CN114993451A - Low-frequency vibration testing system and measuring method - Google Patents
Low-frequency vibration testing system and measuring method Download PDFInfo
- Publication number
- CN114993451A CN114993451A CN202210723210.8A CN202210723210A CN114993451A CN 114993451 A CN114993451 A CN 114993451A CN 202210723210 A CN202210723210 A CN 202210723210A CN 114993451 A CN114993451 A CN 114993451A
- Authority
- CN
- China
- Prior art keywords
- signal
- low
- frequency
- frequency vibration
- upper computer
- 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.)
- Pending
Links
- 238000012360 testing method Methods 0.000 title claims abstract description 19
- 238000000034 method Methods 0.000 title claims description 9
- 238000006073 displacement reaction Methods 0.000 claims abstract description 31
- 230000003750 conditioning effect Effects 0.000 claims abstract description 19
- 238000002955 isolation Methods 0.000 claims abstract description 8
- 230000009467 reduction Effects 0.000 claims description 18
- 238000013016 damping Methods 0.000 claims description 15
- 230000005284 excitation Effects 0.000 claims description 13
- 238000001228 spectrum Methods 0.000 claims description 9
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 230000009466 transformation Effects 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 5
- 238000000354 decomposition reaction Methods 0.000 claims description 4
- 238000000691 measurement method Methods 0.000 claims description 4
- 230000008569 process Effects 0.000 claims description 3
- 238000012216 screening Methods 0.000 claims description 3
- 230000003068 static effect Effects 0.000 claims description 3
- 238000005259 measurement Methods 0.000 abstract description 15
- 238000012545 processing Methods 0.000 abstract description 3
- 230000004044 response Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 5
- 230000001133 acceleration Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 206010063385 Intellectualisation Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000008447 perception Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- 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
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H11/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties
- G01H11/06—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties by electric means
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
Abstract
The invention provides a low-frequency vibration test system, comprising: the vibration isolation bracket is used for mounting the displacement sensor; the displacement sensor is arranged on the vibration isolation support and is arranged in a non-contact manner with the measured object; the displacement sensor is used for measuring a low-frequency vibration signal when a measured object vibrates in a non-contact manner; the signal acquisition unit comprises an input interface, a first signal conditioning circuit, a microprocessor and an output interface which are connected in sequence; the displacement sensor is connected with an input interface, and the output interface is connected with an upper computer; the microprocessor is used for acquiring the digital low-frequency vibration signal output by the first signal conditioning circuit and sending the digital low-frequency vibration signal to the upper computer; and the upper computer is used for processing and analyzing the input digital low-frequency vibration signal. The invention has high measurement precision and good low-frequency response.
Description
Technical Field
The invention belongs to the technical field of vibration testing, and particularly relates to a low-frequency vibration testing system and a measuring method.
Background
The mechanical equipment has a large amount of harmful vibration problems which are recognized by engineering technicians in recent years, and the mechanical equipment can generate vibration of a transmission system when working, impact vibration when starting and stopping, impact vibration of a track or a road surface and other vibration problems. Along with the industrial upgrading, the application scene of mechanical equipment tends to high speed, high precision and high intellectualization increasingly, the mechanical equipment can use a prime motor with larger torque and carry more precise instruments, and the influence of vibration on the mechanical equipment is more obvious. In order to analyze the influence of vibration on mechanical equipment, engineering technicians often calculate the natural frequency and damping of a mechanical structure through general dynamic analysis or empirical formulas in the design stage, but the natural frequency calculation result has large error, the system damping is mainly obtained by experience, and the randomly generated vibration cannot be analyzed. The vibration generated in the operation of the machine is actually measured, and the influence of the vibration on the mechanical equipment is still important to research through vibration signal processing and analysis. For most mechanical equipment, low-frequency signals are mainly generated in the operation process, and a target to be detected is mainly sensitive to low-frequency vibration of 0.5 Hz-500 Hz. Therefore, higher requirements are put on the measurement of the low-frequency vibration of the mechanical equipment.
The vibration measurement is mainly realized by displacement meters, speedometers, accelerometers, gyroscopes and other instruments. When in measurement, the instrument needs to be fixedly connected to a measured object, and the electrical signals are read and stored by an upper computer through a signal conditioning device and a signal acquisition card.
The low-frequency vibration signal has the characteristics of large amplitude, small vibration acceleration and uneasy perception. In low-frequency vibration measurement, a speedometer, an accelerometer and a gyroscope need to fix a sensor part of the instrument on a measured object when measuring vibration, the sensor is often large, a small mechanical structure cannot be provided with the sensor, and even a heavy sensor can change the mode and system damping of the measured object to cause an error measurement result. When the displacement meter is used for measuring vibration, a test system is easily interfered, the sampling frequency is too low, and the low-pass filter is not considered sufficiently, a large number of noise signals often exist in the measurement signals, and the low-frequency measurement signals are submerged in the noise signals, so that the signal-to-noise ratio of the measurement signals is too small, and the signal quality is poor.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a low-frequency vibration testing system and a low-frequency vibration testing method. In order to achieve the technical purpose, the embodiment of the invention adopts the technical scheme that:
in a first aspect, an embodiment of the present invention provides a low-frequency vibration testing system, including:
the vibration isolation bracket is used for mounting the displacement sensor;
the displacement sensor is arranged on the vibration isolation support and is arranged in a non-contact manner with the measured object; the displacement sensor is used for measuring a low-frequency vibration signal when a measured object vibrates in a non-contact manner;
the signal acquisition unit comprises an input interface, a first signal conditioning circuit, a microprocessor and an output interface which are connected in sequence; the displacement sensor is connected with an input interface, and the output interface is connected with an upper computer; the microprocessor is used for acquiring the digital low-frequency vibration signal output by the first signal conditioning circuit and sending the digital low-frequency vibration signal to the upper computer;
and the upper computer processes and analyzes the input digital low-frequency vibration signal to obtain the natural frequency and the damping ratio of the measured object.
Further, the first signal conditioning circuit comprises a Butterworth low-pass filter circuit and an ADC chip.
Further, the low frequency vibration test system further comprises:
the force hammer is used for hammering the measured object to vibrate by the force hammer when the measured object is not excited externally or is in a static state; an IEPE sensor is arranged on the force hammer;
the constant current source adapter is respectively connected with the IEPE sensor and the signal acquisition unit on the force hammer; the IEPE sensor is used for supplying power and converting an excitation force signal measured by the IEPE sensor into an excitation electric signal which can be identified by the signal acquisition unit;
and the second signal conditioning circuit is arranged on the signal acquisition unit and is used for performing low-pass filtering and analog-to-digital conversion on the obtained excitation electric signal.
Further, when the amplitude of the measured object is less than or equal to 10 mm, the displacement sensor selects an eddy current sensor; and when the amplitude of the measured object is larger than 10 mm, selecting a laser displacement sensor.
In a second aspect, an embodiment of the present invention provides a low-frequency vibration measurement method, which is suitable for the low-frequency vibration test system described above, and includes the following steps:
step S101, the low-frequency vibration signal received by the upper computer is an original signal which is a time domain signal;
step S102, the upper computer conducts FFT transformation on the original signal, converts the time domain signal into a frequency domain signal, and displays the power spectrum of the frequency domain signal in a spectrogram; then determining the number of the main frequencies as n in the spectrogram; taking 2n, which is two times of the number of the main frequencies, as the number of singular values;
s103, the upper computer performs singular value decomposition and noise reduction on the original signal by taking 2n as the number of singular values;
step S104, performing FFT transformation on the original signal subjected to noise reduction, converting the signal subjected to noise reduction into a frequency domain signal, converting the frequency domain signal obtained by converting the original signal subjected to noise reduction, and displaying a power spectrum of the frequency domain signal in a spectrogram; the frequency component with the maximum power density in the power spectrum is the natural frequency of the measured object;
step S105, performing EMD on the original signal subjected to noise reduction, and performing EMD to obtain a plurality of IMF components and residual components, as shown in formula (1);
where f (t) is the original signal after noise reduction, imf i (t) is the ith IMF component, r n (t) is the n signal residual components;
step S106, selecting IMF components to perform HT conversion on the IMF components, and screening out IMF components with the frequency equal to or closest to the natural frequency in the step S104;
step S107, drawing a curve according to the screened IMF components; selecting an attenuation part in a curve for the screened IMF component which is equal to or most similar to the natural frequency, calculating a damping ratio by intercepting adjacent peaks of the curve, and introducing a logarithmic attenuation rate delta, wherein the logarithmic attenuation rate delta is expressed as follows:
the damping ratio is derived as follows:
wherein A1 and A2 are adjacent peaks of the curves, and xi is the damping ratio.
Optionally, after step S101, the method further includes:
and step S1011, directly displaying the original signal on a screen of an upper computer.
The technical scheme provided by the embodiment of the invention has the following beneficial effects:
1) by adopting non-contact measurement, the sensor does not need to be arranged on a measured object, and the measurement precision is not influenced.
2) The displacement sensor is used for measuring the amplitude signal, so that the dynamic measurement of the low-frequency vibration signal with high precision, good low-frequency response, convenience and low cost is realized.
Drawings
Fig. 1 is a schematic structural diagram of a low-frequency vibration testing system in an embodiment of the present invention.
Fig. 2 is a schematic diagram of a signal acquisition unit in an embodiment of the present invention.
Fig. 3 is a schematic diagram of a first signal conditioning circuit according to an embodiment of the invention.
Fig. 4 is a flowchart of a measurement method in an embodiment of the present invention.
FIG. 5 is a diagram illustrating a low frequency vibration signal according to an embodiment of the present invention.
Fig. 6 is a schematic diagram of frequency domain signals according to an embodiment of the present invention.
Fig. 7 is a graph illustrating the selected IMF components according to the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
In a first aspect, as shown in fig. 1, an embodiment of the present invention provides a low-frequency vibration testing system, including:
the vibration isolation bracket 1 is used for mounting the displacement sensor 2;
the displacement sensor 2 is arranged on the vibration isolation support 1 and is arranged in a non-contact manner with the measured object 7; the displacement sensor 2 is used for measuring a low-frequency vibration signal of the measured object 7 in a non-contact manner when the measured object vibrates;
the signal acquisition unit 3 comprises an input interface 301, a first signal conditioning circuit 302, a microprocessor 303 and an output interface 304 which are connected in sequence; the displacement sensor 2 is connected with an input interface 301, and the output interface 304 is connected with an upper computer 4; the first signal conditioning circuit 302 is used for performing low-pass filtering and analog-to-digital conversion on the low-frequency vibration signal measured by the displacement sensor 2, and the microprocessor 303 is used for acquiring the digital low-frequency vibration signal output by the first signal conditioning circuit and sending the digital low-frequency vibration signal to the upper computer 4;
and the upper computer 4 is used for processing and analyzing the input low-frequency vibration signal of the digital quantity to obtain the natural frequency and the damping ratio of the measured object 7.
The mechanical vibration is represented as that an object does reciprocating motion at a balance position, and when the vibration occurs, the position of the object changes along with time to present displacement change, which is called as amplitude; the low-frequency vibration signal is characterized in that the amplitude is large and is usually 0.1 mm-100 mm, and the vibration frequency is low and is usually 0.5 Hz-500 Hz; the amplitude is used as an expression form of mechanical vibration, the amplitude-frequency characteristic of low-frequency vibration is utilized, and the amplitude signal is measured in a non-contact manner through the displacement sensor, so that the dynamic measurement of the low-frequency vibration signal with high precision, good low-frequency response, convenience and low cost is realized;
specifically, the signal acquisition unit 3 is usually fabricated on a PCB; as shown in fig. 3, the first signal conditioning circuit 302 includes a butterworth low-pass filter circuit 3021 and an ADC chip 3022, where the butterworth low-pass filter circuit 3021 is used for performing low-pass filtering to filter out high-frequency noise in the low-frequency vibration signal measured by the displacement sensor 2; the ADC chip 3022 is configured to convert the analog low-frequency vibration signal into a digital low-frequency vibration signal; the ADC chip 3022 is a 12-bit ADS7822 chip from TI corporation; the microprocessor 303 communicates with the upper computer 4 through the output interface 304 by serial port communication;
as optimization of this embodiment, an embodiment of the present invention provides a low-frequency vibration testing system, further including:
the force hammer 5 is used for hammering the object to be measured 7 to vibrate through the force hammer 5 when the object to be measured 7 has no external excitation or is in a static state; an IEPE sensor is arranged on the force hammer 5; the IEPE sensor is an acceleration sensor with a magnitude amplifier or a voltage amplifier;
the constant current source adapter 6 is respectively connected with the IEPE sensor on the force hammer 5 and the signal acquisition unit 3; the excitation force signal is used for supplying power to the IEPE sensor and converting the excitation force signal measured by the IEPE sensor into an excitation electric signal which can be identified by the signal acquisition unit 3;
and the second signal conditioning circuit is arranged on the signal acquisition unit 3 and is used for performing low-pass filtering and analog-to-digital conversion on the obtained excitation electric signal.
Specifically, for the displacement sensor 2, when the amplitude of the object to be measured 7 is less than or equal to 10 mm, an eddy current sensor is selected; when the amplitude of the object to be measured 7 is larger than 10 mm, a laser displacement sensor is selected;
during multi-sensor measurement, for example, during simultaneous measurement in two directions of the object to be measured 7, the number of the first signal conditioning circuits 302 needs to be increased and integrated in the signal acquisition unit 3; usually, the number of the displacement sensors 2 corresponds to the number of the first signal conditioning circuits 302;
in a second aspect, an embodiment of the present invention provides a low-frequency vibration measurement method, which is executed on the upper computer 4, and includes the following steps:
step S101, the low-frequency vibration signal received by the upper computer is an original signal which is a time domain signal;
FIG. 5 shows an example of an original signal, with time in seconds on the abscissa and displacement in millimeters on the ordinate;
optionally, in step S1011, the original signal is directly displayed on the screen of the upper computer;
step S102, the upper computer performs FFT (fast Fourier transform) on the original signal, converts the time domain signal into a frequency domain signal, and displays the power spectrum of the frequency domain signal in a spectrogram; then determining the number of the main frequencies as n in the spectrogram; taking 2n, which is two times of the number of the main frequencies, as the number of singular values;
in one example of the spectrogram shown in fig. 6, the abscissa is frequency in hertz (Hz); the ordinate is the power spectral density in decibels (dB); the number of determined dominant frequencies 901 is 2;
s103, the upper computer takes 2n as the number of singular values and carries out singular value decomposition on the original signal; therefore, the noise reduction of the original signal is realized, and the signal-to-noise ratio of the low-frequency vibration signal is improved;
step S104, performing FFT (fast Fourier transform) on the original signal subjected to noise reduction, converting the signal subjected to noise reduction into a frequency domain signal, converting the original signal subjected to noise reduction into the frequency domain signal, and displaying a power spectrum of the frequency domain signal in a spectrogram; the frequency component with the maximum power density in the power spectrum is the natural frequency of the measured object;
step S105, performing EMD (empirical mode decomposition) on the original signal after noise reduction, and obtaining a plurality of IMF (intrinsic mode function) components and residual components through EMD, wherein the IMF components and the residual components are shown in a formula (1);
wherein f (t) is the original signal after noise reduction, imf i (t) is the ith IMF component, r n (t) is the n signal residual components;
step S106, selecting IMF components, carrying out HT transformation (Hilbert transformation) on the IMF components, and screening out IMF components with the frequency equal to or closest to the natural frequency in the step S104;
step S107, drawing a curve according to the screened IMF components; selecting an attenuation part in a curve for the screened IMF component which is equal to or most similar to the natural frequency, calculating a damping ratio by intercepting adjacent peaks of the curve, and introducing a logarithmic attenuation rate delta, wherein the logarithmic attenuation rate delta is expressed as follows:
the damping ratio is derived as follows:
wherein A1 and A2 are adjacent peak values of curves, and xi is a damping ratio; as shown in fig. 7.
Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.
Claims (6)
1. A low frequency vibration testing system, comprising:
the vibration isolation bracket is used for mounting the displacement sensor;
the displacement sensor is arranged on the vibration isolation support and is arranged in a non-contact manner with the measured object; the displacement sensor is used for measuring a low-frequency vibration signal when a measured object vibrates in a non-contact manner;
the signal acquisition unit comprises an input interface, a first signal conditioning circuit, a microprocessor and an output interface which are connected in sequence; the displacement sensor is connected with an input interface, and the output interface is connected with an upper computer; the microprocessor is used for acquiring the digital low-frequency vibration signal output by the first signal conditioning circuit and sending the digital low-frequency vibration signal to the upper computer;
and the upper computer processes and analyzes the input digital low-frequency vibration signal to obtain the natural frequency and the damping ratio of the measured object.
2. The low frequency vibration testing system of claim 1,
the first signal conditioning circuit comprises a Butterworth low-pass filter circuit and an ADC chip.
3. The low frequency vibration testing system of claim 1 further comprising:
the force hammer is used for hammering the object to be measured to vibrate when the object to be measured has no external excitation or is in a static state; an IEPE sensor is arranged on the force hammer;
the constant current source adapter is respectively connected with the IEPE sensor and the signal acquisition unit on the force hammer; the excitation force signal is used for supplying power to the IEPE sensor and converting the excitation force signal measured by the IEPE sensor into an excitation electric signal which can be identified by the signal acquisition unit;
and the second signal conditioning circuit is arranged on the signal acquisition unit and is used for performing low-pass filtering and analog-to-digital conversion on the obtained excitation electric signal.
4. The low frequency vibration testing system of claim 1,
when the amplitude of the measured object is less than or equal to 10 mm, the displacement sensor selects an eddy current sensor; and when the amplitude of the measured object is larger than 10 mm, selecting a laser displacement sensor.
5. A low-frequency vibration measuring method is suitable for the low-frequency vibration testing system of any one of claims 1 to 4, and is characterized by comprising the following steps of:
step S101, the low-frequency vibration signal received by the upper computer is an original signal which is a time domain signal;
step S102, the upper computer conducts FFT transformation on the original signal, converts a time domain signal into a frequency domain signal, and displays a power spectrum of the frequency domain signal in a spectrogram; then determining the number of the main frequencies as n in the spectrogram; taking 2n, which is two times of the number of the main frequencies, as the number of singular values;
s103, the upper computer performs singular value decomposition and noise reduction on the original signal by taking 2n as the number of singular values;
step S104, performing FFT transformation on the original signal subjected to noise reduction, converting the signal subjected to noise reduction into a frequency domain signal, converting the frequency domain signal obtained by converting the original signal subjected to noise reduction, and displaying a power spectrum of the frequency domain signal in a spectrogram; the frequency component with the maximum power density in the power spectrum is the natural frequency of the measured object;
step S105, performing EMD on the original signal subjected to noise reduction, and performing EMD to obtain a plurality of IMF components and residual components, as shown in formula (1);
wherein f (t) is the original signal after noise reduction, imf i (t) is the ith IMF component, r n (t) is the n signal residual components;
step S106, selecting IMF components to perform HT conversion on the IMF components, and screening out IMF components with the frequency equal to or closest to the natural frequency in the step S104;
step S107, drawing a curve according to the screened IMF components; selecting an attenuation part in a curve for the screened IMF component which is equal to or most similar to the natural frequency, calculating a damping ratio by intercepting adjacent peaks of the curve, and introducing a logarithmic attenuation rate delta, wherein the logarithmic attenuation rate delta is expressed as follows:
the damping ratio is derived as follows:
wherein A1 and A2 are adjacent peaks of the curves, and xi is the damping ratio.
6. The low frequency vibration measurement method of claim 5,
after step S101, the method further includes:
and step S1011, directly displaying the original signal on a screen of an upper computer.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210723210.8A CN114993451A (en) | 2022-06-23 | 2022-06-23 | Low-frequency vibration testing system and measuring method |
| CN202321121108.7U CN220153733U (en) | 2022-06-23 | 2023-05-10 | Low-frequency vibration test system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210723210.8A CN114993451A (en) | 2022-06-23 | 2022-06-23 | Low-frequency vibration testing system and measuring method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114993451A true CN114993451A (en) | 2022-09-02 |
Family
ID=83037131
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210723210.8A Pending CN114993451A (en) | 2022-06-23 | 2022-06-23 | Low-frequency vibration testing system and measuring method |
| CN202321121108.7U Active CN220153733U (en) | 2022-06-23 | 2023-05-10 | Low-frequency vibration test system |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202321121108.7U Active CN220153733U (en) | 2022-06-23 | 2023-05-10 | Low-frequency vibration test system |
Country Status (1)
| Country | Link |
|---|---|
| CN (2) | CN114993451A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1869972A (en) * | 2006-06-15 | 2006-11-29 | 沈阳建筑大学 | Structural response analysing method of improving Hibert-Huang transform |
| US20080059086A1 (en) * | 2002-02-21 | 2008-03-06 | Ziyad Duron | System and method for determining and detecting stability loss in structures |
| CN106548137A (en) * | 2016-10-20 | 2017-03-29 | 燕山大学 | Two degree freedom system Identification of Structural Parameters method based on vibration response signal |
| CN107391818A (en) * | 2017-07-07 | 2017-11-24 | 大连理工大学 | A kind of Vibrating modal parameters recognition methods based on state observer |
| CN110261052A (en) * | 2019-06-19 | 2019-09-20 | 西北工业大学 | Using power hammer excitation and photogrammetric Modal Analysis of Structures system and method |
-
2022
- 2022-06-23 CN CN202210723210.8A patent/CN114993451A/en active Pending
-
2023
- 2023-05-10 CN CN202321121108.7U patent/CN220153733U/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080059086A1 (en) * | 2002-02-21 | 2008-03-06 | Ziyad Duron | System and method for determining and detecting stability loss in structures |
| CN1869972A (en) * | 2006-06-15 | 2006-11-29 | 沈阳建筑大学 | Structural response analysing method of improving Hibert-Huang transform |
| CN106548137A (en) * | 2016-10-20 | 2017-03-29 | 燕山大学 | Two degree freedom system Identification of Structural Parameters method based on vibration response signal |
| CN107391818A (en) * | 2017-07-07 | 2017-11-24 | 大连理工大学 | A kind of Vibrating modal parameters recognition methods based on state observer |
| CN110261052A (en) * | 2019-06-19 | 2019-09-20 | 西北工业大学 | Using power hammer excitation and photogrammetric Modal Analysis of Structures system and method |
Non-Patent Citations (1)
| Title |
|---|
| 贺伟: "《HHT理论算法及其在现代信号处理中的应用研究》", 上海科学技术出版社 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN220153733U (en) | 2023-12-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10634554B2 (en) | Integrated vibration measurement and analysis system | |
| CN101674520B (en) | Method and device for analyzing and testing parameter of vibration type pickup | |
| JP3494992B2 (en) | Measurement of sound velocity of gas | |
| US5646350A (en) | Monitoring slow speed machinery using integrator and selective correction of frequency spectrum | |
| Koene et al. | Internet of things based monitoring of large rotor vibration with a microelectromechanical systems accelerometer | |
| CN107830927A (en) | A kind of vibrating sensor is examined and calibrating installation and application method | |
| CN206772429U (en) | Noise source tests and analyzes device | |
| CN102538950A (en) | Acoustic testing method for inherent frequency of engine part | |
| CN111780866B (en) | Diesel engine test base installation state natural frequency testing method and device | |
| Katalin | Studying noise measurement and analysis | |
| KR20130013683A (en) | Earthquake sensor verification system using earthquake recorder and method | |
| CN114354112B (en) | Blade multi-order coupling vibration fatigue analysis method | |
| CN107894262B (en) | Liquid level measuring device and method and engine | |
| CN114993451A (en) | Low-frequency vibration testing system and measuring method | |
| CN108414217B (en) | Gear box noise test system | |
| Veldman | Implementation of an accelerometer transverse sensitivity measurement system | |
| EP1092133B1 (en) | Method and apparatus for determining a resonant frequency of a resonator containing a gas composition | |
| CN112557515B (en) | Acoustic emission sensor test system | |
| CN201435826Y (en) | Vibrating sound pick-up parameter analyzing and testing device | |
| CN113092820A (en) | High-precision acceleration sensor noise performance analysis method and device | |
| CN112229502A (en) | System and method for measuring natural frequency of simply supported beam | |
| RU199936U1 (en) | Vibration measuring device | |
| CN113418592B (en) | Composite measurement system and measurement method for shake-up meter measurement | |
| US20240044696A1 (en) | Method for decimating samples by a float number and associated device, sensor, and machine | |
| JP7410459B2 (en) | Vibration characteristics testing device, method and program for automobile bodies |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20220902 |
|
| WD01 | Invention patent application deemed withdrawn after publication |