CN112924154A - Method and device for extracting damping ratio of structural response signal in high-noise flowing environment - Google Patents
Method and device for extracting damping ratio of structural response signal in high-noise flowing environment Download PDFInfo
- Publication number
- CN112924154A CN112924154A CN202110256907.4A CN202110256907A CN112924154A CN 112924154 A CN112924154 A CN 112924154A CN 202110256907 A CN202110256907 A CN 202110256907A CN 112924154 A CN112924154 A CN 112924154A
- Authority
- CN
- China
- Prior art keywords
- response signal
- time
- frequency
- mechanical structure
- vibration response
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H17/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves, not provided for in the preceding groups
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention provides a method and a device for extracting a damping ratio of a structural response signal in a high-noise flowing environment. Wherein, the method comprises the following steps: exciting a mechanical structure by utilizing a vibration exciter to carry out linear frequency sweeping, and recording a corresponding first vibration response signal based on a sensor; performing autocorrelation processing on the first vibration response signal, and performing fast Fourier transform to obtain the natural frequency of the kth order mode of the mechanical structure; exciting a mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal; performing time-frequency analysis on the second vibration response signal, and determining a ridge line of the vibration response of the mechanical structure corresponding to the natural frequency and freely attenuating along with time; and fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the coefficient is greater than a preset threshold value. By adopting the method disclosed by the invention, the damping ratio of the mechanical structure in the high-noise environment can be quantitatively identified through time-frequency analysis, and the identification precision is improved.
Description
Technical Field
The invention relates to the technical field of computer application, in particular to a method and a device for extracting a structural response signal damping ratio in a high-noise flowing environment. In addition, an electronic device and a non-transitory computer readable storage medium are also related.
Background
In the operation process of a hydraulic machine, the mechanical structure is often subjected to periodic excitation generated by dynamic and static interference, rotating stall, cavitation flow, karman vortex street and the like, and when the excitation frequency is consistent with the natural frequency of the structure, resonance occurs. And the damping ratio is an important parameter for measuring the vibration amplitude at resonance. If the damping ratio of the hydraulic machine under different working conditions can be known in advance in the design stage, important guidance can be provided for predicting the structural stress and deformation. In an actual high-speed flowing environment, under the action of noise, vortex-induced vibration, turbulent noise and the like of a unit, the measurement vibration of a hydraulic mechanical structure is often submerged in the noise, and for a multi-degree-of-freedom vibration system, the vibration response of a single-order mode is easily interfered by other-order modes.
At present, a great number of methods for improving the signal-to-noise ratio exist in the prior art, for example, filtering or autocorrelation is adopted to eliminate noise interference, but these methods may affect the vibration amplitude and the attenuation law of the mechanical structure, and cannot effectively meet the actual use requirements. Therefore, how to provide a method for extracting the damping ratio of the structural response signal in the high-noise flowing environment without filtering is a technical issue to be urgently solved by those skilled in the art.
Disclosure of Invention
Therefore, the invention provides a method and a device for extracting the damping ratio of a structural response signal in a high-noise flowing environment, and aims to solve the problem that in the prior art, a vibration signal of a mechanical structure is easily submerged in a noise signal, so that the damping ratio is difficult to identify.
The invention provides a method for extracting the damping ratio of a structural response signal in a high-noise flowing environment, which comprises the following steps:
the method comprises the steps of firstly exciting a mechanical structure by utilizing a vibration exciter to carry out linear frequency sweeping, and recording a first vibration response signal corresponding to the mechanical structure based on a preset sensor;
performing autocorrelation processing on the first vibration response signal, and performing fast Fourier transform to obtain the natural frequency of the k-th order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor;
performing time-frequency analysis on the second vibration response signal, and determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled;
and fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
Further, the time for exciting the mechanical structure for the first time corresponds to the frequency range of the linear frequency sweep, which is specifically expressed as:
t1≥(fmax-fmin)/m
wherein, t1Time, in units of s, for said first actuation of the mechanical structure; f. ofmaxThe upper limit of the frequency range of the linear sweep frequency is unit Hz; f. ofminThe lower limit of the frequency range of linear sweep frequency is unit Hz; m is the rate of frequency increase in units of 1/s2，1≤m＜1000；
The upper limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fmax≥nfn,k
wherein n is the amplification factor of the sweep frequency range, and n is more than or equal to 1.1; f. ofn,iIs the natural frequency of the k-th order mode;
the lower limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fmin≤fn,k/z
wherein z is a reduction coefficient of the frequency range of the linear frequency sweep, and z is more than or equal to 10;
the sampling frequency of the sensor corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
Further, a scale parameter is adjusted in the autocorrelation processing process, and the function estimation type corresponding to the scale parameter is unbiased estimation;
the hysteresis range of the scale parameter corresponds to the sample data size, and is specifically represented as:
iN≤L≤jN
wherein L is the upper limit of the hysteresis range; -L is the lower limit of the hysteresis range; n is the sample data size; i and j are proportional coefficients of the hysteresis range, i is more than or equal to 0.01 and less than 0.5, and j is more than or equal to 0.5 and less than 1.
Further, the time for exciting the mechanical structure for the second time corresponds to the natural frequency of the k-th order mode, which is specifically expressed as:
wherein, t2Time for said second excitation of the mechanical structure in units of s; i and J are time limiting coefficients of the secondary excitation mechanical structure, I is more than or equal to 1000, and J is more than or equal to 0.001 and less than 1000.
The second recording time when the sensor records the second vibration response signal is specifically represented as:
t2＜t22≤ct2
wherein, t22Is the second recording time in units of s; c is the extension multiple of the second recording time, and c is more than or equal to 1.1;
the sampling frequency in the sensor recording process corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
Further, performing time-frequency analysis on the second vibration response signal to determine a ridge line of the vibration response of the mechanical structure corresponding to the natural frequency, which is freely attenuated along with time, specifically includes: performing time-frequency analysis on the second vibration response signal by adopting a preset target time-frequency analysis method, positioning and extracting a third vibration response signal of the mechanical structure corresponding to the inherent frequency and a ridge line of the third vibration response signal; the target time-frequency analysis method is one of a short-time Fourier transform method and a continuous wavelet transform method.
Further, the method for extracting the damping ratio of the structural response signal in the high-noise flowing environment further includes: within the range of the second recording time, obtaining a third-time vibration response signal corresponding to the natural frequency of the kth-order mode, and carrying out non-dimensionalization processing on the third-time vibration response signal;
the ridge line is a free attenuation area of a third vibration response signal along with time after the second excitation is cancelled, and the specific quantitative expression is as follows:
XA≤y＜YA
wherein A is a dimensionless third vibration response signal; y is the vibrational response of the ridge line; x and Y are limiting coefficients of the vibration response of the ridge line, wherein X is more than or equal to 1% and less than 30%, and Y is more than or equal to 50% and less than 100%.
Further, the fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold specifically includes: fitting the ridge line by adopting a least square fitting method according to a logarithmic attenuation formula, identifying the damping ratio of the mechanical structure when the coefficient of the decision is greater than a preset threshold, and determining the reliability of the identified damping ratio;
if the coefficient is less than or equal to the preset threshold, removing a maximum and minimum target data in the ridge line, continuously fitting the ridge line by adopting a least square fitting method according to a logarithmic attenuation formula until the coefficient is greater than the preset threshold, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than the preset threshold;
the logarithmic decay formula is specifically expressed as:
wherein, y0Is the amplitude, ω, of the vibration responsen＝2πfn；fnNatural frequency of the k-th order mode in Hz;
is the damping angle natural frequency, unit rad/s; phi is the initial phase angle, in units rad/s.
The invention also provides a device for extracting the damping ratio of the structural response signal in the high-noise flowing environment, which comprises:
the first-time vibration response signal acquisition unit is used for exciting the mechanical structure for the first time by utilizing a method of linear frequency sweeping by using a vibration exciter and recording a first-time vibration response signal corresponding to the mechanical structure based on a preset sensor;
the second-time vibration response signal acquisition unit is used for performing autocorrelation processing on the first-time vibration response signal and performing fast Fourier transform to obtain the natural frequency of the kth-order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor;
the ridge line determining unit is used for performing time-frequency analysis on the second vibration response signal, determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled;
and the damping ratio identification unit is used for fitting the ridge line according to a logarithmic attenuation formula and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
Further, the time for exciting the mechanical structure for the first time corresponds to the frequency range of the linear frequency sweep, which is specifically expressed as:
t1≥(fmax-fmin)/m
wherein, t1Time, in units of s, for said first actuation of the mechanical structure; f. ofmaxThe upper limit of the frequency range of the linear sweep frequency is unit Hz; f. ofminThe lower limit of the frequency range of linear sweep frequency is unit Hz; m is the rate of frequency increase in units of 1/s2，1≤m＜1000；
The upper limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fmax≥nfn,k
wherein n is the amplification factor of the sweep frequency range, and n is more than or equal to 1.1; f. ofn,iIs the natural frequency of the k-th order mode;
the lower limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fmin≤fn,k/z
wherein z is a reduction coefficient of the frequency range of the linear frequency sweep, and z is more than or equal to 10;
the sampling frequency of the sensor corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
Further, a scale parameter is adjusted in the autocorrelation processing process, and the function estimation type corresponding to the scale parameter is unbiased estimation;
the hysteresis range of the scale parameter corresponds to the sample data size, and is specifically expressed as
iN≤L≤jN
Wherein L is the upper limit of the hysteresis range; -L is the lower limit of the hysteresis range; n is the sample data size; i and j are proportional coefficients of the hysteresis range, i is more than or equal to 0.01 and less than 0.5, and j is more than or equal to 0.5 and less than 1.
Further, the time for exciting the mechanical structure for the second time corresponds to the natural frequency of the k-th order mode, which is specifically expressed as:
wherein, t2Time for said second excitation of the mechanical structure in units of s; i and J are time limiting coefficients of the secondary excitation mechanical structure, I is more than or equal to 1000, and J is more than or equal to 0.001 and less than 1000.
The second recording time when the sensor records the second vibration response signal is specifically represented as:
t2＜t22≤ct2
wherein, t22Is the second recording time in units of s; c is the extension multiple of the second recording time, and c is more than or equal to 1.1;
the sampling frequency in the sensor recording process corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
Further, the ridge line determining unit is specifically configured to: performing time-frequency analysis on the second vibration response signal by adopting a preset target time-frequency analysis method, positioning and extracting a third vibration response signal of the mechanical structure corresponding to the inherent frequency and a ridge line of the third vibration response signal; the target time-frequency analysis method is one of a short-time Fourier transform method and a continuous wavelet transform method.
Further, the device for extracting the damping ratio of the structural response signal in the high-noise flowing environment further comprises: the data processing unit is used for obtaining a third-time vibration response signal corresponding to the natural frequency of a kth-order mode in a second-time recording time range and carrying out non-dimensionalization processing on the third-time vibration response signal;
the ridge line is a free attenuation area of a third vibration response signal along with time after the second excitation is cancelled, and the specific quantitative expression is as follows:
XA≤y＜YA
wherein A is a dimensionless third vibration response signal; y is the vibrational response of the ridge line; x and Y are limiting coefficients of the vibration response of the ridge line, wherein X is more than or equal to 1% and less than 30%, and Y is more than or equal to 50% and less than 100%.
Further, the damping ratio identification unit is specifically configured to: fitting the ridge line by adopting a least square fitting method according to a logarithmic attenuation formula, identifying the damping ratio of the mechanical structure when the coefficient of the decision is greater than a preset threshold, and determining the reliability of the identified damping ratio;
if the coefficient is less than or equal to the preset threshold, removing a maximum and minimum target data in the ridge line, continuously fitting the ridge line by adopting a least square fitting method according to a logarithmic attenuation formula until the coefficient is greater than the preset threshold, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than the preset threshold;
the logarithmic decay formula is specifically expressed as:
wherein, y0Is the amplitude, ω, of the vibration responsen＝2πfn；fnNatural frequency of the k-th order mode in Hz;
is the damping angle natural frequency, unit rad/s; phi is the initial phase angle, in units rad/s.
The invention also provides an electronic device, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor executes the program to realize the method for extracting the damping ratio of the structural response signal in the high-noise flowing environment.
The present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method of structural response signal damping ratio extraction in a high noise flow environment as described in any one of the above.
According to the method for extracting the damping ratio of the structural response signal in the high-noise flowing environment, the mechanical structure is excited through the vibration exciter, the first vibration response and the second vibration response of the mechanical structure are recorded through the sensor, the ridge line of the free attenuation of the structure is quantitatively positioned after the second vibration response is subjected to time-frequency analysis, the ridge line is fitted through a logarithmic attenuation formula, and the damping ratio of the structure is identified when the coefficient of the fitting curve is larger than a preset threshold value, so that the damping ratio identification can be performed through a time-frequency analysis method, the interference of numerical attenuation on the damping ratio identification caused by a filtering method is avoided, the identification precision of the damping ratio of the mechanical structure is improved, and a complete quantitative evaluation system of the vibration characteristic of the hydraulic machine can be established.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic flow chart of a method for extracting a damping ratio of a structural response signal in a high-noise flowing environment according to an embodiment of the present invention;
FIG. 2 is a time domain signal of a first vibration response provided by an embodiment of the present invention;
fig. 3 is a frequency domain signal after dimensionless processing of a first vibration response signal according to an embodiment of the present invention;
FIG. 4 shows a second post-vibrational response wavelet transform signal provided by an embodiment of the present invention;
FIG. 5 is a time domain signal of a third time vibration response provided by an embodiment of the present invention;
FIG. 6 is a first-order modal ridge and a fitting curve provided in accordance with an embodiment of the present invention;
FIG. 7 is a schematic structural diagram of a structural response signal damping ratio extraction apparatus in a high-noise flow environment according to an embodiment of the present invention;
fig. 8 is a schematic physical structure diagram of an electronic device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention. 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 following describes an embodiment of the method for extracting the damping ratio of the structural response signal in the high-noise flowing environment in detail based on the invention. As shown in fig. 1, which is a schematic flow chart of a method for extracting a damping ratio of a structural response signal in a high-noise flowing environment according to an embodiment of the present invention, the specific process includes the following steps:
step 101: the method for linear frequency sweeping by using the vibration exciter is used for exciting the mechanical structure for the first time, and recording a first vibration response signal corresponding to the mechanical structure based on a preset sensor.
In this step, the time for the vibration exciter to excite the mechanical structure for the first time is the same as the time for the sensor to record the vibration response signal for the first time, and the time for exciting the mechanical structure for the first time corresponds to the frequency range of the linear frequency sweep, which may be specifically expressed as:
t1≥(fmax-fmin)/m
wherein, t1Time, in units of s, for said first actuation of the mechanical structure; f. ofmaxThe upper limit of the frequency range of the linear sweep frequency is unit Hz; f. ofminThe lower limit of the frequency range of linear sweep frequency is unit Hz; m is the rate of frequency increase in units of 1/s2，1≤m＜1000。
The upper limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and may be specifically expressed as:
fmax≥nfn,k
wherein n is the amplification factor of the sweep frequency range, and n is more than or equal to 1.1; f. ofn,iIs the natural frequency of the k-th order mode.
The lower limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and may be specifically expressed as:
fmin≤fn,k/z
wherein z is a reduction coefficient of the frequency range of the linear frequency sweep, and z is more than or equal to 10.
The sampling frequency of the sensor corresponds to the natural frequency of the kth-order mode, and may be specifically expressed as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
Step 102: performing autocorrelation processing on the first vibration response signal, and performing fast Fourier transform to obtain the natural frequency of the k-th order mode of the mechanical structure; and secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor.
And adjusting a scale parameter in the autocorrelation processing process, wherein the function estimation type corresponding to the scale parameter is Unbiased estimation (Unbiased Estimator).
The hysteresis range of the scale parameter corresponds to the sample data size, and may be specifically expressed as:
iN≤L≤jN
wherein L is the upper limit of the hysteresis range; -L is the lower limit of the hysteresis range; n is the sample data size; i and j are proportional coefficients of the hysteresis range, i is more than or equal to 0.01 and less than 0.5, and j is more than or equal to 0.5 and less than 1.
The time for exciting the mechanical structure for the second time corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
wherein, t2Time for said second excitation of the mechanical structure in units of s; i and J are time limiting coefficients of the secondary excitation mechanical structure, I is more than or equal to 1000, and J is more than or equal to 0.001 and less than 1000.
The second recording time when the sensor records the second vibration response signal is specifically represented as:
t2＜t22≤ct2
wherein, t22Is the second recording time in units of s; c is the extension multiple of the second recording time, and c is more than or equal to 1.1.
The sampling frequency in the sensor recording process corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
Step 103: performing time-frequency analysis on the second vibration response signal, and determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridgeline is a region where a third vibration response signal is free to decay with time after the second excitation is cancelled.
In this step, the time-frequency analysis is performed on the second vibration response signal to determine a ridge line at which the vibration response of the mechanical structure corresponding to the natural frequency is free to decay with time, and the specific implementation process may include: and performing time-frequency analysis on the second vibration response signal by adopting a preset target time-frequency analysis method, positioning and extracting a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal. Wherein, the target time-frequency analysis method includes but is not limited to a short-time Fourier transform method, a continuous wavelet transformation method, and the like.
And performing time-frequency analysis on the second vibration response signal, and positioning and extracting a third vibration response signal of the mechanical structure corresponding to the natural frequency of the kth-order mode. In a specific implementation process, a third-time vibration response signal corresponding to the natural frequency of the kth-order mode can be obtained within a second recording time range, and the third-time vibration response signal is subjected to non-dimensionalization processing.
The ridge line is a free attenuation area of the third vibration response signal along with time after the second excitation is cancelled, and the specific quantitative expression is as follows:
XA≤y＜YA
wherein A is a dimensionless third vibration response signal; y is the vibrational response of the ridge line; x and Y are limiting coefficients of the vibration response of the ridge line, wherein X is more than or equal to 1% and less than 30%, and Y is more than or equal to 50% and less than 100%.
Step 104: and fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
In this step, the ridge line is fitted according to a logarithmic attenuation formula, and the damping ratio of the mechanical structure is identified when the corresponding coefficient is greater than a preset threshold, and the specific implementation process may include: and fitting the ridge line by adopting a least square fitting method according to a logarithmic attenuation formula, identifying the damping ratio of the mechanical structure when the coefficient of the decision is larger than a preset threshold, and determining the reliability of the damping ratio obtained by identification. In a specific implementation process, if the coefficient is less than or equal to the preset threshold, further removing a maximum and minimum target data in the ridge lines, and continuing to fit the ridge lines by adopting a least square fitting method according to a logarithmic attenuation formula until the corresponding coefficient is greater than the preset threshold, and identifying the damping ratio of the mechanical structure when the coefficient is greater than the preset threshold.
The logarithmic decay formula is specifically expressed as:
wherein, y0Is the amplitude, ω, of the vibration responsen＝2πfn；fnNatural frequency of the k-th order mode in Hz;
is the damping angle natural frequency, unit rad/s; phi is the initial phase angle, in units rad/s.
The following provides an example of the vibrational response data of a hydrofoil in a high noise environment to further illustrate the method provided by embodiments of the present invention:
in the specific implementation process, if the mechanical structure is the hydrofoil at the flow speed of 5m/s, the hydrofoil (namely the mechanical structure) is excited for the first time by adopting a vibration exciter, the linear frequency sweep frequency is 0.1-3000Hz, and the first excitation time is 100 s. As shown in fig. 2, a sensor is used to record a first vibration response signal of the hydrofoil, the sampling frequency is 1000Hz, the first recording time is 100s, and the first vibration response signal is subjected to non-dimensionalization to obtain a corresponding vibration response time domain diagram. As shown in fig. 3, the first-time vibration response is subjected to autocorrelation processing, the function estimation type of the scale parameter of autocorrelation is unbiased estimation, the sample data size may be set to 20000, the first-time vibration response signal after autocorrelation processing is subjected to fast fourier transform with a flat-top window, the 1 st order mode is located, and the natural frequency of the 1 st order mode is extracted as 236.8 Hz. Exciting the hydrofoil by adopting a vibration exciter according to the natural frequency of the 1 st order mode, wherein the second excitation time is 2 s; the sensor was used to excite a second vibrational response with a second recording time of 2.3 s. As shown in fig. 4, after performing time-frequency analysis by using Morlet wavelet, the change rule of the second vibration response with time of each frequency component is obtained, and a third vibration response signal corresponding to the 1 st order modal natural frequency of 236.8Hz is located. As shown in fig. 5, the third-order vibration response is dimensionless, and a free attenuation region of 10% -65% of the dimensionless third-order vibration response signal is extracted, where the free attenuation region is a ridge line of the 1 st-order mode. And the ridgeline is the vibration response of different time corresponding to the natural frequency after the second excitation is cancelled. As shown in fig. 6, the ridge line is fitted by using a least square fitting method according to a logarithmic attenuation formula, if the coefficient of the fitted curve is greater than a threshold, the damping ratio of the structure can be directly identified, otherwise, a data with the maximum and minimum values in the ridge line are removed, and the ridge line is fitted by using a least square fitting method continuously according to the logarithmic attenuation formula until the coefficient of the fitted curve is greater than the threshold.
Specifically, the threshold may be 0.95, a is the data amount of a ridge line of 5% of free attenuation, a logarithmic attenuation formula is used to perform function fitting on the ridge line based on the least square method, and the initial condition is y00.7, natural frequency f of first order moden236.8 Hz; the threshold value is set to be 0.95, the coefficient of the fit curve is 0.99 larger than the threshold value, and the identified damping ratio is 0.0326.
According to the method for extracting the damping ratio of the structural response signal in the high-noise flowing environment, the mechanical structure is excited through the vibration exciter, the first vibration response and the second vibration response of the mechanical structure are recorded through the sensor, the ridge line of the free attenuation of the structure is quantitatively positioned after the second vibration response is subjected to time-frequency analysis, the ridge line is fitted through a logarithmic attenuation formula, and the damping ratio of the structure is identified when the coefficient of the fitting curve is larger than a preset threshold value, so that the damping ratio identification can be performed through the time-frequency analysis method, the interference of numerical attenuation on the damping ratio identification caused by a filtering method is avoided, the identification precision of the damping ratio of the mechanical structure is improved, and a complete quantitative evaluation system of the vibration characteristics of the hydraulic machine can be established.
Corresponding to the method for extracting the damping ratio of the structural response signal in the high-noise flowing environment, the invention also provides a device for extracting the damping ratio of the structural response signal in the high-noise flowing environment. Since the embodiment of the device is similar to the method embodiment, the description is simple, and please refer to the description of the method embodiment, and the embodiment of the device for extracting the damping ratio of the structural response signal in the high-noise flowing environment described below is only schematic. Fig. 7 is a schematic structural diagram of a device for extracting a structural response signal damping ratio in a high-noise flowing environment according to an embodiment of the present invention. The invention relates to a device for extracting the damping ratio of a structural response signal in a high-noise flowing environment, which comprises the following parts:
a first vibration response signal obtaining unit 701, configured to excite a mechanical structure for the first time by using a linear frequency sweeping method using a vibration exciter, and record a first vibration response signal corresponding to the mechanical structure based on a preset sensor;
a second-time vibration response signal obtaining unit 702, configured to perform autocorrelation processing on the first-time vibration response signal, and perform fast fourier transform to obtain a natural frequency of a kth-order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor;
a ridge line determining unit 703, configured to perform time-frequency analysis on the second vibration response signal, and determine a ridge line where the vibration response of the mechanical structure corresponding to the natural frequency is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled;
a damping ratio identification unit 704, configured to fit the ridge line according to a logarithmic attenuation formula, and identify a damping ratio of the mechanical structure when a corresponding coefficient is greater than a preset threshold.
By adopting the device for extracting the damping ratio of the structural response signal in the high-noise flowing environment, the mechanical structure is excited by the vibration exciter, the first vibration response and the second vibration response of the mechanical structure are recorded by the sensor, the ridge line of the structure free attenuation is quantitatively positioned after the second vibration response is subjected to time-frequency analysis, the ridge line is fitted by adopting a logarithmic attenuation formula, and the damping ratio of the structure is identified when the coefficient of the fitting curve is larger than a preset threshold value, so that the damping ratio identification can be carried out by a time-frequency analysis method, the interference of numerical attenuation on the damping ratio identification caused by a filtering method is avoided, the identification precision of the damping ratio of the mechanical structure is improved, and a complete quantitative evaluation system of the vibration characteristics of the hydraulic machine can be established.
Corresponding to the method for extracting the damping ratio of the structural response signal in the high-noise flowing environment, the invention also provides electronic equipment. Since the embodiment of the electronic device is similar to the above method embodiment, the description is simple, and please refer to the description of the above method embodiment, and the electronic device described below is only schematic. Fig. 8 is a schematic physical structure diagram of an electronic device according to an embodiment of the present invention. The electronic device may include: a processor (processor)801, a memory (memory)802, and a communication bus 803, wherein the processor 801 and the memory 802 communicate with each other via the communication bus 803. The processor 801 may invoke logic instructions in the memory 802 to perform a method of structure response signal damping ratio extraction in a high noise flow environment, the method comprising: the method comprises the steps of firstly exciting a mechanical structure by utilizing a vibration exciter to carry out linear frequency sweeping, and recording a first vibration response signal corresponding to the mechanical structure based on a preset sensor; performing autocorrelation processing on the first vibration response signal, and performing fast Fourier transform to obtain the natural frequency of the k-th order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor; performing time-frequency analysis on the second vibration response signal, and determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled; and fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
Furthermore, the logic instructions in the memory 802 may be implemented in software functional units and stored in a computer readable storage medium when sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
In another aspect, an embodiment of the present invention further provides a computer program product, where the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, where the computer program includes program instructions, and when the program instructions are executed by a computer, the computer is capable of executing the method for extracting a damping ratio of a structural response signal in a high-noise flowing environment, provided by the above-mentioned method embodiments, the method includes: the method comprises the steps of firstly exciting a mechanical structure by utilizing a vibration exciter to carry out linear frequency sweeping, and recording a first vibration response signal corresponding to the mechanical structure based on a preset sensor; performing autocorrelation processing on the first vibration response signal, and performing fast Fourier transform to obtain the natural frequency of the k-th order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor; performing time-frequency analysis on the second vibration response signal, and determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled; and fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
In yet another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, where the computer program is implemented by a processor to execute the method for extracting a damping ratio of a structural response signal in a high-noise flowing environment provided by the foregoing embodiments, where the method includes: the method comprises the steps of firstly exciting a mechanical structure by utilizing a vibration exciter to carry out linear frequency sweeping, and recording a first vibration response signal corresponding to the mechanical structure based on a preset sensor; performing autocorrelation processing on the first vibration response signal, and performing fast Fourier transform to obtain the natural frequency of the k-th order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor; performing time-frequency analysis on the second vibration response signal, and determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled; and fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for extracting a damping ratio of a structural response signal in a high-noise flowing environment is characterized by comprising the following steps:
the method comprises the steps of firstly exciting a mechanical structure by utilizing a vibration exciter to carry out linear frequency sweeping, and recording a first vibration response signal corresponding to the mechanical structure based on a preset sensor;
performing autocorrelation processing on the first vibration response signal, and performing fast Fourier transform to obtain the natural frequency of the k-th order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor;
performing time-frequency analysis on the second vibration response signal, and determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled;
and fitting the ridge line according to a logarithmic attenuation formula, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
2. The method for extracting the damping ratio of the structural response signal in the high-noise flow environment according to claim 1, wherein the time for exciting the mechanical structure for the first time corresponds to the frequency range of the linear frequency sweep, and is specifically expressed as:
t1≥(fmax-fmin)/m
wherein, t1Time, in units of s, for said first actuation of the mechanical structure; f. ofmaxThe upper limit of the frequency range of the linear sweep frequency is unit Hz; f. ofminThe lower limit of the frequency range of linear sweep frequency is unit Hz; m is the rate of frequency increase in units of 1/s2，1≤m＜1000；
The upper limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fmax≥nfn,k
wherein n is the amplification factor of the sweep frequency range, and n is more than or equal to 1.1; f. ofn,kIs the natural frequency of the k-th order mode;
the lower limit of the frequency range of the linear frequency sweep corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fmin≤fn,k/z
wherein z is a reduction coefficient of the frequency range of the linear frequency sweep, and z is more than or equal to 10;
the sampling frequency of the sensor corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
3. The method for extracting the damping ratio of the structural response signal in the high-noise flowing environment according to claim 1, wherein a scale parameter is adjusted in an autocorrelation processing process, and a function estimation type corresponding to the scale parameter is an unbiased estimation;
the hysteresis range of the scale parameter corresponds to the sample data size, and is specifically represented as:
iN≤L≤jN
wherein L is the upper limit of the hysteresis range; -L is the lower limit of the hysteresis range; n is the sample data size; i and j are proportional coefficients of the hysteresis range, i is more than or equal to 0.01 and less than 0.5, and j is more than or equal to 0.5 and less than 1.
4. The method for extracting the damping ratio of the structural response signal in the high-noise flow environment according to claim 1, wherein the time for exciting the mechanical structure for the second time corresponds to the natural frequency of the k-th order mode, and is specifically represented as follows:
wherein, t2Time for said second excitation of the mechanical structure in units of s; i and J are time limiting coefficients of the secondary excitation mechanical structure, I is more than or equal to 1000, and J is more than or equal to 0.001 and less than 1000.
The second recording time when the sensor records the second vibration response signal is specifically represented as:
t2＜t22≤ct2
wherein, t22Is the second recording time in units of s; c is the extension multiple of the second recording time, and c is more than or equal to 1.1;
the sampling frequency in the sensor recording process corresponds to the natural frequency of the kth-order mode, and is specifically represented as:
fs≥ufn,k
wherein f issIs the sampling frequency in Hz; u is the frequency amplification factor, and u is more than or equal to 10.
5. The method for extracting the damping ratio of the structural response signal in the high-noise flowing environment according to claim 1, wherein the time-frequency analysis is performed on the second vibration response signal to determine a ridge line of the vibration response of the mechanical structure, which is free to decay with time, corresponding to the natural frequency, and specifically comprises: performing time-frequency analysis on the second vibration response signal by adopting a preset target time-frequency analysis method, positioning and extracting a third vibration response signal of the mechanical structure corresponding to the inherent frequency and a ridge line of the third vibration response signal; the target time-frequency analysis method is one of a short-time Fourier transform method and a continuous wavelet transform method.
6. The method of claim 5, further comprising: within the range of the second recording time, obtaining a third-time vibration response signal corresponding to the natural frequency of the kth-order mode, and carrying out non-dimensionalization processing on the third-time vibration response signal;
the ridge line is a free attenuation area of a third vibration response signal along with time after the second excitation is cancelled, and the specific quantitative expression is as follows:
XA≤y＜YA
wherein A is a dimensionless third vibration response signal; y is the vibrational response of the ridge line; x and Y are limiting coefficients of the vibration response of the ridge line, wherein X is more than or equal to 1% and less than 30%, and Y is more than or equal to 50% and less than 100%.
7. The method for extracting the damping ratio of the structural response signal in the high-noise flow environment according to claim 1, wherein the ridge line is fitted according to a logarithmic attenuation formula, and the damping ratio of the mechanical structure is identified when a corresponding coefficient is greater than a preset threshold, specifically comprising: fitting the ridge line by adopting a least square fitting method according to a logarithmic attenuation formula, identifying the damping ratio of the mechanical structure when the coefficient of the decision is greater than a preset threshold, and determining the reliability of the identified damping ratio;
if the coefficient is less than or equal to the preset threshold, removing a maximum and minimum target data in the ridge line, continuously fitting the ridge line by adopting a least square fitting method according to a logarithmic attenuation formula until the coefficient is greater than the preset threshold, and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than the preset threshold;
the logarithmic decay formula is specifically expressed as:
wherein, y0Is the amplitude, ω, of the vibration responsen＝2πfn；fnNatural frequency of the k-th order mode in Hz;
is the damping angle natural frequency, unit rad/s; phi is the initial phase angle, in units rad/s.
8. An apparatus for extracting a damping ratio of a structural response signal in a high noise flow environment, comprising:
the first-time vibration response signal acquisition unit is used for exciting the mechanical structure for the first time by utilizing a method of linear frequency sweeping by using a vibration exciter and recording a first-time vibration response signal corresponding to the mechanical structure based on a preset sensor;
the second-time vibration response signal acquisition unit is used for performing autocorrelation processing on the first-time vibration response signal and performing fast Fourier transform to obtain the natural frequency of the kth-order mode of the mechanical structure; secondly exciting the mechanical structure by using the vibration exciter according to the natural frequency, and recording a second vibration response signal based on the sensor;
the ridge line determining unit is used for performing time-frequency analysis on the second vibration response signal, determining a third vibration response signal of the mechanical structure corresponding to the natural frequency and a ridge line of the third vibration response signal which is freely attenuated along with time; the ridge line is an area in which a third vibration response signal is freely attenuated along with time after the second excitation is cancelled;
and the damping ratio identification unit is used for fitting the ridge line according to a logarithmic attenuation formula and identifying the damping ratio of the mechanical structure when the corresponding coefficient is greater than a preset threshold value.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program implements the steps of the method for extracting a damping ratio of a structural response signal in a high noise flow environment as claimed in any one of claims 1 to 7.
10. A non-transitory computer readable storage medium having stored thereon a computer program, which when executed by a processor, performs the steps of the method for structural response signal damping ratio extraction in a high noise flow environment according to any one of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110256907.4A CN112924154B (en) | 2021-03-09 | 2021-03-09 | Method and device for extracting damping ratio of structural response signal in high-noise flowing environment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110256907.4A CN112924154B (en) | 2021-03-09 | 2021-03-09 | Method and device for extracting damping ratio of structural response signal in high-noise flowing environment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112924154A true CN112924154A (en) | 2021-06-08 |
| CN112924154B CN112924154B (en) | 2022-09-23 |
Family
ID=76172169
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110256907.4A Active CN112924154B (en) | 2021-03-09 | 2021-03-09 | Method and device for extracting damping ratio of structural response signal in high-noise flowing environment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112924154B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114001193A (en) * | 2021-09-18 | 2022-02-01 | 上海华兴数字科技有限公司 | Start-stop vibration reduction control method and device for operation machinery and electronic equipment |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100394172B1 (en) * | 2003-04-17 | 2003-08-09 | Do Dam Engineering & Construct | Method for estimating dynamic parameters of structure, making use of morlet wavelet transform |
| CN102222219A (en) * | 2011-06-17 | 2011-10-19 | 东南大学 | Structural concentration modal parameter recognition method based on Moret wavelet transformation |
| CN103267907A (en) * | 2013-04-19 | 2013-08-28 | 上海交通大学 | Method for identifying modal parameters of transformer coil |
| CN108760020A (en) * | 2018-06-01 | 2018-11-06 | 东北大学 | Fiber composite thin plate Non-Linear Vibration characterization test method based on vibration measurement with laser |
| CN109682570A (en) * | 2018-11-08 | 2019-04-26 | 中国农业大学 | A kind of waterpower damping ratio recognition methods of Asymmetric Tail shape hydrofoil |
| CN110926735A (en) * | 2019-11-29 | 2020-03-27 | 邢台市交通运输局 | Bridge structure rapid diagnosis method based on multidimensional dynamic parameters |
| CN111350675A (en) * | 2020-03-10 | 2020-06-30 | 中国农业大学 | Quantitative measurement system for hydraulic damping ratio of rotary centrifugal impeller |
-
2021
- 2021-03-09 CN CN202110256907.4A patent/CN112924154B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100394172B1 (en) * | 2003-04-17 | 2003-08-09 | Do Dam Engineering & Construct | Method for estimating dynamic parameters of structure, making use of morlet wavelet transform |
| CN102222219A (en) * | 2011-06-17 | 2011-10-19 | 东南大学 | Structural concentration modal parameter recognition method based on Moret wavelet transformation |
| CN103267907A (en) * | 2013-04-19 | 2013-08-28 | 上海交通大学 | Method for identifying modal parameters of transformer coil |
| CN108760020A (en) * | 2018-06-01 | 2018-11-06 | 东北大学 | Fiber composite thin plate Non-Linear Vibration characterization test method based on vibration measurement with laser |
| CN109682570A (en) * | 2018-11-08 | 2019-04-26 | 中国农业大学 | A kind of waterpower damping ratio recognition methods of Asymmetric Tail shape hydrofoil |
| CN110926735A (en) * | 2019-11-29 | 2020-03-27 | 邢台市交通运输局 | Bridge structure rapid diagnosis method based on multidimensional dynamic parameters |
| CN111350675A (en) * | 2020-03-10 | 2020-06-30 | 中国农业大学 | Quantitative measurement system for hydraulic damping ratio of rotary centrifugal impeller |
Non-Patent Citations (4)
| Title |
|---|
| KIM, Y等: "Wet damping estimation of the scaled segmented hull model using the random decrement technique", 《OCEAN ENGINEERING》 * |
| ZENG, Y.S.等: "The prediction of hydrodynamic damping characteristics of a hydrofoil with blunt trailing edge", 《IOP CONFERENCE SERIES: EARTH AND ENVIRONMENTAL SCIENCE》 * |
| 王砚等: "《工程振动分析》", 30 September 2016, 文化发展出版社 * |
| 王超等: "基于复小波变换的拉索结构阻尼比识别", 《华中科技大学学报（自然科学版）》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114001193A (en) * | 2021-09-18 | 2022-02-01 | 上海华兴数字科技有限公司 | Start-stop vibration reduction control method and device for operation machinery and electronic equipment |
| CN114001193B (en) * | 2021-09-18 | 2024-03-15 | 上海华兴数字科技有限公司 | Start-stop vibration reduction control method and device for working machine and electronic equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112924154B (en) | 2022-09-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Jacobsen et al. | Using enhanced frequency domain decomposition as a robust technique to harmonic excitation in operational modal analysis | |
| CN109682601B (en) | Early fault identification method for rolling bearing under variable rotating speed working condition | |
| Yu et al. | A new statistical modeling and detection method for rolling element bearing faults based on alpha–stable distribution | |
| Li et al. | Wavelet transform-based higher-order statistics for fault diagnosis in rolling element bearings | |
| Jacobsen et al. | Eliminating the influence of harmonic components in operational modal analysis | |
| Haber | Nonlinearity tests for dynamic processes | |
| CN105723458B (en) | For filtering out noise and going back dynamic threshold method, the system, computer-readable medium of the high fdrequency component that acoustic signal is decayed | |
| CN112101245B (en) | Short-time Fourier transform mechanical impact feature extraction method based on frequency domain window function | |
| RU2488815C2 (en) | Method and apparatus for classifying sound-generating processes | |
| Hu et al. | Bearing fault diagnosis based on an improved morphological filter | |
| Makowski et al. | New techniques of local damage detection in machinery based on stochastic modelling using adaptive Schur filter | |
| CN112924154B (en) | Method and device for extracting damping ratio of structural response signal in high-noise flowing environment | |
| CN101964050A (en) | Method for identifying modal parameter based on model order determination and signal noise elimination | |
| CN114186577A (en) | Vibration acceleration signal denoising method and device based on wavelet transformation | |
| Deák et al. | Optimal Wavelet Selection for the Size Estimation of Manufacturing Defects of Tapered Roller Bearings with Vibration Measurement using Shannon Entropy Criteria. | |
| CN112817047A (en) | Ocean earthquake self-adaptive ghost wave removing method and device, electronic equipment and medium | |
| Spinosa et al. | A noise reduction method for force measurements in water entry experiments based on the Ensemble Empirical Mode Decomposition | |
| CN108398260A (en) | The fast evaluation method of gear-box instantaneous angular velocity based on mixing probabilistic method | |
| Chen et al. | A signal based triangular structuring element for mathematical morphological analysis and its application in rolling element bearing fault diagnosis | |
| WO2019163433A1 (en) | Signal analysis system, method and program | |
| CN102680080B (en) | Unsteady-state signal detection method based on improved self-adaptive morphological filtering | |
| Peeters et al. | Signal pre-processing using cepstral editing for vibration-based bearing fault detection | |
| CN114061746B (en) | Repeated transient signal extraction method in rotary machinery fault diagnosis | |
| Bertot et al. | Refining Envelope Analysis Methods usingWavelet De-Noising to Identify Bearing Faults | |
| CN116429236A (en) | Method and device for suppressing coherent fading noise of optical fiber sensing data |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |