CN103742575A - Motor train unit brake lining wear loss estimation method based on on-line monitoring - Google Patents

Abstract

The invention relates to a motor train unit brake lining wear loss estimation method based on on-line monitoring. The estimation method comprises the following steps of 1) monitoring the operation state of a motor train unit and the working state of a subsystem and transmitting collected train operation date to a ground receiving system; 2) storing the operation data and screening out speed, BC pressure, AC pressure and brake time duration during train operation from the received data through the ground receiving system; 3) according to the screened data, determining the equivalent friction distance of the pressure exerted on a brake lining and a brake disc at an nth time; 4) according to the equivalent friction distance and the BC pressure, determining the total wear loss of the brake lining at the nth time. The motor train unit brake lining wear loss estimation method based on on-line monitoring can help estimate the wear loss of every train brake lining relatively accurately according to the brake condition of every train and can prolong the service life of the brake lining under the premise of guaranteeing the brake performance of the brake lining, thereby avoiding waste and reducing the maintaining cost.

Description

A kind of evaluation method of the rail motor set brake lining wear extent based on on-line monitoring

Technical field

The present invention relates to areas of information technology, be specifically related to a kind of evaluation method of the rail motor set brake lining wear extent based on on-line monitoring.

Background technique

Braking system is one of most important system of motor-car.Brake lining is the critical component of braking system.Its performance is directly connected to the Security of motor-car operation.Under high temperature when braking and the effect of suppressing, can cause certain wearing and tearing to braking system critical component.In order to guarantee the performance of braking system, railway interests generally adopts regularly (distance travelled) to change at present.Produce thus two kinds of risks: the one, owe maintenance; The 2nd, excessively repair.The former causes excessive wear, affects traffic safety, and the latter causes waste, increases maintenance cost.Although Braking System for Multiple Units approximately only accounts for 15% of whole rail motor set cost, because brake lining quantity is many, maintenance load is large, in maintenance cost, but accounts for more than 40%.Therefore, need a kind of effective means to carry out on-line monitoring and estimation to the abrasion condition of brake pads of motor train unit, so that the working life of prediction brake lining.

At present, the wearing and tearing of rail motor set brake lining estimation does not also have effective method, but mainly comprises method and the method based on experience based on physics for the wearing and tearing of general device and the method for life prediction.

1, the method based on physics

Method based on physics is attempted the specific machine power of bonding apparatus gain knowledge (as: damage model of growth) and equipment on-line Condition Monitoring Data, with the residual life of predict device.The method based on physics common in document is mainly used crack propagation model, cracked model of growth etc.For example:

(1) Li etc. has proposed the framework of a rolling bearing life prediction, and this framework comprises a determinacy damage extended model, a diagnostic model and an adaptive algorithm.Wherein, diagnostic model is for estimating flaw size from sensitivities signal; Estimate thus, damage extended model can calculate Defect expanding rate, and predicts next lesion size constantly; Adaptive algorithm is according to the parameter of the deviation online updating damage extended model of predicted value and actual value.

(2) for the oily wet end part of airplane engine, Orsagh etc. have discussed a series of concepts about fault diagnosis and prediction such as information fusion framework, fusion method.In take bearing, as example, the life-span prediction method under bearing contact failure conditions be discussed, before cracked germinating, use Yu-Harris model, after cracked germinating, use cracked extended model., also discussed Yu-Harris model and the randomized method of cracked extended model, the method considered load, misaligned, the uncertain factor in lubricated and manufacture process meanwhile.

But above-mentioned two class methods are completely different from the mechanism of rail motor set brake lining wearing and tearing, cannot be applied to technical field of the present invention and solve technical problem of the present invention.

2, the method based on experience

Method based on experience (empirical-based methods), claims again the method (data-drivenmethods) of data driven, attempts directly the residual life from Condition Monitoring Data (and historical data of same category of device) predict device.

(1) Wujiang proposes a kind of forecasting model based on Markov chain theory.Be defined as example with a certain group of planes brake block review time, discussed respectively the division of brake block state of wear, the structure of transition probability matrix and estimation, and this group of planes brake block state of wear is predicted, it predicts the outcome more identical with actual inspection situation.

(2) suggestion such as Yan carrys out contacting between the characteristic variable of apparatus for establishing and its failure probability with logistic regression, suggestion simultaneously adopts arma modeling to predict characteristic variable, predicted value is inputted to housebroken logistic model and carry out predicting residual useful life.

(3) Yunfeng Zhang, Yang Liu etc. have proposed a kind of Forecasting Methodology based on fuzzy model, based on method of least squares, have considered ambiguity and enchancement factor when research galling characteristic.Its experimental result shows, in the situation that material is similar with operating conditions, if the influence factor of providing, can predict a period of time by this method after the wear extent of material.

(4) Mahardhika Pratama etc. has proposed a kind of mixing dynamic fuzzy neural network (DFNN) and genetic algorithm (GA) Cutter wear prediction milling process.Experimental research shows, the method and the higher precision of prediction of multifunctionality that the algorithm that proposes not only produces, and training time faster, and be compacter and succinct network structure.

But brake pads of motor train unit is once installation, when can only waiting until overhaul conventionally, pulls down its abrasion condition rear manual measurement, rail motor set runnability is complicated, the randomness of braking and sudden all very outstanding, therefore different with group of planes brake lining wear law, also cannot adopt the methods such as above-mentioned son study and training to predict.

The Patents that the wearing and tearing evaluation method of relevant machinery forms is also few.Wherein:

1. the people such as Li Fenghua of University Of Tianjin start with from the corresponding relation formula of setting up between disk cutter rotational frequency and frictional work for 2011 in " development machine disk cutter wear extent is estimated computational methods " patent, and then set up the corresponding relation formula between disk cutter rotational frequency and wear extent, finally can obtain the wear extent of different time, diverse location disk cutter.

2. the Robert of Bosch Co., Ltd and the people such as Wang Zhanjiang of Tsing-Hua University 2011 are " wear extent is determined method, sliding contact part manufacture method and sliding contact part " in patent, provide sliding contact part solid lubricant coating wear extent and determined method, sliding contact part manufacture method, proposition is based on load, how much of contact position pattern, material parameter and calculate sliding contact part and contact between part is distributed, based on contact, distribute, the speed of related movement of contact position, the coefficient of waste of solid lubricant coating is determined solid lubricant coating and wear extent time correlation.

3. the patent in " for determining the method for friction facing wear extent " in 2013 such as the M Ke Naisile of Schaeffler technical concern affiliated company, proposed to determine oil-engine driven Motor Vehicle can automation mechanized operation the method for friction facing wear extent of friction clutch, clutch operating stroke early and described more late clutch operating stroke are relatively also determined to difference mutually, and then definite friction facing wear extent.

But the wear model that above-mentioned patent 1 is used and the wear model of rail motor set brake lining have very big difference, and the method that patent 2 and patent 3 propose all needs more detected parameters, when motor-car high speed operation, is difficult to obtain corresponding data.Therefore above-mentioned three patents are all not suitable for the wear extent estimation of rail motor set brake lining.

Summary of the invention

For above the deficiencies in the prior art, the invention provides a kind of evaluation method of the rail motor set brake lining wear extent based on on-line monitoring.

The present invention adopts following technical proposals:

An evaluation method for rail motor set brake lining wear extent based on on-line monitoring, described evaluation method comprises the steps:

1) rail motor set running state, subsystem work state are monitored, and the train operation data of collection are sent to ground receiving system;

2) described ground receiving system is stored service data, and filters out speed, BC pressure, the AC pressure in train operation and brake lasting time data from the data that receive;

3) according to the data that filter out, determine the n equivalent friction distance of pressure-acting on brake lining and brake disc constantly;

4), according to described equivalent friction distance, BC pressure, determine the n total wear extent of brake lining constantly.

Described equivalent friction distance is:

$S_n=\mathrm{\α}\frac{v_n+v_{n+1}}{2}\×1000\÷60\≈\mathrm{\α}(v_n+v_{n+1})\×8.33\left(m\right)---\left(1\right)$

Wherein: S _nit is the equivalent friction distance of n minute brake lining and brake disc; α is scaling factor, and computational methods are as being α=r/R, and wherein r is the distance of brake lining mounting point and axis wheel, and R is radius of wheel; v _nbe the speed of n minute; v _n+1be the speed of n+1 minute.

The described n constantly total wear extent of brake lining is:

$\mathrm{\ϵ}=\underset{i=1}{\overset{i=n}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_i=\mathrm{\λ}\underset{i=1}{\overset{i=n}{\mathrm{\Σ}}}{f}_{\mathrm{BCi}}{S}_i$

Wherein: f _bCfor rail motor set BC pressure (by force) value; β is BC pressure and positive pressure conversion coefficient;

Brake lining wear extent is directly proportional to the product of the positive pressure of brake lining and brake disc, and scaling factor is made as: ρ, and at i minute wear extent ε _iformula is:

ε _i=ρ×f _i×S _i=ρ×β×f _BCi×μ×S _i=λf _BCiS _i （3）

Wherein: λ=ρ * β * μ.

The brake pad of rail motor set is critical components of braking system, and its performance quality is directly connected to the safe operation of train, because its handling characteristics makes it be easy to wearing and tearing, needs often maintenance and changes.Owing to there is no good monitoring means, brake lining is all changed by the distance travelled of train is unified at present, i.e. plan is repaiied.For guaranteeing safety, the distance travelled of relevant departments' regulation is comparatively conservative, makes excessively to repair comparatively general, brake lining is to be made by special alloy material, usage quantity is large especially (train 280 multi-discs) also, are therefore easy to cause larger waste, in maintenance cost, account for more than 40%.The present invention can be according to the brake condition of every train, and comparatively the wear extent of the every train brake pad of accurate estimation, can guarantee under the prerequisite of brake lining braking ability,

Extend the working life of brake lining, thereby cut the waste, reduce maintenance cost.

Accompanying drawing explanation

Fig. 1: the inventive method flow chart.

Embodiment

For understanding better the present invention, below in conjunction with Fig. 1, by specific embodiment, further illustrate the solution of the present invention,

A kind of evaluation method of the rail motor set brake lining wear extent based on on-line monitoring comprises following content.

1. collecting method

Utilize rail motor set mobile unit (WTD) to monitor rail motor set running state, subsystem work state, and the train operation data of collection are sent to ground system (transmission is spaced apart 1 minute), from the data that receive, filter out speed, BC pressure, the AC pressure in train operation and brake the lasting data such as time, and to remove speed be 0 and wrong and irrational data, obtain for accurate Calculation valid data.

2. the calculating of friction distance

Because train running speed is constantly changing, calculate each minute pressure-acting actual distance (and frictional distance) on brake lining and brake disc and can calculate with the mean velocity of this minute, concrete formula is as follows:

$S_n=\mathrm{\α}\frac{v_n+v_{n+1}}{2}\×1000\÷60\≈\mathrm{\α}(v_n+v_{n+1})\×8.33\left(m\right)---\left(1\right)$

Wherein: S _nit is the equivalent friction distance of n minute brake lining and brake disc; α is scaling factor, and computational methods are as being α=r/R, and wherein r is the distance of brake lining mounting point and axis wheel, and R is radius of wheel; v _nbe the speed of n minute; v _n+1be the speed of n+1 minute.

3. the calculating of brake lining wear extent

Because the material of brake lining and brake disc is fixing alloy material, after of short duration break-in, can think that the kinetic friction factor of brake lining and brake disc trends towards a stable constant, be made as μ.And then can obtain kinetic force of friction f and be:

f=βf _BC×μ （2）

Wherein: f _bCfor rail motor set BC pressure (by force) value; β is BC pressure and positive pressure conversion coefficient.

Brake lining wear extent is directly proportional to the product of the positive pressure of brake lining and brake disc, and scaling factor is made as: ρ, and at i minute wear extent ε _iformula is:

ε _i=ρ×f _i×S _i=ρ×β×f _BCi×μ×S _i=λf _BCiS _i （3）

Wherein: λ=ρ * β * μ.The total wear extent of n moment brake lining is:

$\mathrm{\ϵ}=\underset{i=1}{\overset{i=n}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_i=\mathrm{\λ}\underset{i=1}{\overset{i=n}{\mathrm{\Σ}}}{f}_{\mathrm{BCi}}{S}_i---\left(4\right)$

4. definite method of λ

Determining of λ can adopt method of least squares, and concrete grammar is as follows:

For brake lining j(j=1,2 ..., NN is the quantity of detected brake lining), the rail motor set service data f that utilizes the vehicle-mounted detection facility of rail motor set to pass down _jBCiand the S that utilizes formula (1) to calculate _ji, can obtain

attrition value ε by in-site measurement brake lining in the same period _jn.Can obtain thus following corresponding data table:

Table 1

From formula (4), for parameter lambda, actual measured value and calculated value can produce certain error, now require the quadratic sum of this error minimum, i.e. formula

$\mathrm{\δ}\left(\mathrm{\λ}\right)=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{({\mathrm{\ϵ}}_j-\mathrm{\λ}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}})}^2$

Minimum.To λ, differentiate obtains above formula:

${\mathrm{\δ}}^{\′}\left(\mathrm{\λ}\right)=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}2\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}({\mathrm{\ϵ}}_j-\mathrm{\λ}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}})$

Making above formula is 0 can obtain:

$\underset{j=1}{\overset{N}{\mathrm{\Σ}}}[{\mathrm{\ϵ}}_j\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}-\mathrm{\λ}{\left(\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}\right)}^2]=0$

$\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_j\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}=\mathrm{\λ}\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\left(\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}\right)}^2$

:

$\mathrm{\λ}=\frac{\mathrm{\Σ}{\mathrm{\ϵ}}_j\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}}{\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{\left(\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}\right)}^2}---\left(5\right)$

5. brake lining wear extent estimation

According to formula (5), for brake lining j(j=1,2 ..., NN is the quantity of detected brake lining), its wear extent ε after n minute _jnfor:

${\mathrm{\ϵ}}_{\mathrm{jn}}=\mathrm{\λ}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{f}_{\mathrm{jBCi}}{S}_{\mathrm{ji}}---\left(6\right)$

Wherein, f _jBCiin the data that can pass from vehicle-mounted detection facility, obtain; S _jiavailable formula (1) is calculated.

Four brake linings for a motor-car in domestic certain type rail motor set carry out tracking and monitoring, and to verify the validity of this invention, detailed process and result are described below:

1. according to a large amount of detection and calculated data in early stage, and formula (5) herein, obtain the estimated value of λ, for:

λ=1.875×10 ^-8

2. within every ten days, go to a motor-car servicing center on-the-spot, 4 brake lining thickness of test designated vehicle, meanwhile, add up this stage motor-car relevant braking-distance figures, i.e. BC pressure (f _jBCi) and the corresponding time, recycling (1) formula is calculated equivalent friction apart from S _ji.

3. utilize this paper (6) can calculate the pre-appraisal of abrasion.Result of calculation and measured result see the following form.

As seen from the above table, the maximum error of measured value and estimated value is 0.3mm; Mean square of error is poor is:

$\mathrm{\τ}=\frac{1}{20}\sqrt{\mathrm{\Σ}{\mathrm{\ϵ}}^2}\≈0.025$

At present, the application of bullet train group brake lining thickness prediction or blank, the unit of measurement of brake lining thickness or millimeter (mm) in existing regulations, as: the original depth of rail motor set brake lining is 17mm, when thickness is also left 7mm, must change.As can be seen here, the present invention reaches application demand completely to the estimation precision of brake lining wear extent.

Obviously; the above embodiment of the present invention is only for example of the present invention is clearly described; and be not the restriction to embodiments of the present invention; for those of ordinary skill in the field; can also make other changes in different forms on the basis of the above description; here cannot give all mode of executions exhaustive, every still row in protection scope of the present invention of apparent variation that technological scheme of the present invention extends out or change that belong to.

Claims (3)

1. an evaluation method for the rail motor set brake lining wear extent based on on-line monitoring, is characterized in that, described evaluation method comprises the steps:

1) rail motor set running state, subsystem work state are monitored, and the train operation data of collection are sent to ground receiving system;

2) described ground receiving system is stored service data, and filters out speed, BC pressure, the AC pressure in train operation and brake lasting time data from the data that receive;

3) according to the data that filter out, determine the n equivalent friction distance of pressure-acting on brake lining and brake disc constantly;

4), according to described equivalent friction distance, BC pressure, determine the n total wear extent of brake lining constantly.

2. the evaluation method of a kind of rail motor set brake lining wear extent based on on-line monitoring according to claim 1, is characterized in that, described equivalent friction distance is:

$S_n=\mathrm{\α}\frac{v_n+v_{n+1}}{2}\×1000\÷60\≈\mathrm{\α}(v_n+v_{n+1})\×8.33\left(m\right)---\left(1\right)$

Wherein: S _nit is the equivalent friction distance of n minute brake lining and brake disc; α is scaling factor, and computational methods are as being α=r/R, and wherein r is the distance of brake lining mounting point and axis wheel, and R is radius of wheel; v _nbe the speed of n minute; v _n+1be the speed of n+1 minute.

3. the evaluation method of a kind of rail motor set brake lining wear extent based on on-line monitoring according to claim 1, is characterized in that, the described n constantly total wear extent of brake lining is:

$\mathrm{\ϵ}=\underset{i=1}{\overset{i=n}{\mathrm{\Σ}}}{\mathrm{\ϵ}}_i=\mathrm{\λ}\underset{i=1}{\overset{i=n}{\mathrm{\Σ}}}{f}_{\mathrm{BCi}}{S}_i$

Wherein: f _bCfor rail motor set BC pressure (by force) value; β is BC pressure and positive pressure conversion coefficient;

Brake lining wear extent is directly proportional to the product of the positive pressure of brake lining and brake disc, and scaling factor is made as: ρ, and at i minute wear extent ε _iformula is:

ε _i=ρ×f _i×S _i=ρ×β×f _BCi×μ×S _i=λf _BCiS _i （3）

Wherein: λ=ρ * β * μ.

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