CN102914364B

CN102914364B - Dynamic identifying method for instant contact loss of wheel rail under impact effect of wheel rail

Info

Publication number: CN102914364B
Application number: CN201210399620.8A
Authority: CN
Inventors: 林建辉; 丁建明; 伍川辉; 刘璐; 易彩; 陈春俊; 张兵; 苏燕辰
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2012-10-19
Filing date: 2012-10-19
Publication date: 2014-02-12
Anticipated expiration: 2032-10-19
Also published as: CN102914364A

Abstract

The invention discloses a dynamic identifying method for instant contact loss of a wheel rail under an impact effect of the wheel rail and belongs to a traffic information safety technology. The dynamic identifying method comprises the following steps: firstly, mounting a vibration acceleration sensor above a wheel axle box; collecting axle box vibration acceleration information measured by the vibration acceleration sensor through a background collector; extracting a time-frequency feature for the axle box vibration acceleration, thereby obtaining a time-frequency distribution feature; and drawing a contour map for the time-frequency distribution feature and judging if the wheel rail instantly loses the contact. According to the scheme, the purpose of immediately detecting the ultra-large hidden danger of the instant contact loss of the wheel rail under the impact effect of the wheel rail is achieved according to the dynamic identifying method provided by the invention; the possibility of derailing of a vehicle is eliminated; the technology is mature; the reliability is high; the cost is low; the quantity of the channels is less; the system is simple; the anti-interference property is high; and the social and economical benefits are very obvious.

Description

A kind ofly because causing wheel track moment, wheel-rail impact effect loses the dynamic identifying method of contact

Technical field

The invention belongs to traffic and transport field, specifically, relate to and a kind ofly because wheel-rail impact effect causes wheel track moment, lose the dynamic identifying method of contact.

background technology

Rolling stock is under arms in process, and during wheel brake hard locking, if wheel exists at Rail Surface while moving on the soft objects such as ice and snow, leaf, rotation of wheel motion is become and slided or the motion of trackslipping by rolling, and wheel track will produce sliding friction.For relative rolling friction, sliding friction is violent, and violent sliding friction produces that high temperature makes that wheel tread occurs abrading, peels off, rhegma and fall the wheel faults such as piece, and these defects are brought strike and the injury of intermittence to wheel rail system.Existing theoretical calculation and test test shows, having the wheel-rail impact power of the wheel generation of defect is the several times of wheel track static load, wherein HFS directly has a negative impact to track and wheel, thereby reduce serviceable life, the increase energy consumption of vehicle and circuit and improve maintenance cost, serious is to cause axle temperature to raise to occur that axletree is fervent; Accelerate on the other hand axletree, tread Crack Extension causes axletree cold cut.What pay particular attention to is simultaneously, when rolling stock travelling speed reaches certain value, when flaw size reaches certain value, wheel-rail impact can cause that later wheel track moment loses contact, some meetings make wheel track repeatedly intermittence lose contact, wheel track loses contact and means that the vertical acting force of wheel track is zero, moment derailment coefficients be infinity, as there is the section of large transverse force at bend circuit, track Ultrahigh Bypass etc. in fast running, the derailing that vehicle occurs may be very large.

summary of the invention

The object of the invention is to lose the especially big hidden danger of contact because wheel-rail impact causes wheel track moment, provide a kind of and lose the dynamic identifying method of contact because wheel-rail impact effect causes wheel track moment, the possibility of avoiding vehicle that derailing occurs occurs.

To achieve these goals, the technical solution used in the present invention is as follows:

Because wheel-rail impact effect causes wheel track moment, lose a dynamic identifying method for contact, realize by the following method:

(1) vibration acceleration sensor is installed on to wheel axle box top, and gathers by the collector on backstage the axle box vibration acceleration information that vibration acceleration sensor measures;

(2) axle box vibration acceleration information is carried out to time-frequency characteristics extraction, obtain time-frequency distributions feature;

(3) draw the contour map of time-frequency distributions feature, judge whether moment loses contact to wheel track.

In order to guarantee the accurate measurement of vibration acceleration sensor, in described step (1), the range of vibration acceleration sensor is ± 50g that frequency response is not less than 2kHz, and the sample frequency of collector is not less than 10kHz.

Further obtain video distribution feature, the specific implementation step of described step (2) is as follows:

(2a) select frequency slice function, wherein frequency coordinate , the centre frequency that represents conversion,

Figure DEST_PATH_387190DEST_PATH_IMAGE003

represent frequency resolution,

Figure DEST_PATH_80339DEST_PATH_IMAGE004

expression departs from the number of the resolution of centre frequency, so the basis function of frequency choice function is:

Figure DEST_PATH_735312DEST_PATH_IMAGE005

，

According to

Figure DEST_PATH_19662DEST_PATH_IMAGE006

size, frequency choice function calculates the following three kinds of situations that comprise:

Situation one: when

Figure DEST_PATH_901031DEST_PATH_IMAGE007

and

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time, frequency choice function for:

Figure DEST_PATH_362602DEST_PATH_IMAGE010

Figure DEST_PATH_262425DEST_PATH_IMAGE011

and

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;

Situation two: when

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and time, frequency choice function for:

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Figure DEST_PATH_262928DEST_PATH_IMAGE015

and ;

Situation three: when

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and

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time, frequency choice function

Figure DEST_PATH_915309DEST_PATH_IMAGE009

for:

Figure DEST_PATH_476740DEST_PATH_IMAGE019

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and ;

Wherein,

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for the frequency discrimination factor,

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centered by coordinate corresponding to frequency, meet

Figure DEST_PATH_403108DEST_PATH_IMAGE023

;

(2b) axle box vibration acceleration is carried out to Fourier transform, transformation for mula is as follows:

Figure DEST_PATH_652824DEST_PATH_IMAGE024

(2c) frequency slice function is selected the frequency of Fourier, selects formula as follows:

Figure DEST_PATH_231573DEST_PATH_IMAGE025

(2d) for various centre frequencies, carry out the time-frequency distributions feature that inverse-Fourier transform obtains vibration acceleration:

Figure DEST_PATH_541331DEST_PATH_IMAGE026

。

In order better to realize the present invention, the concrete methods of realizing of described step (3) is as follows:

(3a) draw the contour map of the time-frequency distributions feature of vibration acceleration;

(3b) find time period corresponding to this contour map maximum energy peak value;

(3c) at ceiling capacity, in the time period, find successively second largest energy peak, if there is the decay that local energy increases with frequency in section at one time, exist wheel track that the phenomenon departing from occurs.

The present invention compares compared with prior art, has the following advantages and beneficial effect:

(1) the invention solves a most important problem of present stage, how to judge because wheel-rail impact effect causes its moment and lose contact, avoided a kind of the most severe factor that endangers vehicle operating safety of bringing because of wheel fault, due to the method that can not address the aforementioned drawbacks at present, therefore the present invention is as an important breakthrough in this area, thoroughly changed this sky window, because wheel track loses and contacts with wheel suddenly, the harm bringing is immeasurable, therefore the present invention is a new technology, has thoroughly solved this harm.

(2) recognition methods of the present invention is very simple, only need vibration acceleration sensor and the collector of a passage to collect information needed, and by calculating, feature extraction, relatively can recognize immediately the phenomenon that this instantaneous wheel and wheel track depart from, there is real-time, and process is very simple; Simultaneously the present invention does not need to transform circuit, can carry out system-wide and cover and detect, and reliability is high, easily fill easy care, can meet the needs that wheel moment loses the Dynamic Recognition of contact completely.

(3) the present invention, owing to being a brand-new technology, has advance and superiority, and technology maturation, reliability are high, have good prospect and application market.

accompanying drawing explanation

Fig. 1 is realization flow figure of the present invention.

Fig. 2 is vibration acceleration sensor installation site schematic diagram in the present invention-embodiment.

Fig. 3 is acceleration and the time-frequency characteristics figure thereof when picking rate is 150km/h in the present invention-embodiment.

Fig. 4 is acceleration and the time-frequency characteristics figure thereof when picking rate is 130km/h in the present invention-embodiment.

embodiment

Below in conjunction with accompanying drawing and embodiment, the invention will be further described, and embodiments of the present invention include but not limited to the following example.

Embodiment 1

As shown in Figure 1, acceleration transducer has been installed on axle box in the present invention, the dynamic vibration information for Dynamic Acquisition locomotive vehicle-mounted under wheel fault, and on backstage, do real-time detection computations.

As shown in Figure 1, performing step of the present invention is as follows:

(1) vibration acceleration sensor is arranged on axle box

Installation of sensors orientation as shown in Figure 2, be selected in ± 50g of the range of vibration transducer wherein, frequency response is not less than 2000Hz, the sample frequency of pick-up transducers is not less than 10kHz, and obtains acceleration signal

Figure DEST_PATH_80897DEST_PATH_IMAGE027

.

Wherein as shown in part on Fig. 3 (a) and Fig. 4, collect one group of axle box Vertical Acceleration signal that contains wheel fault, the speed of collection signal is 150km/h and 130km/h, and corresponding frequecy characteristic and same time peak energy are respectively as shown in part under Fig. 3 (b) and Fig. 4.

(2) carry out temporal frequency signature analysis

Applying frequency section wavelet transformation carries out time-frequency characteristics extraction to axle box vibration acceleration, and the detailed step of feature extraction is as follows:

The first step: the selection of frequency slice function and realization

Frequency coordinate is set , wherein

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the centre frequency that represents conversion,

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represent frequency resolution,

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expression departs from the number of the resolution of centre frequency.

The basis function of frequency choice function is described as:

Then calculate predominant frequency choice function.

(1a) when and time, frequency is selected choice function

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for:

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Wherein

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and

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.

(1b) when

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and

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time, frequency is selected choice function

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for:

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Wherein

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and

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.

(1c) when and

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time, frequency choice function

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for:

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Wherein

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and

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.

In above-mentioned formula,

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for the frequency discrimination factor, centered by coordinate corresponding to frequency, meet

Figure DEST_PATH_442749DEST_PATH_IMAGE029

.

Second step: the fast fourier transform that axle box vibration is accelerated:

Figure DEST_PATH_417659DEST_PATH_IMAGE030

。

The 3rd step: frequency slice function is selected the frequency of Fourier:

Figure DEST_PATH_633876DEST_PATH_IMAGE031

The 4th step: carry out the time-frequency distributions feature that inverse-Fourier transform obtains vibration acceleration for different center frequency:

(3) judgement wheel track moment loses the identification of contact

The first step: the contour map of drawing the time-frequency distributions of vibration signal;

Second step: the corresponding time period of finding maximum energy peak value;

The 3rd section: at ceiling capacity, in the time period, find successively other time maximum energy peak value, if there is the decay that local energy increases with frequency in section at one time, exist wheel track that the phenomenon departing from occurs.

According to above-described embodiment, just can realize well the present invention.

Claims

1. because wheel-rail impact effect causes wheel track moment, lose a dynamic identifying method for contact, it is characterized in that, realize by the following method:

(3) draw the contour map of time-frequency distributions feature, judge whether moment loses contact to wheel track;

Wherein, in described step (1), the range of vibration acceleration sensor is ± 50g that frequency response is not less than 2kHz, and the sample frequency of collector is not less than 10kHz;

The specific implementation step of described step (2) is as follows:

(2a) select frequency slice function, wherein frequency coordinate

Figure 2012103996208100001DEST_PATH_IMAGE002

,

Figure 2012103996208100001DEST_PATH_IMAGE004

the centre frequency that represents conversion, represent frequency resolution,

Figure 2012103996208100001DEST_PATH_IMAGE008

Figure 2012103996208100001DEST_PATH_IMAGE010

，

According to

Figure 2012103996208100001DEST_PATH_IMAGE012

Situation one: when

Figure 2012103996208100001DEST_PATH_IMAGE014

and

Figure 2012103996208100001DEST_PATH_IMAGE016

time, frequency choice function for:

and

;

Situation two: when and

time, frequency choice function

for:

and

;

Situation three: when

and

time, frequency choice function

for:

and

;

Wherein,

for the frequency discrimination factor,

centered by coordinate corresponding to frequency, meet

;

。

2. according to claim 1ly a kind ofly because wheel-rail impact effect causes wheel track moment, lose the dynamic identifying method of contact, it is characterized in that, the concrete methods of realizing of described step (3) is as follows: