CN112629786A - Working mode parameter identification method and equipment fault diagnosis method - Google Patents

Working mode parameter identification method and equipment fault diagnosis method Download PDF

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CN112629786A
CN112629786A CN202011407407.8A CN202011407407A CN112629786A CN 112629786 A CN112629786 A CN 112629786A CN 202011407407 A CN202011407407 A CN 202011407407A CN 112629786 A CN112629786 A CN 112629786A
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王成
符伟华
陈叶旺
赖雄鸣
张忆文
陈建伟
应晖
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Huaqiao University
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Abstract

The invention relates to a working modal parameter identification method and an equipment fault diagnosis method, and relates to the technical field of modal parameter identification. The working mode parameter identification method comprises the following steps: acquiring a time domain vibration response signal matrix formed by time domain vibration response signals detected by a vibration sensor within a preset time in a one-dimensional structure of a working modal parameter to be determined; obtaining a modal response matrix by utilizing a Laplace characteristic mapping method according to the time domain vibration response signal matrix; obtaining a modal shape matrix by utilizing a least square method generalized inverse method according to the modal response matrix; and obtaining the modal natural frequency by utilizing a single degree of freedom technology or a Fourier transform method according to the modal response matrix. The invention applies the Laplace feature mapping in manifold learning to the working mode analysis, and has lower time and space complexity.

Description

Working mode parameter identification method and equipment fault diagnosis method
Technical Field
The invention relates to the technical field of modal parameter identification, in particular to a working modal parameter identification method and an equipment fault diagnosis method.
Background
The mode is the vibration characteristic of the structure, and parameters (such as mode natural frequency, vibration mode, damping ratio and the like) of each order of mode are identified through an experimental mode analysis method, so that the dynamic characteristic of the structure can be known, and further damage identification of the structure, fault detection of equipment and the like are performed. However, for many large complex structures, the only excitation available is ambient excitation in the operating state, which results in an inability to measure excitation input. To solve this problem, a method of identifying the modal parameters of a structure by using only the output response of the structure is proposed and widely used.
Currently, there are various methods for identifying the modal parameters of the structure by using the output response of the structure, for example, the modal parameters are identified by using principal component analysis, so that the problem of false modal in the identification process of other methods is solved. The principal component analysis method is a linear method for reducing dimensions by converting a plurality of variables into a few comprehensive variables, namely principal components, through the research on the internal structure of a correlation matrix or a covariance matrix of original data. However, the principal component analysis method must calculate all principal components, which results in high time complexity of the modal parameter identification method using principal component analysis.
Disclosure of Invention
The invention aims to provide a working modal parameter identification method and an equipment fault diagnosis method, and aims to solve the problem that the existing modal parameter identification method is high in time complexity.
In order to achieve the purpose, the invention provides the following scheme:
a working mode parameter identification method comprises the following steps:
arranging a plurality of vibration sensors in a one-dimensional structure of which working modal parameters are to be determined; the vibration sensor is used for detecting a time domain vibration response signal of the linear time-invariant system under the excitation of a natural environment within a preset time; the working modal parameters comprise a modal shape and a modal natural frequency;
acquiring a time domain vibration response signal matrix formed by the time domain vibration response signals detected by each vibration sensor within preset time;
obtaining a modal response matrix by utilizing a Laplace characteristic mapping method according to the time domain vibration response signal matrix;
obtaining a modal shape matrix by utilizing a least square method generalized inverse method according to the modal response matrix;
and obtaining the modal natural frequency by utilizing a single degree of freedom technology or a Fourier transform method according to the modal response matrix.
Optionally, the obtaining a modal response matrix by using a laplacian feature mapping method according to the time domain vibration response signal matrix specifically includes:
the time domain vibration response signal matrix is
Figure BDA0002815670470000021
Wherein
Figure BDA0002815670470000022
Representing a time domain vibration response signal detected by a jth vibration sensor within a preset time t, wherein n represents the total number of the vibration sensors;
acquiring K adjacent time domain vibration response signals closest to the jth time domain vibration response signal;
reconstructing local structural features of the time domain vibration response signal matrix by using the weights of all the adjacent time domain vibration response signals;
performing eigenvalue decomposition on the local structural characteristics of the time domain vibration response signal matrix by using a Laplace eigenvalue mapping method to obtain d eigenvectors corresponding to the minimum non-zero eigenvalues;
and the eigenvectors corresponding to the d minimum non-zero eigenvalues form a time domain vibration response signal dimension reduction matrix, and the modal response matrix corresponds to the time domain vibration response signal dimension reduction matrix.
Optionally, the reconstructing the local structural feature of the time domain vibration response signal matrix by using the weights of all the adjacent time domain vibration response signals specifically includes:
determining the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal through a Gaussian kernel function according to the jth time domain vibration response signal and the kth adjacent time domain vibration response signal which is closest to the jth time domain vibration response signal; k1, 2,. K;
all the time domain vibration response signals and the weights of the adjacent time domain vibration response signals corresponding to the time domain vibration response signals form an adjacency matrix;
according to the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal, the formula is adopted
Figure BDA0002815670470000031
Determining the degree of the time domain vibration response signal; the degree matrix is a diagonal matrix formed by the degrees of the time domain vibration response signals; wherein the content of the first and second substances,
Figure BDA0002815670470000032
in the formula, DjkRepresenting the degree, w, of the j-th of said time-domain vibration response signaljkRepresenting the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal, wherein sigma represents the width parameter of the Gaussian kernel function; the local structural characteristics of the time domain vibration response signal matrix comprise a degree matrix and a Laplace matrix;
determining a laplacian matrix by a formula L ═ D-W according to the adjacency matrix and the degree matrix; where L denotes a laplacian matrix, D denotes a degree matrix, and W denotes an adjacency matrix.
Optionally, the obtaining a modal shape matrix by using a least square method generalized inverse method according to the modal response matrix specifically includes:
according to the modal response matrix, utilizing a least square generalized inverse method phi ═ X (t) QT(t)(Q(t)QT(t))-1Solving to obtain a modal shape matrix; wherein Φ represents a mode shape matrix, x (t) represents a time domain vibration response signal matrix, and q (t) represents a mode response matrix.
Optionally, obtaining a modal natural frequency by using a fourier transform method according to the modal response matrix, specifically including:
substituting the modal response matrix into a Fourier transform formula
Figure BDA0002815670470000033
Obtaining frequency domain data; the maximum frequency value in the frequency domain data is the modal natural frequency.
A working mode parameter identification method comprises the following steps:
arranging a plurality of vibration sensors in a three-dimensional structure of which working modal parameters are to be determined; the vibration sensor is used for detecting a time domain vibration response signal of the linear time-invariant system under the excitation of a natural environment within a preset time; the working modal parameters comprise a modal shape and a modal natural frequency;
acquiring a three-dimensional time domain vibration response signal matrix formed by the time domain vibration response signals detected by each vibration sensor within preset time;
discretizing the three-dimensional time domain vibration response signal matrix to obtain a vibration response signal matrix in the X direction, a vibration response signal matrix in the Y direction and a vibration response signal matrix in the Z direction; x, Y and Z are coordinate axes of a space rectangular coordinate system;
forming an integral modal response matrix of the three-dimensional structure by the vibration response signal matrix in the X direction, the vibration response signal matrix in the Y direction and the vibration response signal matrix in the Z direction;
obtaining a modal coordinate response matrix by utilizing a Laplace characteristic mapping method according to the overall modal response matrix;
obtaining a modal shape matrix by utilizing a least square method generalized inverse method according to the modal coordinate response matrix;
and obtaining the modal natural frequency by utilizing a single degree of freedom technology or a Fourier transform method according to the modal coordinate response matrix.
Optionally, the obtaining a modal coordinate response matrix by using a laplacian feature mapping method according to the overall modal response matrix specifically includes:
the overall modal response matrix is
Figure BDA0002815670470000041
Wherein (X)Three)H×T(t) represents a vibration response signal matrix in the X direction, (Y)Three)H×T(t) a vibration response signal matrix in the Y direction, (Z)Three)H×T(t) a matrix of vibration response signals representing the Z direction;
obtaining the K nearest to each X-direction time domain vibration response signal in the vibration response signal matrix in the X directionXAdjacent X-direction time domain vibration response signals, and K nearest to each Y-direction time domain vibration response signal in the vibration response signal matrix in the Y directionYAdjacent time domain vibration response signals in Y direction and K nearest to each time domain vibration response signal in Z direction in vibration response signal matrix in Z directionZTime domain vibration response signals in adjacent Z directions;
reconstructing the X-direction local structural feature of the X-direction time domain vibration response signal matrix by using the weights of all the adjacent X-direction time domain vibration response signals;
reconstructing Y-direction local structural features of the Y-direction time domain vibration response signal matrix by using the weights of all the adjacent Y-direction time domain vibration response signals;
reconstructing Z-direction local structural features of the Z-direction time domain vibration response signal matrix by using the weights of all the adjacent Z-direction time domain vibration response signals;
respectively aligning the images by using a Laplace characteristic mapping methodCarrying out characteristic value decomposition on the X-direction local structural feature, the Y-direction local structural feature and the Z-direction local structural feature to obtain dXThe X-direction characteristic vector, d, corresponding to the minimum non-zero eigenvalue of the X-direction local structural characteristic decompositionYY-direction feature vector d corresponding to minimum non-zero eigenvalue of Y-direction local structural feature decompositionZZ-direction feature vectors corresponding to the minimum non-zero eigenvalues of the Z-direction local structural feature decomposition;
dXforming an X-direction time domain vibration response signal dimension reduction matrix by the X-direction characteristic vectors, dYForming a Y-direction time domain vibration response signal dimension reduction matrix by the Y-direction characteristic vectors, dZForming a Z-direction time domain vibration response signal dimension reduction matrix by the Z-direction characteristic vectors; the modal response matrix in the X direction corresponds to the dimension reduction matrix of the time domain vibration response signal in the X direction, the modal response matrix in the Y direction corresponds to the dimension reduction matrix of the time domain vibration response signal in the Y direction, and the modal response matrix in the Z direction corresponds to the dimension reduction matrix of the time domain vibration response signal in the Z direction;
and forming a modal coordinate response matrix by the modal response matrix in the X direction, the modal response matrix in the Y direction and the modal response matrix in the Z direction.
Optionally, the reconstructing the X-direction local structural feature of the X-direction time domain vibration response signal matrix by using the weights of all the adjacent X-direction time domain vibration response signals specifically includes:
according to jXThe time domain vibration response signal in the X direction and the distance jXThe k-th nearest to the X-direction time domain vibration response signalXDetermining j th time domain vibration response signal in X direction through Gaussian kernel functionXThe time domain vibration response signal in the X direction and the kthXWeights of the adjacent X-direction time domain vibration response signals; k is a radical ofX=1,2,...,KX
All the X-direction time domain vibration response signals and the weights of the adjacent X-direction time domain vibration response signals corresponding to the X-direction time domain vibration response signals form an X-direction adjacency matrix;
according to jXThe time domain vibration response signal in the X direction and the kthXThe weight of the time domain vibration response signal in the adjacent X direction is calculated by formula
Figure BDA0002815670470000051
Determining an X-direction degree matrix; the X-direction degree matrix is composed of
Figure BDA0002815670470000052
A diagonal matrix is formed; wherein the content of the first and second substances,
Figure BDA0002815670470000053
denotes the j (th)XThe degree of the X-direction time-domain vibration response signal,
Figure BDA0002815670470000054
denotes the j (th)XThe time domain vibration response signal in the X direction and the kthXWeights of the adjacent X-direction time domain vibration response signals; the X-direction local structural characteristics of the X-direction time domain vibration response signal matrix comprise an X-direction degree matrix and an X-direction Laplace matrix;
according to the X-direction adjacency matrix and the X-direction degree matrix, a formula L is obtainedX=DX-WXDetermining an X-direction Laplace matrix; wherein L isXDenotes the X-direction Laplace matrix, DXRepresenting the X-direction degree matrix, WXRepresenting an X-direction adjacency matrix.
Optionally, the obtaining a modal shape matrix by using a least square method generalized inverse method according to the modal coordinate response matrix specifically includes:
according to the modal coordinate response matrix, utilizing least square method generalized inverse method
Figure BDA0002815670470000061
Solving to obtain a modal shape matrix; wherein (phi)Three)3H×SRepresents a mode shape matrix, (H)Three)3H×T(t) represents a wholeModal response matrix, (Q)Three)S×T(t) represents a modal coordinate response matrix,
Figure BDA0002815670470000062
a transpose matrix representing a modal coordinate response matrix.
An equipment fault diagnosis method comprising:
if the equipment to be diagnosed is of a one-dimensional structure, determining the working modal parameters of the equipment to be diagnosed at the current moment by using the working modal parameter identification method;
if the equipment to be diagnosed is in a three-dimensional structure, determining the working modal parameters of the equipment to be diagnosed at the current moment by using the working modal parameter identification method;
obtaining working mode parameters of the equipment to be diagnosed at the last moment;
judging whether the determined working modal parameter of the equipment to be diagnosed at the current moment is completely consistent with the working modal parameter of the equipment to be diagnosed at the last moment or not to obtain a first judgment result;
if the first judgment result is yes, the equipment to be diagnosed has no fault;
and if the first judgment result is negative, the equipment to be diagnosed has a fault.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides a working mode parameter identification method and an equipment fault diagnosis method. The working mode parameter identification method comprises the following steps: arranging a plurality of vibration sensors in a one-dimensional structure of which working modal parameters are to be determined; the vibration sensor is used for detecting a time domain vibration response signal of the linear time-invariant system under the excitation of a natural environment within preset time; the working modal parameters comprise a modal shape and a modal natural frequency; acquiring a time domain vibration response signal matrix formed by time domain vibration response signals detected by each vibration sensor within preset time; obtaining a modal response matrix by utilizing a Laplace characteristic mapping method according to the time domain vibration response signal matrix; obtaining a modal shape matrix by utilizing a least square method generalized inverse method according to the modal response matrix; and obtaining the modal natural frequency by utilizing a single degree of freedom technology or a Fourier transform method according to the modal response matrix. According to the invention, Laplace feature mapping in manifold learning is applied to the working mode analysis, so that the time and space complexity is reduced, and the identification precision of working mode parameters is improved.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
Fig. 1 is a flowchart of a method for identifying working mode parameters of a one-dimensional structure according to an embodiment of the present invention;
fig. 2 is a flowchart of a method for identifying working mode parameters of a three-dimensional structure according to an embodiment of the present invention;
FIG. 3 is a flow chart of a method for diagnosing equipment failure according to an embodiment of the present invention;
FIG. 4 is a finite element model of a three-dimensional cylindrical shell provided by an embodiment of the present invention;
FIG. 5 is a modal natural frequency plot of a three-dimensional cylindrical shell provided by an embodiment of the present invention;
FIG. 6 illustrates a mode shape of a three-dimensional cylindrical shell according to an embodiment of the present invention; FIG. 6(a) is the true mode shape of a three-dimensional cylindrical shell at orders 1,2, 3, 4 and 7; fig. 6(b) shows the mode shapes of the three-dimensional cylindrical shell at 1 st, 2 nd, 3 rd, 4 th and 7 th orders determined by the working mode parameter identification method.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a working modal parameter identification method and an equipment fault diagnosis method, and aims to solve the problem that the existing modal parameter identification method is high in time complexity.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Manifold is a geometric concept that represents a low-dimensional geometry that is tessellated in a high-dimensional space. Based on the geometric concept, the data after dimension reduction needs to be kept in the dimension reduction process of manifold learning, and the geometric constraint relation related to the manifold in the high-dimensional space is also satisfied. At present, algorithms widely used in manifold learning include an equidistant mapping, a local linear embedding algorithm, a laplacian feature mapping method and the like. In recent years, manifold learning is widely applied in a plurality of engineering fields such as image processing, for example, a manifold learning method using local linear embedding is used to identify working mode parameters of a complex three-dimensional continuum structure. The invention aims to introduce a Laplace feature mapping method in manifold learning into a dynamic system to identify working mode parameters of a linear time-invariant structure.
The embodiment provides a working mode parameter identification method which is applied to a one-dimensional structure. Fig. 1 is a flowchart of a working mode parameter identification method for a one-dimensional structure according to an embodiment of the present invention, and referring to fig. 1, the working mode parameter identification method includes:
step 101, arranging a plurality of vibration sensors in a one-dimensional structure of a working modal parameter to be determined; the vibration sensor is used for detecting a time domain vibration response signal of the linear time-invariant system under the excitation of a natural environment within preset time; the working modal parameters comprise a modal shape and a modal natural frequency. The linear time invariant system comprises a multi-degree-of-freedom system, a one-dimensional continuum structure (one-dimensional structure), a two-dimensional continuum structure (two-dimensional structure) and a three-dimensional continuum structure (three-dimensional structure).
Step 102, acquiring a time domain vibration response signal matrix formed by time domain vibration response signals detected by each vibration sensor within preset time. The time-domain vibration response signal matrix x (t) is represented as:
Figure BDA0002815670470000081
wherein the content of the first and second substances,
Figure BDA0002815670470000082
representing a time domain vibration response signal measured by a jth sensor within a preset time t; n denotes the total number of vibration sensors arranged on the one-dimensional structure, j ═ 1, 2.., n; t represents a preset time; t represents the total number of sampling points in the time domain within a preset time T, i is 1, 2. x is the number ofj(i) Representing the vibration response signal measured by the jth sensor at the ith sampling point; x is the number ofj(T) represents the vibration response signal measured by the jth sensor at the tth sampling point,
Figure BDA0002815670470000083
representing a matrix of dimension n x T.
And 103, obtaining a modal response matrix by utilizing a Laplace characteristic mapping method according to the time domain vibration response signal matrix.
Step 103 specifically comprises:
time domain vibration response signal matrix of
Figure BDA0002815670470000091
Wherein
Figure BDA0002815670470000092
Represents the time-domain vibration response signal detected by the jth vibration sensor within the preset time t, and n represents the total number of the vibration sensors.
And acquiring K adjacent time domain vibration response signals closest to the jth time domain vibration response signal. Obtaining a time domain vibration response signal matrix X (t) in the step 102, and regarding each point in the time domain vibration response signal matrix
Figure BDA0002815670470000093
Find K neighbors nearest to it, i.e. adjacent time domain vibration response signals
Figure BDA0002815670470000094
The method for calculating the distance between any two time-domain vibration response signals is a K-nearest neighbor algorithm.
And reconstructing local structural features of the time domain vibration response signal matrix by using the weights of all adjacent time domain vibration response signals. The method specifically comprises the following steps:
determining the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal through a Gaussian kernel function according to the jth time domain vibration response signal and the kth adjacent time domain vibration response signal which is closest to the jth time domain vibration response signal; k is 1, 2. Weight w of each neighborjkSize may be determined by a Gaussian kernel function
Figure BDA0002815670470000095
Calculation of wjkRepresenting the j time-domain vibration response signal
Figure BDA0002815670470000096
And adjacent time domain vibration response signal
Figure BDA0002815670470000097
The weight on the adjacency graph, σ, is the width parameter of the gaussian kernel.
All the time domain vibration response signals and the weights of the adjacent time domain vibration response signals corresponding to the time domain vibration response signals form an adjacency matrix. Through wjkConstructing a adjacency matrix W ═ Wjk]To reconstruct the local structural features of the time-domain vibration response signal matrix x (t).
According to the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal, the formula is used
Figure BDA0002815670470000098
Determining time-domain vibrationsThe degree of the response signal; the degree matrix is a diagonal matrix formed by the degrees of the time domain vibration response signals; wherein D isjkDegree, w, of a j-th time-domain vibration response signaljkRepresenting the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal; the local structural features of the time domain vibration response signal matrix include a degree matrix and a laplacian matrix. Let diagonal matrix D be the degree matrix of x (t) graph and L be the laplacian matrix of the graph.
Determining a Laplace matrix according to the adjacency matrix and the degree matrix by using a formula L-D-W; where L denotes a laplacian matrix, D denotes a degree matrix, and W denotes an adjacency matrix.
And performing eigenvalue decomposition on the local structural characteristics of the time domain vibration response signal matrix by using a Laplace eigenvalue mapping method to obtain d eigenvectors corresponding to the minimum non-zero eigenvalues. Laplace eigenmap pass pair is a formula of Laplace eigenmap
Figure BDA0002815670470000101
(
Figure BDA0002815670470000102
Eigenvectors corresponding to eigenvalues λ) are subjected to eigenvalue decomposition and
Figure BDA0002815670470000103
decomposed d (d < n) minimum non-zero eigenvalues lambda12,…,λd',…,λdCorresponding feature vector
Figure BDA0002815670470000104
Outputting the result after dimension reduction to obtain a matrix after dimension reduction, namely a time domain vibration response signal dimension reduction matrix
Figure BDA0002815670470000105
The purpose of dimension reduction can be achieved, Y (t) corresponds to the modal response matrix Q (t).
Figure BDA0002815670470000106
Denotes λd'Represents the d 'th minimum non-zero characteristic value, d' 1, 2.., d;
Figure BDA0002815670470000107
representing the eigenvector corresponding to the d' th minimum non-zero eigenvalue, wherein the value of d is the same as the order of modal identification, and generally d is<1/10n is considered to be d much smaller than n.
And d eigenvectors corresponding to the minimum non-zero eigenvalues form a time domain vibration response signal dimension reduction matrix, and the modal response matrix corresponds to the time domain vibration response signal dimension reduction matrix.
And 104, obtaining a modal shape matrix by using a least square method generalized inverse method according to the modal response matrix.
Step 104 specifically includes:
according to the modal response matrix, using a least square generalized inverse method phi ═ X (t) QT(t)(Q(t)QT(t))-1Solving to obtain a modal shape matrix; wherein Φ represents a mode shape matrix, x (t) represents a time domain vibration response signal matrix, and q (t) represents a mode response matrix. In the modal coordinate, the time-domain vibration response signal matrix x (t) may be decomposed into x (t) ═ Φ Q (t), where x (t) and Q (t) are known, and the modal shape matrix Φ is obtained by using the least square method generalized inverse method whose formula is Φ ═ x (t) Q (t)T(t)(Q(t)QT(t))-1
And 105, obtaining the natural frequency of the mode by utilizing a single degree of freedom (SDOF) or a Fourier transform method according to the mode response matrix.
According to the modal response matrix, obtaining modal natural frequency by using a Fourier transform method, which specifically comprises the following steps:
substituting the modal response matrix into a Fourier transform formula
Figure BDA0002815670470000108
Obtaining frequency domain data; in the amplitude-frequency map in the frequency domain data, the frequency value corresponding to the maximum amplitude is the modal natural frequency.
In the embodiment, the accuracy of identifying the working modal parameters by the modal shape matrix phi is quantitatively evaluated by adopting the modal confidence parameters MAC, and the effectiveness of identifying the working modal parameters by an algorithm is measured. The modal confidence formula is specifically:
Figure BDA0002815670470000111
wherein phi isiIs the identified ith mode shape matrix,
Figure BDA0002815670470000112
represents the true ith mode shape matrix, phii TAnd
Figure BDA0002815670470000113
respectively represents phiiAnd
Figure BDA0002815670470000114
the transpose of (a) is performed,
Figure BDA0002815670470000115
represents the inner product of two vectors and represents the inner product of the two vectors,
Figure BDA0002815670470000116
is indicative of phiiAnd
Figure BDA0002815670470000117
to the extent of the similarity in the direction of the line,
Figure BDA0002815670470000118
the more its value is close to 1, the higher the accuracy of the mode shape matrix identification. The function of evaluating the accuracy of the modal shape matrix is that if the MAC value is closer to 1, the higher the identification accuracy of the modal shape matrix is, which indicates that the effectiveness of the working modal parameter identification method is higher.
The embodiment also provides a working mode parameter identification method which is applied to a three-dimensional structure. Fig. 2 is a flowchart of a method for identifying working mode parameters of a three-dimensional structure according to an embodiment of the present invention, and referring to fig. 2, the method for identifying working mode parameters includes:
step 201, arranging a plurality of vibration sensors in a three-dimensional structure of working modal parameters to be determined; the vibration sensor is used for detecting a time domain vibration response signal of the linear time-invariant system under the excitation of a natural environment within preset time; the working modal parameters comprise a modal shape and a modal natural frequency.
Step 202, obtaining a three-dimensional time domain vibration response signal matrix formed by time domain vibration response signals detected by each vibration sensor within a preset time. Aiming at a complex three-dimensional structure, a three-dimensional time domain vibration response signal matrix formed by time domain vibration response signals of the three-dimensional structure is as follows:
Figure BDA0002815670470000119
wherein, XThree(t) represents a time-domain vibration response signal in the X direction, YThree(t) time-domain vibration response signal in Y-direction, ZThree(t) representing a time domain vibration response signal in the Z direction, X, Y, Z corresponding to coordinate axes in the X direction, the Y direction and the Z direction of the three-dimensional space rectangular coordinate system respectively; o denotes a modal shape matrix in the X direction, ρ denotes a modal shape matrix in the Y direction, and θ denotes a modal shape matrix in the Z direction (i.e., (Φ)Three)3H×S=[ο;ρ;υ]) (ii) a A (t) represents the time domain vibration response signal of each order
Figure BDA0002815670470000121
A constructed modal response matrix; m represents the order of the mode, and the range value is 1 to infinity;
Figure BDA0002815670470000122
corresponding to X, Y, Z th order mode shape in three directions. The mode shape of the mth order mode of the complex three-dimensional structure can be assembled by assembling X, Y, Z into the mth order mode shape in three directions
Figure BDA0002815670470000123
And (4) performing representation.
Figure BDA0002815670470000124
Also represents the modal coordinates (in terms of m-th order mode of a complex three-dimensional structure)
Figure BDA0002815670470000125
Identification of natural frequency f of mth order mode by using single degree of freedom identification technologym)
In combination with vibration theory, the modal coordinates of X, Y, Z in 3 directions of the complex three-dimensional structure can be derived
Figure BDA0002815670470000126
Are consistent.
Step 203, discretizing the three-dimensional time domain vibration response signal matrix to obtain a vibration response signal matrix in the X direction, a vibration response signal matrix in the Y direction and a vibration response signal matrix in the Z direction; wherein X, Y and Z are coordinate axes of the rectangular space coordinate system. The complex three-dimensional cylindrical shell (three-dimensional structure) is discretized into H detection points, and the total number of the sampling points in the preset time is T. Therefore, the response of the discretized three-dimensional structure in the time domain can be expressed as near as theoretically
Figure BDA0002815670470000127
Wherein, o'H×S、ρ′H×S、υ′H×SThe meaning of (1) is modal shape in X direction, modal shape in Y direction, modal shape in Z direction (o'H×S、ρ′H×S、υ′H×SWhen the cutoff value is S, the values of omicron, rho and upsilon), A (t)S×TModal response matrix being a three-dimensional structure (A (t)S×TWhen the truncation value is S, the value of A (t) is the modal truncation number in the finite element calculation process.
And 204, forming an integral modal response matrix of a three-dimensional structure by the vibration response signal matrix in the X direction, the vibration response signal matrix in the Y direction and the vibration response signal matrix in the Z direction. X, Y, Z vibration response signals in three directions are assembled into an integral module of the whole three-dimensional structureA state response matrix. The overall modal response matrix after assembly can be represented as
Figure BDA0002815670470000131
(HThree)3H×T(t) is the overall modal response matrix of the overall three-dimensional structure; (X)Three)H×T(t)、(YThree)H×T(t)、(ZThree)H×T(t) X, Y, Z directional vibration response signal matrixes respectively; (phi.)Three)3H×SIs a main mode shape vector of each order of complex three-dimensional structure
Figure BDA0002815670470000133
The formed mode shape matrix; (Q)Three)S×T(t) is the modal response of each order of the three-dimensional structure
Figure BDA0002815670470000134
And forming a modal coordinate response matrix.
And step 205, obtaining a modal coordinate response matrix by using a Laplace feature mapping method according to the overall modal response matrix.
Step 205 specifically includes:
the overall modal response matrix is
Figure BDA0002815670470000132
Wherein (X)Three)H×T(t) represents a vibration response signal matrix in the X direction, (Y)Three)H×T(t) a vibration response signal matrix in the Y direction, (Z)Three)H×T(t) represents a vibration response signal matrix in the Z direction.
Obtaining the nearest K of each X-direction time domain vibration response signal in the vibration response signal matrix in the X directionXAdjacent X-direction time domain vibration response signals, and K nearest to each Y-direction time domain vibration response signal in vibration response signal matrix in Y directionYThe time domain vibration response signals in the adjacent Y direction and each time domain vibration response signal in the Z direction in the vibration response signal matrix away from the Z directionNear KZAnd the adjacent Z-direction time domain vibration response signals.
And reconstructing the X-direction local structural characteristics of the X-direction time domain vibration response signal matrix by using the weights of all the adjacent X-direction time domain vibration response signals. The method specifically comprises the following steps:
according to jXTime domain vibration response signal in X direction and distance jXThe k-th nearest to the X-direction time domain vibration response signalXDetermining j th time domain vibration response signal in X direction through Gaussian kernel functionXThe time domain vibration response signal in the X direction and the kthXWeights of the adjacent X-direction time domain vibration response signals; k is a radical ofX=1,2,...,KX
And all the X-direction time domain vibration response signals and the weights of the adjacent X-direction time domain vibration response signals corresponding to the X-direction time domain vibration response signals form an X-direction adjacency matrix.
According to jXThe time domain vibration response signal in the X direction and the kthXThe weight of the time domain vibration response signal in the adjacent X direction is calculated by formula
Figure BDA0002815670470000141
Determining an X-direction degree matrix; the X-direction degree matrix is composed of
Figure BDA0002815670470000142
A diagonal matrix is formed; wherein the content of the first and second substances,
Figure BDA0002815670470000143
denotes the j (th)XThe degree of the X-direction time-domain vibration response signal,
Figure BDA0002815670470000144
denotes the j (th)XThe time domain vibration response signal in the X direction and the kthXWeights of the adjacent X-direction time domain vibration response signals; the X-direction local structural feature of the X-direction time domain vibration response signal matrix comprises an X-direction degree matrix and an X-direction Laplace matrix.
According to the X-direction adjacency matrix and the X-direction degree matrix, the formula LX=DX-WXDetermining an X-direction Laplace matrix; wherein L isXDenotes the X-direction Laplace matrix, DXRepresenting the X-direction degree matrix, WXRepresenting an X-direction adjacency matrix.
And reconstructing the Y-direction local structural feature of the Y-direction time domain vibration response signal matrix by using the weights of all adjacent Y-direction time domain vibration response signals.
And reconstructing the Z-direction local structural feature of the Z-direction time domain vibration response signal matrix by using the weights of all adjacent Z-direction time domain vibration response signals.
Respectively carrying out eigenvalue decomposition on the X-direction local structural feature, the Y-direction local structural feature and the Z-direction local structural feature by using a Laplace feature mapping method to obtain dXX-direction feature vector corresponding to minimum non-zero eigenvalue of X-direction local structural feature decomposition, dYY-direction feature vector corresponding to minimum non-zero eigenvalue of local structure feature decomposition in Y-direction, dZAnd the Z-direction characteristic vector corresponding to the minimum non-zero characteristic value of the Z-direction local structural characteristic decomposition.
dXForming an X-direction time domain vibration response signal dimension reduction matrix by the X-direction characteristic vectors, dYForming a Y-direction time domain vibration response signal dimension reduction matrix by the Y-direction characteristic vectors, dZForming a Z-direction time domain vibration response signal dimension reduction matrix by the Z-direction characteristic vectors; the modal response matrix in the X direction corresponds to the dimension reduction matrix of the time domain vibration response signals in the X direction, the modal response matrix in the Y direction corresponds to the dimension reduction matrix of the time domain vibration response signals in the Y direction, and the modal response matrix in the Z direction corresponds to the dimension reduction matrix of the time domain vibration response signals in the Z direction.
And forming a modal coordinate response matrix by the modal response matrix in the X direction, the modal response matrix in the Y direction and the modal response matrix in the Z direction.
And step 206, obtaining a modal shape matrix by using a least square method generalized inverse method according to the modal coordinate response matrix.
Step 206 specifically includes:
using a minimum of two according to the modal coordinate response matrixGeneralized inverse method of multiplication
Figure BDA0002815670470000151
Solving to obtain a modal shape matrix; wherein (phi)Three)3H×SRepresents a mode shape matrix, (H)Three)3H×T(t) represents the overall modal response matrix, (Q)Three)S×T(t) represents a modal coordinate response matrix,
Figure BDA0002815670470000152
a transpose matrix representing a modal coordinate response matrix.
And step 207, obtaining the modal natural frequency by utilizing a single degree of freedom technology or a Fourier transform method according to the modal coordinate response matrix.
According to the modal coordinate response matrix, obtaining the modal natural frequency by using a Fourier transform method, which specifically comprises the following steps:
substituting the modal coordinate response matrix into a Fourier transform formula
Figure BDA0002815670470000153
Obtaining frequency domain data; the largest frequency value in the frequency domain data is the modal natural frequency.
The present embodiment further provides an apparatus fault diagnosis method, which performs fault diagnosis and health status monitoring on an apparatus by using the working mode parameter identification method, and fig. 3 is a flowchart of the apparatus fault diagnosis method provided in the embodiment of the present invention. Referring to fig. 3, the apparatus fault diagnosis method includes:
a set of multi-channel vibrational response data is collected by a vibration sensor disposed in the device to be diagnosed.
Step 301, if the device to be diagnosed is of a one-dimensional structure, determining the working modal parameters of the device to be diagnosed at the current moment by using a working modal parameter identification method of the one-dimensional structure.
Step 302, if the device to be diagnosed is of a three-dimensional structure, determining the working modal parameters of the device to be diagnosed at the current moment by using a working modal parameter identification method of the three-dimensional structure.
Step 303, obtaining working mode parameters of the equipment to be diagnosed at the last moment.
Step 304, judging whether the determined working mode parameter of the equipment to be diagnosed at the current moment is completely consistent with the working mode parameter of the equipment to be diagnosed at the last moment, and obtaining a first judgment result.
In step 305, if the first determination result is yes, the device to be diagnosed has no fault.
And step 306, if the first judgment result is negative, the equipment to be diagnosed has a fault.
According to the equipment fault diagnosis and health state monitoring method, the plurality of vibration sensor devices are arranged on the structural key points of the equipment to be diagnosed, working modal parameters are identified through vibration response signals measured by the vibration sensors, and modal parameters of the equipment to be diagnosed are detected.
In this embodiment, the method for identifying the working modal parameters of the three-dimensional structure is applied to the three-dimensional cylindrical shell, and the modal parameters of the three-dimensional cylindrical shell are identified:
referring to fig. 4, a three-dimensional cylindrical shell is placed on two bases spaced apart, an excitation device is placed in the space between the two bases, and a baffle is placed on each of the two bottom surfaces of the cylindrical shell. X, Y and Z in FIG. 4 are coordinate axes of a rectangular spatial coordinate system. The parameters of the three-dimensional cylindrical shell are as follows: the cylindrical shell is made of a material having a thickness of 0.005 m, a radius of 0.1825 m and a total length of 0.37 m, and has an elastic modulus of 205GPa, a Poisson ratio of 0.3 and a density of 7850kg/m3. In the process of modal parameter identification, the damping ratios eta of 0.03, 0.05 and 0.1 are artificially set respectively for modal parameter identification. The observation points of the vibration sensors on the cylindrical shell are arranged in the following rule: first, the cylindrical shell is divided axially uniformly into 38 turns along its length, and then 115 observation points are arranged uniformly in each turn, so that a total of H38 × 115 4370 vibration sensor observation points are arranged on the surface of the cylindrical shell. After the vibration sensor is arranged, Gaussian white noise excitation is applied to the cylindrical shell by using an excitation device, and the three-dimensional cylindrical shell is obtained by samplingThe vibration response signal of (1). Wherein, the sampling frequency of the signal acquisition equipment is set to 5120Hz, and the time length of the sampling is set to 1 second, namely T is 5120.
Performing modal parameter identification on the three-dimensional cylindrical shell by using a working modal parameter identification method of a three-dimensional structure to obtain a modal coordinate response matrix (Q)Three)S×T(t) and responding to the modal coordinates with a matrix (Q)Three)S×T(t) performing FFT to obtain modal natural frequency, wherein the modal natural frequency of the three-dimensional cylindrical shell at 1 st, 2 nd, 3 rd, 4 th and 7 th orders is shown in figure 5; response matrix (Q) according to modal coordinatesThree)S×T(t) obtaining a mode shape matrix by using a least square method generalized inverse method, wherein the mode shapes of the three-dimensional cylindrical shell in the 1 st, 2 nd, 3 rd, 4 th and 7 th orders are shown in fig. 6(b), and the real mode shapes of the three-dimensional cylindrical shell in the 1 st, 2 nd, 3 rd, 4 th and 7 th orders are shown in fig. 6(a) and numbers marked in fig. 6 represent the fluctuation range of the signals.
The confidence coefficient of the working mode parameter identification method (LE method) based on the laplace feature mapping of the present invention is shown in table 1, and table 1 is the confidence coefficient of the working mode parameter identification method based on the laplace feature mapping of the present invention in the 1 st, 2 nd, 3 th, 4 th and 7 th orders.
TABLE 1
Figure BDA0002815670470000171
The modal natural frequencies identified by the LE method of the present invention are referred to in table 2. The relative error rate of the LE method is the relative error between the modal natural frequency solved by the LE method and the true modal natural frequency. Table 2 shows the true modal natural frequencies at orders 1,2, 3, 4 and 7, and the relative error rates at orders 1,2, 3, 4 and 7 of the working modal parameter identification method based on laplace feature mapping according to the present invention.
TABLE 2
Figure BDA0002815670470000172
The invention discloses a working modal parameter identification method based on Laplace feature mapping, which applies the Laplace feature mapping in manifold learning to working modal analysis, in particular to a working modal parameter identification method aiming at linear engineering structures and three-dimensional linear engineering structures, and can effectively detect the working modal parameters of the linear engineering structures and the three-dimensional linear engineering structures. The identification precision of the Laplace feature mapping method for identifying the working modal parameters is higher than that of the principal component analysis algorithm for identifying the working modal parameters, and the Laplace feature mapping method has the characteristic of low time and space complexity, because the time overhead of the Laplace matrix L of the construction diagram of the Laplace feature mapping method is low. In addition, the time-varying transient working mode parameters (transient working mode shape and natural frequency of the transient working mode) of the linear time-invariant structure can be identified on line in real time only by actually measuring the non-stationary vibration response signal, and the method has great advantages compared with the traditional test mode parameter identification technology which needs to measure the excitation and response signals at the same time.
The method for identifying the working modal parameters of the three-dimensional structure based on the Laplace feature mapping can effectively identify the working modal parameters (modal shape and modal frequency) of the three-dimensional structure, and can be used for equipment fault diagnosis, health monitoring and structural analysis and optimization. Compared with the working modal parameter identification method using a principal component analysis method, the method can greatly improve the identification precision of the first order and the second order, reduce the time and memory overhead, be more easily used for equipment fault diagnosis, health monitoring and system structure analysis and optimization, and have greater advantages compared with the traditional test modal parameter identification technology which needs to measure excitation and response signals simultaneously.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (10)

1. A working mode parameter identification method is characterized by comprising the following steps:
arranging a plurality of vibration sensors in a one-dimensional structure of which working modal parameters are to be determined; the vibration sensor is used for detecting a time domain vibration response signal of the linear time-invariant system under the excitation of a natural environment within a preset time; the working modal parameters comprise a modal shape and a modal natural frequency;
acquiring a time domain vibration response signal matrix formed by the time domain vibration response signals detected by each vibration sensor within preset time;
obtaining a modal response matrix by utilizing a Laplace characteristic mapping method according to the time domain vibration response signal matrix;
obtaining a modal shape matrix by utilizing a least square method generalized inverse method according to the modal response matrix;
and obtaining the modal natural frequency by utilizing a single degree of freedom technology or a Fourier transform method according to the modal response matrix.
2. The method for identifying working modal parameters according to claim 1, wherein the obtaining a modal response matrix by using a laplacian eigenmap method according to the time-domain vibration response signal matrix specifically comprises:
the time domain vibration response signal matrix is
Figure FDA0002815670460000011
Wherein
Figure FDA0002815670460000012
Representing a time domain vibration response signal detected by a jth vibration sensor within a preset time t, wherein n represents the total number of the vibration sensors;
acquiring K adjacent time domain vibration response signals closest to the jth time domain vibration response signal;
reconstructing local structural features of the time domain vibration response signal matrix by using the weights of all the adjacent time domain vibration response signals;
performing eigenvalue decomposition on the local structural characteristics of the time domain vibration response signal matrix by using a Laplace eigenvalue mapping method to obtain d eigenvectors corresponding to the minimum non-zero eigenvalues;
and the eigenvectors corresponding to the d minimum non-zero eigenvalues form a time domain vibration response signal dimension reduction matrix, and the modal response matrix corresponds to the time domain vibration response signal dimension reduction matrix.
3. The method according to claim 2, wherein the reconstructing the local structural feature of the time-domain vibro-responsive signal matrix using the weights of all the adjacent time-domain vibro-responsive signals specifically comprises:
determining the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal through a Gaussian kernel function according to the jth time domain vibration response signal and the kth adjacent time domain vibration response signal which is closest to the jth time domain vibration response signal; k1, 2,. K;
all the time domain vibration response signals and the weights of the adjacent time domain vibration response signals corresponding to the time domain vibration response signals form an adjacency matrix;
according to the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal, the formula is adopted
Figure FDA0002815670460000021
Determining the degree of the time domain vibration response signal; the degree matrix is a diagonal matrix formed by the degrees of the time domain vibration response signals; wherein the content of the first and second substances,
Figure FDA0002815670460000022
in the formula, DjkDegree, w, of a j-th time-domain vibration response signaljkRepresenting the weight of the jth time domain vibration response signal and the kth adjacent time domain vibration response signal, wherein sigma represents the width parameter of the Gaussian kernel function; the local structural characteristics of the time domain vibration response signal matrix comprise a degree matrix and a Laplace matrix;
determining a laplacian matrix by a formula L ═ D-W according to the adjacency matrix and the degree matrix; where L denotes a laplacian matrix, D denotes a degree matrix, and W denotes an adjacency matrix.
4. The method for identifying working modal parameters according to claim 1, wherein the obtaining a modal shape matrix by using a least square generalized inverse method according to the modal response matrix specifically comprises:
according to the modal response matrix, utilizing a least square generalized inverse method phi ═ X (t) QT(t)(Q(t)QT(t))-1Solving to obtain a modal shape matrix; wherein Φ represents a mode shape matrix, x (t) represents a time domain vibration response signal matrix, and q (t) represents a mode response matrix.
5. The method for identifying working modal parameters according to claim 1, wherein obtaining modal natural frequencies by using a fourier transform method according to the modal response matrix specifically comprises:
substituting the modal response matrix into a Fourier transform formula
Figure FDA0002815670460000023
Obtaining frequency domain data; the maximum frequency value in the frequency domain data is the modal natural frequency.
6. A working mode parameter identification method is characterized by comprising the following steps:
arranging a plurality of vibration sensors in a three-dimensional structure of which working modal parameters are to be determined; the vibration sensor is used for detecting a time domain vibration response signal of the linear time-invariant system under the excitation of a natural environment within a preset time; the working modal parameters comprise a modal shape and a modal natural frequency;
acquiring a three-dimensional time domain vibration response signal matrix formed by the time domain vibration response signals detected by each vibration sensor within preset time;
discretizing the three-dimensional time domain vibration response signal matrix to obtain a vibration response signal matrix in the X direction, a vibration response signal matrix in the Y direction and a vibration response signal matrix in the Z direction; x, Y and Z are coordinate axes of a space rectangular coordinate system;
forming an integral modal response matrix of the three-dimensional structure by the vibration response signal matrix in the X direction, the vibration response signal matrix in the Y direction and the vibration response signal matrix in the Z direction;
obtaining a modal coordinate response matrix by utilizing a Laplace characteristic mapping method according to the overall modal response matrix;
obtaining a modal shape matrix by utilizing a least square method generalized inverse method according to the modal coordinate response matrix;
and obtaining the modal natural frequency by utilizing a single degree of freedom technology or a Fourier transform method according to the modal coordinate response matrix.
7. The method for identifying working modal parameters according to claim 6, wherein the obtaining a modal coordinate response matrix by using a laplace feature mapping method according to the overall modal response matrix specifically comprises:
the overall modal response matrix is
Figure FDA0002815670460000031
Wherein (X)Three)H×T(t) in the X directionVibration response signal matrix, (Y)Three)H×T(t) a vibration response signal matrix in the Y direction, (Z)Three)H×T(t) a matrix of vibration response signals representing the Z direction;
obtaining the K nearest to each X-direction time domain vibration response signal in the vibration response signal matrix in the X directionXAdjacent X-direction time domain vibration response signals, and K nearest to each Y-direction time domain vibration response signal in the vibration response signal matrix in the Y directionYAdjacent time domain vibration response signals in Y direction and K nearest to each time domain vibration response signal in Z direction in vibration response signal matrix in Z directionZTime domain vibration response signals in adjacent Z directions;
reconstructing the X-direction local structural feature of the X-direction time domain vibration response signal matrix by using the weights of all the adjacent X-direction time domain vibration response signals;
reconstructing Y-direction local structural features of the Y-direction time domain vibration response signal matrix by using the weights of all the adjacent Y-direction time domain vibration response signals;
reconstructing Z-direction local structural features of the Z-direction time domain vibration response signal matrix by using the weights of all the adjacent Z-direction time domain vibration response signals;
respectively carrying out eigenvalue decomposition on the X-direction local structural feature, the Y-direction local structural feature and the Z-direction local structural feature by utilizing a Laplace feature mapping method to obtain dXThe X-direction characteristic vector, d, corresponding to the minimum non-zero eigenvalue of the X-direction local structural characteristic decompositionYY-direction feature vector d corresponding to minimum non-zero eigenvalue of Y-direction local structural feature decompositionZZ-direction feature vectors corresponding to the minimum non-zero eigenvalues of the Z-direction local structural feature decomposition;
dXforming an X-direction time domain vibration response signal dimension reduction matrix by the X-direction characteristic vectors, dYForming a Y-direction time domain vibration response signal dimension reduction matrix by the Y-direction characteristic vectors, dZThe Z-direction characteristic vector forms a Z-direction time domain vibration response signalReducing the dimension matrix; the modal response matrix in the X direction corresponds to the dimension reduction matrix of the time domain vibration response signal in the X direction, the modal response matrix in the Y direction corresponds to the dimension reduction matrix of the time domain vibration response signal in the Y direction, and the modal response matrix in the Z direction corresponds to the dimension reduction matrix of the time domain vibration response signal in the Z direction;
and forming a modal coordinate response matrix by the modal response matrix in the X direction, the modal response matrix in the Y direction and the modal response matrix in the Z direction.
8. The method according to claim 7, wherein the reconstructing the X-direction local structural feature of the X-direction time-domain vibration response signal matrix by using the weights of all the adjacent X-direction time-domain vibration response signals specifically comprises:
according to jXThe time domain vibration response signal in the X direction and the distance jXThe k-th nearest to the X-direction time domain vibration response signalXDetermining j th time domain vibration response signal in X direction through Gaussian kernel functionXThe time domain vibration response signal in the X direction and the kthXWeights of the adjacent X-direction time domain vibration response signals; k is a radical ofX=1,2,...,KX
All the X-direction time domain vibration response signals and the weights of the adjacent X-direction time domain vibration response signals corresponding to the X-direction time domain vibration response signals form an X-direction adjacency matrix;
according to jXThe time domain vibration response signal in the X direction and the kthXThe weight of the time domain vibration response signal in the adjacent X direction is calculated by formula
Figure FDA0002815670460000051
Determining an X-direction degree matrix; the X-direction degree matrix is composed of
Figure FDA0002815670460000052
A diagonal matrix is formed; wherein the content of the first and second substances,
Figure FDA0002815670460000053
denotes the j (th)XThe degree of the X-direction time-domain vibration response signal,
Figure FDA0002815670460000054
denotes the j (th)XThe time domain vibration response signal in the X direction and the kthXWeights of the adjacent X-direction time domain vibration response signals; the X-direction local structural characteristics of the X-direction time domain vibration response signal matrix comprise an X-direction degree matrix and an X-direction Laplace matrix;
according to the X-direction adjacency matrix and the X-direction degree matrix, a formula L is obtainedX=DX-WXDetermining an X-direction Laplace matrix; wherein L isXDenotes the X-direction Laplace matrix, DXRepresenting the X-direction degree matrix, WXRepresenting an X-direction adjacency matrix.
9. The method for identifying working modal parameters according to claim 6, wherein the obtaining a modal shape matrix by using a least square generalized inverse method according to the modal coordinate response matrix specifically comprises:
according to the modal coordinate response matrix, utilizing least square method generalized inverse method
Figure FDA0002815670460000055
Solving to obtain a modal shape matrix; wherein (phi)Three)3H×SRepresents a mode shape matrix, (H)Three)3H×T(t) represents the overall modal response matrix, (Q)Three)S×T(t) represents a modal coordinate response matrix,
Figure FDA0002815670460000056
a transpose matrix representing a modal coordinate response matrix.
10. An apparatus fault diagnosis method, comprising:
if the equipment to be diagnosed is of a one-dimensional structure, determining the working modal parameters of the equipment to be diagnosed at the current moment by using the working modal parameter identification method according to any one of claims 1 to 5;
if the equipment to be diagnosed is of a three-dimensional structure, determining the working mode parameters of the equipment to be diagnosed at the current moment by using the working mode parameter identification method according to any one of claims 6 to 9;
obtaining working mode parameters of the equipment to be diagnosed at the last moment;
judging whether the determined working modal parameter of the equipment to be diagnosed at the current moment is completely consistent with the working modal parameter of the equipment to be diagnosed at the last moment or not to obtain a first judgment result;
if the first judgment result is yes, the equipment to be diagnosed has no fault;
and if the first judgment result is negative, the equipment to be diagnosed has a fault.
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CN113358308A (en) * 2021-06-03 2021-09-07 哈尔滨工业大学 Combined structure transverse displacement determination method based on limited measuring points and global mode
CN113358308B (en) * 2021-06-03 2022-10-25 哈尔滨工业大学 Combined structure transverse displacement determination method based on limited measuring points and global mode
CN114936582A (en) * 2022-06-08 2022-08-23 华侨大学 Working modal parameter identification method and system and fault position identification method
CN115015390A (en) * 2022-06-08 2022-09-06 华侨大学 MWTLMDS-based curtain wall working modal parameter identification method and system
CN117093843A (en) * 2023-10-19 2023-11-21 华侨大学 Signal reconstruction and working mode parameter identification method, device, equipment and medium
CN117093843B (en) * 2023-10-19 2024-02-20 华侨大学 Signal reconstruction and working mode parameter identification method, device, equipment and medium
CN117470752A (en) * 2023-12-28 2024-01-30 广东省有色工业建筑质量检测站有限公司 Method for detecting prestress grouting content in steel pipe truss body
CN117470752B (en) * 2023-12-28 2024-05-07 广东省有色工业建筑质量检测站有限公司 Method for detecting prestress grouting content in steel pipe truss body

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