CN113959555B - Method and device for intercepting vibration signal - Google Patents

Method and device for intercepting vibration signal Download PDF

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Publication number
CN113959555B
CN113959555B CN202010700195.6A CN202010700195A CN113959555B CN 113959555 B CN113959555 B CN 113959555B CN 202010700195 A CN202010700195 A CN 202010700195A CN 113959555 B CN113959555 B CN 113959555B
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envelope
vibration
point
signal
gradient
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CN113959555A (en
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胡昌权
宋伟
张波
冯丞科
刘辉
梁兵
张庆
龚伟
周文洪
芶俊轶
韩光谱
谢利平
雷英
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Petrochina Co Ltd
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Petrochina Co Ltd
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    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation

Abstract

The application provides a method and a device for intercepting vibration signals, and belongs to the technical field of fault diagnosis. The method comprises the following steps: determining a first starting point and a first ending point of the interception window, and adjusting the position of the first starting point and the position of the first ending point according to a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals to obtain a second starting point and a second ending point of the interception window; and intercepting the vibration signal according to the second starting point and the second ending point of the intercepting window to obtain an impact signal. The first starting point and the first ending point of the interception window are adjusted through a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals; therefore, the impact signals in the vibration signals are intercepted through the intercepting window with adjustable width, and the accuracy of the obtained impact signals is high.

Description

Method and device for intercepting vibration signal
Technical Field
The application relates to the technical field of equipment state monitoring, in particular to a method and a device for intercepting vibration signals.
Background
A vibration signal is generated when the machine is in operation. The vibration signals comprise basic vibration signals and impact signals; wherein the impact signal is a signal of significantly higher amplitude than the base vibration signal and of shorter duration. Since the reciprocating mechanical motion of the mechanical device generates periodic impact signals during normal operation of the mechanical device, the state of the device can be monitored by intercepting the impact signals in the vibration signals.
In the related art, an impact signal in a vibration signal is intercepted by a window method. Firstly, determining the peak value of a vibration signal, and then intercepting the vibration signal near the peak value in the vibration signal through an intercepting window with a preset length to obtain the vibration signal with the preset length; taking the intercepted vibration signal with the preset length as an impact signal in the vibration signal.
However, in the related art, since the sequence lengths of the impact signals generated by different mechanical devices are different, the vibration signals are intercepted through the intercepting window with a preset length, and when the sequence length of the impact signals is small, the intercepted vibration signals with the preset length contain noise signals except the impact signals; when the sequence length of the impact signals is large, the intercepted vibration signals with preset length can contain incomplete impact signals. Therefore, the accuracy of intercepting the impact signal in the vibration signal by the interception window method of the preset length is low.
Disclosure of Invention
The embodiment of the application provides a method and a device for intercepting vibration signals, which can improve the accuracy of intercepting impact signals in the vibration signals. The technical scheme is as follows:
in one aspect, the present application provides a method of intercepting a vibration signal, the method comprising:
Determining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted based on a first sliding window, and determining a plurality of second vibration effective values of the vibration signals based on a second sliding window;
determining an effective value average value of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values according to the plurality of first vibration effective values;
determining a first peak value of the vibration signal and a first location point of the first peak value;
determining a first starting point and a first ending point of the interception window according to the first peak value, the first position point, the effective value mean value, the effective value standard deviation and the plurality of second vibration effective values;
determining a first envelope signal corresponding to the vibration signal and determining a second envelope signal corresponding to the noise signal;
determining a plurality of first envelope gradients of the first envelope signal within the intercept window from the first envelope signal, the first start point, and the first end point, and a plurality of second envelope gradients of the noise signal from the second envelope signal;
according to the first envelope gradients and the second envelope gradients, the positions of the first starting point and the first ending point are adjusted to obtain a second starting point and a second ending point of the intercepting window;
And intercepting the vibration signal according to the second starting point and the second ending point of the intercepting window to obtain an impact signal.
In one possible implementation manner, the determining, based on the first sliding window, a plurality of first vibration effective values of a noise signal in the vibration signal to be intercepted includes:
according to a first sliding window, obtaining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted through the following formula I;
equation one:
wherein s (k) is a noise signal at a sequence number k; n (N) w I is the serial number of the position point included in the first sliding window, Y is the width of the first sliding window ns (i) And n is the sequence length of the noise signal, and is the first vibration effective value corresponding to the ith position point.
In another possible implementation manner, the determining, based on the second sliding window, a plurality of second vibration effective values of the vibration signal includes:
obtaining a plurality of second vibration effective values of the vibration signal according to a second sliding window through the following formula II;
formula II:
wherein s (k) is a vibration signal at a sequence number k; n (N) w And for the width of the second sliding window, i is the serial number of the position point included in the second sliding window, Y (i) is a second vibration effective value corresponding to the serial number i, and n is the sequence length of the vibration signal.
In another possible implementation manner, the determining, according to the plurality of first vibration effective values, an effective value average value of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values includes:
according to the plurality of first vibration effective values, determining an effective value average value of the plurality of first vibration effective values through the following formula III; and determining an effective value standard deviation of the plurality of first vibration effective values by the following formula four;
and (3) a formula III:
equation four:
wherein i is the serial number of the position point included in the first sliding window, Y ns (i) And (3) for the first vibration effective value corresponding to the sequence number i, mu is the effective value mean value, sigma is the effective value standard deviation, and n is the sequence length of the noise signal.
In another possible implementation manner, the determining the first envelope signal corresponding to the vibration signal includes:
determining a first energy operator signal corresponding to the vibration signal through the following formula five;
performing second-order maximum envelope processing on the first energy operator signal to obtain a first envelope signal;
formula five:
Ψ(i)＝s 2 (i)-s(i+1)s(i-1)，2≤i≤n-1
wherein, ψ is the first energy operator signal, s (i) is the vibration signal at the sequence number i, i is the sequence number of the position point of the vibration signal, and n is the sequence length of the vibration signal.
In another possible implementation manner, the determining the first starting point and the first ending point of the interception window according to the first peak value, the first position point, the effective value mean value, the effective value standard deviation, and the plurality of second vibration effective values includes:
determining a plurality of position points corresponding to the plurality of second vibration effective values;
responding to the fact that the first peak value is larger than a standard parameter, selecting a first starting point and a first ending point which are closest to the first position point and correspond to the second vibration effective value which are smaller than the standard parameter from the plurality of position points on the left side and the right side of the first position point; the standard parameter is the sum of the effective value mean and three times of the effective value standard deviation.
In another possible implementation manner, the determining, according to the first envelope signal, a plurality of first envelope gradients of the first envelope signal within the interception window includes:
determining a target envelope signal of the first envelope signal in the interception window according to the first starting point and the first ending point;
performing gradient processing on the target envelope signal through the following formula six to obtain a plurality of first envelope gradients of the first envelope signal in the interception window;
Formula six:
T(i)＝B(i+1)-B(i),1≤i<n
wherein T is the first envelope gradient, B is the target envelope signal, n is the sequence length of the target envelope signal, and i is the sequence number of the position point of the target envelope signal.
In another possible implementation manner, the adjusting the position of the first starting point and the position of the first ending point according to the first envelope gradients and the second envelope gradients to obtain a second starting point and a second ending point of the intercepting window includes:
determining a gradient mean value of the plurality of second coating gradients and a gradient standard deviation of the plurality of second coating gradients according to the plurality of second coating gradients;
determining a plurality of third envelope gradients from the plurality of first envelope gradients that is greater than a sum of the gradient mean and three times the gradient standard deviation;
in response to the gradient duty cycle being greater than a preset ratio, taking the first starting point as the second starting point and the first ending point as the second ending point; the gradient duty cycle is the ratio of the sequence length of the plurality of third envelope gradients to the sequence length of the plurality of first envelope gradients;
and adjusting the position of the first starting point and the position of the first ending point until the gradient duty ratio is smaller than the preset ratio to obtain a third starting point and a third ending point of the intercepting window, wherein the third starting point is used as the second starting point, and the third ending point is used as the second ending point.
In another possible implementation manner, the adjusting the position of the first start point and the position of the first end point until the gradient duty ratio is greater than the preset ratio, to obtain a third start point and a third end point of the interception window includes:
determining a first adjustment step size of the first starting point and a second adjustment step size of the first ending point through the following formula seven;
adjusting the first starting point through the first adjusting step length, and adjusting the first ending point through the second adjusting step length until the gradient duty ratio is larger than the preset ratio to obtain a third starting point and a third ending point of the intercepting window;
formula seven:
Lt＝2(μ T +3σ T )，
ω＝X 2 -X 1 ，
n_Step 1 ＝[Step 1 ],
n_Step 2 ＝[Step 2 ],
wherein T is the first envelope gradient, ave_T 1 For the gradient average value of 5 position points before and after the first starting point of the first envelope gradient, ave_T 2 For the gradient average value of the first envelope gradient at 5 position points before and after the first end point, mu T For the gradient mean value, σ T To the standard deviation of the gradient, X 1 For the first starting point, X 2 X is the first end point Tmax X is the location point of maximum first envelope gradient Tmin A position point of the minimum first envelope gradient, P is the gradient duty ratio, n_step 1 For the first adjustment Step, n_step 2 And (5) adjusting the step length for the second step length.
In another possible implementation, the method further includes:
and if the gradient duty ratio is not larger than the preset ratio after the position of the first starting point and the position of the first ending point are adjusted, intercepting the vibration signal is canceled.
In another aspect, the present application provides an apparatus for intercepting a vibration signal, the apparatus comprising:
the first determining module is used for determining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted based on a first sliding window and a plurality of second vibration effective values of the vibration signals based on a second sliding window;
the second determining module is used for determining an effective value average value of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values according to the plurality of first vibration effective values;
a third determining module for determining a first peak value of the vibration signal and a first location point of the first peak value;
a fourth determining module, configured to determine a first starting point and a first ending point of the interception window according to the first peak value, the first location point, the effective value mean value, the effective value standard deviation, and the plurality of second vibration effective values;
A fifth determining module, configured to determine a first envelope signal corresponding to the vibration signal, and determine a second envelope signal corresponding to the noise signal;
a sixth determining module, configured to determine a plurality of first envelope gradients of the first envelope signal within the interception window according to the first envelope signal, the first start point, and the first end point, and determine a plurality of second envelope gradients of the noise signal according to the second envelope signal;
the adjusting module is used for adjusting the position of the first starting point and the position of the first ending point according to the first envelope gradients and the second envelope gradients to obtain a second starting point and a second ending point of the interception window;
and the intercepting module is used for intercepting the vibration signal according to the second starting point and the second ending point of the intercepting window to obtain an impact signal.
In one possible implementation manner, the first determining module includes:
the first determining unit is used for obtaining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted according to a first sliding window through the following formula I;
Equation one:
wherein s (k) is a noise signal at a sequence number k; n (N) w I is the serial number of the position point included in the first sliding window, Y is the width of the first sliding window ns (i) And n is the sequence length of the noise signal, and is the first vibration effective value corresponding to the ith position point.
In another possible implementation manner, the first determining module includes:
the second determining unit is used for obtaining a plurality of second vibration effective values of the vibration signal according to a second sliding window through the following formula II;
formula II:
wherein s (k) is a vibration signal at a sequence number k; n (N) w And for the width of the second sliding window, i is the serial number of the position point included in the second sliding window, Y (i) is a second vibration effective value corresponding to the serial number i, and n is the sequence length of the vibration signal.
In another possible implementation manner, the second determining module is configured to determine, according to the plurality of first vibration effective values, an effective value average value of the plurality of first vibration effective values through the following formula three; and determining an effective value standard deviation of the plurality of first vibration effective values by the following formula four;
and (3) a formula III:
equation four:
Wherein i is the serial number of the position point included in the first sliding window, Y ns (i) And (3) for the first vibration effective value corresponding to the sequence number i, mu is the effective value mean value, sigma is the effective value standard deviation, and n is the sequence length of the noise signal.
In another possible implementation manner, the fifth determining module includes:
a fifth determining unit, configured to determine a first energy operator signal corresponding to the vibration signal according to the following formula five;
performing second-order maximum envelope processing on the first energy operator signal to obtain a first envelope signal;
formula five:
Ψ(i)＝s 2 (i)-s(i+1)s(i-1)，2≤i≤n-1
wherein, ψ is the first energy operator signal, s (i) is the vibration signal at the sequence number i, i is the sequence number of the position point of the vibration signal, and n is the sequence length of the vibration signal.
In another possible implementation manner, the fourth determining module is configured to determine a plurality of location points corresponding to the plurality of second vibration effective values; responding to the fact that the first peak value is larger than a standard parameter, selecting a first starting point and a first ending point which are closest to the first position point and correspond to the second vibration effective value which are smaller than the standard parameter from the plurality of position points on the left side and the right side of the first position point; the standard parameter is the sum of the effective value mean and three times of the effective value standard deviation.
In another possible implementation manner, the sixth determining module includes:
a sixth determining unit, configured to determine a target envelope signal of the first envelope signal within the interception window according to the first start point and the first end point; performing gradient processing on the target envelope signal through the following formula six to obtain a plurality of first envelope gradients of the first envelope signal in the interception window; formula six:
T(i)＝B(i+1)-B(i),1≤i<n
wherein T is the first envelope gradient, B is the target envelope signal, n is the sequence length of the target envelope signal, and i is the sequence number of the position point of the target envelope signal.
In another possible implementation manner, the adjusting module includes:
a third determining unit, configured to determine a gradient mean value of the plurality of second envelope gradients and a gradient standard deviation of the plurality of second envelope gradients according to the plurality of second envelope gradients;
a fourth determining unit configured to determine a plurality of third envelope gradients greater than a sum of the gradient mean and three times the gradient standard deviation from the plurality of first envelope gradients;
the first adjusting unit is used for responding to the fact that the gradient duty ratio is larger than a preset ratio, taking the first starting point as the second starting point and taking the first ending point as the second ending point; the gradient duty cycle is the ratio of the sequence length of the plurality of third envelope gradients to the sequence length of the plurality of first envelope gradients;
And the second adjusting unit is used for adjusting the position of the first starting point and the position of the first ending point in response to the gradient duty ratio being smaller than the preset ratio until the gradient duty ratio is larger than the preset ratio, obtaining a third starting point and a third ending point of the intercepting window, taking the third starting point as the second starting point and taking the third ending point as the second ending point.
In another possible implementation manner, the second adjusting unit is configured to determine a first adjustment step size of the first starting point and a second adjustment step size of the first ending point through the following formula seven; adjusting the first starting point through the first adjusting step length, and adjusting the first ending point through the second adjusting step length until the gradient duty ratio is larger than the preset ratio to obtain a third starting point and a third ending point of the intercepting window;
formula seven:
Lt＝2(μ T +3σ T )，
ω＝X 2 -X 1 ，
n_Step 1 ＝[Step 1 ],
n_Step 2 ＝[Step 2 ],
wherein T is the first envelope gradient, ave_T 1 For the gradient average value of 5 position points before and after the first starting point of the first envelope gradient, ave_T 2 For the gradient average value of the first envelope gradient at 5 position points before and after the first end point, mu T For the gradient mean value, σ T To the standard deviation of the gradient, X 1 For the first starting point, X 2 X is the first end point Tmax X is the location point of maximum first envelope gradient Tmin A position point of the minimum first envelope gradient, P is the gradient duty ratio, n_step 1 For the first adjustment Step, n_step 2 And (5) adjusting the step length for the second step length.
In another possible implementation, the apparatus further includes:
and the cancellation module is used for canceling interception of the vibration signal if the gradient duty ratio is not larger than the preset ratio after the position of the first starting point and the position of the first ending point are adjusted.
The beneficial effects that technical scheme that this application embodiment provided brought are:
in the embodiment of the application, a first starting point and a first ending point of the interception window are determined, and the position of the first starting point and the position of the first ending point are adjusted according to a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals to obtain a second starting point and a second ending point of the interception window; and intercepting the vibration signal according to the second starting point and the second ending point of the intercepting window to obtain an impact signal. The first starting point and the first ending point of the interception window are adjusted through a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals; therefore, the impact signals in the vibration signals are intercepted through the intercepting window with adjustable width, and the accuracy of the obtained impact signals is high.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method of intercepting vibration signals provided according to an embodiment of the present application;
FIG. 2 is a flow chart of a method for intercepting vibration signals according to an embodiment of the present application;
fig. 3 is a schematic diagram of a cylinder head vibration acceleration signal of a diesel engine according to an embodiment of the present application;
FIG. 4 is a schematic diagram of a second vibration effective value of a cylinder head vibration acceleration signal provided according to an embodiment of the present application;
fig. 5 is a schematic diagram of a first energy operator signal corresponding to a cylinder head vibration acceleration signal according to an embodiment of the present application;
fig. 6 is a schematic diagram of a first envelope signal provided according to an embodiment of the present application;
FIG. 7 is a schematic illustration of a first envelope gradient provided in accordance with an embodiment of the present application;
FIG. 8 is a schematic diagram of an impact signal of a cylinder head vibration acceleration signal of a diesel engine according to an embodiment of the present application;
FIG. 9 is a schematic diagram of vibration signals of a normal cylinder head of a diesel engine according to an embodiment of the present application;
FIG. 10 is a schematic diagram of an impact signal of a vibration signal of a normal cylinder head of a diesel engine according to an embodiment of the present application;
FIG. 11 is a schematic diagram of vibration signals of a diesel engine misfire fault provided according to an embodiment of the present application;
FIG. 12 is a schematic diagram of an impact signal of a vibration signal of a diesel engine misfire fault according to an embodiment of the present application;
fig. 13 is a block diagram of an apparatus for intercepting a vibration signal according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
Fig. 1 is a flow chart of a method for intercepting vibration signals provided by the application. Referring to fig. 1, the method includes:
101. the computer device determines a plurality of first vibration effective values of the noise signal in the vibration signal to be intercepted based on the first sliding window, and determines a plurality of second vibration effective values of the vibration signal based on the second sliding window.
The vibration signal is generated by mechanical equipment within a preset time period. The preset time period may be any value between 1 and 500 minutes. The larger the preset time length is, the more the serial numbers of the position points included in the vibration signals are, and the longer the serial length of the vibration signals is. The first sliding window is a vibration signal with a first preset width; the first predetermined width may be any value between 10 and 50 serial numbers. The second sliding window is a vibration signal with a second preset width; the second preset width may be any value between 10 and 50 serial numbers. Optionally, the first preset width is the same as the second preset width. For example, the first preset width is 17 serial numbers, and the second preset width is 17 serial numbers.
In one possible implementation, the computer device selects a noise signal from the base vibration signal. Correspondingly, the computer equipment determines a plurality of amplitudes in the vibration signal to be intercepted, and determines the median of the plurality of amplitudes; determining a plurality of basic vibration signals with the amplitude smaller than the median from the vibration signals to be intercepted; acquiring the sequence length of a plurality of basic vibration signals; and taking the basic vibration signal with the largest sequence length as a noise signal.
In one possible implementation, the computer device determines a plurality of first vibration effective values of a noise signal in the vibration signal to be intercepted based on a first sliding window, including: the computer equipment obtains a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted according to the first sliding window through the following formula I. Equation one:
wherein s (k) is a noise signal at a sequence number k; n (N) w I is the serial number of the position point included in the first sliding window, Y is the width of the first sliding window ns (i) And n is the sequence length of the noise signal, and is the first vibration effective value corresponding to the ith position point.
The computer device determining a plurality of second vibration effective values of the vibration signal based on the second sliding window, comprising: the computer equipment obtains a plurality of second vibration effective values of the vibration signal according to a second sliding window through the following formula II. Formula II:
wherein s (k) is a vibration signal at a sequence number k; n (N) w And i is the serial number of the position point included in the second sliding window, Y (i) is the second vibration effective value corresponding to the serial number i, and n is the sequence length of the vibration signal.
102. The computer device determines an effective value mean of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values according to the plurality of first vibration effective values.
In one possible implementation, this step is: the computer equipment determines an effective value average value of the plurality of first vibration effective values according to the plurality of first vibration effective values through the following formula III; and determining an effective value standard deviation of the plurality of first vibration effective values by the following formula four;
and (3) a formula III:
equation four:
wherein i is the serial number of the position point included in the first sliding window, Y ns (i) And (3) for the first vibration effective value corresponding to the sequence number i, mu is an effective value mean value, sigma is an effective value standard deviation, and n is the sequence length of the noise signal.
103. The computer device determines a first peak value of the vibration signal and a first location point of the first peak value.
In one possible implementation, the computer device determines a plurality of amplitudes in the vibration signal to be intercepted, and selects a first amplitude with the largest value from the plurality of amplitudes; determining the serial number of a position point where the first amplitude is located in the vibration signal; the first amplitude is set as a first peak value of the vibration signal, and the number of the position point is set as a first position point.
It should be noted that, referring to fig. 2, after the computer intercepts the impact signal corresponding to the first peak value in the vibration signal, the impact signal is zeroed to obtain a new vibration signal to be intercepted. Accordingly, the computer device determines the first peak value of the vibration signal and the first location point of the first peak value as follows: the method comprises the steps that computer equipment determines a plurality of amplitudes in a new vibration signal to be intercepted, and a first amplitude with the largest value is selected from the plurality of amplitudes; determining the serial number of a position point where the first amplitude is located in the vibration signal; the first amplitude is set as a first peak value of the vibration signal, and the number of the position point is set as a first position point.
104. The computer device determines a first starting point and a first ending point of the intercept window based on the first peak, the first location point, the effective value mean and effective value standard deviation, and the plurality of second vibration effective values.
In one possible implementation, this step is: the computer equipment determines a plurality of position points corresponding to the plurality of second vibration effective values; and in response to the first peak value being greater than the standard parameter, selecting a first starting point and a first ending point which are closest to the first position point and correspond to the second vibration effective value which are smaller than the standard parameter from the plurality of position points on the left side and the right side of the first position point. The standard parameters are the sum of the mean value of the effective values and three times of standard deviation of the effective values, namely the standard parameters are as follows: μ+3σ.
105. The computer device determines a first envelope signal corresponding to the vibration signal and determines a second envelope signal corresponding to the noise signal.
In one possible implementation, the computer device determines a first envelope signal corresponding to the vibration signal, including: the computer equipment determines a first energy operator signal corresponding to the vibration signal through the following formula five; and performing second-order maximum envelope processing on the first energy operator signal to obtain a first envelope signal.
Formula five:
Ψ(i)＝s 2 (i)-s(i+1)s(i-1)，2≤i≤n-1
wherein, ψ is the first energy operator signal, s (i) is the vibration signal at the sequence number i, i is the sequence number of the position point of the vibration signal, and n is the sequence length of the vibration signal.
In one possible implementation manner, the fifth formula is a Teager energy operator formula, and accordingly, the computer device determines the first energy operator signal corresponding to the vibration signal through the Teager energy operator formula.
Optionally, the step of performing second-order maximum envelope processing on the first energy operator signal by the computer device to obtain a first envelope signal includes: the computer equipment determines a maximum value in the first energy operator signal, and carries out linear difference on the maximum value to obtain a first-order maximum value envelope signal; and carrying out maximum value envelope on the first-order maximum value envelope signal to obtain a second-order maximum value envelope signal, and taking the second-order maximum value envelope signal as a first envelope signal. It should be noted that the sequence length of the first-order maximum value envelope signal obtained by linearly differencing the maximum value is the same as the sequence length of the vibration signal.
Optionally, the computer device determines the maxima in the first energy operator signal by the following first maxima formula. The first maximum formula is as follows:
Wherein s (i) is the vibration signal at the sequence number i, s (i+1) is the vibration signal at the sequence number i+1, id max Serial number s of maximum position point of vibration signal max N is the maximum value of the vibration signal, and n is the sequence length of the vibration signal.
In one possible implementation, the computer device determines a second envelope signal corresponding to the noise signal, including: the computer equipment determines a second energy operator signal corresponding to the noise signal through the following formula eight; and performing second-order maximum envelope processing on the second energy operator signal to obtain a second envelope signal.
Formula eight:
wherein, t is ns For the second energy operator signal s ns (i) The vibration signal at the number i is the number of the position point of the noise signal, and n is the sequence length of the noise signal.
Optionally, the step of performing second-order maximum envelope processing on the second energy operator signal by the computer device to obtain a second envelope signal includes: the computer equipment determines a maximum value in the second energy operator signal, and carries out linear difference on the maximum value to obtain a first-order maximum value envelope signal; and carrying out maximum value envelope on the first-order maximum value envelope signal to obtain a second-order maximum value envelope signal, and taking the second-order maximum value envelope signal as a second envelope signal. It should be noted that the sequence length of the first-order maximum value envelope signal obtained by linearly differencing the maximum value is the same as the sequence length of the noise signal.
Optionally, the computer device determines the maxima in the second energy operator signal by the following second maxima formula. Wherein the second maximum formula is:
wherein s is ns (i) Is the noise signal at sequence number i, s ns (i+1) is the noise signal at sequence number i+1, id max Serial number s of maximum position point of noise signal max N is the sequence length of the noise signal, which is the maximum value of the noise signal.
106. The computer device determines a plurality of first envelope gradients of the first envelope signal within the intercept window based on the first envelope signal, the first start point, and the first end point, and a plurality of second envelope gradients of the noise signal based on the second envelope signal.
In one possible implementation, the step of determining, by the computer device, a plurality of first envelope gradients of the first envelope signal within the interception window from the first envelope signal is: the computer equipment determines a target envelope signal of the first envelope signal in the interception window according to the first starting point and the first ending point; and carrying out gradient processing on the target envelope signal through the following formula six to obtain a plurality of first envelope gradients of the first envelope signal in the interception window. Wherein, formula six is:
T(i)＝B(i+1)-B(i),1≤i＜n
Wherein T is a first envelope gradient, B is a target envelope signal, n is the sequence length of the target envelope signal, and i is the sequence number of the position point of the target envelope signal. It should be noted that the first envelope gradient is an absolute value of the gradient value.
The computer device determines a plurality of second envelope gradients of the noise signal from the second envelope signal by: the computer equipment carries out gradient processing on the noise signals through the following formula nine to obtain a plurality of second envelope gradients of the noise signals. Wherein, formula nine is:
T ns (i)＝B ns (i+1)-B ns (i),1≤i＜n
wherein T is ns For the second envelope gradient, B ns For the second envelope signal, n is the sequence length of the second envelope signal, and i is the sequence number of the position point of the second envelope signal. It should be noted that the second envelope gradient is an absolute value of the gradient value.
107. The computer equipment adjusts the position of the first starting point and the position of the first ending point according to the first envelope gradients and the second envelope gradients to obtain a second starting point and a second ending point of the interception window.
In one possible implementation, the present step includes the following steps (1) to (3):
(1) The computer equipment determines gradient mean values of the second coating gradients and gradient standard deviations of the second coating gradients according to the second coating gradients; a plurality of third envelope gradients greater than the sum of the gradient mean and three times the gradient standard deviation is determined from the plurality of first envelope gradients.
Optionally, the gradient mean value is a second envelope gradient mean value corresponding to the noise signal, i.e. μ T . Wherein the standard deviation of the gradient is the standard deviation of the absolute value of the second envelope gradient corresponding to the noise signal, i.e. sigma T . The third inclusion gradient is greater than mu T +3σ T 。
(2) The computer device takes the first start point as the second start point and the first end point as the second end point in response to the gradient duty cycle being greater than the preset ratio.
The gradient duty cycle is the ratio of the sequence length of the plurality of third envelope gradients to the sequence length of the plurality of first envelope gradients. Correspondingly, the method comprises the following steps: the computer device determines a gradient duty cycle, and when the gradient duty cycle is greater than a preset ratio, takes the first starting point as a second starting point and takes the first ending point as a second ending point. Wherein, the preset ratio can be any value between 70% and 90%; such as 75%, 80%, 85%, etc. For example, with continued reference to fig. 2, the preset ratio is set to 80%.
(3) And the computer equipment responds to the fact that the gradient duty ratio is smaller than a preset ratio, adjusts the position of the first starting point and the position of the first ending point until the gradient duty ratio is larger than the preset ratio, obtains a third starting point and a third ending point of the interception window, takes the third starting point as a second starting point and takes the third ending point as a second ending point.
Optionally, with continued reference to fig. 2, when the gradient duty cycle is less than the preset ratio, the computer device adjusts the position of the first start point and the position of the first end point, and determines the adjusted gradient duty cycle.
And when the adjusted gradient duty ratio is larger than the preset ratio, stopping adjusting the position of the first starting point and the position of the first ending point by the computer equipment to obtain a third starting point and a third ending point of the adjusted interception window.
And when the adjusted gradient duty ratio is smaller than the preset ratio, the computer equipment continuously adjusts the position of the first starting point and the position of the first ending point until the adjusted gradient duty ratio is larger than the preset ratio, and stops adjusting the position of the first starting point and the position of the first ending point to obtain a third starting point and a third ending point of the adjusted interception window.
In one possible implementation manner, the computer device adjusts the position of the first starting point and the position of the first ending point until the gradient duty ratio is greater than a preset ratio, and the step of obtaining the third starting point and the third ending point of the interception window is: the computer equipment determines a first adjustment step length of the first starting point and a second adjustment step length of the first ending point through the following formula seven; and adjusting the first starting point through a first adjusting step length, and adjusting the first ending point through a second adjusting step length until the gradient duty ratio is larger than a preset ratio to obtain a third starting point and a third ending point of the interception window.
Formula seven:
/>
Lt＝2(μ T +3σ T )，
ω＝X 2 -X 1 ，
n_Step 1 ＝[Step 1 ],
n_Step 2 ＝[Step 2 ],
wherein T is a first envelope gradient, ave_T 1 For the gradient mean value of the first envelope gradient at 5 position points before and after the first starting point, ave_t 2 For the gradient mean value of the first envelope gradient at 5 position points before and after the first end point, mu T Is gradient mean value, sigma T Is the standard deviation of gradient, X 1 For a first starting point, X 2 X is the first end point Tmax X is the location point of maximum first envelope gradient Tmin The position point of the minimum first envelope gradient, P is the gradient duty ratio, n_step 1 For a first adjustment Step, n_step 2 For a second adjustment step.
One point to be noted is that the first adjustment Step length n_step 1 For Step 1 Rounding to zero; second adjustment Step size n_step 2 For Step 2 Rounding to zero. In the formula, step is determined 1 And Step 2 The same logarithmic function of (a), e.g. Ln, log 2 、Log 10 Etc. In the embodiment of the present application, the base of the logarithmic function is not particularly limited, and may be set and modified as needed.
Another point to be described is that, with continued reference to fig. 2, before the computer device adjusts the position of the first start point and the position of the first end point, it needs to be determined whether the position of the first start point and the position of the first end point can be adjusted continuously. When the position of the first starting point and the position of the first ending point cannot be continuously adjusted, the gradient duty ratio is determined again. When the gradient duty ratio is smaller than the preset ratio, the impact signal is set to zero, namely the impact signal is abandoned. And when the gradient duty ratio is larger than the preset ratio, taking the third starting point as the second starting point and taking the third ending point as the second ending point.
Wherein, the computer device confirms whether the position of the first starting point and the position of the first ending point can be continuously adjusted or not has the following two implementation manners:
first kind: the computer device determining a distance between a location of the first start point and a location of the first end point; when the distance is smaller than the preset distance, the position of the first starting point and the position of the first ending point can not be continuously adjusted, and when the distance is not smaller than the preset distance, the position of the first starting point and the position of the first ending point can be continuously adjusted. The preset distance can be any value between 1 and 20 serial numbers. For example, 5, 10, 15, etc.
Second kind: the computer equipment determines the adjustment times of the position of the first starting point and the position of the first ending point; when the adjustment times are larger than the preset times, the position of the first starting point and the position of the first ending point are determined to be unable to be continuously adjusted, and when the adjustment times are not larger than the preset times, the position of the first starting point and the position of the first ending point are determined to be able to be continuously adjusted. Wherein the preset times can be any value between 20 and 100 times. For example, 20 times, 25 times, 30 times, etc.
108. And the computer equipment intercepts the vibration signal according to the second starting point and the second ending point of the interception window to obtain an impact signal.
Alternatively, this step may be: the computer equipment determines the position point serial number of the second starting point and the position point serial number of the second ending point, intercepts the vibration signal between the position point serial number of the second starting point and the position point serial number of the second ending point in the vibration signal, and obtains an impact signal.
It should be noted that, with continued reference to fig. 2, the computer device zeroes the impact signal, i.e., deletes the impact signal with the largest peak value in the vibration signal. Accordingly, the computer device determines whether the first peak is greater than the standard parameter before determining the first start point and the first end point of the truncated window. When the first peak value is greater than the standard parameter, the computer device continues to execute step 104; and when the first peak value is smaller than the standard parameter, stopping intercepting the impact signals in the vibration signals by the computer equipment, and counting the impact signals intercepted before.
In the embodiment of the application, a first starting point and a first ending point of the interception window are determined, and the position of the first starting point and the position of the first ending point are adjusted according to a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals to obtain a second starting point and a second ending point of the interception window; and intercepting the vibration signal according to the second starting point and the second ending point of the intercepting window to obtain an impact signal. The first starting point and the first ending point of the interception window are adjusted through a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals; therefore, the impact signals in the vibration signals are intercepted through the intercepting window with adjustable width, and the accuracy of the obtained impact signals is high.
The following description will take a computer device for intercepting an impact signal in a cylinder cover vibration acceleration signal of a 12-cylinder 4-stroke diesel engine by the method for intercepting a vibration signal as an example.
Step (1): the computer device determining a plurality of first vibration effective values Yns (i) of the noise signal based on the first sliding window; wherein i is the sequence number of the position point included in the first sliding window. Determining a plurality of second vibration effective values Y (i) of the cylinder cover vibration acceleration signal based on the second sliding window; wherein i is the sequence number of the position point included in the second sliding window.
In the embodiment of the application, the cylinder cover vibration acceleration signal of the diesel engine is shown in fig. 3. Wherein the sequence length of the cylinder head vibration acceleration signal n=2920. The computer device determines a plurality of second vibration effective values of the cylinder head vibration acceleration signal as shown in fig. 4; wherein the width N of the second sliding window w ＝17。
Step (2): the computer device determines an effective value mean of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values according to the plurality of first vibration effective values.
Optionally, the computer device determines, according to the plurality of first vibration effective values, an effective value average value of the noise component as: μ= 5.0020, and the effective standard deviation is determined to be σ= 3.7958.
Step (3): the computer device determining a first peak value F of the vibration acceleration signal 1 =108.1 and first position point SP F1 ＝1830。
Step (4): the computer equipment determines a plurality of position points corresponding to the plurality of second vibration effective values; selecting a first starting point 1X which is closest to the first position point and has a corresponding second vibration effective value smaller than the standard parameter from a plurality of position points on the left side and the right side of the first position point 1 =1776 and first termination point 1X 2 =2021. The standard parameter is the mean μ of the noise effective values plus three times the standard deviation σ, that is, the standard parameter is μ+3σ= 24.7756.
Step (5): the computer device determines a first envelope signal corresponding to the head vibration acceleration signal and a second envelope signal corresponding to the noise signal.
In one possible implementation, the fifth formula is a Teager energy operator formula; the computer equipment determines a first energy operator signal corresponding to the cylinder cover vibration acceleration signal through a Teager energy operator formula as shown in fig. 5. And performing second-order maximum value envelope processing on the first energy operator signal to obtain a first envelope signal as shown in fig. 6.
Step (6): the computer device determines a plurality of first envelope gradients of the first envelope signal within the intercept window based on the first envelope signal, the first start point, and the first end point, and a plurality of second envelope gradients of the noise signal based on the second envelope signal.
Wherein the plurality of first envelope gradients are T (i) =b (i+1) -B (i), 1.ltoreq.i < n. Wherein T is a first envelope gradient, B is a target envelope signal, n is the sequence length of the target envelope signal, and i is the sequence number of the position point of the target envelope signal. A plurality of first envelope gradients within the truncated window are shown in fig. 7.
Wherein the plurality of second envelope gradients are T ns (i)＝B ns (i+1)-B ns (i) I is more than or equal to 1 and less than n, wherein T ns For the second envelope gradient, B ns For the second envelope signal, n is the sequence length of the second envelope signal, and i is the sequence number of the position point of the second envelope signal.
Step (7): the computer equipment adjusts the position of the first starting point and the position of the first ending point according to the first envelope gradients and the second envelope gradients to obtain a second starting point and a second ending point of the interception window.
In an embodiment of the present application, the computer device determines a gradient mean μ of the plurality of second envelope gradients from the plurality of second envelope gradients T = 1.1728 determining the gradient standard deviation σ of the plurality of second envelope gradients T = 1.3193; a plurality of third envelope gradients greater than the sum of the gradient mean and three times the gradient standard deviation is determined from the plurality of first envelope gradients.
In the embodiment of the application, the computer device sets the preset ratio to 80%. Computer device determines that greater than mu T +3σ T Gradient duty cycle p= 78.46% for the plurality of third envelope gradients of=1.1728+3× 1.3193 = 5.1307. Computer device determines p= 78.46%<80% of the first starting point and the first ending point.
The computer device determining a first adjustment step size of the first start point and a second adjustment step size of the first end point; the computer device adjusts the first starting point through a first adjustment step length and adjusts the first ending point through a second adjustment step length:[1776+Step 1 ,2021-Step 2 ]＝[1776,2015]the adjusted gradient ratio p=80.75% is determined, satisfying P being equal to or greater than 80%.
Wherein the computer device determines the first adjustment step size of the first start point and the second adjustment step size of the first end point by the following equation seven. It should be noted that Step is determined in the seventh equation 1 And Step 2 Log function of Log 2 。
Formula seven:
Lt＝2(μ T +3σ T )＝2×5.1307＝10.26
ω＝1X 2 -1X 1 ＝2021-1776＝245
Ave_T 1 ≥Lt,Ave_T 2 <Lt
Step 1 ＝0
Step 2 ＝1+ln[ω(1-P)+1]＝1+log 2 [245×(1-78.46％)+1]＝6.75
n_Step 1 ＝[Step 1 ]＝0
n_Step 2 ＝[Step 2 ]＝6
wherein T is a first envelope gradient, ave_T 1 For the gradient mean value of the first envelope gradient at 5 position points before and after the first starting point, ave_t 2 For the gradient mean value of the first envelope gradient at 5 position points before and after the first end point, mu T Is gradient mean value, sigma T Is the standard deviation of gradient, X 1 For a first starting point, X 2 For the first end point, P is the gradient duty cycle, n_step 1 For the first adjustment step length of 0, n_step 2 For a second adjustment step size of 6.
Step (8): the computer equipment receives the second starting point of the window according to the second starting point of the interception windowAnd a second termination point, intercepting the cylinder cover vibration acceleration signal to obtain an impact signal CJ 1 。
Step (9): for the impact signal CJ 1 And setting zero to obtain a new cylinder cover vibration acceleration signal to be intercepted. And the computer equipment continues to execute the steps 103 to 108 on the new cylinder cover vibration acceleration signal to be intercepted to obtain a new impact signal.
In the embodiment of the application, the computer equipment repeats steps 103 to 108 on the cylinder cover vibration acceleration signal after the zero setting process; the computer device determines a new first peak value F 2 =60.8 and the first peak position SP F2 =479; the computer device determines the new first start point and the first end point to be 2X by equation seven 1 =394 and 2X 2 =612. The computer device determines the gradient duty cycle p= 74.89%<80%, a first adjustment step size and a second adjustment step size are determined.
The computer device adjusts the first starting point through a first adjustment step length and adjusts the first ending point through a second adjustment step length: [394+n_step 1 ,612-n_Step 2 ]＝[399,606]The adjusted gradient duty cycle p= 78.85% was determined <80%, the condition that P is more than or equal to 80% is not met, the first starting point is continuously adjusted through the first adjusting step length, and the first ending point is adjusted through the second adjusting step length to obtain [403,601 ]]The readjusted gradient duty cycle p= 82.41% was calculated>80 percent, satisfies P not less than 80 percent, and obtains the impact signal CJ 2 。
It should be noted that Step is determined in the seventh equation 1 And Step 2 Log function of Log 2 。
Formula seven:
Lt＝2(μ T +3σ T )＝2×5.1307＝10.26
ω＝X 2 -X 1 ＝612-394＝218
Ave_T 1 <Lt,Ave_T 2 <Lt
Step 1 ＝1+log 2 [ωρ 1 (1-P)+1]＝1+log 2 [218×0.3172×(1-74.89％)+1]＝5.20
Step 2 ＝1+log 2 [ωρ 2 (1-P)+1]＝1+log 2 [218×0.6828×(1-74.89％)+1]＝6.26
n_Step 1 ＝[Step 1 ]＝5
n_Step 2 ＝[Step 2 ]＝6
wherein T is a first envelope gradient, ave_T 1 For the gradient mean value of the first envelope gradient at 5 position points before and after the first starting point, ave_t 2 For the gradient mean value of the first envelope gradient at 5 position points before and after the first end point, mu T Is gradient mean value, sigma T Is the standard deviation of gradient, X 1 For a first starting point, X 2 X is the first end point Tmax X is the location point of maximum first envelope gradient Tmin The position point of the minimum first envelope gradient, P is the gradient duty ratio, n_step 1 For a first adjustment Step, n_step 2 For a second adjustment step.
Step 10: the computer equipment repeats the impact signal CJ of the cylinder cover vibration acceleration signal of the diesel engine obtained in the step 9 1 ，CJ 2 ，CJ 3 As shown in fig. 8.
The method for intercepting the vibration signal of the internal combustion engine by using the computer equipment is used for intercepting the ignition impact signal in the vibration signal of the internal combustion engine, and the ignition impact of the internal combustion engine is monitored.
In the embodiment of the application, since the ignition phase of the internal combustion engine is at a specific crank angle, the vibration signal is intercepted in a whole period according to the working period of the internal combustion engine, the vibration signal sequence is converted into the crank angle, and if no ignition impact occurs in the ignition phase, the fire fault is diagnosed.
For example, a 20 cylinder 4 stroke MTU965TB33 diesel engine B9 cylinder head vibration signal is selected, FIG. 9 is a vibration signal of a normal cylinder head of the diesel engine, and FIG. 10 is a normal shock signal intercepted by the method of intercepting a vibration signal of the present application. Fig. 11 is a vibration signal of a misfire fault of a diesel engine, and fig. 12 is a shock waveform under the misfire fault intercepted by the method of intercepting a vibration signal of the present application. The computer device determines that no firing pulse has occurred in the firing phase as determined by the absence of a firing waveform taken in fig. 12, diagnosing a misfire fault.
Fig. 13 is a block diagram of an apparatus for intercepting a vibration signal according to an embodiment of the present application. Referring to fig. 13, the apparatus includes:
a first determining module 1301, configured to determine, based on a first sliding window, a plurality of first vibration effective values of a noise signal in the vibration signal to be intercepted, and determine, based on a second sliding window, a plurality of second vibration effective values of the vibration signal;
A second determining module 1302, configured to determine, according to the plurality of first vibration effective values, an effective value average value of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values;
a third determining module 1303 for determining a first peak value of the vibration signal and a first position point of the first peak value;
a fourth determining module 1304, configured to determine a first starting point and a first ending point of the interception window according to the first peak value, the first location point, the effective value mean value, the effective value standard deviation, and the plurality of second vibration effective values;
a fifth determining module 1305, configured to determine a first envelope signal corresponding to the vibration signal, and determine a second envelope signal corresponding to the noise signal;
a sixth determining module 1306, configured to determine a plurality of first envelope gradients of the first envelope signal within the interception window according to the first envelope signal, the first start point, and the first end point, and determine a plurality of second envelope gradients of the noise signal according to the second envelope signal;
an adjusting module 1307, configured to adjust the position of the first start point and the position of the first end point according to the plurality of first envelope gradients and the plurality of second envelope gradients, so as to obtain a second start point and a second end point of the interception window;
The interception module 1308 is configured to intercept the vibration signal according to the second start point and the second end point of the interception window, and obtain an impact signal.
In one possible implementation, the first determining module 1301 includes:
the first determining unit is used for obtaining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted according to the first sliding window through the following formula I;
equation one:
wherein s (k) is a noise signal at a sequence number k; n (N) w I is the serial number of the position point included in the first sliding window, Y is the width of the first sliding window ns (i) And n is the sequence length of the noise signal, and is the first vibration effective value corresponding to the ith position point.
In another possible implementation manner, the first determining module 1301 includes:
a second determining unit, configured to obtain a plurality of second vibration effective values of the vibration signal according to a second sliding window through the following formula two;
formula II:
wherein s (k) is the sequence number kA vibration signal at; n (N) w And i is the serial number of the position point included in the second sliding window, Y (i) is the second vibration effective value corresponding to the serial number i, and n is the sequence length of the vibration signal.
In another possible implementation manner, the second determining module 1302 is configured to determine, according to the plurality of first vibration effective values, an effective value average value of the plurality of first vibration effective values through the following formula three; and determining an effective value standard deviation of the plurality of first vibration effective values by the following formula four;
and (3) a formula III:
equation four:
wherein i is the serial number of the position point included in the first sliding window, Y ns (i) And (3) for the first vibration effective value corresponding to the sequence number i, mu is an effective value mean value, sigma is an effective value standard deviation, and n is the sequence length of the noise signal.
In another possible implementation, the fifth determining module 1305 includes:
a fifth determining unit, configured to determine a first energy operator signal corresponding to the vibration signal according to the following formula five;
performing second-order maximum envelope processing on the first energy operator signal to obtain a first envelope signal;
formula five:
Ψ(i)＝s 2 (i)-s(i+1)s(i-1)，2≤i≤n-1
wherein, ψ is the first energy operator signal, s (i) is the vibration signal at the sequence number i, i is the sequence number of the position point of the vibration signal, and n is the sequence length of the vibration signal.
In another possible implementation manner, the fourth determining module 1304 is configured to determine a plurality of location points corresponding to the plurality of second vibration effective values; responding to the fact that the first peak value is larger than the standard parameter, selecting a first starting point and a first ending point which are closest to the first position point and correspond to the second vibration effective value which are smaller than the standard parameter from the plurality of position points on the left side and the right side of the first position point; the standard parameters are the sum of the mean value of the effective values and three times of standard deviation of the effective values.
In another possible implementation, the sixth determining module 1306 includes:
a sixth determining unit, configured to determine a target envelope signal of the first envelope signal within the interception window according to the first start point and the first end point; performing gradient processing on the target envelope signal through the following formula six to obtain a plurality of first envelope gradients of the first envelope signal in the interception window; formula six:
T(i)＝B(i+1)-B(i),1≤i<n
wherein T is a first envelope gradient, B is a target envelope signal, n is the sequence length of the target envelope signal, and i is the sequence number of the position point of the target envelope signal.
In another possible implementation, the adjusting module 1307 includes:
a third determining unit, configured to determine a gradient mean value of the plurality of second envelope gradients and a gradient standard deviation of the plurality of second envelope gradients according to the plurality of second envelope gradients;
a fourth determination unit configured to determine a plurality of third envelope gradients greater than a sum of a gradient mean and three times a gradient standard deviation from the plurality of first envelope gradients;
the first adjusting unit is used for responding to the fact that the gradient duty ratio is larger than a preset ratio, taking the first starting point as a second starting point and taking the first ending point as a second ending point; the gradient duty ratio is the ratio of the sequence length of the plurality of third envelope gradients to the sequence length of the plurality of first envelope gradients;
The second adjusting unit is used for adjusting the position of the first starting point and the position of the first ending point in response to the gradient duty ratio being smaller than the preset ratio until the gradient duty ratio is larger than the preset ratio, obtaining a third starting point and a third ending point of the interception window, taking the third starting point as the second starting point, and taking the third ending point as the second ending point.
In another possible implementation manner, the second adjusting unit is configured to determine a first adjusting step size of the first starting point and a second adjusting step size of the first ending point through the following formula seven; adjusting the first starting point through a first adjusting step length, and adjusting the first ending point through a second adjusting step length until the gradient duty ratio is larger than a preset ratio to obtain a third starting point and a third ending point of the intercepting window;
formula seven:
Lt＝2(μ T +3σ T )，
ω＝X 2 -X 1 ，
n_Step 1 ＝[Step 1 ],
n_Step 2 ＝[Step 2 ],
wherein T is a first envelope gradient, ave_T 1 For the gradient mean value of the first envelope gradient at 5 position points before and after the first starting point, ave_t 2 Ladder for 5 position points before and after the first end point for the first envelope gradientDegree mean, mu T Is gradient mean value, sigma T Is the standard deviation of gradient, X 1 For a first starting point, X 2 X is the first end point Tmax X is the location point of maximum first envelope gradient Tmin The position point of the minimum first envelope gradient, P is the gradient duty ratio, n_step 1 For a first adjustment Step, n_step 2 For a second adjustment step.
In another possible implementation, the apparatus further includes:
and the cancellation module is used for canceling interception of the vibration signal if the gradient duty ratio is not larger than the preset ratio after the position of the first starting point and the position of the first ending point are adjusted.
In the embodiment of the application, a first starting point and a first ending point of the interception window are determined, and the position of the first starting point and the position of the first ending point are adjusted according to a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals to obtain a second starting point and a second ending point of the interception window; and intercepting the vibration signal according to the second starting point and the second ending point of the intercepting window to obtain an impact signal. The first starting point and the first ending point of the interception window are adjusted through a plurality of first envelope gradients corresponding to the vibration signals and a plurality of second envelope gradients corresponding to the noise signals; therefore, the impact signals in the vibration signals are intercepted through the intercepting window with adjustable width, and the accuracy of the obtained impact signals is high.
The foregoing description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, since it is intended that all modifications, equivalents, improvements, etc. that fall within the spirit and scope of the invention.

Claims (10)

1. A method of intercepting a vibration signal, the method comprising:
determining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted based on a first sliding window, and determining a plurality of second vibration effective values of the vibration signals based on a second sliding window;
determining an effective value average value of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values according to the plurality of first vibration effective values;
determining a first peak value of the vibration signal and a first location point of the first peak value;
determining a first starting point and a first ending point of the interception window according to the first peak value, the first position point, the effective value mean value, the effective value standard deviation and the plurality of second vibration effective values;
determining a first envelope signal corresponding to the vibration signal and determining a second envelope signal corresponding to the noise signal;
Determining a plurality of first envelope gradients of the first envelope signal within the intercept window from the first envelope signal, the first start point, and the first end point, and a plurality of second envelope gradients of the noise signal from the second envelope signal;
according to the first envelope gradients and the second envelope gradients, the positions of the first starting point and the first ending point are adjusted to obtain a second starting point and a second ending point of the intercepting window;
intercepting the vibration signal according to a second starting point and a second ending point of the intercepting window to obtain an impact signal;
the adjusting the position of the first starting point and the position of the first ending point according to the first envelope gradients and the second envelope gradients to obtain a second starting point and a second ending point of the interception window includes:
determining a gradient mean value of the plurality of second coating gradients and a gradient standard deviation of the plurality of second coating gradients according to the plurality of second coating gradients;
determining a plurality of third envelope gradients from the plurality of first envelope gradients that is greater than a sum of the gradient mean and three times the gradient standard deviation;
In response to the gradient duty cycle being greater than a preset ratio, taking the first starting point as the second starting point and the first ending point as the second ending point; the gradient duty cycle is the ratio of the sequence length of the plurality of third envelope gradients to the sequence length of the plurality of first envelope gradients;
and adjusting the position of the first starting point and the position of the first ending point until the gradient duty ratio is smaller than the preset ratio to obtain a third starting point and a third ending point of the intercepting window, wherein the third starting point is used as the second starting point, and the third ending point is used as the second ending point.
2. The method of claim 1, wherein determining a plurality of first vibration significance values of a noise signal in the vibration signal to be intercepted based on the first sliding window comprises:
according to a first sliding window, obtaining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted through the following formula I;
equation one:
wherein,for serial number->A noise signal at; />For the width of the first sliding window, < > >For the serial number of the location point comprised in said first sliding window +.>Is->First vibration effective value corresponding to each position point, < >>Is the sequence length of the noise signal.
3. The method of claim 1, wherein determining a plurality of second vibration effective values of the vibration signal based on a second sliding window comprises:
obtaining a plurality of second vibration effective values of the vibration signal according to a second sliding window through the following formula II;
formula II:
wherein,for serial number->A vibration signal at; />For the width of the second sliding window, < >>For the serial number of the location point comprised in said second sliding window +.>For serial number->Second vibration effective value corresponding to the position, < >>For the sequence length of the vibration signal.
4. The method of claim 1, wherein determining an effective value mean of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values from the plurality of first vibration effective values comprises:
according to the plurality of first vibration effective values, determining an effective value average value of the plurality of first vibration effective values through the following formula III; and determining an effective value standard deviation of the plurality of first vibration effective values by the following formula four;
And (3) a formula III:
equation four:
wherein,for the serial number of the location point comprised in said first sliding window +.>For serial number->A corresponding first vibration effective value, < >>For the mean value of the effective value, +.>For the effective value standard deviation, +.>Is the sequence length of the noise signal.
5. The method of claim 1, wherein determining a first envelope signal corresponding to the vibration signal comprises:
determining a first energy operator signal corresponding to the vibration signal through the following formula five;
performing second-order maximum envelope processing on the first energy operator signal to obtain a first envelope signal;
formula five:
wherein, thereinFor said first energy operator signal, < >>For serial number->Vibration signal of place,/->For the serial number of the location point of the vibration signal, < >>For the sequence length of the vibration signal.
6. The method of claim 1, wherein said determining a first start point and a first end point of the intercept window based on said first peak, said first location point, said effective value mean and said effective value standard deviation, and said plurality of second vibration effective values comprises:
determining a plurality of position points corresponding to the plurality of second vibration effective values;
Responding to the fact that the first peak value is larger than a standard parameter, selecting a first starting point and a first ending point which are closest to the first position point and correspond to the second vibration effective value which are smaller than the standard parameter from the plurality of position points on the left side and the right side of the first position point; the standard parameter is the sum of the effective value mean and three times of the effective value standard deviation.
7. The method of claim 1, wherein said determining a plurality of first envelope gradients of said first envelope signal within said intercept window from said first envelope signal, said first start point and said first end point comprises:
determining a target envelope signal of the first envelope signal in the interception window according to the first starting point and the first ending point;
performing gradient processing on the target envelope signal through the following formula six to obtain a plurality of first envelope gradients of the first envelope signal in the interception window;
formula six:
wherein,for the first envelope gradient, +.>For the target envelope signal, < >>For the sequence length of the target envelope signal, < > is>Is the sequence number of the location point of the target envelope signal.
8. The method of claim 1, wherein said adjusting the position of the first start point and the position of the first end point until the gradient duty cycle is greater than the preset ratio, obtaining a third start point and a third end point of the clipping window, comprises:
determining a first adjustment step size of the first starting point and a second adjustment step size of the first ending point through the following formula seven;
adjusting the first starting point through the first adjusting step length, and adjusting the first ending point through the second adjusting step length until the gradient duty ratio is larger than the preset ratio to obtain a third starting point and a third ending point of the intercepting window;
formula seven:
wherein,for the first envelope gradient，/>For the gradient mean value of the first envelope gradient at 5 position points before and after the first starting point>For the gradient mean value of the first envelope gradient at 5 position points before and after the first end point,/for the first envelope gradient>For the gradient mean ∈>For the gradient standard deviation +.>For the first starting point,/>As a consequence of the first end point,for the location point of maximum first envelope gradient, < >>For the location point of the smallest first envelope gradient, < > >For the gradient duty cycle +.>For the first adjustment step, +.>And (5) adjusting the step length for the second step length.
9. The method according to claim 1, wherein the method further comprises:
and if the position of the first starting point and the position of the first ending point are adjusted, the gradient duty ratio is not larger than the preset ratio, and interception of the vibration signal is canceled.
10. An apparatus for intercepting a vibration signal, the apparatus comprising:
the first determining module is used for determining a plurality of first vibration effective values of noise signals in the vibration signals to be intercepted based on a first sliding window and a plurality of second vibration effective values of the vibration signals based on a second sliding window;
the second determining module is used for determining an effective value average value of the plurality of first vibration effective values and an effective value standard deviation of the plurality of first vibration effective values according to the plurality of first vibration effective values;
a third determining module for determining a first peak value of the vibration signal and a first location point of the first peak value;
a fourth determining module, configured to determine a first starting point and a first ending point of the interception window according to the first peak value, the first location point, the effective value mean value, the effective value standard deviation, and the plurality of second vibration effective values;
A fifth determining module, configured to determine a first envelope signal corresponding to the vibration signal, and determine a second envelope signal corresponding to the noise signal;
a sixth determining module, configured to determine a plurality of first envelope gradients of the first envelope signal within the interception window according to the first envelope signal, the first start point, and the first end point, and determine a plurality of second envelope gradients of the noise signal according to the second envelope signal;
the adjusting module is used for adjusting the position of the first starting point and the position of the first ending point according to the first envelope gradients and the second envelope gradients to obtain a second starting point and a second ending point of the interception window;
the intercepting module is used for intercepting the vibration signal according to the second starting point and the second ending point of the intercepting window to obtain an impact signal;
the adjustment module comprises:
a third determining unit, configured to determine a gradient mean value of the plurality of second envelope gradients and a gradient standard deviation of the plurality of second envelope gradients according to the plurality of second envelope gradients;
a fourth determining unit configured to determine a plurality of third envelope gradients greater than a sum of the gradient mean and three times the gradient standard deviation from the plurality of first envelope gradients;
The first adjusting unit is used for responding to the fact that the gradient duty ratio is larger than a preset ratio, taking the first starting point as the second starting point and taking the first ending point as the second ending point; the gradient duty cycle is the ratio of the sequence length of the plurality of third envelope gradients to the sequence length of the plurality of first envelope gradients;
and the second adjusting unit is used for adjusting the position of the first starting point and the position of the first ending point in response to the gradient duty ratio being smaller than the preset ratio until the gradient duty ratio is larger than the preset ratio, obtaining a third starting point and a third ending point of the intercepting window, taking the third starting point as the second starting point and taking the third ending point as the second ending point.
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