CN117851873A

CN117851873A - Bearing running state evaluation method and system based on dynamic contact angle

Info

Publication number: CN117851873A
Application number: CN202410257441.3A
Authority: CN
Inventors: 李修文; 黄贵发; 曾承志; 龚妙; 杨荣华
Original assignee: Beijing Tangzhi Science & Technology Development Co ltd; Tangzhi Science & Technology Hunan Development Co ltd
Current assignee: Beijing Tangzhi Science & Technology Development Co ltd; Tangzhi Science & Technology Hunan Development Co ltd
Priority date: 2024-03-07
Filing date: 2024-03-07
Publication date: 2024-04-09
Anticipated expiration: 2044-03-07

Abstract

The application provides a bearing running state evaluation method and system based on a dynamic contact angle, and relates to the field of running state monitoring of rolling bearings running at high speed in mechanical equipment such as aeroengines, gas turbines, high-speed railway locomotives and the like, wherein the method comprises the following steps: acquiring an original vibration signal; processing the original vibration signal to obtain a frequency spectrum signal; according to the frequency spectrum signal, calculating to obtain an actual frequency conversion; according to the actual rotation frequency and a preset contact angle dynamic range, calculating to obtain a plurality of groups of fault characteristic frequencies, wherein the contact angle dynamic range comprises a plurality of contact angle values, and each contact angle value corresponds to one group of fault characteristic frequencies; respectively establishing a corresponding fault characteristic matrix according to the fault characteristic frequency of each group and the preset frequency multiplication of the fault characteristic frequency; and analyzing and processing each fault characteristic matrix to obtain a state evaluation result. The fault feature of the rolling bearing can be accurately extracted, so that the accuracy of the running state evaluation of the rolling bearing is improved.

Description

Bearing running state evaluation method and system based on dynamic contact angle

Technical Field

The application relates to the field of monitoring of running states of rotating mechanical parts, in particular to a method and a system for evaluating the running states of a bearing based on a dynamic contact angle.

Background

The rolling bearing is used as a core component in rotary mechanical equipment, and the health state of the rolling bearing directly influences the health state of the whole mechanical equipment. Particularly, the rolling bearing in mechanical equipment such as an aeroengine, a gas turbine, a high-speed railway locomotive and the like generally works under severe working conditions of high temperature, high pressure and high rotating speed, belongs to a fault multiple component, and mainly has the following difficulties in evaluating the running state of the high-rotating speed rolling bearing: the high-rotation-speed rolling bearing has the advantages that due to large design play, high rotation speed and light load, the contact angle of the rolling body is dynamically changed in the operation process, the rolling body and the retainer are relatively unstable in operation, the actual characteristic frequency of the bearing has certain fluctuation compared with a theoretical value, and the fault characteristics are difficult to accurately extract.

Therefore, how to accurately extract the fault characteristics of the rolling bearing to improve the accuracy of the running state evaluation of the rolling bearing is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

In order to solve the technical problems, the application provides a bearing running state evaluation method based on a dynamic contact angle, which can accurately extract fault characteristics of a rolling bearing so as to improve the accuracy of the running state evaluation of the rolling bearing. The application also provides a bearing running state evaluation system based on the dynamic contact angle, which has the same technical effect.

A first object of the present application is to provide a method for evaluating the running state of a bearing based on a dynamic contact angle.

The first object of the present application is achieved by the following technical solutions:

a bearing running state evaluation method based on a dynamic contact angle comprises the following steps:

acquiring an original vibration signal;

processing the original vibration signal to obtain a frequency spectrum signal;

according to the frequency spectrum signal, calculating to obtain an actual frequency conversion;

calculating a plurality of groups of fault characteristic frequencies according to the actual rotating frequency and a preset contact angle dynamic range, wherein the contact angle dynamic range comprises a plurality of contact angle values, and each contact angle value corresponds to one group of fault characteristic frequencies;

respectively establishing a corresponding fault characteristic matrix according to the fault characteristic frequency of each group and preset frequency multiplication of the fault characteristic frequency;

and analyzing and processing each fault characteristic matrix to obtain a state evaluation result.

Preferably, in the method for evaluating the running state of the bearing based on the dynamic contact angle, the processing the original vibration signal to obtain a spectrum signal includes:

preprocessing the original vibration signal to obtain a preprocessed signal;

And performing fast Fourier transform on the preprocessing signal to obtain a frequency spectrum signal.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, calculating an actual rotation frequency according to the spectrum signal includes:

and carrying out frequency search and calculation in the frequency spectrum signal according to the rotor frequency, the number of stages of the blades and the number of the blades of each stage of the rotating mechanical equipment to obtain the actual frequency.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, the performing frequency searching and calculating in the frequency spectrum signal according to a rotor rotation frequency, a number of stages of blades and a number of blades of each stage of the rotating mechanical device to obtain an actual rotation frequency includes:

establishing a frequency search interval corresponding to each stage of blades according to rotor frequency, the number of stages of blades and the number of blades of each stage of rotary mechanical equipment;

according to the frequency search interval corresponding to each stage of blade, performing frequency search in the frequency spectrum signal to obtain the frequency corresponding to the maximum amplitude value, and taking the frequency as the actual blade vibration frequency corresponding to each stage of blade;

calculating to obtain a reference rotation frequency value corresponding to each stage of blade according to the actual blade vibration frequency corresponding to each stage of blade and the number of blades of each stage;

And carrying out statistical analysis according to the reference frequency conversion value corresponding to each stage of blade to obtain the actual frequency conversion.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, the establishing a frequency search interval corresponding to each stage of blades according to a rotor rotation frequency, a stage number of the blades and a blade number of each stage of the rotating mechanical device includes:

according to the number of stages of the blades of the rotary mechanical equipment and the number of the blades of each stage, constructing a blade number matrix, specifically:

；

in the method, in the process of the invention,representing the leaf number matrix,/->Representing the number of stages of said blade,/->Indicate->The number of stage blades;

according to the rotor frequency of the rotary mechanical equipment and the blade number matrix, calculating to obtain a blade vibration frequency matrix, wherein the blade vibration frequency matrix specifically comprises the following components:

in (I)>Representing the blade vibration frequency matrix, +.>Indicate->Blade vibration frequency corresponding to the stage blade, +.>，/>Representing the rotor rotation frequency;

establishing a frequency search interval corresponding to each stage of blade according to the blade vibration frequency corresponding to each stage of blade in the blade vibration frequency matrix and a first preset frequency interval threshold, wherein the first stage of blade comprises a first frequency search interval and a second frequency search interval, wherein the first frequency search interval is a frequency search interval of the first frequency search interval and the second frequency search interval is a frequency search interval of the first frequency search intervalThe frequency search interval corresponding to the stage blade is specifically:

；

in the method, in the process of the invention, Indicate->Frequency value in frequency search interval corresponding to stage blade,/->Representing the first preset frequency interval threshold.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, the calculating, according to the actual blade vibration frequency corresponding to each stage of blade and the number of blades of each stage, a reference rotation frequency value corresponding to each stage of blade includes:

according to the actual blade vibration frequency corresponding to each stage of blade, an actual blade vibration frequency matrix is established, specifically:

；

in the method, in the process of the invention,representing the actual blade vibration frequency matrix, +.>Indicate->The actual blade vibration frequency corresponding to the stage blade;

according to the actual blade vibration frequency matrix and the blade number matrix, calculating to obtain a reference frequency conversion matrix, wherein the reference frequency conversion matrix specifically comprises the following components:

；

in the method, in the process of the invention,representing the reference transfer matrix,/a>Indicate->The reference rotation frequency value corresponding to the stage blade,。

preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, the performing statistical analysis according to the reference rotation frequency value corresponding to each stage of blade to obtain an actual rotation frequency includes:

according to the reference frequency conversion value corresponding to each stage of blade, carrying out average value operation to obtain actual frequency conversion, wherein the method specifically comprises the following steps:

；

In the method, in the process of the invention,representing the actual frequency of rotation.

carrying out outlier rejection processing on the reference frequency conversion value corresponding to each stage of blade to obtain a processed reference frequency conversion value;

and obtaining the actual frequency conversion according to the processed reference frequency conversion value and the least square method.

calculating a discrete degree index of each reference frequency conversion value according to the reference frequency conversion value corresponding to each stage of blade;

and determining an actual frequency conversion according to the discrete degree index of each reference frequency conversion value.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, a discrete degree index of each reference rotating frequency value is calculated according to the reference rotating frequency value corresponding to each stage of blade; determining an actual frequency of rotation according to the discrete degree index of each reference frequency of rotation value, including:

And carrying out normalization processing on the reference frequency conversion value corresponding to each stage of blade to obtain a normalized reference frequency conversion value corresponding to each stage of blade, wherein the calculation formula is as follows:

；

in the method, in the process of the invention,indicate->Normalized reference frequency value corresponding to the stage blade, < > in>；

According to the normalized reference frequency conversion value corresponding to each stage of blade, respectively calculating an entropy value corresponding to each reference frequency conversion value, wherein the calculation formula is as follows:

；

in the method, in the process of the invention,indicate->Entropy value of the reference frequency conversion value corresponding to the stage blade;

according to the entropy value corresponding to each reference frequency conversion value, calculating to obtain the entropy value deviation degree corresponding to each reference frequency conversion value, wherein the calculation formula is as follows:

；

in the method, in the process of the invention,indicate->Entropy value deviation degree of the reference frequency conversion value corresponding to the stage blade;

and carrying out normalization processing on the entropy value deviation degree corresponding to each reference frequency conversion value to obtain entropy value weight corresponding to each reference frequency conversion value, wherein the entropy value weight is used as a discrete degree index of each reference frequency conversion value, and the calculation formula is as follows:

；

in the method, in the process of the invention,indicate->Entropy weight of the reference frequency conversion value corresponding to the stage blade, i.e. +.>The discrete degree index of the reference frequency conversion value corresponding to the stage blade;

And selecting the reference frequency conversion value corresponding to the maximum value in the discrete degree index as an actual frequency conversion.

Preferably, in the method for evaluating the running state of a bearing based on a dynamic contact angle, the fault characteristic frequency of each group includes one or more of a cage-to-outer ring fault characteristic frequency, a cage-to-inner ring fault characteristic frequency, an outer ring fault characteristic frequency, an inner ring fault characteristic frequency, a roller end face fault characteristic frequency and a roller circumference fault characteristic frequency, and a specific calculation formula is as follows:

characteristic frequency of retainer collision outer ring fault：

；

Characteristic frequency of retainer collision inner ring fault：

；

Characteristic frequency of outer ring failure：

;

Characteristic frequency of inner ring failure:

;

Characteristic frequency of roller end face fault:

;

Characteristic frequency of roller circumference failure:

;

In the method, in the process of the invention,represents the diameter of the bearing, +.>Indicating the diameter of the rolling element->Indicating the number of rolling elements->Representing said actual frequency of rotation,/->Represents the contact angle dynamic range, < >>，/>Representing the number of the contact angle values in the contact angle dynamic range, +/->Represents +.>And each contact angle takes a value.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, the analyzing and processing each fault feature matrix to obtain a state evaluation result includes:

Taking each value of the fault characteristic frequency of each group in each fault characteristic matrix and the preset frequency multiplication of the fault characteristic frequency as one fault characteristic frequency element of each fault characteristic matrix respectively;

according to each fault characteristic frequency element in each fault characteristic matrix, calculating a frequency spectrum peak value corresponding to each fault characteristic frequency element in the frequency spectrum signal;

according to the frequency spectrum peak value corresponding to each fault characteristic frequency element, judging whether each fault characteristic frequency element meets a preset confidence coefficient requirement or not respectively, so as to obtain fault characteristic frequency elements meeting the confidence coefficient requirement in each fault characteristic matrix;

according to the number of fault characteristic frequency elements of each fault category meeting the confidence coefficient requirements in each fault characteristic matrix, judging whether the fault characteristic frequency elements of each fault category meeting the confidence coefficient requirements in each fault characteristic matrix meet preset multi-order requirements or not respectively, so as to obtain the fault characteristic frequency elements meeting the multi-order requirements in each fault characteristic matrix;

according to each fault characteristic frequency element meeting the multi-order requirement in each fault characteristic matrix, calculating a conventional vibration frequency threshold value corresponding to each fault characteristic frequency element meeting the multi-order requirement;

Judging whether each fault characteristic frequency element meeting the multi-order requirement meets a preset independence requirement according to the conventional vibration frequency threshold value corresponding to each fault characteristic frequency element meeting the multi-order requirement, so as to obtain the fault characteristic frequency element meeting the independence requirement in each fault characteristic matrix;

judging whether the original vibration signal meets a preset working condition, if so, considering that the bearing has faults meeting the fault category corresponding to the fault characteristic frequency element required by the independence.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, the calculating, in the spectrum signal, a spectrum peak value corresponding to each fault characteristic frequency element according to each fault characteristic frequency element in each fault characteristic matrix includes:

establishing a peak search interval corresponding to each fault characteristic frequency element according to each fault characteristic frequency element in each fault characteristic matrix;

and carrying out peak value calculation in the frequency spectrum signal according to the peak value searching interval corresponding to each fault characteristic frequency element to obtain a frequency spectrum peak value corresponding to each fault characteristic frequency element.

Preferably, in the method for evaluating a bearing running state based on a dynamic contact angle, the step of respectively determining whether each fault characteristic frequency element meets a preset confidence requirement according to the spectrum peak value corresponding to each fault characteristic frequency element, so as to obtain the fault characteristic frequency element meeting the confidence requirement in each fault characteristic matrix includes:

according to the peak value searching interval corresponding to each fault characteristic frequency element, calculating to obtain the average value of the amplitude value of the spectrum signal in the peak value searching interval, or calculating to obtain the average value of the peak value of the spectrum signal in the peak value searching interval, wherein the average value is used as a spectrum threshold value corresponding to each fault characteristic frequency element;

dividing the frequency spectrum peak value corresponding to each fault characteristic frequency element by the frequency spectrum threshold value corresponding to each fault characteristic frequency element to obtain a first multiple ratio corresponding to each fault characteristic frequency element;

for each fault characteristic frequency element in each fault characteristic matrix, judging whether the first multiple ratio corresponding to the fault characteristic frequency element is larger than a first preset threshold value or not, and if yes, judging whether the first multiple ratio corresponding to the fault characteristic frequency element is larger than a first preset threshold value or not: judging whether the frequency spectrum peak value corresponding to the fault characteristic frequency element is larger than or equal to a second preset threshold value, if so, considering that the fault characteristic frequency element meets the preset confidence coefficient requirement, and accordingly obtaining the fault characteristic frequency element meeting the confidence coefficient requirement in each fault characteristic matrix.

Preferably, in the method for evaluating a bearing running state based on a dynamic contact angle, the determining, according to the number of fault feature frequency elements of each fault class in each fault feature matrix that meets the confidence coefficient requirement, whether the fault feature frequency element of each fault class in each fault feature matrix that meets the confidence coefficient requirement meets a preset multi-order requirement, so as to obtain the fault feature frequency element in each fault feature matrix that meets the multi-order requirement includes:

and respectively judging whether the number of the fault characteristic frequency elements of each fault category meeting the confidence coefficient requirement in the fault characteristic matrix is larger than or equal to a third preset threshold value or not, if so, considering that the fault characteristic frequency elements of the same fault category meeting the confidence coefficient requirement in the fault characteristic matrix meet preset multi-order requirements, thereby obtaining the fault characteristic frequency elements meeting the multi-order requirements in each fault characteristic matrix.

Preferably, in the bearing running state evaluation method based on a dynamic contact angle, the calculating a conventional vibration frequency threshold corresponding to each fault feature frequency element meeting the multi-order requirement according to each fault feature frequency element meeting the multi-order requirement in each fault feature matrix includes:

calculating the integer multiple ratio of each fault characteristic frequency element meeting the multi-order requirement in each fault characteristic matrix to the actual rotating frequency, wherein the calculation formula is as follows:

;

in the method, in the process of the invention,representing a fault characteristic frequency element satisfying said multi-order requirement,/a>Representing the actual frequency of rotation of the device,representing a rounding function>Representation->The corresponding integer multiple ratio;

multiplying the integer multiple ratio corresponding to each fault characteristic frequency element meeting the multi-order requirement with the actual rotating frequency to obtain a conventional vibration frequency threshold corresponding to each fault characteristic frequency element meeting the multi-order requirement.

Preferably, in the bearing running state evaluation method based on a dynamic contact angle, the determining, according to the conventional vibration frequency threshold value corresponding to each fault characteristic frequency element satisfying the multiple-order requirement, whether each fault characteristic frequency element satisfying the multiple-order requirement satisfies a preset independence requirement, so as to obtain a fault characteristic frequency element satisfying the independence requirement in each fault characteristic matrix includes:

And respectively judging whether the absolute value of the difference between the fault characteristic frequency elements meeting the multi-order requirements and the corresponding conventional vibration frequency threshold is larger than or equal to a fourth preset threshold or not for each fault characteristic frequency element meeting the multi-order requirements, and if so, considering that the fault characteristic frequency elements meeting the multi-order requirements meet the preset independence requirements, thereby obtaining the fault characteristic frequency elements meeting the independence requirements in each fault characteristic matrix.

Preferably, in the method for evaluating a bearing running state based on a dynamic contact angle, if it is determined that a certain fault feature frequency element in a certain fault feature matrixThe corresponding first multiple ratio is smaller than or equal to a first preset threshold value, or a certain fault characteristic frequency element in a certain fault characteristic matrix is judged to be +.>The corresponding frequency spectrum peak value is smaller than a second preset threshold value, or a fault characteristic frequency element which meets the confidence coefficient requirement and is corresponding to a certain fault characteristic frequency element in a certain fault characteristic matrix is judged>The number of fault characteristic frequency elements of the same fault class is less than a third preset threshold, further comprising:

judging fault characteristic frequency element Whether the following condition is satisfied:

;

in the method, in the process of the invention,representing a fault signature frequency element +.>Corresponding to said first multiple ratio, +.>Representing the element +/f of the fault signature matrix meeting the confidence requirement>Number of fault characteristic frequency elements of the same fault class, +.>Representing absolute value>And->Representing preset parameters;

if yes, consider the fault characteristic frequency elementThe multi-order requirement is satisfied.

Preferably, in the method for evaluating a running state of a bearing based on a dynamic contact angle, the determining whether the original vibration signal meets a preset working condition includes:

judging whether the number of the rotation speed types in the rotation speed working condition corresponding to the original vibration signal exceeds a fifth preset threshold or whether the signal duration corresponding to the original vibration signal exceeds a sixth preset threshold, and if so, considering that the original vibration signal meets the preset working condition.

A second object of the present application is to provide a dynamic contact angle based bearing operating condition assessment system.

The second object of the present application is achieved by the following technical solutions:

a dynamic contact angle based bearing operating condition assessment system comprising:

An acquisition unit configured to acquire an original vibration signal;

the processing unit is used for processing the original vibration signal to obtain a frequency spectrum signal;

the first calculation unit is used for calculating and obtaining actual frequency conversion according to the frequency spectrum signal;

the second calculation unit is used for calculating and obtaining a plurality of groups of fault characteristic frequencies according to the actual rotation frequency and a preset contact angle dynamic range, wherein the contact angle dynamic range comprises a plurality of contact angle values, and each contact angle value corresponds to one group of fault characteristic frequencies;

the building unit is used for respectively building a corresponding fault characteristic matrix according to the fault characteristic frequency of each group and the preset frequency multiplication of the fault characteristic frequency;

and the analysis unit is used for carrying out analysis processing on each fault characteristic matrix to obtain a state evaluation result.

According to the technical scheme, the original vibration signal is obtained; processing the original vibration signal to obtain a frequency spectrum signal; according to the frequency spectrum signal, calculating to obtain an actual frequency conversion; according to the actual rotation frequency and a preset contact angle dynamic range, calculating to obtain a plurality of groups of fault characteristic frequencies, wherein the contact angle dynamic range comprises a plurality of contact angle values, and each contact angle value corresponds to one group of fault characteristic frequencies; respectively establishing a corresponding fault characteristic matrix according to the fault characteristic frequency of each group and the preset frequency multiplication of the fault characteristic frequency; and analyzing and processing each fault characteristic matrix to obtain a state evaluation result. According to the technical scheme, the dynamic change of the contact angle of the rolling body in the running process is reflected by setting the dynamic range of the contact angle, the bearing fault characteristics are extracted by the dynamic change, the fault characteristic matrix is constructed, the accurate extraction of the fault characteristics under the unstable running condition of the rolling bearing is realized, the characteristic extraction search range is enlarged, and the accuracy of the running state assessment of the rolling bearing is improved. In summary, the above technical solution can accurately extract the fault characteristics of the rolling bearing, so as to improve the accuracy of the running state evaluation of the rolling bearing.

In addition, according to the technical scheme, a series of confidence level criteria, a multi-order criteria, an independence criteria, a working condition criteria and other diagnosis criteria are set, and the threshold judgment and the interference recognition are sequentially carried out on the bearing fault characteristics, so that the accuracy of the running state evaluation of the rolling bearing is further improved, the online automatic diagnosis of the rolling bearing fault is realized, and the support of historical big data is not needed.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic flow chart of a method for evaluating an operating state of a bearing based on a dynamic contact angle in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a dynamic contact angle-based bearing operation state evaluation system in an embodiment of the present application.

Detailed Description

In order to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below, and it is obvious that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

In the embodiments provided in the present application, it should be understood that the disclosed method and system may be implemented in other manners. The system embodiments described below are merely illustrative, and for example, the division of units and modules is merely a logical function division, and other divisions may be implemented in practice such as: multiple units or modules may be combined or may be integrated into another system, or some features may be omitted, or not performed. In addition, the various components shown or discussed may be coupled or directly coupled or communicatively coupled to each other via some interface, whether indirectly coupled or communicatively coupled to devices or modules, whether electrically, mechanically, or otherwise.

In addition, each functional unit in each embodiment of the present application may be integrated in one processor, or each unit may be separately used as one device, or two or more units may be integrated in one device; the functional units in the embodiments of the present application may be implemented in hardware, or may be implemented in a form of hardware plus a software functional unit.

Those of ordinary skill in the art will appreciate that: all or part of the steps of implementing the method embodiments described below may be performed by program instructions and associated hardware, and the foregoing program instructions may be stored in a computer readable storage medium, which when executed, perform steps comprising the method embodiments described below; and the aforementioned storage medium includes: a mobile storage device, a Read Only Memory (ROM), a magnetic disk or an optical disk, or the like, which can store program codes.

It should be appreciated that the terms "system," "apparatus," "unit," and/or "module," if used herein, are merely one method for distinguishing between different components, elements, parts, portions, or assemblies at different levels. However, if other words can achieve the same purpose, the word can be replaced by other expressions.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" or "a number" is two or more, unless explicitly defined otherwise.

If a flowchart is used in the present application, the flowchart is used to describe the operations performed by the system according to embodiments of the present application. It should be appreciated that the preceding or following operations are not necessarily performed in order precisely. Rather, the steps may be processed in reverse order or simultaneously. Also, other operations may be added to or removed from these processes.

It should also be noted that, in this document, terms such as "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such article or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in an article or apparatus that comprises such element.

The embodiment of the application is written in a progressive manner.

As shown in fig. 1, an embodiment of the present application provides a method for evaluating an operating state of a bearing based on a dynamic contact angle, including:

s101, acquiring an original vibration signal;

in S101, specifically, the original vibration signal of the rolling bearing may be obtained through a vibration sensor disposed on a rotating mechanical device, where the rotating mechanical device may be an aero-engine, a gas turbine, a rotating mechanical device in a high-speed railway locomotive, etc., the vibration sensor may be disposed at a reasonable position on the rotating mechanical device, such as an engine case measuring point, etc., and the obtaining manner of the original vibration signal may also be other.

S102, processing an original vibration signal to obtain a frequency spectrum signal;

in S102, specifically, the original vibration signal may be subjected toPerforming fast Fourier transform (Fast Fourier Transform, FFT) to obtain spectral signal +.>In order to extract frequency domain features from the spectral signals, and to evaluate the running state of the rolling bearing on the basis of the frequency domain features, wherein +.>Representing the number of sample points->Representing the signal frequency points.

In other embodiments, one implementation manner of the step specifically includes:

s1021, preprocessing an original vibration signal to obtain a preprocessed signal;

in S1021, specifically, the preprocessing process may include filtering noise reduction processing, and by performing filtering noise reduction processing on the original vibration signal, signal noise interference may be reduced, which is beneficial to improving the subsequent fault recognition effect. For the rolling bearing, the fault mainly occurs in the high-frequency component of the original vibration signal, so that the low-frequency component in the original vibration signal can be removed, and the filtering method can adopt high-pass filtering, so that the application is not limited to the method.

S1022, performing fast Fourier transform on the preprocessed signals to obtain spectrum signals.

In S1022, specifically, by performing fast fourier transform on the preprocessed signal, a spectrum signal is obtained For subsequent frequency domain analysis.

S103, calculating to obtain actual frequency conversion according to the frequency spectrum signal;

in S103, specifically, the actual frequency conversion may be calculated according to the spectrum signal based on the existing frequency conversion calculation method, for example, the peak search method is used to extract the instantaneous frequency conversion in the spectrum signal, and the least square method is used to perform data fitting on the instantaneous frequency conversion to obtain the actual frequency conversion, which is not limited in this application.

S104, calculating a plurality of groups of fault characteristic frequencies according to the actual rotating frequency and a preset contact angle dynamic range, wherein the contact angle dynamic range comprises a plurality of contact angle values, and each contact angle value corresponds to one group of fault characteristic frequencies;

in S104, specifically, a contact angle dynamic range may be preset according to dynamic changes of the contact angle of the rolling element during the operation, where the contact angle dynamic range includes a plurality of contact angle values; for example, assuming that a dynamic change interval of a contact angle of a certain rolling element during operation is [20,70] degrees, a value may be taken at intervals of preset degrees in the interval [20,70], for example, a value may be taken at intervals of one degree, to obtain the interval [20,21, …,70], which is not particularly limited as a preset contact angle dynamic range. According to the actual rotation frequency and each contact angle value in the preset contact angle dynamic range, a group of fault characteristic frequencies corresponding to each contact angle value can be calculated respectively. It should be noted that, each group of fault characteristic frequencies may include fault characteristic frequencies of one or more fault categories, and specific types of the fault characteristic frequencies may be set according to actual application requirements.

In some embodiments, the failure feature frequencies of each group, including one or more of a cage-to-outer ring failure feature frequency, a cage-to-inner ring failure feature frequency, an outer ring failure feature frequency, an inner ring failure feature frequency, a roller end face failure feature frequency, and a roller circumference failure feature frequency, are calculated as follows:

characteristic frequency of retainer collision outer ring fault：

；

Characteristic frequency of retainer collision inner ring fault：

；

Characteristic frequency of outer ring failure：

；

Characteristic frequency of inner ring failure：

；

Characteristic frequency of roller end face fault：

；

Characteristic frequency of roller circumference failure：

；

In the method, in the process of the invention,represents the diameter of the bearing, +.>Indicating the diameter of the rolling element->Indicating the number of rolling elements->Representing the actual frequency of rotation>Represents the contact angle dynamic range>，/>Represents the number of contact angle values in the dynamic range of the contact angle, +.>Represents +.>The individual contact angles take on values.

S105, respectively establishing a corresponding fault characteristic matrix according to the fault characteristic frequency of each group and the preset frequency multiplication of the fault characteristic frequency;

in S105, specifically, a preset multiple of the failure feature frequency of each group may be calculated according to the failure feature frequency of each group; respectively establishing a corresponding fault characteristic matrix according to the fault characteristic frequency of each group and the preset frequency multiplication of the fault characteristic frequency of each group; the specific value of the preset frequency multiplication can be set based on actual application requirements. For example, a preset frequency multiplication is set to Frequency multiplication of order, wherein->For positive integers greater than 1, the +.A.of the failure characteristic frequency of each group can be calculated from the failure characteristic frequency of each group>Frequency multiplication of order, wherein +.>The order multiplication includes more than 1 to +.>Doubling of all integer multiples of the multiple; according to the failure characteristic frequency of each group and +.>And (5) step frequency multiplication, respectively establishing a corresponding fault characteristic matrix. Through the step, a fault feature matrix corresponding to each contact angle value can be established, so that the accurate extraction of fault features of the rolling bearing under the unstable operation condition is realized, the feature extraction search range is enlarged, and the accuracy of the running state evaluation of the rolling bearing is improved.

In a specific embodiment, the fault characteristic frequency of each group comprises 6 categories of fault characteristic frequencies of cage-to-outer ring fault characteristic frequency, cage-to-inner ring fault characteristic frequency, outer ring fault characteristic frequency, inner ring fault characteristic frequency, roller end face fault characteristic frequency and roller circumference fault characteristic frequency, and the contact angle dynamic range is，/>Presetting the frequency multiplication as +.>For example, in this step, a total of +. >Personal->Failure feature moment of dimension->Each fault characteristic matrix comprises a contact angle value 6 under the condition of corresponding contact angle valueCharacteristic frequency of seed fault and +.>The specific formalization expression of the order frequency multiplication is as follows:

；

…

；

in the method, in the process of the invention,indicating a contact angle value of +.>Time-corresponding fault feature matrix +_>Indicating a contact angle value of +.>Time-corresponding fault feature matrix +_>Indicating a contact angle value of +.>Time-corresponding fault feature matrix +_>Indicating a contact angle value of +.>Calculated retainer bump outer ring failure characteristic frequency, < ->Indicating a contact angle value of +.>Calculated characteristic frequency of retainer bump inner ring failure, < ->Indicating a contact angle value of +.>The calculated characteristic frequency of the outer ring failure,indicating a contact angle value of +.>Calculated characteristic frequency of inner ring failure, +.>Indicating a contact angle value of +.>Calculated characteristic frequency of roller end face failure, +.>Indicating a contact angle value of +.>Calculated characteristic frequency of roller circumference failure, +.>Representing the failure characteristic frequency of the retainer touching the outer ring>Is->Double frequency of>Indicating that the retainer touches the inner ringBarrier characteristic frequency->Is->Double frequency of>Representing the characteristic frequency of the outer ring failure +.>Is->Double frequency of>Representing the characteristic frequency of inner loop failure- >Is->Double frequency of>Characteristic frequency of fault of end face of roller>Is->Double frequency of>Characteristic frequency of circumferential failure of the roller>Is->Double frequency multiplication.

It should be noted that the formal expression of the above fault feature matrix is only an example, and the arrangement manner of the fault feature frequencies of each type in the fault feature matrix may be set based on actual application requirements, which is not limited in this application.

S106, analyzing and processing each fault characteristic matrix to obtain a state evaluation result.

In S106, specifically, an existing rolling bearing operation state evaluation method may be adopted, and analysis processing is performed on each fault feature matrix to obtain a state evaluation result. For example, each fault feature frequency in each fault feature matrix may be compared with a preset frequency threshold, and a state evaluation result may be output according to the comparison result, where the state evaluation result may be that the bearing is in a normal running state, or that the bearing has a fault of some kind, which is not limited in this application.

Aiming at the running state evaluation of the high-rotation-speed rolling bearing, the following difficulties mainly exist: the high-rotation-speed rolling bearing has the advantages that due to large design play, high rotation speed and light load, the contact angle of the rolling body is dynamically changed in the operation process, the rolling body and the retainer are relatively unstable in operation, the actual characteristic frequency of the bearing has certain fluctuation compared with a theoretical value, and the fault characteristics are difficult to accurately extract.

The above embodiment, by acquiring the original vibration signal; processing the original vibration signal to obtain a frequency spectrum signal; according to the frequency spectrum signal, calculating to obtain an actual frequency conversion; according to the actual rotation frequency and a preset contact angle dynamic range, calculating to obtain a plurality of groups of fault characteristic frequencies, wherein the contact angle dynamic range comprises a plurality of contact angle values, and each contact angle value corresponds to one group of fault characteristic frequencies; respectively establishing a corresponding fault characteristic matrix according to the fault characteristic frequency of each group and the preset frequency multiplication of the fault characteristic frequency; and analyzing and processing each fault characteristic matrix to obtain a state evaluation result. According to the technical scheme, the dynamic change of the contact angle of the rolling body in the running process is reflected by setting the dynamic range of the contact angle, the bearing fault characteristics are extracted by the dynamic change, the fault characteristic matrix is constructed, the accurate extraction of the fault characteristics under the unstable running condition of the rolling bearing is realized, the characteristic extraction search range is enlarged, and the accuracy of the running state assessment of the rolling bearing is improved. In summary, the above embodiments can accurately extract the fault characteristics of the rolling bearing to improve the accuracy of the rolling bearing operation state evaluation.

In other embodiments of the present application, one implementation manner of the step of calculating the actual frequency conversion according to the spectrum signal specifically includes: and carrying out frequency search and calculation in the frequency spectrum signal according to the rotor frequency, the number of stages of the blades and the number of the blades of each stage of the rotating mechanical equipment to obtain the actual frequency.

Wherein the rotating mechanical device can be an aeroengine with strong aerodynamic noise interference, and a large number of high-amplitude blade vibration frequencies exist in the vibration spectrum，/>Wherein->Representing the number of single stage blades, < > of blades>Representing rotor rotation frequency, namely, shaft rotation frequency of the aero-engine; based on this, the rotor frequency of the aero-engine can be increased by +.>The number of stages of blades, the number of blades per stage, in the spectral signal +.>And (3) performing frequency searching and calculating to obtain the actual frequency conversion. One implementation manner of the steps specifically includes:

s201, establishing a frequency search interval corresponding to each stage of blades according to rotor rotation frequency, the number of stages of the blades and the number of the blades of each stage of the rotating mechanical equipment;

in S201, specifically, a blade number matrix may be constructed according to the number of stages of the blades of the rotating machinery and the number of blades of each stage, specifically:

；

In the method, in the process of the invention,representing a matrix of leaf numbers>Representing the number of stages of the blade>Indicate->The number of stage blades; the rotating mechanical device may be an aero-engine; the number of stages of the blades can be the number of stages of the impeller of the aero-engine; the number of blades per stage may be the number of blades on each stage of the impeller of the aircraft engine. />

According to the rotor frequency and the blade number matrix of the rotary mechanical equipment, calculating to obtain a blade vibration frequency matrix, wherein the blade vibration frequency matrix specifically comprises the following components:

；

in the method, in the process of the invention,representing a blade vibration frequency matrix>Indicate->The corresponding blade vibration frequency of the stage blade,，/>representing rotor rotation frequency; rotor frequency conversion can beThe corresponding theoretical frequency conversion during sampling; each stage of blades may correspond to a blade vibration frequency in a blade vibration frequency matrix.

Establishing a frequency search interval corresponding to each stage of blade according to the blade vibration frequency corresponding to each stage of blade in the blade vibration frequency matrix and a first preset frequency interval threshold;

the specific value of the first preset frequency interval threshold value can be set based on actual application requirements, and for the blade vibration frequency corresponding to each stage of blades, the first preset frequency interval threshold value with the same value can be adopted, and the first preset frequency interval threshold value with different values can also be adopted. In the first place The frequency search interval corresponding to the stage blade is exemplified and can be expressed as:

；

in the method, in the process of the invention,indicate->Frequency value in frequency search interval corresponding to stage blade,/->Representing a first preset frequency interval threshold; according to the method, a frequency search interval corresponding to each stage of blade can be obtained.

S202, performing frequency search in the frequency spectrum signal according to the frequency search interval corresponding to each stage of blade to obtain the frequency corresponding to the maximum amplitude value, wherein the frequency is used as the actual blade vibration frequency corresponding to each stage of blade;

in S202, specifically, in the firstFor example, the frequency search interval corresponding to the stage blade can calculate the spectrum signalThe maximum in this interval, i.e. +.>Wherein->Represents a maximum function, in this case->Indicate->The actual blade vibration frequency corresponding to the stage blade. According to the method, the vibration frequency of the actual blade corresponding to each stage of blade can be obtained.

S203, calculating a reference rotation frequency value corresponding to each stage of blade according to the actual blade vibration frequency corresponding to each stage of blade and the number of blades of each stage;

in S203, specifically, the actual blade vibration frequency corresponding to each stage of blade may be divided by the number of blades corresponding to each stage of blade, to obtain a reference rotation frequency value corresponding to each stage of blade; one implementation method of the steps specifically comprises the following steps:

S2031, establishing an actual blade vibration frequency matrix according to the actual blade vibration frequency corresponding to each stage of blade, wherein the actual blade vibration frequency matrix specifically comprises the following steps:

；

in the method, in the process of the invention,representing an actual blade vibration frequency matrix;

in S2031, specifically, each stage of blades may correspond to one actual blade vibration frequency in the actual blade vibration frequency matrix.

S2032, calculating a reference frequency conversion matrix according to an actual blade vibration frequency matrix and a blade number matrix, wherein the reference frequency conversion matrix is specifically:

；

in the method, in the process of the invention,representing a reference transfer matrix, ">Indicate->The reference rotation frequency value corresponding to the stage blade,；

in S2032, specifically, each stage of blade may correspond to one reference frequency conversion value in the reference frequency conversion matrix, so as to obtain a reference frequency conversion value corresponding to each stage of blade.

S204, carrying out statistical analysis according to the reference frequency conversion value corresponding to each stage of blade to obtain the actual frequency conversion.

In S204, specifically, an existing statistical calculation method may be adopted to calculate and process the reference frequency conversion value in the reference frequency conversion matrix, so as to obtain an actual frequency conversion, thereby implementing adaptive extraction of the actual frequency conversion of the rolling bearing of the aero-engine.

In some embodiments, one implementation manner of the step specifically includes:

；

in the method, in the process of the invention,the actual rotation frequency is represented, and the actual rotation frequency can be simply and efficiently calculated by carrying out mean value operation on the reference rotation frequency value corresponding to each stage of blades.

In other embodiments, one implementation of this step may further include:

carrying out outlier rejection processing on the reference frequency conversion value corresponding to each stage of blade to obtain a processed reference frequency conversion value; and obtaining the actual frequency conversion according to the processed reference frequency conversion value and the least square method.

In this embodiment, specifically, through outlier rejection processing, the reference frequency conversion value with obvious abnormality in the reference frequency conversion values corresponding to each stage of blades may be rejected, so as to obtain a processed reference frequency conversion value, and then, a least square method is adopted to perform data fitting on the processed reference frequency conversion value, so as to obtain an actual frequency conversion, so that a more accurate actual frequency conversion can be obtained.

In other embodiments, one implementation of this step may further include:

calculating a discrete degree index of each reference frequency conversion value according to the reference frequency conversion value corresponding to each stage of blade; and determining the actual rotating frequency according to the discrete degree index of each reference rotating frequency value.

In this embodiment, specifically, the discrete degree index is used to measure the discrete degree of the data, and by calculating the discrete degree index of each reference frequency value, one reference frequency value in the reference frequency values corresponding to each stage of blades can be determined as the actual frequency, so that more accurate actual frequency can be obtained. For example, the degree of dispersion of the reference frequency conversion value corresponding to each stage of blade can be evaluated by calculating the entropy weight, and one implementation manner of the step is specifically as follows:

firstly, carrying out normalization processing on a reference frequency conversion value corresponding to each stage of blade to obtain a normalized reference frequency conversion value corresponding to each stage of blade, wherein the calculation formula is as follows:

；

And then, according to the normalized reference frequency conversion value corresponding to each stage of blade, respectively calculating the entropy value corresponding to each reference frequency conversion value, wherein the calculation formula is as follows:

；

in the method, in the process of the invention,indicate->Entropy value of reference frequency conversion value corresponding to the stage blade;

；

in the method, in the process of the invention,indicate- >Entropy value deviation degree of reference frequency conversion value corresponding to the stage blade;

；

in the method, in the process of the invention,indicate->Entropy weight of the reference frequency conversion value corresponding to the stage blade, i.e. +.>Discrete degree index of the reference frequency conversion value corresponding to the stage blade; />The larger the value of (2), the more trusted the corresponding reference frequency-converted value;

and selecting a reference frequency conversion value corresponding to the maximum value in the discrete degree index as an actual frequency conversion.

In the above embodiment, according to the rotor frequency, the number of stages of the blades, the number of the blades of each stage and the spectrum signal of the rotating mechanical device, the reference frequency conversion value corresponding to each stage of the blades is calculated, and the actual frequency conversion is calculated and obtained through a plurality of statistical analysis methods, so that the self-adaptive accurate extraction of the actual frequency conversion of the rolling bearing of the rotating mechanical device is realized, and the accuracy of the running state evaluation of the rolling bearing is improved.

In other embodiments of the present application, considering that the rolling bearing of the rotating mechanical device has characteristics of unstable characteristic frequency and complex signal, the accuracy of the running state evaluation method for determining whether the bearing has a corresponding fault by performing simple threshold judgment on the fault characteristic frequency is still to be improved. Based on the above, the step of analyzing and processing each fault feature matrix to obtain a state evaluation result is implemented in one implementation manner, which specifically includes:

S301, taking each fault characteristic frequency of each group in each fault characteristic matrix and each value of preset frequency multiplication of the fault characteristic frequency as one fault characteristic frequency element of each fault characteristic matrix respectively;

in S301, specifically, each value of the fault characteristic frequency of each group in each fault characteristic matrix and each value of the preset multiple of the fault characteristic frequency of each group in each fault characteristic matrix may be respectively used as an independent fault characteristic frequency element in each fault characteristic matrix;

in the specific embodiment, the contact angle is taken as the valueTime-dependent fault feature matrix->For example, the fault signature matrix may be +.>Is comprised of->、/>、/>、…、/>Is used as a fault feature matrix +.>Is a fault characteristic frequency element of (1), a fault characteristic matrix->Together include->And fault signature frequency elements.

S302, calculating a frequency spectrum peak value corresponding to each fault characteristic frequency element in the frequency spectrum signal according to each fault characteristic frequency element in each fault characteristic matrix;

in S302, specifically, according to each fault characteristic frequency element in each fault characteristic matrix, frequency searching and peak value calculation may be performed in the spectrum signal to obtain a spectrum peak value corresponding to each fault characteristic frequency element, where one implementation manner of this step specifically includes:

S3021, establishing a peak search interval corresponding to each fault characteristic frequency element according to each fault characteristic frequency element in each fault characteristic matrix;

in S3021, specifically, a peak search interval corresponding to each fault feature frequency may be established according to each fault feature frequency element in each fault feature matrix and the second preset frequency interval threshold; the specific value of the second preset frequency interval threshold may be set based on actual application requirements, and for each fault characteristic frequency element of each fault class, the second preset frequency interval threshold with the same value or different values may be adopted.

In the specific embodiment, the contact angle is taken as the valueTime-dependent fault feature matrix->For example, the frequency element +.>(it should be noted that->Can be a fault feature matrix->Any one of the fault-characteristic frequency elements, i.e. +.>Can be +.>、/>、/>、…、/>Any one of) and a second preset frequency interval threshold, a fault signature frequency element +.>The corresponding peak search interval is specifically: />Wherein- >Representing the fault characteristic frequency element->A corresponding second preset frequency interval threshold. A peak search interval corresponding to each fault signature frequency element can be established accordingly.

S3022, carrying out peak value calculation in the frequency spectrum signal according to the peak value search interval corresponding to each fault characteristic frequency element to obtain a frequency spectrum peak value corresponding to each fault characteristic frequency element.

In S3022, specifically, for each failure characteristic frequency element, a maximum amplitude value of the spectrum signal in a peak search interval corresponding to each failure characteristic frequency element may be calculated as one spectrum peak corresponding to each failure characteristic frequency element.

In the specific embodiment, the contact angle is taken as the valueTime-dependent fault feature matrix->Is a certain fault characteristic frequency element +.>For example, the spectral signal +.>At->Amplitude maximum value of interval as fault characteristic frequency element +.>Corresponding spectral peaks. Accordingly, a frequency spectrum peak value corresponding to each fault characteristic frequency element can be obtained.

S303, judging whether each fault characteristic frequency element meets the preset confidence coefficient requirement according to the frequency spectrum peak value corresponding to each fault characteristic frequency element, so as to obtain the fault characteristic frequency element meeting the confidence coefficient requirement in each fault characteristic matrix;

In S303, specifically, an overrun determination may be performed according to the spectrum peak value corresponding to each fault characteristic frequency element, so as to determine whether each fault characteristic frequency element meets a preset confidence requirement. One implementation manner of the step specifically comprises the following steps:

s3031, calculating to obtain the average value of the amplitude of the spectrum signal in the peak value searching interval according to the peak value searching interval corresponding to each fault characteristic frequency element, or calculating to obtain the average value of the peak value of the spectrum signal in the peak value searching interval as a spectrum threshold value corresponding to each fault characteristic frequency element;

in S3031, specifically, for each fault characteristic frequency element, an amplitude average value of all amplitude values of the spectrum signal in the peak value search interval corresponding to each fault characteristic frequency element may be calculated, or a peak average value of all peak values of the spectrum signal in the peak value search interval corresponding to each fault characteristic frequency element may be calculated as one spectrum threshold value corresponding to each fault characteristic frequency element.

In the specific embodiment, the contact angle is taken as the valueTime-dependent fault feature matrix->Is a certain fault characteristic frequency element +. >For example, the spectral signal +.>At->Amplitude mean or peak mean of interval as fault characteristic frequency element +.>A corresponding spectral threshold. Accordingly, a frequency spectrum threshold corresponding to each fault characteristic frequency element can be obtained.

S3032, dividing the frequency spectrum peak value corresponding to each fault characteristic frequency element by the frequency spectrum threshold value corresponding to each fault characteristic frequency element to obtain a first multiple ratio corresponding to each fault characteristic frequency element;

in S3032, the contact angle is specifically taken asTime-dependent fault feature matrix->Is a certain fault characteristic frequency element +.>For example, let the fault signature frequency element +.>The corresponding spectral peak is +.>Fault characteristic frequency elementThe corresponding spectral threshold is +.>Will->As a fault-characteristic frequency element->A corresponding first multiple ratio. From this, a first multiple ratio corresponding to each failure characteristic frequency element can be obtained.

S3033, for each fault characteristic frequency element in each fault characteristic matrix, judging whether a first multiple ratio corresponding to the fault characteristic frequency element is larger than a first preset threshold value or not, and if so, judging: judging whether the frequency spectrum peak value corresponding to the fault characteristic frequency element is larger than or equal to a second preset threshold value, if so, considering that the fault characteristic frequency element meets the preset confidence coefficient requirement, and obtaining the fault characteristic frequency element meeting the confidence coefficient requirement in each fault characteristic matrix.

In S3033, the contact angle is specifically taken asTime-dependent fault feature matrix->Is a certain fault characteristic frequency element +.>For example, determine the failure characteristic frequency element +.>Corresponding first multiple ratio->If the value of (2) is greater than the first preset threshold, if not, it can be considered +.>Spectral lines corresponding to the intervals do not belong to effective fault spectral lines; if yes, it can be regarded as->The spectral lines corresponding to the intervals are relatively prominent, and the subsequent judgment is continued, namely the fault characteristic frequency element is judged>Corresponding spectral peak->Whether greater than or equal to the second preset threshold, if not, it can be considered +.>Spectral lines corresponding to the intervals do not belong to effective fault spectral lines; if yes, it can be regarded as->The spectrum line corresponding to the interval has effective peak value, and is considered as fault characteristic frequency element +.>And meets the confidence requirement. In the step, judging each fault characteristic frequency element in each fault characteristic matrix one by one, so as to obtain all fault characteristic frequency elements meeting the confidence coefficient requirement in each fault characteristic matrix. The first preset threshold value and the second preset threshold value can be set based on actual application requirements, and for each fault characteristic frequency element of each fault class, the first preset threshold value and the second preset threshold value with the same value or different values can be adopted, and when the spectrum threshold value is the amplitude value average value or the peak value average value, the corresponding first preset threshold value can be set to be different.

S304, judging whether the fault characteristic frequency elements of each fault category meeting the confidence coefficient requirements in each fault characteristic matrix meet the preset multi-order requirements according to the number of the fault characteristic frequency elements of each fault category meeting the confidence coefficient requirements in each fault characteristic matrix, so as to obtain the fault characteristic frequency elements meeting the multi-order requirements in each fault characteristic matrix;

in S304, specifically, according to the fault feature frequency elements meeting the confidence requirement in each fault feature matrix, the number of fault feature frequency elements meeting the confidence requirement in each fault category in each fault feature matrix may be obtained. If a certain number of fault characteristic frequency elements of the same fault class meeting the confidence coefficient requirement exist in a certain fault characteristic matrix, and the frequency intervals accord with the multiple relation, the fault characteristic frequency elements of the same fault class meeting the confidence coefficient requirement in the fault characteristic matrix can be considered to meet the preset multi-order requirement. In the step, by judging the fault characteristic frequency elements of each fault category meeting the confidence coefficient requirement in each fault characteristic matrix in a class-by-class manner, all the fault characteristic frequency elements meeting the multi-order requirement in each fault characteristic matrix can be obtained.

In a specific embodiment, according to the actual rotation frequency and a preset contact angle dynamic range, calculating to obtain a plurality of groups of fault characteristic frequencies, wherein each group of fault characteristic frequencies can comprise one or more of a cage-to-outer ring fault characteristic frequency, a cage-to-inner ring fault characteristic frequency, an outer ring fault characteristic frequency, an inner ring fault characteristic frequency, a roller end face fault characteristic frequency and a roller circumference fault characteristic frequency; accordingly, the failure categories may include one or more of cage-to-outer ring failure, cage-to-inner ring failure, outer ring failure, inner ring failure, roller end face failure, and roller circumference failure.

and respectively judging whether the number of the fault characteristic frequency elements of each fault category meeting the confidence coefficient requirement in each fault characteristic matrix is larger than or equal to a third preset threshold value, if so, considering that the fault characteristic frequency elements of the same fault category meeting the confidence coefficient requirement in the fault characteristic matrix meet the preset multi-order requirement, thereby obtaining the fault characteristic frequency elements meeting the multi-order requirement in each fault characteristic matrix.

In the specific embodiment, the contact angle is taken as the valueTime-dependent fault feature matrix->For example, if the fault feature matrix +.>Of the fault characteristic frequency elements meeting the confidence requirement +.>The number of fault characteristic frequency elements of the same fault class is greater than or equal to a third preset threshold value, the fault characteristic matrix can be considered +.>Of the fault characteristic frequency elements satisfying the confidence requirement +.>The fault characteristic frequency elements with the same fault category meet the requirement of multi-order property; it should be noted that if the fault feature matrix +.>The fault characteristic frequency elements meeting the confidence coefficient requirement belong to a plurality of different fault categories, and then the fault characteristic matrixes can be respectively counted>The number of fault characteristic frequency elements of each fault category meeting the confidence coefficient requirement is then respectively compared with a third preset threshold value to obtain a fault characteristic matrix +.>And all the fault characteristic frequencies meeting the multi-order requirement. Wherein the third preset threshold may be set based on actual application requirements,for the fault characteristic frequency elements of different fault categories, a third preset threshold value with the same value or different values can be adopted, and the application is not particularly limited.

S305, calculating a conventional vibration frequency threshold value corresponding to each fault characteristic frequency element meeting the multi-order requirement according to each fault characteristic frequency element meeting the multi-order requirement in each fault characteristic matrix;

in S305, specifically, one implementation manner of this step specifically includes: calculating the integer multiple ratio of each fault characteristic frequency element meeting the multi-order requirement in each fault characteristic matrix to the actual rotating frequency, wherein the calculation formula is as follows:

；

in the method, in the process of the invention,representing fault characteristic frequency elements satisfying the requirement of multilevel property,/->Representing the actual frequency of rotation>Representing a rounding function>Representation->A corresponding integer multiple ratio;

In the specific embodiment, the contact angle is taken as the valueFailure corresponding to timeFeature matrix->Is a fault characteristic frequency element satisfying the requirement of multilevel>For example, the fault signature frequency element +.>Is>Integer multiple ratio >Will->As a fault characteristic frequency element +.>A corresponding conventional vibration frequency threshold; thus, a conventional vibration frequency threshold value corresponding to each fault characteristic frequency element meeting the multi-order requirement can be obtained.

S306, judging whether each fault characteristic frequency element meeting the multi-order requirement meets the preset independence requirement according to a conventional vibration frequency threshold value corresponding to each fault characteristic frequency element meeting the multi-order requirement, so as to obtain the fault characteristic frequency element meeting the independence requirement in each fault characteristic matrix;

in S306, specifically, the objective of this step is to prevent the fault characteristic frequency and its higher-order spectrum from being misidentified as the rotation frequency or the blade vibration frequency, and when the absolute value of the difference between a certain fault characteristic frequency element satisfying the multi-order requirement and the conventional vibration frequency threshold corresponding to the fault characteristic frequency element exceeds a certain threshold, it can be considered that misidentification is not caused, that is, the fault characteristic frequency element satisfies the preset independence requirement; and judging each fault characteristic frequency element meeting the multi-order requirement one by one, so that all fault characteristic frequency elements meeting the independence requirement in each fault characteristic matrix can be obtained.

and respectively judging whether the absolute value of the difference value between each fault characteristic frequency element meeting the multi-order requirement and the corresponding conventional vibration frequency threshold value is larger than or equal to a fourth preset threshold value, and if so, considering that the fault characteristic frequency element meeting the multi-order requirement meets the preset independence requirement, thereby obtaining the fault characteristic frequency element meeting the independence requirement in each fault characteristic matrix.

In particular embodiments, the contact angle isTime-dependent fault feature matrix->Failure characteristic frequency of one of them satisfying the requirement of multilevel>For example, let the fault signature frequency element +.>The corresponding conventional vibration frequency threshold value isBy judging->Whether the value of (2) is greater than or equal to a fourth preset threshold, if so, the fault signature frequency element can be considered +_>Is>Is->Order misalignment, fault characteristic frequency element considered to meet the requirement of multiple orders ++>The independence requirement is met; in the step, judging each fault characteristic frequency meeting the multi-order requirement in each fault characteristic matrix one by one, so as to obtain all fault characteristic frequencies meeting the independence requirement in each fault characteristic matrix. The fourth preset threshold value can be set based on actual application requirements, and for each fault characteristic frequency element of different fault categories, the fourth preset threshold value with the same or different values can be adopted. In the step, through the independence judgment, the fault characteristic frequency and the higher-order spectrum thereof can be effectively prevented from being mistakenly identified as the rotation frequency or the blade vibration frequency.

S307, judging whether the original vibration signal meets the preset working condition, if so, considering that the bearing has faults of fault categories corresponding to the fault characteristic frequency elements meeting the independence requirement.

In S307, specifically, a preset working condition may be set according to an actual application requirement; if the original vibration signal meets the preset working condition, the original vibration signal can be considered to be effective, namely the bearing can be considered to have faults of fault categories corresponding to the fault characteristic frequency elements meeting the independence requirement under the condition that the contact angle corresponding to the fault characteristic frequency elements meeting the independence requirement is the value.

In some embodiments, one implementation manner of the step of determining whether the original vibration signal meets the preset working condition specifically includes:

judging whether the number of the rotating speed types in the rotating speed working condition corresponding to the original vibration signal exceeds a fifth preset threshold or whether the signal duration corresponding to the original vibration signal exceeds a sixth preset threshold, and if so, considering that the original vibration signal meets the preset working condition;

in a specific embodiment, the fifth preset threshold and the sixth preset threshold may be based on real The fifth preset threshold may be set to 2, which is not particularly limited in this application. Take the contact angle as the valueTime-dependent fault feature matrix->Is a fault characteristic frequency element satisfying the independence requirement +.>For example, if it is determined that the number of the rotation speed types in the rotation speed working condition corresponding to the original vibration signal exceeds the fifth preset threshold, or the duration of the signal corresponding to the original vibration signal exceeds the sixth preset threshold, the original vibration signal may be considered valid, that is, the bearing may be considered as having a contact angle of ++>In the case of a fault characteristic frequency element +.>Faults of the corresponding fault class.

In other embodiments, if the number of fault feature frequency elements of a certain fault class satisfying the independence requirement in a certain fault feature matrix is zero, it may be considered that the bearing does not have a fault of the fault class under the condition of the corresponding contact angle value; if the number of fault characteristic frequency elements meeting all preset fault categories of the independence requirement in a certain fault characteristic matrix is zero, the bearing can be considered to have no fault of the preset fault categories under the condition of corresponding contact angle values; if the number of fault characteristic frequency elements meeting all preset fault categories required by independence in all fault characteristic matrixes is zero, the bearing can be considered to be normal in the current running state under the condition that the bearing has no fault of the preset fault category in the corresponding contact angle dynamic range, and the application is not limited to the situation.

In the embodiment, a series of confidence level criteria, multi-order criteria, independence criteria, working condition criteria and other diagnosis criteria are set, and the threshold judgment and interference recognition are sequentially carried out on the bearing fault characteristics, so that the accuracy of the running state evaluation of the rolling bearing is further improved, the online automatic diagnosis of the rolling bearing fault is realized, and the support of historical big data is not needed.

In other embodiments of the present application, if a certain failure feature frequency element in a certain failure feature matrix is determinedThe corresponding first multiple ratio is smaller than or equal to a first preset threshold value, or a certain fault characteristic frequency element in a certain fault characteristic matrix is judged>The corresponding frequency spectrum peak value is smaller than a second preset threshold value, or the frequency spectrum peak value is judged to be in certain fault characteristic matrix and meet the confidence coefficient requirement>The number of fault characteristic frequency elements of the same fault class is less than a third preset threshold, further comprising:

judging fault characteristic frequency elementWhether the following condition is satisfied:

；

in the method, in the process of the invention,representing the failure feature frequency element in the failure feature matrix +.>Corresponding first multiple ratio, ++>Representing the frequency elements of the fault feature matrix meeting the confidence requirements >Number of fault characteristic frequency elements of the same fault class, +.>Representing absolute value>And->Representing preset parameters, e.g. ->Can be set to 1, ">Can be set to 3;

if yes, consider the fault characteristic frequency elementMeets the requirement of multilevel. />

Specifically, the contact angle is taken asTime-dependent fault feature matrix->Is a certain fault characteristic frequency element +.>For example, if a failure feature matrix is determined +.>The fault characteristic frequency element->Corresponding first multiple ratioIs smaller than or equal to a first preset threshold value, or judges that the fault feature matrix is +>The fault characteristic frequency element->Corresponding spectral peak->Is smaller than a second preset threshold value, or judges that the fault feature matrix is +>The element of the frequency characteristic of the fault which meets the confidence requirement +.>The number of fault characteristic frequency elements of the same fault class +.>If the threshold value is smaller than the third preset threshold value, the +.>And->Whether the following condition is satisfied:

；

if yes, consider the fault characteristic frequency elementMeets the multi-order requirement, and can continue to return to S305 to calculate the fault characteristic frequency element ++>A corresponding normal vibration frequency threshold value and continuously judging the fault characteristic frequency element +.>Whether a preset independence requirement is satisfied.

In this embodiment, by setting the above-mentioned judgment conditions, the fault characteristic frequency element which is very close to the boundary values of the confidence criterion and the multistage criterion can be re-identified as the fault characteristic frequency element which meets the multistage requirement, so that the accuracy of the running state evaluation of the rolling bearing can be further improved.

As shown in fig. 2, in another embodiment of the present application, there is also provided a bearing operating state evaluation system based on a dynamic contact angle, including:

an acquisition unit 10 for acquiring an original vibration signal;

a processing unit 11, configured to process the original vibration signal to obtain a spectrum signal;

a first calculating unit 12, configured to calculate an actual frequency conversion according to the spectrum signal;

the second calculating unit 13 is configured to calculate, according to the actual rotation frequency and a preset contact angle dynamic range, a plurality of sets of fault feature frequencies, where the contact angle dynamic range includes a plurality of contact angle values, and each contact angle value corresponds to a set of fault feature frequencies;

a building unit 14, configured to build a corresponding fault feature matrix according to the fault feature frequency of each group and the preset frequency multiplication of the fault feature frequency;

and the analysis unit 15 is used for carrying out analysis processing on each fault characteristic matrix to obtain a state evaluation result.

In other embodiments of the present application, the processing unit 11, when performing processing on the original vibration signal to obtain a spectrum signal, is specifically configured to:

preprocessing the original vibration signal to obtain a preprocessed signal;

and performing fast Fourier transform on the preprocessed signals to obtain frequency spectrum signals.

In other embodiments of the present application, the first calculating unit 12 is specifically configured to, when performing calculation to obtain an actual frequency conversion according to the spectrum signal:

In other embodiments of the present application, the first calculating unit 12 is specifically configured to, when performing frequency searching and calculating in the spectrum signal according to the rotor frequency of the rotating mechanical device, the number of stages of the blades, and the number of blades of each stage, obtain the actual frequency conversion:

In other embodiments of the present application, the first calculating unit 12 is specifically configured to, when executing the establishment of the frequency search interval corresponding to each stage of blades according to the rotor frequency of the rotating mechanical device, the number of stages of blades, and the number of blades of each stage:

；

in the method, in the process of the invention,representing a matrix of leaf numbers>Representing the number of stages of the blade>Indicate->The number of stage blades;

in (I)>Representing a blade vibration frequency matrix>Indicate->Blade vibration frequency corresponding to the stage blade, +.>，/>Representing rotor rotation frequency;

establishing a frequency search interval corresponding to each stage of blade according to the blade vibration frequency corresponding to each stage of blade in the blade vibration frequency matrix and a first preset frequency interval threshold, wherein the first stage of blade is a first stage of blade The frequency search interval corresponding to the stage blade is specifically:

；

in the method, in the process of the invention,indicate->Frequency value in frequency search interval corresponding to stage blade,/->Representing a first preset frequency interval threshold.

In other embodiments of the present application, the first calculating unit 12 is specifically configured to, when performing calculation to obtain a reference rotation frequency value corresponding to each stage of blade according to an actual blade vibration frequency corresponding to each stage of blade and the number of blades of each stage:

according to the actual blade vibration frequency corresponding to each stage of blade, an actual blade vibration frequency matrix is established, and the method specifically comprises the following steps:

；

in the method, in the process of the invention,representing the actual blade vibration frequency matrix,/->Indicate->The actual blade vibration frequency corresponding to the stage blade;

；

in the method, in the process of the invention,representing a reference transfer matrix, ">Indicate->The reference rotation frequency value corresponding to the stage blade,；/>

in other embodiments of the present application, the first calculating unit 12 is specifically configured to, when performing statistical analysis according to the reference frequency conversion value corresponding to each stage of blade to obtain an actual frequency conversion:

；

and determining the actual rotating frequency according to the discrete degree index of each reference rotating frequency value.

In other embodiments of the present application, the first calculating unit 12 calculates the discrete degree index of each reference frequency conversion value according to the reference frequency conversion value corresponding to each stage of blade; according to the discrete degree index of each reference frequency conversion value, the method is particularly used for determining the actual frequency conversion:

；

According to the normalized reference frequency conversion value corresponding to each stage of blade, respectively calculating the entropy value corresponding to each reference frequency conversion value, wherein the calculation formula is as follows:

；

in the method, in the process of the invention,indicate->Entropy value deviation degree of reference frequency conversion value corresponding to the stage blade;

；

in the method, in the process of the invention,indicate->Entropy weight of the reference frequency conversion value corresponding to the stage blade, i.e. +.>Discrete degree index of the reference frequency conversion value corresponding to the stage blade;

In other embodiments of the present application, the failure feature frequencies of each group include one or more of a cage-to-outer ring failure feature frequency, a cage-to-inner ring failure feature frequency, an outer ring failure feature frequency, an inner ring failure feature frequency, a roller end face failure feature frequency, and a roller circumference failure feature frequency, and the specific calculation formulas are as follows:

Characteristic frequency of retainer collision outer ring fault：

；

Characteristic frequency of retainer collision inner ring fault：

；

Characteristic frequency of outer ring failure：

；

Characteristic frequency of inner ring failure：

；

Characteristic frequency of roller end face fault：

；

Characteristic frequency of roller circumference failure：

；

In other embodiments of the present application, the analysis unit 15 is specifically configured to, when performing analysis processing on each fault feature matrix to obtain a state evaluation result:

taking each fault characteristic frequency of each group in each fault characteristic matrix and each value of preset frequency multiplication of the fault characteristic frequency as one fault characteristic frequency element of each fault characteristic matrix respectively;

according to the frequency spectrum peak value corresponding to each fault characteristic frequency element, judging whether each fault characteristic frequency element meets the preset confidence coefficient requirement or not respectively, so as to obtain the fault characteristic frequency element meeting the confidence coefficient requirement in each fault characteristic matrix;

According to the number of fault characteristic frequency elements of each fault category meeting the confidence coefficient requirement in each fault characteristic matrix, judging whether the fault characteristic frequency elements of each fault category meeting the confidence coefficient requirement in each fault characteristic matrix meet the preset multi-order requirement or not respectively, so as to obtain the fault characteristic frequency elements meeting the multi-order requirement in each fault characteristic matrix;

judging whether each fault characteristic frequency element meeting the multi-order requirement meets the preset independence requirement according to the conventional vibration frequency threshold value corresponding to each fault characteristic frequency element meeting the multi-order requirement, so as to obtain the fault characteristic frequency element meeting the independence requirement in each fault characteristic matrix;

judging whether the original vibration signal meets the preset working condition, if so, considering that the bearing has faults of fault types corresponding to the fault characteristic frequency elements meeting the independence requirement.

In other embodiments of the present application, the analysis unit 15 is specifically configured to, when performing calculation of one spectral peak value corresponding to each failure feature frequency element in the spectral signal according to each failure feature frequency element in each failure feature matrix:

and carrying out peak value calculation in the frequency spectrum signal according to the peak value searching interval corresponding to each fault characteristic frequency element to obtain one frequency spectrum peak value corresponding to each fault characteristic frequency element.

In other embodiments of the present application, the analysis unit 15 is specifically configured to, when executing the spectrum peak corresponding to each fault characteristic frequency element, determine whether each fault characteristic frequency element meets a preset confidence requirement, so as to obtain a fault characteristic frequency element in each fault characteristic matrix, where the fault characteristic frequency element meets the confidence requirement:

For each fault characteristic frequency element in each fault characteristic matrix, judging whether a first multiple ratio corresponding to the fault characteristic frequency element is larger than a first preset threshold value or not, and if so, judging whether: judging whether the frequency spectrum peak value corresponding to the fault characteristic frequency element is larger than or equal to a second preset threshold value, if so, considering that the fault characteristic frequency element meets the preset confidence coefficient requirement, and obtaining the fault characteristic frequency element meeting the confidence coefficient requirement in each fault characteristic matrix.

In other embodiments of the present application, the analysis unit 15 is specifically configured to, when executing the number of fault feature frequency elements of each fault class that satisfies the confidence requirement in each fault feature matrix, determine whether the fault feature frequency element of each fault class that satisfies the confidence requirement in each fault feature matrix satisfies a preset multi-order requirement, so as to obtain the fault feature frequency element of each fault feature matrix that satisfies the multi-order requirement:

In other embodiments of the present application, the analysis unit 15 is specifically configured to, when executing the fault signature frequency elements that satisfy the multi-order requirement according to each of the fault signature matrices, calculate a normal vibration frequency threshold value corresponding to each of the fault signature frequency elements that satisfy the multi-order requirement:

；

In other embodiments of the present application, the analysis unit 15 is specifically configured to, when executing the conventional vibration frequency threshold corresponding to each of the fault characteristic frequency elements satisfying the multi-order requirement, determine whether each of the fault characteristic frequency elements satisfying the multi-order requirement satisfies the preset independence requirement, thereby obtaining the fault characteristic frequency element satisfying the independence requirement in each of the fault characteristic matrices:

In other embodiments of the present application, the analysis unit 15 is further configured to, if it is determined that a certain fault characteristic frequency element in a certain fault characteristic matrixThe corresponding first multiple ratio is smaller than or equal to a first preset threshold value, or a certain fault characteristic frequency element in a certain fault characteristic matrix is judged>The corresponding frequency spectrum peak value is smaller than a second preset threshold value, or the frequency spectrum peak value is judged to be in certain fault characteristic matrix and meet the confidence coefficient requirement>When the number of fault signature frequency elements of the same fault class is less than a third preset threshold,

；

in the method, in the process of the invention,representing the failure feature frequency element in the failure feature matrix +. >Corresponding first multiple ratio, ++>Representing the frequency elements of the fault feature matrix meeting the confidence requirements>Number of fault characteristic frequency elements of the same fault class, +.>Representing absolute value>And->Representing preset parameters;

if yes, consider the fault characteristic frequency elementMeets the requirement of multilevel.

In other embodiments of the present application, the analysis unit 15 is specifically configured to, when executing the determination of whether the original vibration signal meets the preset working condition:

judging whether the number of the rotating speed types in the rotating speed working condition corresponding to the original vibration signal exceeds a fifth preset threshold or whether the signal duration corresponding to the original vibration signal exceeds a sixth preset threshold, and if so, considering that the original vibration signal meets the preset working condition.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The method for evaluating the running state of the bearing based on the dynamic contact angle is characterized by comprising the following steps of:

acquiring an original vibration signal;

processing the original vibration signal to obtain a frequency spectrum signal;

2. The method as claimed in claim 1, wherein said processing said raw vibration signal to obtain a spectral signal comprises:

preprocessing the original vibration signal to obtain a preprocessed signal;

3. The method as claimed in claim 1, wherein said calculating an actual frequency conversion from said spectral signal comprises:

4. A method as claimed in claim 3, wherein said performing frequency searching and calculating in said spectrum signal based on rotor frequency, number of stages of blades and number of blades per stage of the rotating machine to obtain an actual frequency of rotation comprises:

5. The method as set forth in claim 4, wherein the establishing a frequency search interval corresponding to each stage of blades according to the rotor frequency, the number of stages of blades, and the number of blades of each stage of the rotating machine includes:

；

in the method, in the process of the invention,indicate->Stage blade correspondenceFrequency values in the frequency search interval, +.>Representing the first preset frequency interval threshold.

6. The method as set forth in claim 5, wherein the calculating a reference rotation frequency value corresponding to each stage of blades according to the actual blade vibration frequency corresponding to each stage of blades and the number of blades of each stage includes:

；

7. the method as set forth in claim 6, wherein said performing a statistical analysis based on the reference rotation frequency value corresponding to each stage of blades to obtain an actual rotation frequency includes:

；

8. The method as set forth in claim 6, wherein said performing a statistical analysis based on the reference rotation frequency value corresponding to each stage of blades to obtain an actual rotation frequency includes:

9. The method as set forth in claim 6, wherein said performing a statistical analysis based on the reference rotation frequency value corresponding to each stage of blades to obtain an actual rotation frequency includes:

10. The method as claimed in claim 9, wherein the step of calculating a discrete degree index of each reference frequency conversion value according to the reference frequency conversion value corresponding to each stage of blade; determining an actual frequency of rotation according to the discrete degree index of each reference frequency of rotation value, including:

；

11. The method of claim 1, wherein the failure signature frequencies of each group include one or more of a cage-to-outer ring failure signature frequency, a cage-to-inner ring failure signature frequency, an outer ring failure signature frequency, an inner ring failure signature frequency, a roller end face failure signature frequency, and a roller circumference failure signature frequency, and the specific calculation formula is as follows:

Characteristic frequency of retainer collision outer ring fault：

；

Characteristic frequency of retainer collision inner ring fault：

；

Characteristic frequency of outer ring failure：

；

Characteristic frequency of inner ring failure：

；

Characteristic frequency of roller end face fault：

；

Characteristic frequency of roller circumference failure：

；

12. The method of claim 1, wherein said analyzing each of said fault feature matrices to obtain a state evaluation result comprises:

13. The method as set forth in claim 12, wherein said calculating a spectral peak value corresponding to each fault signature frequency element in said spectral signal according to each fault signature frequency element in each fault signature matrix includes:

14. The method as set forth in claim 13, wherein the step of respectively determining whether each fault-feature-frequency element meets a preset confidence requirement according to the spectrum peak value corresponding to each fault-feature-frequency element, so as to obtain fault-feature-frequency elements meeting the confidence requirement in each fault-feature matrix includes:

15. The method as set forth in claim 14, wherein the step of determining whether the fault characteristic frequency element of each fault class satisfying the confidence requirement in each fault characteristic matrix satisfies a preset multi-order requirement according to the number of fault characteristic frequency elements of each fault class satisfying the confidence requirement in each fault characteristic matrix, respectively, includes:

16. The method as set forth in claim 15, wherein said calculating a normal vibration frequency threshold value corresponding to each of the failure feature frequency elements satisfying the multi-order requirement based on each of the failure feature frequency elements satisfying the multi-order requirement in each of the failure feature matrices includes:

；

in the method, in the process of the invention,representing a fault characteristic frequency element satisfying said multi-order requirement,/a >Representing said actual frequency of rotation,/->Representing a rounding function>Representation->The corresponding integer multiple ratio;

17. The method as set forth in claim 16, wherein the determining whether each of the fault signature frequency elements satisfying the multiple-order requirement satisfies a preset independence requirement according to the conventional vibration frequency threshold corresponding to each of the fault signature frequency elements satisfying the multiple-order requirement, thereby obtaining the fault signature frequency elements satisfying the independence requirement in each of the fault signature matrices, includes:

18. The method as set forth in claim 15, wherein if a certain failure feature frequency element in a certain of said failure feature matrices is determinedThe corresponding first multiple ratio is smaller than or equal to a first preset threshold value, or a certain fault characteristic frequency element in a certain fault characteristic matrix is judged to be +.>The corresponding frequency spectrum peak value is smaller than a second preset threshold value, or a fault characteristic frequency element which meets the confidence coefficient requirement and is corresponding to a certain fault characteristic frequency element in a certain fault characteristic matrix is judged>The number of fault characteristic frequency elements of the same fault class is less than a third preset threshold, further comprising:

；

19. The method of claim 12, wherein said determining whether said original vibration signal meets a predetermined operating condition comprises:

20. A dynamic contact angle based bearing operating condition assessment system, comprising:

an acquisition unit configured to acquire an original vibration signal;