrm{\&Sigma;}}}{x}_{\mathrm{<figure-callout\; id="2"\; label="i"\; filenames="HDA0000105546700000043.png,HDA0000105546700000051.png"\; state="\{\{state\}\}">i</figure-callout>}}^2}$

${\mathrm{RMS}}_4=\sqrt{\frac{1}{7}\underset{i=4}{\overset{10}{\mathrm{\&Sigma;}}}{\mathrm{<figure-callout\; id="2"\; label="x\; i"\; filenames="HDA0000105546700000043.png,HDA0000105546700000051.png"\; state="\{\{state\}\}">x</figure-callout>}}_i^{}}$

${\mathrm{<figure-callout\; id="5"\; label="RMS"\; filenames="HDA0000105546700000012.png,HDA0000105546700000042.png"\; state="\{\{state\}\}">RMS</figure-callout>}}_5=\sqrt{\frac{1}{7}\underset{i=5}{\overset{11}{\mathrm{\&Sigma;}}}{\mathrm{<figure-callout\; id="2"\; label="x\; i"\; filenames="HDA0000105546700000043.png,HDA0000105546700000051.png"\; state="\{\{state\}\}">x</figure-callout>}}_i^{}}$

Can know that through the calculated amount analysis be linear the computing time of the algorithm of the mobile effective value of aforementioned calculation axle box vertical acceleration, promptly computation complexity is O (N).

S404, confirm the position of welded joint, and extract the effective value of the axle box vertical acceleration at each welded joint place according to the effective value of axle box vertical acceleration.

Specifically comprise: a plurality of effective values are divided into one group, calculate the aviation value m and the variances sigma of every group of effective value, draw the reference value R of axle box vertical acceleration effective value according to said aviation value m and variances sigma _TWith axle box vertical acceleration effective value greater than reference value R _TThe transfinite position at a place of big value confirm as the big value welded joint that transfinites; According to the welded joint periodic spacings, confirm the transfinite position of all welded joints of welded joint centre of big value; Get near a plurality of big values same welded joint and transfinite the maxim of an effective value as the effective value of the axle box vertical acceleration at this welded joint place.

The welded joint Precision Orientation Algorithm is following:

(1) a plurality of effective values are divided into one group, calculate the aviation value m and the variances sigma of the effective value of each group, as, by formula the reference value R of the effective value of axle box vertical acceleration is calculated in (3) _T, the reference value that obtains has only demonstrated one group reference value among Fig. 8 a-Fig. 8 c shown in the dotted line among Fig. 8 a-Fig. 8 c;

R _T＝m+2.5σ (3)

(2) find out effective value greater than reference value R _TPoint, being defined as big value transfinites a little, the transfinite position at a place of these big values is exactly a welded joint, is designated as The result as among Fig. 8 a greater than shown in ' o ' point of zero; Owing to have a plurality of big values to transfinite a little around the same welded joint, so a plurality of ' o ' point is arranged;

(3)

carried out polymerization; The big value at same welded joint place transfinited keep a maxim; With ' o ' point that guarantees that same welded joint has only 1 big value to transfinite, the big value after the polymerization transfinite welded joint be designated as result as among Fig. 8 b greater than shown in ' o ' point of zero;

(4) be approximately 100m according to the welded joint periodic spacings; Find out the big value welded joint in the middle of the welded joint that transfinites; Obtain all welded joints at last, and the cooresponding axle box vertical acceleration of all welded joints effective value, as among Fig. 8 c greater than shown in ' o ' point of zero.

S405, if the axle box vertical acceleration effective value at welded joint place greater than threshold value, judges that then this welded joint state is bad.

The mode of confirming threshold value is following: according to the effective value of the axle box vertical acceleration at said welded joint place, draw the distribution curve of the axle box vertical acceleration effective value at welded joint place; In the distribution curve with the axle box vertical acceleration effective value at welded joint place, corresponding probability greater than the effective value of setting threshold value as the threshold value that detects the welded joint state.

With Fig. 9 is example, and in the distribution curve of the axle box vertical acceleration effective value at welded joint place shown in Figure 9, the hypothetical probabilities threshold value is 99.5%, and then corresponding probability is that 99.5% effective value 50m/s/s is exactly a threshold value of passing judgment on the welded joint state.Final detection result is shown in figure 10, and the effective value of state process and poor welding joint is apparently higher than the effective value at other welded joint place.

Corresponding to the method for Fig. 4 a, the embodiment of the invention also provides a kind of high speed railway welded joint state-evaluation system.Figure 11 is the schematic diagram of embodiment of the invention rail in high speed railway welded joint status detection system, and shown in figure 11, this system comprises:

Acceleration/accel sampling setup 110 is used for the axle box vertical acceleration is carried out time sampling, obtains the time sampling signal of axle box vertical acceleration; Band pass filter means 111 is used for the time sampling signal of said axle box vertical acceleration is carried out bandpass filtering; Effective value computer device 112 is used for the effective value of the axle box vertical acceleration after the calculation of filtered; Welded joint registration device 113 is used for confirming according to the effective value of said axle box vertical acceleration the position of welded joint, and extracts the effective value of the axle box vertical acceleration at each welded joint place; Whether connector status detecting device 114, the axle box vertical acceleration effective value that is used to judge the welded joint place greater than threshold value, if greater than threshold value then judge that this welded joint state is bad.

Shown in figure 11; This system also comprises the logical upper cut-off frequency generating apparatus 115 of band; Shown in Figure 11 a, the logical upper cut-off frequency generating apparatus of this band comprises: resonance and demodulation unit 1150 is used in the cooresponding frequency limit of the power spectrum of axle box vertical acceleration; The axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency; Percentum curve drawing unit 1151, the first dominant frequency energy that is used for calculating each power envelope spectrum accounts for the percentum of this power envelope spectrum gross energy, draws the relation curve of said percentum and its corresponding frequency; Upper cut-off frequency is confirmed unit 1152, is used for the peak value frequency points corresponding of said relation curve percentum is confirmed as the upper cut-off frequency of bandpass filtering.

Figure 11 b is the refinement functional block diagram of welded joint registration device 113; Shown in Figure 11 b; Welded joint registration device 113 specifically comprises: reference value generation unit 1130; Be used for a plurality of effective values are divided into one group, calculate the aviation value m and the variances sigma of every group of effective value, draw the reference value R of axle box vertical acceleration effective value according to said aviation value m and variances sigma _TFirst welded joint is confirmed unit 1131, is used for axle box vertical acceleration effective value greater than reference value R _TThe transfinite position at a place of big value confirm as the big value welded joint that transfinites; Second welded joint is confirmed unit 1132, is used for according to the welded joint periodic spacings, confirms the transfinite position of all welded joints of welded joint centre of big value; The welded joint effective value is confirmed unit 1133, and being used to get near the same welded joint a plurality of big value transfinites the maxim of an effective value as the effective value of the axle box vertical acceleration at this welded joint place.

Shown in figure 11, this system also comprises threshold process device 116; Shown in Figure 11 c, threshold process device 116 specifically comprises: distribution curve drawing unit 1160, be used for effective value according to the axle box vertical acceleration at said welded joint place, and draw the distribution curve of the axle box vertical acceleration effective value at welded joint place; Threshold value is confirmed unit 1161, is used for the distribution curve with the axle box vertical acceleration effective value at welded joint place, and corresponding probability is greater than the threshold value of the effective value of setting threshold value as detection welded joint state.

The beneficial effect that technical scheme of the present invention is brought: through in-depth analysis to the axle box vertical acceleration data of more than 1000 kilometer actual measurement of certain line; The binding resonant demodulation techniques calculate the distribution function curve of welded joint place effective value can be found out, the distribution curve that twice data acquisition and calculation obtains under the identical operating mode coincide consistent.Therefore, new welded joint Precision Orientation Algorithm is stable, and the distribution curve that obtains has good repeatability.And, utilize new method of inspection that welded joint state is completely passed judgment on, can effectively detect high speed railway welded joint state, for reasonable economy instructs the maintenance of welded joint that strong theoretical foundation is provided.

Above embodiment is only in order to the technical scheme of the explanation embodiment of the invention, but not to its restriction; Although the embodiment of the invention has been carried out detailed explanation with reference to previous embodiment; Those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these are revised or replacement, do not make the spirit and the scope of each embodiment technical scheme of the essence disengaging embodiment of the invention of relevant art scheme.

List of references:

[1]C.Esweld.Modern?Railway?Track[M].Duisburg：MRT-productions，2001.

[2]M.Bocciolone，A.

，A.Cigada，A.Collina.A?Measurement?System?for?Quick?Rail?Inspection?and?Effective?Track?Maintenance?Strategy[J].Mechanical?Systems?and?Signal?Processing，2007(21)：1242-1254.

[3]Sunaga?Y.，T.Ide.and?M.Kanao.A?practical?use?of?axle-box?acceleration?to?control?the?short?wave?track?irregularities?on?SHINKANSEN[J].RTRI?quarterly?Report?1995，9(2)：35-40.

[4]Sunaga?Y.，Snal，I.and?Ide，T..A?method?to?control?the?short?wave?track?irregularities?utilizing?axle-box?acceleration[J].RTRI?quarterly?Report，1997，38(4)：176-181.

[5]Yoshida，M.，Shinowaki，S.and?Sunaga，Y..A?study?on?lateral?axle-box?acceleration?for?detecting?irregularities?of?rail?joints?on?sharp?curves[J].Jointed?Railway?Technology?Symposium(J-Rail2004)，2004，11：91-54.

[6]Hirofumi?TANAKA，Atsushi?FURUKAWA.Management?Method?for?Large?Wheel?Loads?and?Lateral?Forces?Using?Axle-box?Acceleration?and?Track?Irregularity[J].RTRI?quarterly?Report，2009，50(2)：116-122.

[7]Eric?G.Berggren，Martin?X.D.Li，Jan?Spannar.A?new?approach?to?the?analysis?and?presentation?of?vertical?track?geometry?quality?and?rail?roughness[J].Wear?2008(265)：1488-1496.

[8]A?Bracciali?and?G?Cascini.Detection?of?corrugation?and?wheelflats?of?railway?wheels?using?energy?and?cepstrum?analysis?of?rail?acceleration[J].Proc?Instn?Mech?Engrs，1997，211，(Part?E)：109-116.

[9]Grassie，S.L.Rail?corrugation：advances?in?measurement，understanding?and?treatment[J].Wear，2005，258：1224-1234.

[10]Hempelmann，K.and?Knothe，K.An?extended?linear?model?for?the?prediction?of?short?pitch?corrugation[J].Wear，1996，191：161-169.

Claims (10)

1. rail in high speed railway welded joint status detection method is characterized in that said method comprises:

The axle box vertical acceleration is carried out time sampling, obtain the time sampling signal of axle box vertical acceleration;

Time sampling signal to said axle box vertical acceleration carries out bandpass filtering;

The effective value of the axle box vertical acceleration after the calculation of filtered;

Confirm the position of welded joint according to the effective value of said axle box vertical acceleration, and extract the effective value of the axle box vertical acceleration at each welded joint place;

Whether the axle box vertical acceleration effective value of judging the welded joint place greater than threshold value, if greater than threshold value then judge that this welded joint state is bad.

2. method according to claim 1 is characterized in that, before the time sampling signal to said axle box vertical acceleration carried out bandpass filtering, said method also comprised: the lower-frequency limit F that preestablishes bandpass filtering _L, and the upper cut-off frequency F that dynamically confirms bandpass filtering _HWherein, dynamically confirm the upper cut-off frequency F of bandpass filtering _HSpecifically comprise:

In the cooresponding frequency limit of the power spectrum of axle box vertical acceleration, the axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency;

Calculate the percentum that the first dominant frequency energy in each power envelope spectrum accounts for this power envelope spectrum gross energy, draw the relation curve of said percentum and its corresponding frequency;

The peak value frequency points corresponding of percentum in the said relation curve is confirmed as the upper cut-off frequency of bandpass filtering.

3. method according to claim 2; It is characterized in that; In the cooresponding frequency limit of said power spectrum in the axle box vertical acceleration; The axle box vertical acceleration is carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency comprise:

The energy of supposing the axle box vertical acceleration mainly is distributed in [F _a-F _b] between the Hz, to frequency from F _aHz is to F _bHz scans, and supposes that frequency increment is F _cHz, then the j time sweep rate is F _j=Fa+ (j-1) * FcHz; Repeat the following step A-step C, up to accomplishing [F _a-F _b] scanning of Hz frequency limit;

A, the axle box vertical acceleration is carried out [F _L, F _j] the Hz bandpass filtering, generate filtered signal x _j(t); F wherein _LBe lower-frequency limit;

B, utilize the Hilbert conversion to extract x _j(t) envelope obtains a _j(t);

C, to a _j(t) carry out the refinement Fourier analysis, obtain and F _jThe power envelope spectrum of the cooresponding axle box vertical acceleration of Hz.

4. method according to claim 1 is characterized in that, the effective value of the axle box vertical acceleration after the said calculation of filtered comprises:

Suppose that the axle box vertical acceleration signal behind the bandpass filtering is { x _i, i=1,2 ... N}, N representes sampling number, the window width of supposing effective value is K; The sum of squares of K point before calculating Obtain the 1st effective value: ${\mathrm{RMS}}_1=\sqrt{S/K};$

To the j circulation, j=2,3 ... N-K+1, calculate all the other effective values: ${\mathrm{RMS}}_j=\sqrt{(S+x_{j+K-1}^2-x_{j-1}^2)/K}.$

5. method according to claim 1 is characterized in that, confirms the position of welded joint according to the effective value of said axle box vertical acceleration, and the effective value that extracts the axle box vertical acceleration at each welded joint place comprises:

A plurality of effective values are divided into one group, calculate the aviation value m and the variances sigma of every group of effective value, draw the reference value R of axle box vertical acceleration effective value according to said aviation value m and variances sigma _T

With axle box vertical acceleration effective value greater than reference value R _TThe transfinite position at a place of big value confirm as the big value welded joint that transfinites;

According to the welded joint periodic spacings, confirm the transfinite position of all welded joints of welded joint centre of big value;

Get near a plurality of big values same welded joint and transfinite the maxim of an effective value as the effective value of the axle box vertical acceleration at this welded joint place.

6. method according to claim 1 is characterized in that, before whether the axle box vertical acceleration effective value of judging the welded joint place was greater than threshold value, said method also comprised:

According to the effective value of the axle box vertical acceleration at said welded joint place, draw the distribution curve of the axle box vertical acceleration effective value at welded joint place;

In the distribution curve with the axle box vertical acceleration effective value at welded joint place, corresponding probability greater than the effective value of setting threshold value as the threshold value that detects the welded joint state.

7. rail in high speed railway welded joint status detection system is characterized in that said system comprises:

The acceleration/accel sampling setup is used for the axle box vertical acceleration is carried out time sampling, obtains the time sampling signal of axle box vertical acceleration;

Band pass filter means is used for the time sampling signal of said axle box vertical acceleration is carried out bandpass filtering;

The effective value computer device is used for the effective value of the axle box vertical acceleration after the calculation of filtered;

The welded joint registration device is used for confirming according to the effective value of said axle box vertical acceleration the position of welded joint, and extracts the effective value of the axle box vertical acceleration at each welded joint place;

Whether connector status detecting device, the axle box vertical acceleration effective value that is used to judge the welded joint place greater than threshold value, if greater than threshold value then judge that this welded joint state is bad.

8. system according to claim 7 is characterized in that, said system also comprises the logical upper cut-off frequency generating apparatus of band, and the logical upper cut-off frequency generating apparatus of said band comprises:

The resonance and demodulation unit is used in the cooresponding frequency limit of the power spectrum of axle box vertical acceleration, the axle box vertical acceleration being carried out resonance and demodulation, obtain respectively with said frequency limit in the power envelope spectrum of the cooresponding axle box vertical acceleration of each frequency;

Percentum curve drawing unit, the first dominant frequency energy that is used for calculating each power envelope spectrum accounts for the percentum of this power envelope spectrum gross energy, draws the relation curve of said percentum and its corresponding frequency;

Upper cut-off frequency is confirmed the unit, is used for the peak value frequency points corresponding of said relation curve percentum is confirmed as the upper cut-off frequency of bandpass filtering.

9. system according to claim 7 is characterized in that, said welded joint registration device comprises:

The reference value generation unit is used for a plurality of effective values are divided into one group, calculates the aviation value m and the variances sigma of every group of effective value, draws the reference value R of axle box vertical acceleration effective value according to said aviation value m and variances sigma _T

First welded joint is confirmed the unit, is used for axle box vertical acceleration effective value greater than reference value R _TThe transfinite position at a place of big value confirm as the big value welded joint that transfinites;

Second welded joint is confirmed the unit, is used for according to the welded joint periodic spacings, confirms the transfinite position of all welded joints of welded joint centre of big value;

The welded joint effective value is confirmed the unit, and being used to get near the same welded joint a plurality of big value transfinites the maxim of an effective value as the effective value of the axle box vertical acceleration at this welded joint place.

10. system according to claim 7 is characterized in that said system also comprises the threshold process unit, and said threshold process unit specifically comprises:

The distribution curve drawing unit is used for the effective value according to the axle box vertical acceleration at said welded joint place, draws the distribution curve of the axle box vertical acceleration effective value at welded joint place;

Threshold value is confirmed the unit, is used for the distribution curve with the axle box vertical acceleration effective value at welded joint place, and corresponding probability is greater than the threshold value of the effective value of setting threshold value as detection welded joint state.

Images