CN110084127A - A kind of magnetic suspension rotor vibration measurement method of view-based access control model - Google Patents

A kind of magnetic suspension rotor vibration measurement method of view-based access control model Download PDF

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CN110084127A
CN110084127A CN201910246595.1A CN201910246595A CN110084127A CN 110084127 A CN110084127 A CN 110084127A CN 201910246595 A CN201910246595 A CN 201910246595A CN 110084127 A CN110084127 A CN 110084127A
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phase
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CN110084127B (en
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彭聪
曾聪
江驹
王雁刚
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Nanjing University of Aeronautics and Astronautics
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H9/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/20—Analysis of motion
    • G06T7/269—Analysis of motion using gradient-based methods
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/40—Analysis of texture
    • G06T7/41—Analysis of texture based on statistical description of texture
    • G06T7/42—Analysis of texture based on statistical description of texture using transform domain methods
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V10/00—Arrangements for image or video recognition or understanding
    • G06V10/40—Extraction of image or video features
    • G06V10/44—Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components
    • G06V10/443—Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components by matching or filtering
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
    • G06V20/00—Scenes; Scene-specific elements
    • G06V20/40—Scenes; Scene-specific elements in video content
    • G06V20/46—Extracting features or characteristics from the video content, e.g. video fingerprints, representative shots or key frames

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Abstract

The present invention discloses a kind of magnetic suspension rotor vibration measurement method of view-based access control model, acquires vibration video of the magnetic suspension rotor under different working condition by being equipped with the high speed camera of optical lens first；Then it uses the steerable pyramid constructed based on Gabor filter that image space domain information is converted to the image frequency domain information of different scale, different directions, the vibration displacement signal of magnetic suspension motor is extracted further according to the local phase change in image frequency domain information；Then second order derivation is carried out to the vibration displacement signal using LOG operator, acceleration signal is calculated；Fast Fourier Transform finally is carried out to the acceleration signal and obtains target spectrum figure.The present invention has given full play to the advantages of vision measurement, can measurement of full field, can only change algorithm under the configuration and mounting condition for not changing existing equipment and be obtained with the information of different dimensions, it is adaptable.

Description

A kind of magnetic suspension rotor vibration measurement method of view-based access control model
Technical field
The present invention relates to a kind of magnetic suspension rotor vibration measurement methods of view-based access control model, belong to technical field of visual measurement.
Background technique
Increasingly mature with magnetic levitation technology, magnetic suspension rotor is revolved in the high speed such as magnetic suspension blower, magnetic suspension compressor Turn machinery field to be widely used.Rotor is one of most important component in Magnetic levitation apparatus, due to its complicated machine Electric structure and generate mechanical oscillation.Vibration is an important factor for influencing equipment working state and service life.If without effective Inhibit, badly damaged, or even damaging property consequence may be caused to equipment.Effective measurement of vibration is effective inhibition vibration Dynamic premise.The vibration measurement of slewing can be with identifying system parameter, the working condition of monitoring device, the event of diagnostic device Barrier.Therefore, analysis of vibration measurement occupies increasingly consequence in engineering field, however, exploitation one is adaptable, oneself Dynamicization degree is high, Vibration-Measuring System with high accuracy is still a huge challenge.
From the point of view of existing vibration measurement technique, there are two types of measurement methods: one is contact type measurement, another kind is non-connects Touching measurement.Contact type measurement needs for sensor to be regularly arranged on measurement object by certain, and connects on matched Position machine software.However, contact measurement can generate mass loading effect, it, can only in the case where not providing whole audience spatial resolution Measure the corresponding signal of a single point position.In addition, for some large scale structures, it is time-consuming and consume to handle all wiring and instrument Take manpower.Non-cpntact measurement usually relies on certain electromagnetic radiation to transmit information, and this method and traditional contact measurement method are not Together, different dimension informations can be obtained in the case where not changing existing equipment configuration and installation.For example, being surveyed for vibrating The laser vibration measurer of amount does not need to be mounted on sensor and any quality load effect in structure.However, laser vibration measurer Comparatively more expensive, it is relatively low to big low-frequency vibration treatment effeciency.Digital camera combination image processing algorithm is another Kind non-contact measurement method, the also known as vibration measurement of view-based access control model.Compared to laser vibrometer, digital camera have low cost, The advantages of suitable for measurement of full field.But in the prior art, three-dimensional digital image related (DIC) and the light stream based on intensity of illumination Method etc. is usually used in the measurement of large-amplitude vibration, and rotor oscillation belongs to sub-pix rank small movements, it is difficult to distinguish with noise It opens, and the precision measured with three-dimensional digital image related (DIC) and the optical flow method based on intensity of illumination is lower.Therefore, how high The extraction rotor oscillation signal of precision is the key points and difficulties of research.
Summary of the invention
To solve the above problems, the present invention is under existing vision measuring method, according to the computer theory based on phase, It is proposed a kind of magnetic suspension rotor vibration measurement method of view-based access control model.This method is according to the collected motor oscillating of high speed camera Video sequence, image is changed to frequency domain from transform of spatial domain by design direction steerable pyramid, and utilizes the phase of reference frame and motion frame Position variation relation solves the displacement movement information of interframe, and then the acceleration signal vibrated and is converted into spectrogram, measures The frequency signal of magnetic suspension rotor.
Specific technical solution is as follows:
A kind of magnetic suspension rotor vibration measurement method of view-based access control model, comprising the following steps:
S1. vibration view of the magnetic suspension rotor under different working condition is acquired by being equipped with the high speed camera of optical lens Frequently；
S2. the figure for using the steerable pyramid constructed based on Gabor filter to include by the vibration video Image space domain information is converted to the image frequency domain information of different scale, different directions, according to the part in image frequency domain information The vibration displacement signal of phase change extraction magnetic suspension motor；
S3. second order derivation is carried out to the vibration displacement signal using LOG operator, acceleration signal is calculated；
S4. Fast Fourier Transform is carried out to the acceleration signal and obtains target spectrum figure.
Preferably, the step S2 is specifically included:
S21. Gabor filter is designed as convolution kernel function using Two-Dimensional Gabor Wavelets, is filtered by the Gabor Device is converted into frequency domain information for the video image spatial-domain information that video includes is vibrated；Low pass subband in the frequency domain information Part includes the global information of video image, and high pass subband part includes the detailed information of video image；The Gabor filtering The corresponding two-dimensional Gabor function expression of device is as follows:
Wherein, x and y represents space pixel coordinate；θ ∈ (0 °, 360 °) indicates the side of parallel stripes in Gabor filtering core To；λ is the wavelength of SIN function；ψ is the phase offset for tuning function；γ is space aspect ratio；The mark of σ expression Gaussian function Quasi- deviation；xθAnd yθIndicate the space variable comprising directional information, expression formula is as follows:
xθ=xcos θ+ysin θ, yθ=-xsin θ+ycos θ
S22. linear combination will be carried out with the Gabor filter in multiple and different directions, while scale is carried out to video image Transformation, to construct steerable pyramid；
S23. video image is resolved by different scale by the steerable pyramid, multiple directions include video figure Thus the subband of the structural information of picture and marginal information series completes for the video image information to be transformed into different scale, no Equidirectional frequency domain information；According to the phase difference of two frame of phase calculation of two frames in frequency domain information, corresponding direction is thus obtained Displacement signal.
Preferably, the realization process of the steerable pyramid is as follows:
Video image first passes around high-pass filter H0(ω) and low-pass filter L0(ω) is decomposed into high pass, low pass two A subband；Then low pass subband image is broken down into the band logical subband B of K different directions againk-1(ω) and low pass subband L1 (ω), while to low pass subband L1The row and column of (ω) carries out two sampling again respectively；Above-mentioned decomposable process is repeated after two sampling, Loop iteration, until the one of dimension of row and column not can be carried out down-sampled.
Preferably, the displacement of corresponding direction is obtained according to the phase difference of two frame of phase calculation of two frames in the frequency domain information The calculation of signal is as follows:
Assuming that the time interval between two successive frames of video is Δ t, local motion occurs at spatial position (x, y) (Δ x, Δ y), it is I (x, y, t that first frame, which is defined as image intensity,0) reference frame, by the second frame definition be image intensity I (x+Δx,y+Δy,t0The motion frame of+Δ t)；
Using two-dimensional Gabor function carry out convolution algorithm, by image intensity I (x, y, t) be converted into frequency domain information F (x, y, T) as follows:
It is expressed as follows with the form of integral:
For extracting horizontal motion, space variable is enabled to be expressed as xθ=x, yθ=y, reference frame conversion are as follows:
Motion frame conversion are as follows:
Above-mentioned formula is rearranged, the phase term that will be independent of integration variable is placed on except integral, then simplify formula:
The phase term of two formulas is allTherefore final definite integral result is also identical, is expressed asThe phase angle for calculating two frames is as follows:
The phase difference that two frame of horizontal direction is calculated is:
Thus the displacement signal of corresponding direction is obtained.
Preferably, step S23 further includes being weighted space Gaussian Blur to the phase angle to improve signal-to-noise ratio, specific to wrap It includes:
For nth frame, weighted phases signalIt calculates are as follows:
Wherein, ANIndicate the amplitude of nth frame,Indicate the phase of nth frame；H (x, y) is two-dimensional Gaussian function, is indicated Are as follows:
Wherein, the width of the standard deviation ρ representation space domain filter of Gaussian filter.
Preferably, in step S1, the highest resolution of the high speed camera is 4096 × 3076, can continuously adjust pixel The pixel size of range and the time for exposure of exposure time range, and using LED light as light source.
Preferably, the step S1 is specifically included: be arranged magnetic suspension rotor revolving speed be 6000rpm, 9000rpm, 12000rpm and 15000rpm, the frame rate that high speed camera is arranged is 300fps, 500fps, 600fps and 800fps, and record is simultaneously Save corresponding vibration video sequence.
The magnetic suspension rotor vibration measurement method of view-based access control model proposed by the present invention has following compared to existing technology The utility model has the advantages that
(1) present invention uses the optical flow method based on phase, is no longer based on original pixel intensities value, but passes through analysis chart The phase change of picture moves to extract；Relative to the image change due to contrast and scale generation, image phase information is than figure As the robustness of intensity is stronger.
(2) present invention is different from the methods of traditional contact type measurement and laser interferometry, can not change now Have under configuration and the mounting condition of equipment, only changes the information that algorithm is obtained with different dimensions, it is more adaptable.
Detailed description of the invention
Fig. 1 is vision measurement experiment porch figure；
Fig. 2 is Gabor filter real part imaginary part figure；
Fig. 3 is steerable pyramid structure chart；
Specific embodiment
The magnetic suspension rotor vibration measurement method of view-based access control model proposed by the present invention shakes according to the motor of high speed camera acquisition Dynamic video extracts the vibration of magnetic suspension motor by calculating the local phase change of frequency domain using the optical flow method based on phase Displacement signal；Then second order derivation is carried out to displacement signal and obtains acceleration signal；Finally utilize Fast Fourier Transform (FFT) spectrogram is obtained.The present invention is described in detail with specific implementation step with reference to the accompanying drawing.
The specific implementation method of the magnetic suspension rotor vibration measurement method of view-based access control model disclosed by the invention is as follows:
Step 1: the vibration video with high speed camera acquisition magnetic suspension motor under different working condition.
As shown in Figure 1, needing to build vision measurement platform before acquisition, mainly by magnetic suspension rotor, high speed camera (high quality optical lens are installed), light source, tripod, acceleration transducer, magnetic suspension rotor control platform and be used for data The computer of storage forms.High speed camera used in the present invention is the high-speed camera of IO industrial group, and highest resolution is 4096 × 3076, and the size of any pixel coverage is adjusted.When resolution ratio reduces, the minimum frame week of camera can be increased Phase (maximum frame per second), and recalculate the range of time for exposure.High speed camera is fixed by tripod and is adjusted to position appropriate It sets.Light source is using LED light as light source.In the present embodiment, the vertical range of video camera and magnetic suspension rotor is about 0.8 meter, together When with LED light illuminate magnetic suspension rotor, enough brightness conditions are provided, the quality of shooting image is improved.Acceleration transducer Probe identifies that direction is vertically mounted on motor surface according to it.
Using magnetic suspension rotor control platform control magnetic suspension rotor revolving speed, revolving speed set gradually for 6000rpm, 9000rpm, 12000rpm and 15000rpm (rev/min), correspondingly, the frame rate of high-speed camera be set as 300fps, 500fps, 600fps and 800fps (frame/second), successively record vibrates video sequence and stores in a computer.All videos It is all to be shot with the resolution ratio of 1024 × 1024 pixels.
Step 2:, using the optical flow method based on phase, the local phase by calculating frequency domain becomes according to the video of acquisition Change, extracts the vibration displacement signal of magnetic suspension motor.
Optical flow method based on phase refers to: the steerable pyramid constructed based on Gabor filter being used to obtain Image frequency domain information calculates corresponding motion information further according to the variation of phase in image frequency domain information.Detailed process is such as Under:
(1) Gabor filter is designed
Image space domain information can be converted into frequency domain information by Gabor filter, low pass in the frequency domain information Band part includes the global information of image, and the detailed information of image can embody in high pass subband part.Using two Gabor wavelet is tieed up as convolution kernel function and designs Gabor filter, corresponding two-dimensional Gabor function expression is as follows:
Wherein, space variable xθAnd yθIncluding directional information, expression formula is as follows:
xθ=xcos θ+ysin θ, yθ=-xsin θ+ycos θ (2)
Wherein, x and y represents space pixel coordinate；θ ∈ (0 °, 360 °) indicates the side of parallel stripes in Gabor filtering core To；λ is the wavelength of SIN function；ψ is the phase offset for tuning function；γ is space aspect ratio, determines Gabor function Shape；σ indicates the standard deviation of Gaussian function, it determines the size of Gabor filtering core acceptable area.
Fig. 2 (a), (b) respectively illustrate two-dimensional Gabor filter in the real number and void in 0 °, 45 °, 90 ° and 135 ° direction It is several right.The characteristics of direction having using Gabor filter and frequency selectivity, thus it is possible to vary θ extracts the position of different directions Move information.
(2) steerable pyramid is constructed
Linear combination is carried out using the Gabor filter in multiple and different directions, while change of scale is carried out to image, thus Construct steerable pyramid.Direction steerable pyramid can be by the frame picture breakdown in video at different scale, Duo Gefang To subband series, wherein the subband of all directions does not have aliasing, has the characteristics that translation invariant and invariable rotary, can Neatly to extract the structural information and marginal information of image, image information is transformed into the frequency domain of different scale, different directions Information.
The realization process of steerable pyramid structure is as shown in Figure 3.Fig. 3 left-hand component indicates image steerable pyramid Decomposable process, right-hand component indicate restructuring procedure.Image first passes around high-pass filter H0(ω) and low-pass filter L0 (ω) is decomposed into two high pass, low pass subbands, this is a pretreated process.Low pass subband image is broken down into K not again Equidirectional band logical subband Bk-1(ω) and low pass subband L1(ω), while to low pass subband L1The row and column of (ω) respectively again into Row two is sampled, and repeats above-mentioned decomposable process, loop iteration, until the one of dimension of row and column not can be carried out drop after two sampling Until sampling.It can be seen that by steerable pyramid by vibrate video image information conversion can be obtained different scale, The frequency domain information of different directions.
(3) displacement signal is extracted
The frequency domain information of the different scale, different directions that are obtained by steerable pyramid, according to the phase in frequency domain Information can extract the displacement signal of corresponding direction.
Below by taking horizontal motion as an example, the specific method for extracting displacement signal is introduced:
Assuming that the time interval between two sequential frame images of video is Δ t, part fortune occurs at spatial position (x, y) Dynamic change in location is (Δ x, Δ y).It is I (x, y, t that first frame, which is defined as image intensity,0) reference frame, the second frame is determined Justice is image intensity I (x+ Δ x, y+ Δ y, t0The motion frame of+Δ t).Convolution algorithm is carried out using two-dimensional Gabor function, will be schemed Picture intensity I (x, y, t) is converted into frequency domain information F (x, y, t), as follows:
Independent variable x, y in original function is replaced with into u, v, the form that formula (3) integrates is expressed as follows:
For extracting horizontal motion, space variable can be expressed as xθ=x, yθ=y, so reference frame can turn It is changed to:
Motion frame can be converted are as follows:
Above-mentioned formula is rearranged, the phase term that will be independent of integration variable is placed on except integral, is then simplified formula, is obtained It arrives:
The phase term of two formulas is allTherefore final definite integral result is also identical, table It is shown as
Calculate the phase angle of two frames:
The phase difference for obtaining two frames is:
So horizontal motion is directly proportional to phase difference.
Similar, small echo direction θ=pi/2 will be changed, the movement in the direction y can be measured；Change small echo direction, it will be able to Estimate the movement in corresponding small echo direction.The phase difference i.e. displacement signal of two interframe can extract two frames by calculating phase difference Between displacement signal.
(4) noise processed
The noise of input image sequence can cause the noise of phase signal, influence final displacement and extract as a result, due to making an uproar The phase signal of sound always short arc is weighted sky to phase using local amplitude to reduce these meaningless signals Between Gaussian Blur make an uproar to reduce signal bottom.
Before calculating phase difference, local amplitude can be used, space Gaussian Blur is weighted to phase to improve noise Than calculation is as follows:
For nth frame, weighted phases signalIt may be calculated:
Wherein, ANWithRespectively indicate the amplitude and phase signal of nth frame；H (x, y) is two-dimensional Gaussian function, can be indicated Are as follows:
The width of the standard deviation ρ representation space domain filter of Gaussian filter, standard deviation ρ is bigger, and dimensional Gaussian image is got over Width, filter effect are better.This method calculation amount is small, but improves signal-to-noise ratio, reduces noise lower limit, preferably reflects reality Border signal.
Step 3: carrying out second order derivation to displacement signal obtains acceleration signal.
Second order derivation is carried out to displacement signal using LOG operator, calculates acceleration signal.LOG operator, i.e. Gauss are drawn This function of pula is combining for gaussian sum Laplce, and the kernel function of LOG operator is as follows:
Displacement signal is filtered by Gaussian function, Laplace function carries out second order to filtered displacement signal Derivation.Second order derivation result, that is, acceleration signal of displacement signal.
Step 4: obtain spectrogram using Fast Fourier Transform (FFT), and with accelerometer measures Comparative result.
Fast Fourier Transform (FFT) (FFT) is carried out to the acceleration signal that step 3 obtains, obtains the frequency spectrum of acceleration signal Figure, the conversion process are the prior art, and non-present invention innovative point, details are not described herein again specific conversion process.
In conclusion being acquired using the optical flow method based on phase to high speed camera the present invention is based on the thought of vision guide To motor oscillating image carry out displacement extraction, be converted into acceleration signal after second order derivation, it is last fast fourier transformed Required spectrogram is obtained afterwards.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any Modification, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.

Claims (7)

1. a kind of magnetic suspension rotor vibration measurement method of view-based access control model, it is characterised in that: the following steps are included:
S1. vibration video of the magnetic suspension rotor under different working condition is acquired by being equipped with the high speed camera of optical lens；
S2. the image for using the steerable pyramid constructed based on Gabor filter to include by the vibration video is empty Between domain information be converted to the image frequency domain information of different scale, different directions, according to the local phase in image frequency domain information The vibration displacement signal of change detection magnetic suspension motor；
S3. second order derivation is carried out to the vibration displacement signal using LOG operator, acceleration signal is calculated；
S4. Fast Fourier Transform is carried out to the acceleration signal and obtains target spectrum figure.
2. a kind of magnetic suspension rotor vibration measurement method of view-based access control model according to claim 1, it is characterised in that: described Step S2 is specifically included:
S21. Gabor filter is designed as convolution kernel function using Two-Dimensional Gabor Wavelets, it will by the Gabor filter The video image spatial-domain information that vibration video includes is converted into frequency domain information；Low pass subband part packet in the frequency domain information Global information containing video image, high pass subband part include the detailed information of video image；The Gabor filter is corresponding Two-dimensional Gabor function expression is as follows:
Wherein, x and y represents space pixel coordinate；θ ∈ (0 °, 360 °) indicates the direction of parallel stripes in Gabor filtering core；λ It is the wavelength of SIN function；ψ is the phase offset for tuning function；γ is space aspect ratio；The standard deviation of σ expression Gaussian function Difference；xθAnd yθIndicate the space variable comprising directional information, expression formula is as follows:
xθ=x cos θ+y sin θ, yθ=-x sin θ+y cos θ
S22. linear combination will be carried out with the Gabor filter in multiple and different directions, while change of scale is carried out to video image, To construct steerable pyramid；
S23. video image is resolved by different scale by the steerable pyramid, multiple directions include video image The subband of structural information and marginal information series, thus completes the video image information being transformed into different scale, non-Tongfang To frequency domain information；According to the phase difference of two frame of phase calculation of two frames in frequency domain information, the displacement of corresponding direction is thus obtained Signal.
3. a kind of magnetic suspension rotor vibration measurement method of view-based access control model according to claim 2, it is characterised in that: described The realization process of steerable pyramid is as follows:
Video image first passes around high-pass filter H0(ω) and low-pass filter L0(ω) is decomposed into two high pass, low pass sons Band；Then low pass subband image is broken down into the band logical subband B of K different directions againk-1(ω) and low pass subband L1(ω), together When to low pass subband L1The row and column of (ω) carries out two sampling again respectively；Two sampling after repeat above-mentioned decomposable process, loop iteration, Until the one of dimension of row and column not can be carried out down-sampled.
4. a kind of magnetic suspension rotor vibration measurement method of view-based access control model according to claim 2, it is characterised in that:
In step S23, the displacement of corresponding direction is obtained according to the phase difference of two frame of phase calculation of two frames in the frequency domain information The calculation of signal is as follows:
Assuming that time interval between two successive frames of video is Δ t, spatial position (x, y) occur local motion (Δ x, Δ y), it is I (x, y, t that first frame, which is defined as image intensity,0) reference frame, by the second frame definition be image intensity I (x+ Δ x, y+Δy,t0The motion frame of+Δ t)；
Convolution algorithm is carried out using two-dimensional Gabor function, converts frequency domain information F (x, y, t) such as image intensity I (x, y, t) Under:
It is expressed as follows with the form of integral:
For extracting horizontal motion, space variable is enabled to be expressed as xθ=x, yθ=y, reference frame conversion are as follows:
Motion frame conversion are as follows:
Above-mentioned formula is rearranged, the phase term that will be independent of integration variable is placed on except integral, then simplify formula:
The phase term of two formulas is allTherefore final definite integral result is also identical, is expressed as
The phase angle for calculating two frames is as follows:
The phase difference that two frame of horizontal direction is calculated is:
Thus the displacement signal of corresponding direction is obtained.
5. a kind of magnetic suspension rotor vibration measurement method of view-based access control model according to claim 4, it is characterised in that:
Step S23 further includes being weighted space Gaussian Blur to the phase angle to improve signal-to-noise ratio, is specifically included:
For nth frame, weighted phases signalIt calculates are as follows:
Wherein, ANIndicate the amplitude of nth frame,Indicate the phase of nth frame；H (x, y) is two-dimensional Gaussian function, is indicated are as follows:
Wherein, the width of the standard deviation ρ representation space domain filter of Gaussian filter.
6. according to claim 1 to the magnetic suspension rotor vibration measurement method of view-based access control model described in 5 any one, feature exists In: in step S1, the highest resolution of the high speed camera is 4096 × 3076, can continuously adjust the pixel size of pixel coverage With the time for exposure of exposure time range, and using LED light as light source.
7. according to claim 1 to the magnetic suspension rotor vibration measurement method of view-based access control model described in 5 any one, feature exists In: the step S1 is specifically included: be arranged magnetic suspension rotor revolving speed be 6000rpm, 9000rpm, 12000rpm and 15000rpm, the frame rate that high speed camera is arranged is 300fps, 500fps, 600fps and 800fps, is recorded and saved corresponding Vibrate video sequence.
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CN111353400A (en) * 2020-02-24 2020-06-30 南京航空航天大学 Whole scene vibration intensity atlas analysis method based on visual vibration measurement
CN112001361A (en) * 2019-12-26 2020-11-27 合肥工业大学 Euler visual angle-based multi-target micro vibration frequency measurement method
CN112254801A (en) * 2020-12-21 2021-01-22 浙江中自庆安新能源技术有限公司 Micro-vibration vision measurement method and system
CN112348782A (en) * 2020-10-27 2021-02-09 天津大学 Change detection method based on plurality of controllable pyramids
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