CN103344432A - Method for detecting fiber bragg grating acoustic emission of helicopter bearing fault - Google Patents
Method for detecting fiber bragg grating acoustic emission of helicopter bearing fault Download PDFInfo
- Publication number
- CN103344432A CN103344432A CN2013102195673A CN201310219567A CN103344432A CN 103344432 A CN103344432 A CN 103344432A CN 2013102195673 A CN2013102195673 A CN 2013102195673A CN 201310219567 A CN201310219567 A CN 201310219567A CN 103344432 A CN103344432 A CN 103344432A
- Authority
- CN
- China
- Prior art keywords
- bragg grating
- fault
- acoustic emission
- helicopter
- signal
- 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
Images
Abstract
The invention provides a method for detecting fiber bragg grating acoustic emission of a helicopter bearing fault in order to detect an early-time state of the fault of rolling bearings on a helicopter, enhance the capacity for recognizing the fault of the bearings of the helicopter and prolong the service life of the bearings of the helicopter. The detecting method includes the steps of sensor installation, signal sensing and demodulation, wherein the sensor installation includes pasting-installation of a grating sensor (packaged or non-packaged), the single-fiber-bragg-grating sensing method is adopted for the sensing, and the demodulation includes photoelectric conversion, amplification, acquiring, resonance demodulation processing and the like. The method for detecting fiber bragg grating acoustic emission of the helicopter bearing fault is mainly used for detecting the fault of the bearings of the helicopter and faults of bearings of other rotating machines at the home position and on line. Compared with traditional detecting methods (eye observing, vibration, magnetic powder and the like), the method for detecting fiber bragg grating acoustic emission of the helicopter bearing fault can effectively detect the early-time state of the faults and accurately judge the fault type and the fault severity order, and the method has great significance for on-condition maintenance and service life prolonging of the helicopter.
Description
Technical field
The invention belongs to the acoustic emission testing technology field, particularly the fiber grating acoustic emission detection method of bearing fault such as helicopter tail transmission shaft spring bearing.
Background technology
The tail transmission shaft of helicopter mainly is that the moment of torsion with main reducing gear passes to tail-rotor, and it is contained in the tail boom, is high-speed rotary part, and wherein the tail transmission shaft spring bearing is critical component.At present, adopt visual, hand to touch that original detection method such as temperature is judged more or based on the detection method of vibration, all can not effectively find fault (especially initial failure).Bearing fault (crackle, wearing and tearing, spot corrosion, peel off, become flexible etc.) will be through a slow expansion process, this stage is not enough to cause that bearing obviously vibrates, acoustic emission signal is then apparent in view, thereby acoustic emission detection energy early prediction bearing fault, compare traditional vibration signal detection method, its unique advantages is arranged.In the lower system of robustnesss such as aircraft speed change, the early stage Weak fault of bearing will cause catastrophic consequence, need carry out effective detection differentiation or the status monitoring of initial failure.
Owing to be high-speed rotary part, when the tail transmission shaft bearing produced fault, trouble spot and miscellaneous part bumped, and produce instantaneous spike, be acoustic emission signal, therefore detect this acoustic emission signal and can judge that the fault of tail transmission shaft bearing takes place, development.
Fiber grating is the photosensitivity of utilizing fiber optic materials, produces the refractive index that changes along the fibre core axial cyclic in fibre core.When a branch of broadband light enters Fiber Bragg Grating FBG, have only the very narrow light that satisfies its conditioned reflex (bragg wavelength) to be reflected back by Fiber Bragg Grating FBG, remaining light transmission and going out, its effect come down to form wave filter or the catoptron of an arrowband in fibre core.Because Fiber Bragg Grating FBG is only launched its interested wavelength, is often used in sensing, is used widely in the monitoring structural health conditions of highway, bridge, mine, geologic prospecting, railway, oil/gas pipeline.
Existing fiber grating acoustic emission sensor-based system such as Chinese patent CN201110207340.8 " a kind of acoustic emission signal sensor-based system based on Fiber Bragg Grating FBG ", CN201110238795.6 " a kind of acoustic emission signal power-type lossless detection method based on Fiber Bragg Grating FBG " etc. have realized the accurate detection of acoustic emission signal, have enlarged the application of fiber grating in the acoustic emission detection field.
Summary of the invention
The objective of the invention is to, overcome existing technology limitation, Fiber Bragg Grating FBG is introduced the acoustic emission field, the fiber grating acoustic emission detection method of helicopter bearing fault is provided, and this method has the detection sensitivity height, is not subjected to electromagnetic interference (EMI), characteristics such as the online detection of original position under the ground run state when being fit to daily servicing.
The technical scheme that the present invention adopts in order to achieve the above object is: the fiber grating acoustic emission detection method of helicopter bearing fault links to each other narrowband optical signal with the sensor fibre Bragg grating; Out of order bearing can produce acoustic emission signal at work, propagates through material and arrives the sensor fibre Bragg grating, reflects modulated light signal; Modulated light signal is electric signal through opto-electronic conversion, and electric signal carries out resonance and demodulation again and handles through after amplifying, gathering;
Wherein narrowband optical signal is generated by the narrow-band tunable laser instrument, and its centre wavelength is at the 3dB of sensor fibre Bragg grating reflectance spectrum point place, and make the sensor fibre Bragg grating have the highest sensitivity (being the working point) this moment; When the bearing working of fault, the collision of its trouble spot and remaining part, can outwards send stress wave, be acoustic emission signal, near the sensor fibre Bragg grating that this acoustic emission signal is coupled in the bearing receives, and causes that the centre wavelength of sensor fibre Bragg grating changes, reflection output modulated light signal, this modulated light signal is electric signal by opto-electronic conversion, after amplifying, gathering, carries out resonance and demodulation again and handles.
Further, described sensor fibre Bragg grating is coupled near the surface of the material the bearing: if the sensor fibre Bragg grating does not encapsulate, then be pasted on the surface of material with 502 glue; If the sensor fibre Bragg grating encapsulates, the sensor fibre Bragg grating after then will encapsulating uses vaseline to be coupled in the surface of material and fixes by mightiness belt;
Further, described sensor fibre Bragg grating reflectance spectrum three dB bandwidth is less than 0.3nm, and the foveal reflex rate is greater than 90%, and side mode suppression ratio is less than 15dB.
The present invention's advantage compared with prior art is:
1, traditional helicopter bearing fault detection means (visual, vibration, magnetic etc.) fault diagnosis rate is not high, be difficult to find initial failure, and fiber grating acoustic emission method for sensing provided by the invention has the higher detection precision, carry out in the time of can be in conjunction with daily servicing, installation and simple to operate, can detect the initial failure state of bearing, accurately identify fault type, it is looked the feelings maintenance and lengthens the life significant.
2, with based on the detection method of vibration transducer and piezoelectric type calibrate AE sensor compare, the spectrum back noise is little, and spectral line is clear, clean, the order of severity of easier resolution failure-frequency and analysis of failure.
Description of drawings
Fig. 1 is the fiber grating acoustic emission detection method of helicopter bearing fault;
Among the figure: 1, out of order bearing, 2, acoustic emission signal, 3, the sensor fibre Bragg grating, 4, narrowband optical signal, 5, modulated light signal, 6, electric signal, 7, amplify, gather, 8, resonance and demodulation handles;
Fig. 2 is single fibre grating acoustic emission sensing principle; LD is the narrow linewidth light source, and FBG is Fiber Bragg Grating FBG;
Fig. 3 is rolling bearing inner structure synoptic diagram and each several part fault characteristic frequency theoretical formula;
Fig. 4 is resonance and demodulation algorithm synoptic diagram;
Fig. 5, the 6th detects the resonance and demodulation spectrogram of the bearing of outer ring fault; The detected housing washer fault-signal of Fig. 5 (a) 600r/min rotating speed lower piezoelectric pottery calibrate AE sensor; The detected housing washer fault-signal of fiber grating calibrate AE sensor under Fig. 5 (b) 600r/min rotating speed.The detected housing washer fault-signal of Fig. 6 (a) 1200r/min rotating speed lower piezoelectric pottery calibrate AE sensor; The detected housing washer fault-signal of fiber grating calibrate AE sensor under Fig. 6 (b) 1200r/min rotating speed.
Embodiment
Below in conjunction with accompanying drawing the specific embodiment of the present invention is described, in order to understand the present invention better.What need point out especially is that in the following description, when perhaps the detailed description that adopts known function and design can desalinate main contents of the present invention, these were described in here and will be left in the basket.
As shown in Figure 1, the fiber grating acoustic emission detection method of helicopter bearing fault of the present invention comprises: sensor installation, sensing and demodulation three parts; Wherein, sensor is installed and is comprised mounting of grating sensor (having encapsulated or not encapsulation); Sensing adopts the single fibre grating sensing method; The demodulation part comprises opto-electronic conversion, amplification, collection, resonance and demodulation processing etc.Concrete enforcement is as follows: narrowband optical signal 4 is generated by the narrow-band tunable laser instrument, and its centre wavelength is at the 3dB of sensor fibre Bragg grating 3 reflectance spectrums point place, and make sensor fibre Bragg grating 3 have the highest sensitivity (being the working point) this moment; When the bearing 1 of fault is worked, the collision of its trouble spot and remaining part, can outwards send instantaneous spike, be acoustic emission signal 2, near the sensor fibre Bragg grating 3 that this acoustic emission signal 2 is coupled in the bearing receives, and causes that the centre wavelength of sensor fibre Bragg grating 3 changes, reflection output modulated light signal 5, this modulated light signal 5 is electric signal 6 by opto-electronic conversion, after amplification, gathering 7, carries out resonance and demodulation again and handles 8.
Sensor fibre Bragg grating 3, be reflectance spectrum three dB bandwidth less than the grating of 0.3nm, reflectivity is more than 90%.By the narrowband optical signal 4 that the narrow-band tunable laser instrument generates, its centre wavelength is at the 3dB of sensor fibre Bragg grating 3 reflectance spectrums point place, and make sensor fibre Bragg grating 3 have the highest sensitivity (being the working point) this moment.As shown in Figure 2, the centre wavelength of narrowband optical signal is modulated at sensor fibre Bragg grating 3 reflectance spectrum 3dB point places, spectrum maintains static, and the reflectance spectrum of sensor fibre Bragg grating 3 can be along with the effect (strain in the external world, stress, temperature etc.) drift about the generation, and then the convolution (being lap among Fig. 2) that causes the two changes, make the reflected light signal 5 of sensor fibre Bragg grating 3 change thereupon, change through showing as electric signal 6 after the opto-electronic conversion, namely know the external influence information that causes that sensor fibre Bragg grating 3 reflectance spectrums change by electric signal 6 being carried out demodulation.
When the bearing 1 of fault is worked, the collision of its trouble spot and remaining part, can outwards send instantaneous spike, it is acoustic emission signal 2, acoustic emission signal 2 belongs to stress wave, the sensor fibre Bragg grating 3 that is coupled near the material surface of bearing receives, changed the grid region Cycle Length of sensor fibre Bragg grating 3, simultaneously because elasto-optical effect causes the grid region variations in refractive index, cause the center emission wavelength of sensor fibre Bragg grating 3 to change, drift about reflectance spectrum takes place, output modulated light signal 5.
Modulated light signal 5 is electric signal 6 through opto-electronic conversion.Modulated light signal 5 is through reflection for several times, optical fiber interface, optical path loss etc., and signal is extremely faint, and has broad frequency band, so need to locate with bandwidth, signal to noise ratio (S/N ratio) height, the fast photodetector of slewing rate.
After electric signal 6 amplifications, collecting in the computing machine, carry out resonance and demodulation and handle 8.Because when out of order bearing moves, the acoustic emission signal 2 that the collision of trouble spot and remaining part is sent belongs to burst signal, it has characteristics such as signal spectrum is wide, low frequency signal content is abundant, this also makes acoustic emission signal 2 usually be flooded by low-frequency interference signal, can not effectively be analyzed.The resonance and demodulation algorithm is from the high-frequency signal content of acoustic emission signal 2: because acoustic emission signal 2 has wideer frequency spectrum, therefore it can cause the high-frequency resonance of bearing itself, by a bandpass filter with low-frequency interference signal and the filtering of ultrahigh frequency undesired signal, obtain the high-frequency signal through the resonance amplification, wherein also contain the failure message of bearing.Again the high-frequency signal after amplifying is carried out demodulation: use Hilbert transform (envelope detection) to extract the waveform of high-frequency signal, pass through low-pass filtering filtering high-frequency interferencing signal again, obtain comprising the low frequency signal of bearing fault information, after the FFT conversion, obtain the frequency spectrum of acoustic emission signal 2, the failure-frequency that theoretical formula or the experimental formula (Fig. 3) by bearing fault obtains can be learnt the fault type of bearing.Because in fact demodulation is the high-frequency resonance signal, therefore in bearing fault early signal intensity hour, also can detect fault-signal clearly owing to the resonance (resonance of signal plays amplification) of signal, really realize early detection and the type identification of helicopter bearing fault.Fig. 4 is resonance and demodulation algorithm synoptic diagram.Fig. 5, the 6th, the situation when application this method detects physical fault bearing (outer ring spot corrosion fault): when the axle rotating speed is respectively 600r/min and 1200r/min, adopt the rolling bearing fault time domain data of piezoelectric ceramics calibrate AE sensor and the collection of fiber grating calibrate AE sensor to utilize after the resonance and demodulation algorithm frequency domain data that obtains.
Find by contrast: the signal that fiber grating acoustic emission and piezoelectric ceramics acoustic emission detection method collect all can reflect bearing outer ring failure-frequency and frequency multiplication thereof effectively.The signal that the piezoelectric ceramics calibrate AE sensor collects is when the side frequency of analysis of failure frequency, and the interference that is subjected to composing back noise is comparatively serious; And that the fiber grating calibrate AE sensor collects at the bottom of the signal spectrum is comparatively clean, be conducive to analyze failure-frequency and frequency multiplication thereof, can tell simultaneously the side frequency composition of failure-frequency preferably, the order of severity that will help analysis of failure like this, side frequency is more many, and the ratio that the amplitude of side frequency accounts for the dominant frequency amplitude is more high, and then fault is more serious.Therefore, fiber grating acoustic emission detection method better effects if.In general, rotating speed more high (〉 600r/min), failure-frequency is more obvious; The working speed of helicopter bearing is generally higher, and this method has very strong specific aim.
Grating sensor collects at the bottom of the signal spectrum comparatively totally among Fig. 5,6, is because sensor does not have the intrinsic oscillation characteristics of piezoelectric sensor in essence.The acoustic emission signal of piezoelectric ceramics calibrate AE sensor collection is the stack (adding signals such as electromagnetic interference (EMI)) of the acoustic emission wave oscillator signal of the acoustic emission signal of acoustic emission source and piezoceramic transducer self, therefore basic noise is more, and the spectral line of failure-frequency is difficult for differentiating at the bottom of the background spectra.Adopt fiber grating acoustic emission detection device then not have such problem, because fiber-optic grating sensor itself does not exist an acoustic emission wave in the problem of sensor internal reciprocating vibration.This is to adopt fiber-optic grating sensor than the advantage on the piezoelectric ceramics sensor cardinal principle when carrying out the bearing fault signals collecting.Simultaneously, this method has the advantages that the electromagnetic interference (EMI) of not being subjected to influences.The fiber grating calibrate AE sensor is lighter, on installing and fixing, also has special advantages; Can carry out adaptability processing to sensor base material (organic glass) according to measured bearing (seat) size and dimension as the need encapsulation, improve coupling efficiency by increasing coupling area.
When implementing the detection of helicopter bearing fault, can be in conjunction with line service, when ground run, carry out under the stabilization of speed state, be applicable to the fault detect of helicopter rolling bearings such as tail transmission shaft spring bearing, rotor spring bearing, tail-rotor control handwheel bearing, engine, generator and other rotating machinery centre bearers.
Although above the illustrative embodiment of the present invention is described; so that the technician of present technique neck understands the present invention; but should be clear; the invention is not restricted to the scope of embodiment; to those skilled in the art; as long as various variations appended claim limit and the spirit and scope of the present invention determined in, these variations are apparent, all utilize innovation and creation that the present invention conceives all at the row of protection.
Claims (3)
1. the fiber grating acoustic emission detection method of helicopter bearing fault links to each other narrowband optical signal (4) with sensor fibre Bragg grating (3); Out of order bearing (1) can produce acoustic emission signal (2) at work, propagates through material and arrives sensor fibre Bragg grating (3), reflects modulated light signal (5); Modulated light signal (5) is electric signal (6) through opto-electronic conversion, and electric signal (6) carries out resonance and demodulation processing (8) again and obtains fault spectrum, thereby carry out fault distinguishing through after amplification, gathering (7);
Its feature may further comprise the steps:
Wherein narrowband optical signal (4) is generated by the narrow-band tunable laser instrument, and its centre wavelength makes sensor fibre Bragg grating (3) have the highest sensitivity (being the working point) at the 3dB point place of sensor fibre Bragg grating (3) reflectance spectrum; When the bearing (1) of fault is worked, the collision of its trouble spot and remaining part, can outwards send instantaneous spike, be acoustic emission signal (2), near the sensor fibre Bragg grating (3) that this acoustic emission signal (2) is coupled in the bearing receives, the centre wavelength that causes sensor fibre Bragg grating (3) changes, reflection output modulated light signal (5), this modulated light signal (5) is electric signal (6) by opto-electronic conversion, after amplification, gathering (7), carry out resonance and demodulation again and handle (8).
2. the fiber grating acoustic emission detection method of helicopter bearing fault according to claim 1, it is characterized in that: described sensor fibre Bragg grating (3) is coupled near the surface of the material the bearing: if sensor fibre Bragg grating (3) does not encapsulate, then be pasted on the surface of material with 502 glue; If sensor fibre Bragg grating (3) encapsulates, the sensor fibre Bragg grating (3) after then will encapsulating uses vaseline to be coupled in the surface of material and fixes by mightiness belt.
3. the fiber grating acoustic emission detection method of helicopter bearing fault according to claim 1, it is characterized in that: described sensor fibre Bragg grating (3) reflectance spectrum three dB bandwidth is less than 0.3nm, and the foveal reflex rate is greater than 90%, and side mode suppression ratio is less than 15dB.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013102195673A CN103344432A (en) | 2013-06-04 | 2013-06-04 | Method for detecting fiber bragg grating acoustic emission of helicopter bearing fault |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013102195673A CN103344432A (en) | 2013-06-04 | 2013-06-04 | Method for detecting fiber bragg grating acoustic emission of helicopter bearing fault |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103344432A true CN103344432A (en) | 2013-10-09 |
Family
ID=49279246
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013102195673A Pending CN103344432A (en) | 2013-06-04 | 2013-06-04 | Method for detecting fiber bragg grating acoustic emission of helicopter bearing fault |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103344432A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103674538A (en) * | 2013-12-18 | 2014-03-26 | 北京航天测控技术有限公司 | Multi-fault mode identification method and device of swashplate of helicopter |
| CN103693211A (en) * | 2013-12-25 | 2014-04-02 | 北京航天测控技术有限公司 | Test method for helicopter rotating part signal and wireless collecting device therefor |
| CN105004522A (en) * | 2015-07-15 | 2015-10-28 | 上海电机学院 | Blower fan shaft system fault diagnosing and state monitoring system based on optical signal |
| CN108139366A (en) * | 2015-07-30 | 2018-06-08 | 天津生态城数聚空间信息技术有限公司 | Health monitor method and system based on sound emission |
| CN108613733A (en) * | 2018-05-28 | 2018-10-02 | 黑龙江大学 | Resonant train bearing damage detection sensor based on fiber grating |
| CN109219921A (en) * | 2016-06-07 | 2019-01-15 | Abb瑞士股份有限公司 | The method and apparatus for the determination that the determination of torsional deflection for the rotary shaft in electro-mechanical powertrain and DC link degrade |
| CN109270346A (en) * | 2018-10-22 | 2019-01-25 | 贵州电网有限责任公司 | Polarization state waveform signal processing method at a kind of OPGW lightning stroke |
| CN110621971A (en) * | 2017-02-22 | 2019-12-27 | Cmte发展有限公司 | Optical acoustic sensing system and method |
| CN110672319A (en) * | 2019-10-11 | 2020-01-10 | 大连海事大学 | Large ship shafting centering safety state evaluation method based on attractor |
| WO2021198301A3 (en) * | 2020-03-30 | 2021-11-18 | Airbus Operations Limited | Sensor assembly |
| CN113984385A (en) * | 2021-10-25 | 2022-01-28 | 北京航空航天大学 | Armored vehicle gear box fault diagnosis method research based on optical fiber ring acoustic emission sensor |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102313779A (en) * | 2011-07-22 | 2012-01-11 | 北京航空航天大学 | Acoustic emission signal sensing system based on fiber Bragg grating |
| JP2012037480A (en) * | 2010-08-11 | 2012-02-23 | Ihi Inspection & Instrumentation Co Ltd | Ae measuring method and equipment by optical fiber sensor using wide band light |
| JP2012037479A (en) * | 2010-08-11 | 2012-02-23 | Ihi Inspection & Instrumentation Co Ltd | Ae measurement method and device for the same |
| CN102419348A (en) * | 2011-08-19 | 2012-04-18 | 北京航空航天大学 | Acoustic emission signal power type nondestructive detecting method based on fiber Bragg grating |
| CN102680581A (en) * | 2012-06-07 | 2012-09-19 | 北京航空航天大学 | Matched-type fiber-grating acoustic emission sensing method with temperature compensation |
| CN102914432A (en) * | 2012-10-24 | 2013-02-06 | 宣化钢铁集团有限责任公司 | Vibration and acoustic transmission signal regulation instrument for detecting mechanical faults |
| JP2013061162A (en) * | 2011-09-12 | 2013-04-04 | Ihi Inspection & Instrumentation Co Ltd | Measurement method and measurement device using fbg sensor |
-
2013
- 2013-06-04 CN CN2013102195673A patent/CN103344432A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012037480A (en) * | 2010-08-11 | 2012-02-23 | Ihi Inspection & Instrumentation Co Ltd | Ae measuring method and equipment by optical fiber sensor using wide band light |
| JP2012037479A (en) * | 2010-08-11 | 2012-02-23 | Ihi Inspection & Instrumentation Co Ltd | Ae measurement method and device for the same |
| CN102313779A (en) * | 2011-07-22 | 2012-01-11 | 北京航空航天大学 | Acoustic emission signal sensing system based on fiber Bragg grating |
| CN102419348A (en) * | 2011-08-19 | 2012-04-18 | 北京航空航天大学 | Acoustic emission signal power type nondestructive detecting method based on fiber Bragg grating |
| JP2013061162A (en) * | 2011-09-12 | 2013-04-04 | Ihi Inspection & Instrumentation Co Ltd | Measurement method and measurement device using fbg sensor |
| CN102680581A (en) * | 2012-06-07 | 2012-09-19 | 北京航空航天大学 | Matched-type fiber-grating acoustic emission sensing method with temperature compensation |
| CN102914432A (en) * | 2012-10-24 | 2013-02-06 | 宣化钢铁集团有限责任公司 | Vibration and acoustic transmission signal regulation instrument for detecting mechanical faults |
Non-Patent Citations (2)
| Title |
|---|
| 李孟源 等: "《声发射检测及信号处理》", 31 October 2010, 科学出版社, article "声发射原理", pages: 1-2 * |
| 梅宏斌: "《滚动轴承振动监测与诊断》", 30 November 1995, 机械工业出版社, article "共振解调原理", pages: 17-19 * |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103674538A (en) * | 2013-12-18 | 2014-03-26 | 北京航天测控技术有限公司 | Multi-fault mode identification method and device of swashplate of helicopter |
| CN103693211A (en) * | 2013-12-25 | 2014-04-02 | 北京航天测控技术有限公司 | Test method for helicopter rotating part signal and wireless collecting device therefor |
| CN103693211B (en) * | 2013-12-25 | 2016-09-21 | 北京航天测控技术有限公司 | The method of testing of a kind of helicopter rotary part signal and wireless collection equipment |
| CN105004522A (en) * | 2015-07-15 | 2015-10-28 | 上海电机学院 | Blower fan shaft system fault diagnosing and state monitoring system based on optical signal |
| CN105004522B (en) * | 2015-07-15 | 2017-10-27 | 上海电机学院 | Blower fan shaft system fault diagnosis and condition monitoring system based on optical signal |
| CN108139366A (en) * | 2015-07-30 | 2018-06-08 | 天津生态城数聚空间信息技术有限公司 | Health monitor method and system based on sound emission |
| CN109219921B (en) * | 2016-06-07 | 2022-12-27 | Abb瑞士股份有限公司 | Method and apparatus for determination of torsional deformation of a rotating shaft and determination of DC link degradation in an electromechanical drive train |
| CN109219921A (en) * | 2016-06-07 | 2019-01-15 | Abb瑞士股份有限公司 | The method and apparatus for the determination that the determination of torsional deflection for the rotary shaft in electro-mechanical powertrain and DC link degrade |
| CN110621971A (en) * | 2017-02-22 | 2019-12-27 | Cmte发展有限公司 | Optical acoustic sensing system and method |
| CN108613733A (en) * | 2018-05-28 | 2018-10-02 | 黑龙江大学 | Resonant train bearing damage detection sensor based on fiber grating |
| CN109270346A (en) * | 2018-10-22 | 2019-01-25 | 贵州电网有限责任公司 | Polarization state waveform signal processing method at a kind of OPGW lightning stroke |
| CN110672319A (en) * | 2019-10-11 | 2020-01-10 | 大连海事大学 | Large ship shafting centering safety state evaluation method based on attractor |
| WO2021198301A3 (en) * | 2020-03-30 | 2021-11-18 | Airbus Operations Limited | Sensor assembly |
| CN113984385A (en) * | 2021-10-25 | 2022-01-28 | 北京航空航天大学 | Armored vehicle gear box fault diagnosis method research based on optical fiber ring acoustic emission sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103344432A (en) | Method for detecting fiber bragg grating acoustic emission of helicopter bearing fault | |
| CN102680581B (en) | Matched-type fiber-grating acoustic emission sensing method with temperature compensation | |
| US9146095B2 (en) | FBG vibration detection system, apparatus and vibration detection method using the system | |
| CN102507205B (en) | Method for checking vibration fault of fan blade of aerial engine | |
| CN106680535B (en) | The differential-type optical accelerometer of laser beat frequency is realized based on Fiber Bragg Grating Reflective Spectrum Characteristics | |
| CN201892569U (en) | High-sensitivity and low-frequency vibrating sensor based on MMF-TFBG optical fiber structure | |
| CN101109649A (en) | Optical fiber grating sensing measuring method and device for detecting running state of rotating machine | |
| CN105277271A (en) | Ultrasonic vibrating phase shift fiber grating sensing detection system and application thereof | |
| JP5586009B2 (en) | Vibration detection system, apparatus using the system, and vibration detection method | |
| CN103245913B (en) | The method and system of Generator Set sub-synchronous oscillation input and analysis | |
| CN105277270A (en) | Dual-mode vibration detection system based on fiber grating sensing | |
| CN103487133A (en) | Method and device for improving signal to noise ratio of laser micro-vibration sensing system | |
| CN109799435A (en) | A kind of local discharge sensor combining graphene diaphragm and micro optical fiber interference cavity and the detection method based on this | |
| CN107389978A (en) | A kind of weak reflective Bragg gratings accelerometer and its method for sensing | |
| CN103472136A (en) | Acoustic emission sensing system based on single mode fiber coupler | |
| Bachar et al. | Fault diagnosis of gear transmissions via optic Fiber Bragg Grating strain sensors | |
| CN107976264B (en) | System and method for simultaneously demodulating distributed temperature and fiber bragg grating by using fiber Raman scattering light | |
| CN204359896U (en) | For the Fiber Bragg Grating ultrasonic wave detecting system that electrical network local discharge of electrical equipment detects | |
| CN101769762B (en) | Sensing demodulating system for optical chirped-grating | |
| CN102692268B (en) | Distributed optical fiber vibration sensor for structural vibration detection | |
| CN102095892B (en) | Fiber bragg grating acceleration transducer based on fabrication structure | |
| CN202075306U (en) | FBG (fiber bragg grating) acceleration transducer based on tapered structure | |
| CN201993214U (en) | Distributed optical fiber vibrating sensor for structural vibration detection | |
| CN107422037A (en) | A kind of matching Fiber Bragg Grating FBG of contrast type surveys ultrasonic signal method for sensing | |
| CN107703326A (en) | A kind of compact detonation rate measuring system based on chirped fiber grating |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20131009 |