CN112395550A - Rotary machine fault early warning method based on visual characteristic parameter matrix - Google Patents
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Abstract
The invention provides a rotary machine fault early warning method based on a visual characteristic parameter matrix. According to the method, the characteristic frequency of the equipment is automatically calculated through the equipment process parameters, the frequency domain characteristics and the time domain characteristics are extracted, the comprehensive fault early warning of the multi-dimensional characteristic parameters is realized, and the problem of insufficient warning is reduced; according to the invention, after the system applying the method is deployed, the upper limit and the lower limit of the threshold can be adaptively adjusted based on data, so that the workload and uncertainty of manually adjusting the threshold are reduced, and the working efficiency and the early warning accuracy are effectively improved; according to the method, through l1 trend filtering, the filtered data trend reflects the state change trend of the equipment more accurately, and the probability of false alarm is reduced; according to the method, the thermodynamic diagram is used for displaying the difference matrix of the characteristic parameters and the threshold value, the multichannel comprehensive display of the equipment state is achieved, the information expression mode is optimized, and the fault information is clear at a glance.
Description
Technical Field
The invention relates to a rotary machine fault early warning method based on a visual characteristic parameter matrix, and belongs to the technical field of state monitoring.
Background
The rotating machinery is widely applied to the fields of ships, aerospace, power plants, metallurgy and the like, and the safe and reliable operation of equipment not only relates to the economic benefit of enterprises, but also influences the safety of production. Therefore, the realization of the fault early warning of the rotating machinery equipment has important value for reducing the maintenance cost of the equipment and improving the utilization rate of the equipment in the life cycle. At present, a common mechanical equipment state monitoring system adopts a vibration total value trend curve based on a fixed threshold value to realize fault early warning, and the method has the following defects:
(1) due to the complex working condition of the equipment, the original data has larger disturbance and can not accurately reflect the change trend of the vibration total value;
(2) only the vibration total value is used for fault early warning, the characteristics are single, and the fault early warning accuracy rate is very limited;
(3) the trend map is adopted for early warning, and under the condition that more test channels and characteristic values exist, the excessive map and the poor information visualization effect are caused;
(4) the threshold is fixed and invariable, corresponding thresholds need to be determined for different working conditions of different equipment, the workload is large, and artificial interference is easily introduced, so that the early warning effect is poor;
disclosure of Invention
The technical problem to be solved by the invention is as follows: the multi-channel and multi-characteristic parameter comprehensive fault early warning false alarm rate is high, the visualization effect is poor, and the like.
In order to solve the technical problem, the technical scheme of the invention is to provide a rotary machine fault early warning method based on a visual characteristic parameter matrix, which is characterized by comprising the following steps of:
in formula (1), M is the total number of sensor channels tested on the device, and then:
for the inner ring vibration characteristic frequency of the mth sensor channel tested on the device,n is the equipment rotating speed obtained by the mth sensor channel;
fi (m)for the outer ring vibration characteristic frequency of the mth sensor channel tested on the device, Dmthe diameter of a bearing pitch circle is used, d is the diameter of a bearing rolling element and is troublesome supplement, alpha is a bearing contact angle, and Z is the number of gear teeth;
the characteristic frequency of vibration when the retainer of the mth sensor channel tested on the device touches the outer ring,
the characteristic frequency of vibration when the cage of the mth sensor channel tested on the device hits the inner ring,
for the rolling element vibration characteristic frequency of the mth sensor channel tested on the device,
for the rms value of the mth sensor channel tested on the device,n is the sample sequence length, x (i) is the ith sample data;
for the kurtosis factor of the mth sensor channel tested on the device,x is sample data, E (X) is a sample mean value, and sigma is a sample variance;
the inner ring vibration characteristic frequency, the outer ring vibration characteristic frequency, the vibration characteristic frequency when the retainer touches the outer ring, the vibration characteristic frequency when the retainer touches the inner ring, the rolling body vibration characteristic frequency, the gear meshing frequency, the root mean square value, the margin factor, the kurtosis factor and the pulse factor are all characteristic parameters;
step 2, after acquiring trend data of stable operation of equipment with a certain data volume by M sensor channels, calculating probability density distribution of each characteristic parameter in a characteristic parameter matrix shown in formula (1), calculating a beta distribution shape parameter most approximate to actual data by least square fitting to obtain a beta distribution probability density model beta (gamma, eta) of the trend data, calculating an adaptive threshold interval of each characteristic parameter by using the beta distribution probability density model beta (gamma, eta), wherein Th1 represents the upper threshold limit of the adaptive threshold interval of a certain characteristic parameter, and Th2 represents the lower threshold limit of the adaptive threshold interval of a certain characteristic parameter;
step 3, carrying out l1 trend filtering on the trend data to obtain a trend curve of each characteristic parameter in the characteristic parameter matrix shown in the formula (1), and estimating to obtain a new characteristic parameter matrix;
in the above formula, the superscript of Th1 indicates the sensor channel to which it belongs, and the subscript of Th1 indicates the specific characteristic parameter to which it belongs;
and 5, visually displaying the states of the characteristic parameters according to the predefined thermal grade based on the difference matrix obtained in the step 4.
Preferably, in step 2, after normalizing the trend data, calculating the probability density distribution of each characteristic parameter, and then fitting the shape parameters γ and η of the beta distribution by using a least square method to solve the beta distribution model β (γ and η), wherein the ith trend data X is subjected to the following formula (2)iNormalization:
in the formula (2), the reaction mixture is,for normalized trend data, XminIs the minimum of all N trend data, XmaxIs the maximum of all N trend data.
Preferably, in step 2, after obtaining the beta distribution probability density model β (γ, η), the bilateral α quantile λ is calculated by using the following formulas (3) and (4)1、λ2:
In the formulas (3) and (4),is a random variable and is used as a random variable,for random variables less than λ1The probability of (a) of (b) being,for random variables greater than λ2A is a quantile;
based on bilateral alpha quantiles lambda1、λ2Th1 and Th2 are calculated by the following formulas (5) and (6):
Th1=λ1×(Xmax-Xmin)+Xmin (5)
Th2=λ2×(Xmax-Xmin)+Xmin (6)
thereby obtaining the adaptive threshold interval of each characteristic parameter.
Preferably, in step 3, the l1 trend filtering is performed by using the following formula (7):
in equation (7), y is a time series of eigenvalues, λ is a non-negative parameter that controls the smoothness of the trend line and the size of the balance remainder to achieve a balance between the trend of the control estimation and the signal redundancy, and θ ═ θ (θ ═ θ1,θ2,…,θn) Are characteristic parameters (n is the number of characteristic parameters). A is the lower triangular matrix:
Compared with the prior art, the invention has the following beneficial effects:
1) according to the method, the characteristic frequency of the equipment is automatically calculated through the equipment process parameters, the frequency domain characteristics and the time domain characteristics are extracted, the comprehensive fault early warning of the multi-dimensional characteristic parameters is realized, and the problem of insufficient warning is reduced;
2) according to the invention, after the system applying the method is deployed, the upper limit and the lower limit of the threshold can be adaptively adjusted based on data, so that the workload and uncertainty of manually adjusting the threshold are reduced, and the working efficiency and the early warning accuracy are effectively improved;
3) according to the method, through l1 trend filtering, the filtered data trend reflects the state change trend of the equipment more accurately, and the probability of false alarm is reduced;
4) according to the method, the thermodynamic diagram is used for displaying the difference matrix of the characteristic parameters and the threshold value, the multichannel comprehensive display of the equipment state is achieved, the information expression mode is optimized, the fault information is clear at a glance, the running state of the equipment is mastered in real time, and the technical support is provided for the fault early warning of the equipment.
Drawings
FIG. 1 is a flow chart of a fault early warning method provided by the present invention;
fig. 2 is a visual characteristic parameter matrix obtained by the present invention.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.
As shown in fig. 1, the invention relates to a rotary machine fault early warning method based on a visual characteristic parameter matrix, which comprises the following steps:
in formula (1), M is the total number of sensor channels tested on the device, and then:
for the inner ring vibration characteristic frequency of the mth sensor channel tested on the device,n is the equipment rotating speed obtained by the mth sensor channel;
fi (m)for the outer ring vibration characteristic frequency of the mth sensor channel tested on the device, Dmthe diameter of a bearing pitch circle, d is the diameter of a bearing rolling element, alpha is a bearing contact angle, and Z is the number of gear teeth;
the characteristic frequency of vibration when the retainer of the mth sensor channel tested on the device touches the outer ring,
the characteristic frequency of vibration when the cage of the mth sensor channel tested on the device hits the inner ring, for the rolling element vibration characteristic frequency of the mth sensor channel tested on the device,
for the rms value of the mth sensor channel tested on the device,n is the sample sequence length, x (i) is the ith sample data;
for the kurtosis factor of the mth sensor channel tested on the device,x is sample data, E (X) is a sample mean value, and sigma is a sample variance;
the inner ring vibration characteristic frequency, the outer ring vibration characteristic frequency, the vibration characteristic frequency when the retainer touches the outer ring, the vibration characteristic frequency when the retainer touches the inner ring, the rolling body vibration characteristic frequency, the gear meshing frequency, the root mean square value, the margin factor, the kurtosis factor and the pulse factor are all characteristic parameters;
setting parameters such as a bearing, a gear, a rotating speed and the like of equipment, and extracting characteristic frequency; setting the arrangement of measuring points of the equipment for determining the number of rows of the characteristic parameter matrix
Step 2, calculating a characteristic parameter matrix according to the set parameters, recording real-time vibration data, and continuously enriching a trend database until the requirement of the data volume of threshold dynamic adjustment is met; after acquiring trend data of stable operation of equipment with a certain data volume by M sensor channels, calculating probability density distribution of each characteristic parameter in a characteristic parameter matrix shown in formula (1), calculating a beta distribution shape parameter most approximate to actual data by least square fitting to obtain a beta distribution probability density model beta (gamma, eta) of the trend data, calculating an adaptive threshold interval of each characteristic parameter by using the beta distribution probability density model beta (gamma, eta), wherein Th1 represents the upper threshold limit of the adaptive threshold interval of a certain characteristic parameter, and Th2 represents the lower threshold limit of the adaptive threshold interval of a certain characteristic parameter;
in the step, after the trend data is normalized, the probability density distribution of each characteristic parameter is calculated, then the least square method is used for fitting the shape parameters gamma and eta of the beta distribution, and the beta distribution model beta (gamma and eta) is solved, wherein the following formula (2) is adopted for the ith trend data XiNormalization:
in the formula (2), the reaction mixture is,for normalized trend data, XminIs the minimum of all N trend data, XmaxThe maximum value of all the N trend data;
after a beta distribution probability density model beta (gamma, eta) is obtained, the alpha quantiles lambda at two sides of the model beta (gamma, eta) are calculated by using the following formulas (3) and (4)1、λ2:
In the formulas (3) and (4),is a random variable and is used as a random variable,for random variables less than λ1The probability of (a) of (b) being,for random variables greater than λ2A is a quantile;
based on bilateral alpha quantiles lambda1、λ2Th1 and Th2 are calculated by the following formulas (5) and (6):
Th1=λ1×(Xmax-Xmin)+Xmin (5)
Th2=λ2×(Xmax-Xmin)+Xmin (6)
thereby obtaining the self-adaptive threshold interval of each characteristic parameter;
step 3, carrying out l1 trend filtering on the trend data to obtain a trend curve of each characteristic parameter in the characteristic parameter matrix shown in the formula (1), and estimating to obtain a new characteristic parameter matrix;
in this step, the l1 trend filtering is performed using the following equation (7):
in equation (7), y is a time series of eigenvalues, λ is a non-negative parameter that controls the smoothness of the trend line and the size of the balance remainder to achieve a balance between the trend of the control estimation and the signal redundancy, and θ ═ θ (θ ═ θ1,θ2,…,θn) Are characteristic parameters (n is the number of characteristic parameters). A is the lower triangular matrix:
in the above formula, the superscript of Th1 indicates the sensor channel to which it belongs, and the subscript of Th1 indicates the specific characteristic parameter to which it belongs;
and 5, visually displaying the states of the characteristic parameters according to the predefined thermal grade based on the difference matrix obtained in the step 4. As shown in fig. 2, the visual display of the device state is realized according to the colors of the parameters in the set thermodynamic diagram display matrix, wherein the thermodynamic diagram shows that the characteristic parameter of the position exceeds the upper threshold, and the deeper the color shows that the difference is larger, the device is about to fail.
Claims (4)
1. A rotary machine fault early warning method based on a visual characteristic parameter matrix is characterized by comprising the following steps:
step 1, constructing a characteristic parameter matrix:
in formula (1), M is the total number of sensor channels tested on the device, and then:
for the inner ring vibration characteristic frequency of the mth sensor channel tested on the device,n is the equipment rotating speed obtained by the mth sensor channel;
fi (m)for the outer ring vibration characteristic frequency of the mth sensor channel tested on the device, Dmthe diameter of a bearing pitch circle, d is the diameter of a bearing rolling element, alpha is a bearing contact angle, and Z is the number of gear teeth;
the characteristic frequency of vibration when the retainer of the mth sensor channel tested on the device touches the outer ring,
the characteristic frequency of vibration when the cage of the mth sensor channel tested on the device hits the inner ring,
for the rolling element vibration characteristic frequency of the mth sensor channel tested on the device,
for the rms value of the mth sensor channel tested on the device,n is the sample sequence length, x (i) is the ith sample data;
for the kurtosis factor of the mth sensor channel tested on the device,x is sample data, E (X) is a sample mean value, and sigma is a sample variance;
the inner ring vibration characteristic frequency, the outer ring vibration characteristic frequency, the vibration characteristic frequency when the retainer touches the outer ring, the vibration characteristic frequency when the retainer touches the inner ring, the rolling body vibration characteristic frequency, the gear meshing frequency, the root mean square value, the margin factor, the kurtosis factor and the pulse factor are all characteristic parameters;
step 2, after acquiring trend data of stable operation of equipment with a certain data volume by M sensor channels, calculating probability density distribution of each characteristic parameter in a characteristic parameter matrix shown in formula (1), calculating a beta distribution shape parameter most approximate to actual data by least square fitting to obtain a beta distribution probability density model beta (gamma, eta) of the trend data, calculating an adaptive threshold interval of each characteristic parameter by using the beta distribution probability density model beta (gamma, eta), wherein Th1 represents the upper threshold limit of the adaptive threshold interval of a certain characteristic parameter, and Th2 represents the lower threshold limit of the adaptive threshold interval of a certain characteristic parameter;
step 3, carrying out l1 trend filtering on the trend data to obtain a trend curve of each characteristic parameter in the characteristic parameter matrix shown in the formula (1), and estimating to obtain a new characteristic parameter matrix;
step 4, calculating a difference matrix of the feature parameter matrix obtained in step 3 in the upper threshold limit of the adaptive threshold interval of each feature parameter obtained in step 2, as shown in the following formula:
in the above formula, the superscript of Th1 indicates the sensor channel to which it belongs, and the subscript of Th1 indicates the specific characteristic parameter to which it belongs;
and 5, visually displaying the states of the characteristic parameters according to the predefined thermal grade based on the difference matrix obtained in the step 4.
2. The method as claimed in claim 1, wherein in step 2, after normalizing the trend data, calculating the probability density distribution of each characteristic parameter, and then fitting the shape parameters γ and η of the beta distribution by using the least square method to solve the beta distribution model β (γ, η), wherein the ith trend data X is obtained by using the following formula (2)iNormalization:
3. A process as claimed in claim 1The rotary machine fault early warning method based on the visual characteristic parameter matrix is characterized in that in the step 2, after a beta distribution probability density model beta (gamma, eta) is obtained, the following formulas (3) and (4) are utilized to calculate alpha quantiles lambda of two sides of the rotary machine1、λ2:
In the formulas (3) and (4),is a random variable and is used as a random variable,for random variables less than λ1The probability of (a) of (b) being,for random variables greater than λ2A is a quantile;
based on bilateral alpha quantiles lambda1、λ2Th1 and Th2 are calculated by the following formulas (5) and (6):
Th1=λ1×(Xmax-Xmin)+Xmin (5)
Th2=λ2×(Xmax-Xmin)+Xmin (6)
thereby obtaining the adaptive threshold interval of each characteristic parameter.
4. The rotating machine fault early warning method based on the visualized characteristic parameter matrix as claimed in claim 1, wherein in step 3, the l1 trend filtering is performed by using the following formula (7):
in equation (7), y is a time series of eigenvalues, λ is a non-negative parameter that controls the smoothness of the trend line and the size of the balance remainder to achieve a balance between the trend of the control estimation and the signal redundancy, and θ ═ θ (θ ═ θ1,θ2,…,θn) Is a characteristic parameter, n is the number of the characteristic parameters, A is a lower triangular matrix:
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114135477A (en) * | 2021-10-11 | 2022-03-04 | 昆明嘉和科技股份有限公司 | Pump equipment state monitoring dynamic threshold early warning method |
CN116756490A (en) * | 2023-06-15 | 2023-09-15 | 沈阳航空航天大学 | Rolling bearing fault early warning method based on beta distribution and EEMD-CMSE |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110208019A (en) * | 2019-05-14 | 2019-09-06 | 北京博华信智科技股份有限公司 | A kind of dynamic equipment condition monitoring dynamic threshold method for early warning |
CN111120348A (en) * | 2019-12-25 | 2020-05-08 | 中国石化销售股份有限公司华南分公司 | Centrifugal pump fault early warning method based on support vector machine probability density estimation |
CN111222247A (en) * | 2020-01-13 | 2020-06-02 | 北京化工大学 | Early fault early warning method for rotary machine |
-
2020
- 2020-11-19 CN CN202011302101.6A patent/CN112395550B/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN110208019A (en) * | 2019-05-14 | 2019-09-06 | 北京博华信智科技股份有限公司 | A kind of dynamic equipment condition monitoring dynamic threshold method for early warning |
CN111120348A (en) * | 2019-12-25 | 2020-05-08 | 中国石化销售股份有限公司华南分公司 | Centrifugal pump fault early warning method based on support vector machine probability density estimation |
CN111222247A (en) * | 2020-01-13 | 2020-06-02 | 北京化工大学 | Early fault early warning method for rotary machine |
Non-Patent Citations (2)
Title |
---|
张明等: "基于动态自学习阈值和趋势滤波的机械故障智能预警方法", 《振动与冲击》 * |
马波等: "变分自编码器在机械故障预警中的应用", 《计算机工程与应用》 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114135477A (en) * | 2021-10-11 | 2022-03-04 | 昆明嘉和科技股份有限公司 | Pump equipment state monitoring dynamic threshold early warning method |
CN114135477B (en) * | 2021-10-11 | 2024-04-02 | 昆明嘉和科技股份有限公司 | Dynamic threshold early warning method for monitoring state of machine pump equipment |
CN116756490A (en) * | 2023-06-15 | 2023-09-15 | 沈阳航空航天大学 | Rolling bearing fault early warning method based on beta distribution and EEMD-CMSE |
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