CN105157820B - A kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam - Google Patents
A kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam Download PDFInfo
- Publication number
- CN105157820B CN105157820B CN201510197209.6A CN201510197209A CN105157820B CN 105157820 B CN105157820 B CN 105157820B CN 201510197209 A CN201510197209 A CN 201510197209A CN 105157820 B CN105157820 B CN 105157820B
- Authority
- CN
- China
- Prior art keywords
- frequency
- degree
- spectrum
- harmonics
- fence
- 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.)
- Active
Links
Landscapes
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention discloses a kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam, it is characterised in that comprises the following steps：Vibration signal power spectrum G (ω) first derivative or second dervative is calculated, obtains composing mutation degree ab(ω) or prompt degree ag(ω)；The threshold value of setting spectrum mutation degree or prompt degree is respectively ab‑maxAnd ag‑max；Find ab(ωi)=ab‑maxOr ag(ωi)=ag‑maxThe Frequency point ω at placei；Find Frequency point ωiFirst spectrum mutation degree is negative or Frequency point ω afterwardsiThe 3rd prompt degree is negative frequency point ω afterwardsj, Frequency point ωjAs harmonics frequencies omegah；Pass through the harmonics frequencies omega of identificationhBuild frequency fence seam and reject all harmonics frequencies, obtain the true intrinsic frequency of mechanical structure.This method detection accuracy is high, can obtain the structural natural frequencies of mechanical structure in the operating condition, be mechanical structure ONLINE RECOGNITION and monitoring, and structural damage recognizes etc. and to provide strong means.
Description
Technical field
The invention belongs to the dynamic analysis field of mechanized equipment structure, more particularly, to one kind based on spectrum derivative and
The harmonics frequency identification and elimination method of frequency fence seam.
Background technology
It is most important to improve its service behaviour for improving vibration resistance for the dynamics of mechanical structure.ONLINE RECOGNITION
During mechanical structure dynamics, it will usually by the severe jamming of the periodic signals such as power supply power frequency component, rotary part, so that
The intrinsic frequency of mechanism in itself is flooded.At present, the processing for these periodic signals is all generally that the original signal of collection is entered
The special filtering of row, so as to filter periodic signal, but when the intrinsic frequency and the fundamental frequency of periodic signal of structure or its frequency multiplication connect
When near, filtering method is likely to also filter out the intrinsic frequency of structure, so as to cause the loss of structural dynamic characteristics.Separately
Outside, the rotating speed of rotary part may change in the course of the work, the fundamental frequency and its frequency multiplication of its caused periodic vibration signal
Also can change therewith, it is difficult to automatic identification.
It is automatic accurate with the premise of unknown vibration signal frequency composition therefore, it is necessary to propose a kind of new method
Ground identifies and rejects the harmonics frequency of interference signal, while preserves the intrinsic frequency information of mechanical structure.
The content of the invention
For the disadvantages mentioned above and/or Improvement requirement of prior art, the invention provides one kind based on spectrum derivative and frequency
The harmonics frequency identification and elimination method of fence seam, its mode stitched by using spectrum derivative combination frequency fence realize harmonics frequency
Rate accurately identifying and rejecting, and can correspondingly obtain the true intrinsic frequency of lathe in the operating condition, thus especially suitable
In in unknown vibration signal frequency composition, and in the case that harmonics frequency signal changes often, accurate to obtain mechanism truly intrinsic
The occasions such as frequency.
To achieve the above object, the present invention propose it is a kind of based on spectrum derivative and frequency fence seam harmonics frequency identification and
Elimination method, it is characterised in that comprise the following steps：
Step (1)：To the mechanical structure as measurement object, its vibration response signal is tested to obtain vibration response signal
Power spectrum G (ω), vibration response signal power spectrum G (ω) first derivative or second dervative are then calculated, is derived from
Compose mutation degree ab(ω) or prompt degree ag(ω), while identify the natural frequency ω of all mode of mechanical structurej, then utilize spectrum
Mutation degree ab(ω) or prompt degree ag(ω) identifies the harmonics frequency of interference signal from vibration response signal power spectrum G (ω)
ωh, wherein ω represents frequency；
Step (2)：Pass through the harmonics frequencies omega of identificationhStructure frequency fence is stitched to complete operation in detail below：
Step (2-1)：The centre frequency that frequency fence stitches is preset as ωref, frequency domain width be 2 Δ ω；
Step (2-2)：Build frequency fence seam [ωref–Δω,ωref+ Δ ω], wherein ωref=n ωh, n is just whole
Number；
Step (2-3)：The frequency fence seam built with step (2-2) is all described intrinsic to what is identified in step (1)
Frequencies omegajFiltration treatment is performed, obtains the filter result of true intrinsic frequency for reflecting the mechanical structure.
As it is further preferred that the step (1) includes following sub-step：
Step (1-1)：Vibration signal power spectrum G (ω) first derivative or second dervative is calculated, obtains composing mutation degree ab
(ω) or prompt degree ag(ω), it is as follows：
Or
Step (1-2)：The threshold value of setting spectrum mutation degree or prompt degree is respectively ab-maxAnd ag-max, wherein, it is prominent to obtain the spectrum
Variation ab(ω) or prompt degree agThe standard deviation of each numerical value of (ω) on frequency domain axle at each Frequency point, ab-maxOr ag-maxIt is set to
3 times of respective above-mentioned standard difference；
Step (1-3)：Find spectrum mutation degree ab(ωi)=ab-maxOr prompt degree ag(ωi)=ag-maxThe Frequency point ω at placei；
Step (1-4)：Find the Frequency point ωiAfterwards first spectrum mutation degree be negative value or Frequency point ωi3rd victory afterwards
Spend the Frequency point ω for negative valuej, Frequency point ωjAs harmonics frequencies omegah。
As it is further preferred that the Δ ω is preferably set to 0.25Hz.
In general, by the contemplated above technical scheme of the present invention compared with prior art, mainly possess following
Technological merit：
1. first, the present invention is solved in on-line measurement, measurement signal is often subject to AC power frequency signal and periodic motion
Part harmonic wave interference and cause model analysis the problem of false mode occur, can be in unknown vibration signal frequency composition, and believe
In the case that harmonics in number changes often, accurately identify and reject the harmonics frequency in vibration signal, it is effective to weaken online
The interference of AC power frequency signal and rotary part periodic vibration signal to Modal Parameter Identification in measurement process, improve model analysis
Accuracy.
Secondly, human error caused by rejecting harmonics frequency by experience this invention removes operating personnel, detection efficiency
Height, the structural modal intrinsic frequency of mechanical structure in the operating condition can be obtained, be mechanical structure ONLINE RECOGNITION and monitoring, and
Structural damage identification etc. provides strong instrument.
Brief description of the drawings
Fig. 1 is vibration signal power spectrum, spectrum mutation degree and prompt degree schematic diagram；
Fig. 2 is frequency fence seam schematic diagram；
Fig. 3 is vibration signal power spectrum under lathe operating mode, spectrum mutation degree and prompt degree instance graph.
Embodiment
In order to make the purpose , technical scheme and advantage of the present invention be clearer, it is right below in conjunction with drawings and Examples
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.As long as in addition, technical characteristic involved in each embodiment of invention described below
Conflict can is not formed each other to be mutually combined.
The present invention a kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam, this method, which calculates, shakes
The first derivative (referred to as composing mutation degree) or second dervative (being referred to as prompt degree) of the power spectrum of dynamic original signal, according to spectrum mutation degree
Or there is the feature of extreme value near the harmonics frequency of periodic signal in prompt degree, can be accurately positioned harmonics Frequency point, such as Fig. 1；So
The characteristic of spike is occurred at fundamental frequency and its integral multiple (i.e. frequency multiplication) place of periodic signal according to the power spectrum of vibration original signal afterwards, if
Put the frequency fence seam of frequency domain narrower in width, the harmonics frequency that integral filter is identified, such as Fig. 2；As seen from Figure 1,3.2,4,
5th, near the harmonic frequency such as 8 and 12Hz, the mutation degree of response signal power spectrum shows " N " shape, it may appear that obvious positive and negative two
Individual kurtosis, and just the first mutation degree between two spikes is the point of negative value to harmonic frequency, because before harmonic frequency
The power spectral value of several points suddenly increases, therefore the power spectrum first derivative at these points is local positive number maximum, and harmonic wave
The starting point suddenly to diminish for power spectrum at frequency, therefore the first derivative at this point is the first negative value after positive number maximum；
And the power spectral value of several points is still also big at the Amplitude Ratio harmonic frequency point for reducing rapidly and reducing after harmonic frequency, therefore
The negative maximum in current situation portion can be pointed out at these.And the prompt degree of power spectrum shows " M " shape near harmonic frequency, to prompt degree
Change analyzed knowable to, harmonic frequency is the point that the 3rd prompt degree is negative value after first spike.And in other frequencies
At point, power spectrum change is little, and mutation degree and prompt degree are all average level.As can be seen here, the mutation degree near harmonic frequency and
For prompt degree with significantly different at other Frequency points, mutation degree shows " N " shape, and prompt degree shows " M " shape.The essence of this phenomenon is
Forced vibration response (or AC power power frequency component) does not have damping characteristic, causes the power spectrum to be at fundamental frequency and its frequency multiplication
Reveal the spike of mutation, therefore, this rule has popularity and certainty.Meanwhile harmonic frequency point is in mutation degree and prompt degree
In position be to determine again, i.e., the first negative value point after first spike of " N " shape mutation degree, " M " shape victory first spike of degree
The 3rd prompt degree is the point of negative value afterwards.Therefore, sound can be positioned by composing mutation degree or prompt degree according to these rules and characteristic
Harmonic frequency point in induction signal power spectrum, realize and search frequency fence seam center frequency automatically in the case of without pre-known information
Rate, while the harmonics frequency for coordinating the seam filtering of frequency fence to identify, you can reach before unknown vibration signal frequency composition
Put, automatically and accurately identify and reject interference signal harmonics frequency simultaneously storage configuration intrinsic frequency information purpose.
Embodiment 1：
A kind of harmonics frequency identification and elimination method based on spectrum mutation degree and frequency fence seam, comprise the following steps：
(1) X and Y-direction of the lathe under machining state vibration response signal are measured, obtains X and the vibration letter of Y-direction
Power frequency spectrum G (ω), wherein, signal sampling frequencies 1024Hz；And identify the natural frequency ω of all modej, utilize spectrum
Mutation degree identifies harmonics frequencies omega from vibration signal power spectrum G (ω)h；
(1-1) calculates vibration signal power spectrum G (ω) of the lathe under machining state first derivative, that is, composes mutation degree ab
(ω), such as Fig. 3, its frequency domain section is identical with vibration signal power spectrum G (ω) frequency domain section, is the one of signal sampling frequencies
Half；
The threshold value a of (1-2) setting spectrum mutation degreebmaxEqual to each frequency point spectrum mutation degree ab3 times of the standard deviation of (ω)；
(1-3) finds spectrum mutation degree ab(ωi)=ab-maxThe frequencies omega at placei；
(1-4) finds frequencies omegaiFirst spectrum mutation degree is the Frequency point ω of negative value afterwardsj, it is respectively 0.25,5.25,
16.75,33.25,200,300 and 321Hz, these frequencies be harmonics frequencies omegah；
(2) the harmonics frequencies omega of identification is passed throughhBuild frequency fence seam and reject all harmonics frequencies
The Δ ω of frequency domain width 2 of (2-1) setpoint frequency fence seam is 3Hz；
(2-2) frequencies omega centered on the harmonics frequency identified in step (1-4) respectivelyref, structure frequency fence seam
[ωref–Δω,ωref+ Δ ω], wherein ωref=n ωh, n=1,2,3 ...；
All natural frequency ωs that (2-3) is identified with the frequency fence seam filtering of structurej, you can obtain the true of structure
Intrinsic frequency.
Embodiment 2：
A kind of harmonics frequency identification stitched based on Jie Du and frequency fence and elimination method, are comprised the following steps：
(1) X and Y-direction of the lathe under machining state vibration response signal are measured, obtains X and the vibration letter of Y-direction
Power frequency spectrum G (ω), wherein, signal sampling frequencies 1024Hz；And identify the natural frequency ω of all modej, utilize victory
Degree identifies harmonics frequencies omega from vibration signal power spectrum G (ω)h；
(1-1) calculates vibration signal power spectrum G (ω) of the lathe under machining state second dervative, i.e., prompt degree ag
(ω), such as Fig. 3, its frequency domain section is identical with vibration signal power spectrum G (ω) frequency domain section, is the one of signal sampling frequencies
Half；
(1-2) sets the threshold value a of prompt degreeg-maxEqual to each Frequency point victory degree ag3 times of the standard deviation of (ω)；
(1-3) finds prompt degree ag(ωi)=ag-maxThe frequencies omega at placei；
(1-4) finds ωiThe 3rd prompt degree is the point of negative value afterwards, respectively 0.25,5.25,16.75,33.25,200,
300 and 321Hz, these frequencies are harmonics frequencies omegah；
(2) the harmonics frequencies omega of identification is passed throughhBuild frequency fence seam and reject all harmonics frequencies：
(2-1) setpoint frequency fence seam half-breadth Δ ω is 1.5Hz；
(2-2) frequencies omega centered on the harmonics frequency identified in (1-4) respectivelyh, structure frequency fence seam [ωref–
Δω,ωref+ Δ ω], wherein：ωref=n ωh, n=1,2,3 ...；
All natural frequency ωs that (2-3) is identified with the frequency fence seam filtering of structurejIt can obtain the true of structure
Intrinsic frequency.
As it will be easily appreciated by one skilled in the art that the foregoing is merely illustrative of the preferred embodiments of the present invention, not to
The limitation present invention, all any modification, equivalent and improvement made within the spirit and principles of the invention etc., all should be included
Within protection scope of the present invention.
Claims (2)
1. a kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam, it is characterised in that including as follows
Step：
Step (1)：To the mechanical structure as measurement object, its vibration response signal is tested to obtain vibration response signal power
G (ω) is composed, then calculates vibration response signal power spectrum G (ω) first derivative or second dervative, it is prominent to be derived from spectrum
Variation ab(ω) or prompt degree ag(ω), while identify the natural frequency ω of all mode of mechanical structurej, then utilize spectrum mutation
Spend ab(ω) or prompt degree ag(ω) identifies the harmonics frequencies omega of interference signal from vibration response signal power spectrum G (ω)h, its
Middle ω represents frequency；Specifically include following sub-step：
Step (1-1)：Vibration signal power spectrum G (ω) first derivative or second dervative is calculated, obtains composing mutation degree ab(ω) or
Prompt degree ag(ω), it is as follows：
Or
Step (1-2)：The threshold value of setting spectrum mutation degree or prompt degree is respectively ab-maxAnd ag-max, wherein, obtain the spectrum mutation degree
ab(ω) or prompt degree agThe standard deviation of each numerical value of (ω) on frequency domain axle at each Frequency point, ab-maxOr ag-maxIt is set to respective
3 times of above-mentioned standard difference；
Step (1-3)：Find spectrum mutation degree ab(ωi)=ab-maxOr prompt degree ag(ωi)=ag-maxThe Frequency point ω at placei；
Step (1-4)：Find the Frequency point ωiAfterwards first spectrum mutation degree be negative value or Frequency point ωiThe 3rd prompt degree is afterwards
The Frequency point of negative value, the Frequency point are harmonics frequencies omegah；
Step (2)：Pass through the harmonics frequencies omega of identificationhStructure frequency fence is stitched to complete operation in detail below：
Step (2-1)：The centre frequency that frequency fence stitches is preset as ωref, frequency domain width be 2 Δ ω；
Step (2-2)：Build frequency fence seam [ωref–Δω,ωref+ Δ ω], wherein ωref=n ωh, n is positive integer；
Step (2-3)：The frequency fence built with step (2-2) stitches all intrinsic frequencies to being identified in step (1)
ωjFiltration treatment is performed, obtains the filter result of true intrinsic frequency for reflecting the mechanical structure.
2. a kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam as claimed in claim 1, its
It is characterised by, the Δ ω is set as 0.25Hz.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510197209.6A CN105157820B (en) | 2015-04-24 | 2015-04-24 | A kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510197209.6A CN105157820B (en) | 2015-04-24 | 2015-04-24 | A kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105157820A CN105157820A (en) | 2015-12-16 |
| CN105157820B true CN105157820B (en) | 2018-01-26 |
Family
ID=54798759
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510197209.6A Active CN105157820B (en) | 2015-04-24 | 2015-04-24 | A kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105157820B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105628185B (en) * | 2015-12-28 | 2018-11-06 | 江西飞尚科技有限公司 | A kind of vibrating wire sensor frequency tripling screen method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101354315A (en) * | 2008-09-05 | 2009-01-28 | 爱立迈科（宁波）计测仪器有限公司 | Device and method for tracking and detecting engine state based on vibration signal |
| CN104198031A (en) * | 2014-07-30 | 2014-12-10 | 东风康明斯发动机有限公司 | Torsional vibration signal detection method and device for engine crankshaft |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1338873A1 (en) * | 2000-11-06 | 2003-08-27 | NSK Ltd., | Abnormality diagnosing device and method for mechanical equipment |
-
2015
- 2015-04-24 CN CN201510197209.6A patent/CN105157820B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101354315A (en) * | 2008-09-05 | 2009-01-28 | 爱立迈科（宁波）计测仪器有限公司 | Device and method for tracking and detecting engine state based on vibration signal |
| CN104198031A (en) * | 2014-07-30 | 2014-12-10 | 东风康明斯发动机有限公司 | Torsional vibration signal detection method and device for engine crankshaft |
Non-Patent Citations (2)
| Title |
|---|
| Estimation of CNC machine–tool dynamic parameters based on random cutting excitation through operational modal analysis;Bin Li等;《International Journal of Machine Tools & Manufacutre》;20130417;第71卷;全文 * |
| Estimation of FRFs of machine tools in output-only modal analysis;Hui Cai等;《Int J Adv Manuf Technol》;20141010;第77卷;全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105157820A (en) | 2015-12-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Garcia-Perez et al. | The application of high-resolution spectral analysis for identifying multiple combined faults in induction motors | |
| Soualhi et al. | Detection and diagnosis of faults in induction motor using an improved artificial ant clustering technique | |
| Vitek et al. | Detection of eccentricity and bearings fault using stray flux monitoring | |
| Bacha et al. | An improved combination of Hilbert and Park transforms for fault detection and identification in three-phase induction motors | |
| CN102706560B (en) | The state monitoring method and device of a kind of wind power generating set | |
| CN108169583B (en) | Autotransformer direct-current magnetic bias discrimination method and system with neutral point grounded through capacitor | |
| AU2013301993B2 (en) | Method and apparatus for determining a frequency line pattern within at least one amplitude spectrum | |
| CN110058157B (en) | Motor monitoring method and system based on symmetric component method and multi-dimensional index fusion | |
| Samanta et al. | Minimum distance-based detection of incipient induction motor faults using Rayleigh quotient spectrum of conditioned vibration signal | |
| Tian et al. | A review of fault diagnosis for traction induction motor | |
| CN105157820B (en) | A kind of harmonics frequency identification and elimination method based on spectrum derivative and frequency fence seam | |
| Ondel et al. | Fault detection and diagnosis in a set “inverter–induction machine” through multidimensional membership function and pattern recognition | |
| CN109934136B (en) | Rolling bearing fault diagnosis method based on Duffing vibrator and eigen mode component | |
| Frosini et al. | Multiple faults detection in low voltage inverter-fed induction motors | |
| CN105606894B (en) | Instantaneous Frequency Estimation method based on simulated annealing | |
| Kabul et al. | An alternative approach for the detection of broken rotor bars and bearing faults of induction motor based on vibration signals | |
| Pandarakone et al. | Fault classification of outer-race bearing damage in low-voltage induction motor with aid of fourier analysis and SVM | |
| Zarei et al. | Broken rotor bars detection via Park's vector approach based on ANFIS | |
| CN109001556B (en) | Discrimination method and system for forced ultralow frequency oscillation | |
| Yang et al. | Condition monitoring and fault diagnosis of generators in power networks | |
| JP6646416B2 (en) | Rotating machine short circuit diagnosis apparatus and rotating machine short circuit diagnosis method | |
| CN103746372B (en) | The on-line automatic identification method of power grid oscillation mode type and association dispatcher-controlled territory | |
| CN102680080A (en) | Unsteady-state signal detection method based on improved self-adaptive morphological filtering | |
| Lindh et al. | Automatic bearing fault classification combining statistical classification and fuzzy logic | |
| CN105628380B (en) | A kind of Fault Classification of adjustable middle intelligence model bearing fault grader |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |