CN115183799A - Strain and structure body vibration simultaneous measurement system and method based on grating - Google Patents
Strain and structure body vibration simultaneous measurement system and method based on grating Download PDFInfo
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- G—PHYSICS
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- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/36—Forming the light into pulses
- G01D5/38—Forming the light into pulses by diffraction gratings
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- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
- G01B11/165—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge by means of a grating deformed by the object
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Abstract
The invention relates to a strain and structure body vibration simultaneous measurement system and method based on a grating, wherein the system comprises: the device comprises a light source generator, a light path transmitter, a charge coupler, a photoelectric detector and a data analysis end; wherein the light source generator is used for generating an initial light source signal; the optical path transmitter is used for processing the initial light source signal to obtain a reflected light signal, and dividing the reflected light signal into a first light source signal and a second light source signal for transmission; the charge coupler is used for converting the first light source signal into a spectral electric signal; the photoelectric detector is used for converting the second light source signal into an intensity electric signal; the data analysis end is used for demodulating and analyzing the spectrum electric signal and the intensity electric signal. The invention solves the problems that a plurality of sensing gratings are needed when strain and vibration are measured simultaneously and the complexity of a demodulation system is high.
Description
Technical Field
The invention relates to the technical field of health monitoring, in particular to a system and a method for simultaneously measuring strain and structural body vibration based on a grating.
Background
With the rapid development of national infrastructure, the problems and hidden dangers brought by the fatigue damage of the structure body are more and more, and in order to prevent the greater economic property loss and even casualties brought by the fatigue damage, the health monitoring of the structure body becomes a very important protective measure. The sensor is an effective means for acquiring the structural health condition, and plays a vital role in the process of solving various engineering application problems. Among them, the electric sensor is the most widely used sensor type, and due to its electric driving principle and the defect that it is difficult to perform distributed measurement, an obvious short plate is exposed in the fields of large-scale civil engineering, petrochemical industry and the like where electric sparks need to be avoided. The optical fiber sensor takes light waves as a carrier and optical fibers as a transmission medium, and has very excellent performance in measuring various parameters such as temperature, humidity, strain, vibration and the like. Among a plurality of optical fiber sensing methods, weak grating array sensing is one of the most representative methods, and the method has the advantages of small occupied volume, light weight, high sensitivity, electromagnetic interference resistance, distributed measurement and the like.
In various large-scale engineering and structural body health monitoring scenes, the measurement requirements of strain and vibration parameters are great, for example, the strain parameters of the structural body are used for calculating the stress condition of the structural body, and the change of the natural vibration frequency of the structural body is used for estimating the structural health condition of the structural body. Ordinary electric sensor can't deal with the environment of strict insulation and be difficult to accomplish and measure the distributing type, and weak grating array sensing technique then can be fine deals with this type of sensing environment, satisfies the monitoring demand.
However, the weak grating array sensing technology still has many problems in the situation of simultaneously measuring strain and vibration parameters, although the change of the strain parameters can be reflected by the central wavelength data of the sensing grating, the vibration frequency is difficult to directly obtain, and a few vibration measuring systems combining the interference principle and the grating sensing are greatly influenced by noise, and most of the systems need an extra time delay optical fiber to be matched with the sensing optical fiber, so that the system structure is more complex, and the robustness is poor. The too complex of the vibration measurement system also brings great challenges to the requirement of simultaneously measuring strain and vibration by using a single sensing optical fiber, and the strain measurement system and the vibration measurement system are directly superposed and are difficult to play a role in a complex engineering environment.
Disclosure of Invention
In view of this, it is necessary to provide a grating-based strain and structure vibration simultaneous measurement system and a grating-based strain and structure vibration simultaneous measurement method, which are used to solve the problems in the prior art that an extra time delay optical fiber is required to be matched with a sensing optical fiber when strain and vibration are measured simultaneously, so that the system structure is more complicated and the robustness is poor.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a grating-based simultaneous strain and structure vibration measurement system, comprising: the device comprises a light source generator, a light path transmitter, a charge coupler, a photoelectric detector and a data analysis end; the light source generator is connected with the optical path transmitter, the optical path transmitter is respectively connected with the charge coupler and the photoelectric detector, and the charge coupler and the photoelectric detector are respectively connected with the data analysis end;
wherein, the light source generator is used for generating an initial light source signal; the light path transmitter is used for processing the initial light source signal to obtain a reflected light signal, and dividing the reflected light signal into a first light source signal and a second light source signal for transmission; the charge coupler is used for converting the first light source signal into a spectral electric signal; the photoelectric detector is used for converting the second light source signal into an intensity electric signal; and the data analysis end is used for demodulating and analyzing the spectrum electric signal and the intensity electric signal.
Preferably, the optical path transmitter comprises a band-pass filter, a light source amplifier, an optical circulator, a grating sensing array and an optical coupler; the band-pass filter, the light source amplifier, the optical circulator and the grating sensing array are sequentially connected; the optical coupler is connected with the optical circulator;
the band-pass filter is used for filtering an initial light source signal to obtain an optical signal with a preset bandwidth; the light source amplifier is used for amplifying the optical signal with the preset bandwidth; the grating sensing array is used for transmitting the amplified preset bandwidth optical signal and sensing and collecting strain and vibration information; the optical coupler is used for dividing the preset bandwidth optical signal after information acquisition into a first light source signal and a second light source signal.
Preferably, the system also comprises an FPGA module; the FPGA module is connected with the light source amplifier;
the FPGA module is used for controlling and recording the modulation process of the optical signal and carrying out addressing query on the grating.
Preferably, the system also comprises a first data acquisition card and a second data acquisition card; the first data acquisition card is respectively and electrically connected with the charge coupler and the data analysis end; the second data acquisition card is respectively and electrically connected with the photoelectric detector and the data analysis end;
the first data acquisition card is used for acquiring the spectral electric signals and transmitting the spectral electric signals to the data analysis end; the second data acquisition card is used for acquiring the intensity electric signal and transmitting the intensity electric signal to the data analysis end.
In a second aspect, the present invention further provides a method for simultaneously measuring strain and structural body vibration based on a grating, where the system for simultaneously measuring strain and structural body vibration based on a grating includes:
the light path transmitter transmits an initial light source signal generated by the light source generator to obtain a reflected light signal;
the optical path transmitter divides the reflected light signal into a first light source signal and a second light source signal;
the charge coupler acquires a spectral electric signal according to the first light source signal, and the photoelectric detector acquires an intensity electric signal according to the second light source signal;
and analyzing the spectrum electric signal and the intensity electric signal through a data analysis end to obtain strain information and frequency information.
Preferably, the optical path transmitter transmits the initial light source signal generated by the light source generator to obtain the reflected light signal, and includes:
filtering and amplifying the initial light source signal to obtain a pulse light signal;
fixing the grating sensing array on the structural body, and applying a preset stress to the structural body;
and transmitting the pulse light signals to a grating sensing array, and collecting the spectrum signals and the intensity signals to obtain reflected light signals.
Preferably, the transmitting the collected light signal to the grating sensor array, collecting the spectrum signal and the intensity signal, and obtaining the reflected light signal includes:
based on the grating sensing array, the pulse light signals are reflected by the grating to obtain reflected light signals; acquiring spectral information and intensity information of the reflected light signals respectively by collecting the reflected light signals; preferably, the charge-coupled device obtains the spectrum electrical signal according to the first light source signal, and the photodetector obtains the intensity electrical signal according to the second light source signal, and the charge-coupled device includes:
the charge coupler converts the first reflected optical signal into a spectral electrical signal;
the photodetector converts the second reflected light signal into an electrical intensity signal.
Preferably, the analyzing the spectrum electric signal through the data analysis end to obtain the strain information includes:
the data analysis end analyzes the spectrum electric signal to obtain a spectrum;
and the data analysis end determines the drift of the central wavelength according to the spectrum to obtain strain information.
Preferably, the analyzing the intensity electrical signal by the data analyzing terminal to obtain the frequency information includes:
the data analysis end continuously collects the intensity electric signals and records the light intensity periodic variation caused by the left and right deviation of the central wavelength;
and the data analysis end performs Fourier demodulation on the light intensity periodic variation to obtain frequency information.
The beneficial effects of adopting the embodiment are as follows: the invention provides a system and a method for simultaneously measuring strain and structural body vibration based on a grating, wherein an initial light source generated by a light source generator transmits the initial light source to a sensing grating array with consistent central wavelength through a light path transmitter to obtain vibration and strain related information, then the light after the information is obtained is divided into two paths, the two paths of light respectively convert optical signals into strain information and vibration information through a charge coupler and a photoelectric detector, and additional time delay optical fibers are not required to be added to be matched with the sensing optical fibers, so that the complexity of the system structure is reduced, the robustness of the system is improved, then the strain information and the vibration information are transmitted to a data analysis end to be processed, the measurement of the strain and the vibration is completed, the strain and the vibration parameters are simultaneously measured through one set of sensing system, the time delay optical fibers are omitted compared with an interference vibration measuring system, the complicated interference arm matching step is omitted, the structure of the system is simpler, and the noise resistance of the system is improved.
Drawings
FIG. 1 is a structural frame diagram of an embodiment of a system for simultaneously measuring strain and vibration of a structure based on a grating according to the present invention;
FIG. 2 is a schematic structural diagram of an embodiment of a distributed weak grating sensor array provided in the present invention;
FIG. 3 is a schematic flow chart diagram illustrating one embodiment of a method for simultaneously measuring strain and structure vibration based on a grating according to the present invention;
fig. 4 is a schematic wavelength diagram of an embodiment of a center wavelength of a grating provided in the present invention.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
The invention provides a system and a method for simultaneously measuring strain and structural body vibration based on a grating, which are respectively explained below.
Referring to fig. 1, fig. 1 is a structural frame diagram of an embodiment of a system for simultaneously measuring strain and structural body vibration based on a grating according to the present invention, and an embodiment of the present invention discloses a system for simultaneously measuring strain and structural body vibration based on a grating, including: a light source generator 10, an optical path transmitter 20, a charge coupler 30, a photodetector 40 and a data analysis end 50; the light source generator 10 is connected with the optical path transmitter 20, the optical path transmitter 20 is respectively connected with the charge coupler 30 and the photoelectric detector 40, and the charge coupler 30 and the photoelectric detector 40 are respectively connected with the data analysis end 50;
wherein, the light source generator 10 is used for generating an initial light source signal; the optical path transmitter 20 is configured to process the initial light source signal to obtain a reflected light signal, and divide the reflected light signal into a first light source signal and a second light source signal for transmission; the charge coupler 30 is used for converting the first light source signal into a spectral electric signal; the photodetector 40 is used for converting the second light source signal into an intensity electrical signal; the data analysis end 50 is used for demodulating and analyzing the spectrum electric signal and the intensity electric signal.
In the above embodiment, the light source generator 10 is a broadband light source (ASE), and the broadband light source emits a light beam with an initial bandwidth, it is understood that the light source generator 10 of the present invention may also be other light sources as long as it can emit a light source that is stable and meets the measurement requirement.
The optical path transmitter 20 includes a plurality of components, the optical path transmitter 20 not only is used for transmitting the light beam, but also can process the light beam, the stability of the light during information acquisition is improved, so that the accuracy of the information acquisition is improved, and a grating sensing array which senses strain and vibration and has a consistent center wavelength is also included.
The CCD, which is an acronym for charge coupled device, i.e. charge coupler 30, is a special semiconductor device with many identical photosensitive elements, called pixels. In this embodiment, the charge coupler 30 is used to convert the optical signal reflected by the grating into an electrical signal, so as to facilitate processing of the spectral information reflected by the grating, and the working wavelength range of the CCD covers the central wavelength of the grating, thereby ensuring that the central wavelength of the grating is within the working range of the charge coupler 30.
Photodetector 40 (PD) operates on the principle that radiation causes a change in the conductivity of the irradiated material. The device is used for detecting the intensity information of the light reflected by the grating and converting the light intensity signal into an electric signal for demodulating the vibration frequency. It should be noted that the present embodiment does not further limit the specific models of the charge-coupled device 30CCD and the photodetector 40 (PD).
Compared with the prior art, according to the system for simultaneously measuring strain and structural body vibration based on the grating, the initial light source generated by the light source generator transmits the initial light source through the light path transmitter to obtain the information related to vibration and strain, the light after the information is obtained is divided into two paths, the two paths of light respectively convert the light signals into the strain information and the vibration information through the charge coupler and the photoelectric detector, additional time delay optical fibers do not need to be added to be matched with the sensing optical fibers, the complexity of the system structure is reduced, the robustness of the system is improved, then the strain information and the vibration information are transmitted to the data analysis end to be processed, the measurement of the strain and the vibration is completed, the strain and the vibration parameters are simultaneously measured through one set of sensing system, the time delay optical fibers are omitted compared with an interference vibration measurement system, the complicated interference arm matching step is omitted, the structure of the system is simpler, and the noise resistance of the system is improved.
In some embodiments of the present invention, the optical path transmitter 20 includes a band pass filter, a light source amplifier, an optical circulator, a grating sensing array, and an optical coupler; the band-pass filter, the light source amplifier, the optical circulator and the grating sensing array are sequentially connected; the optical coupler is connected with the optical circulator;
the band-pass filter is used for filtering an initial light source signal to obtain an optical signal with a preset bandwidth; the light source amplifier is used for amplifying the optical signal with the preset bandwidth; the grating sensing array is used for transmitting the amplified preset bandwidth optical signal and acquiring information; the optical coupler is used for dividing the preset bandwidth optical signal after information acquisition into a first light source signal and a second light source signal.
In the above embodiments, the Band Pass Filter (BPF) is used to filter the broadband light emitted from the light source to generate the narrow-band light, i.e., the preset-bandwidth light.
The light source amplifier is a semiconductor laser (SOA), plays a role in amplifying light, and is also used as an optical switch to be matched with the FPGA module to complete modulation of the pulse light source.
The light source amplifier also comprises an erbium-doped fiber amplifier (EDFA) which is used for carrying out secondary amplification on the pulse light so that the pulse light source can obtain sufficiently strong reflected light when irradiating the low-reflectivity weak grating.
The optical circulator is a multi-port optical device with nonreciprocal characteristics. The optical signal is input from the first port, enters the second port, and reaches the third port through grating reflection, and the loss is large when the optical signal is reversed, so that the optical signal becomes an unconnected port.
Referring to fig. 2, fig. 2 is a schematic structural diagram of an embodiment of a distributed weak grating sensor array according to the present invention, where the grating sensor array is a distributed weak grating sensor array (FBG) for sensing an amplified light beam and acquiring data from the distributed weak grating sensor array, in this embodiment, the number of gratings is more than three, and the central wavelengths of all gratings are consistent.
The optical coupler is a 1-to-2 coupler and is used for dividing the light after information acquisition into two light beams to realize different processing on the light beams.
In some embodiments of the invention, further comprising an FPGA module; the FPGA module is connected with the light source amplifier;
the FPGA module is used for controlling and recording the modulation process of the optical signal and carrying out addressing query on the grating.
In the above embodiment, the FPGA module is a field programmable gate array module, and the parameter of the pulsed light can be adjusted by programming through the FPGA module, so that the pulsed light can be controlled and the modulation process of the pulsed light can be recorded, and the addressing query of each grating can be realized by programming.
In some embodiments of the invention, a first data acquisition card and a second data acquisition card are also included; the first data acquisition card is respectively and electrically connected with the charge coupler 30 and the data analysis end 50; the second data acquisition card is respectively and electrically connected with the photoelectric detector 40 and the data analysis end 50;
the first data acquisition card is used for acquiring the spectrum electric signal and transmitting the spectrum electric signal to the data analysis end 50; the second data acquisition card is used for acquiring the intensity electrical signal and transmitting the intensity electrical signal to the data analysis terminal 50.
In the above embodiment, the first data acquisition card and the second data acquisition card are DAQs, and are used for acquiring the reflected light signal data and transmitting the reflected light signal data to the PC terminal (data analysis terminal 50) for data processing and demodulation.
Referring to fig. 3, fig. 3 is a schematic flow chart of an embodiment of a method for simultaneously measuring strain and structure vibration based on a grating according to the present invention, and in some aspects of the embodiment of the present invention, the present invention further provides a method for simultaneously measuring strain and structure vibration based on a grating, where the system for simultaneously measuring strain and structure vibration based on a grating includes:
s301, transmitting an initial light source signal generated by a light source generator by a light path transmitter to obtain a reflected light signal;
s302, the optical path transmitter divides the reflected light signal into a first light source signal and a second light source signal;
s303, acquiring a spectral electric signal by the charge coupler according to the first light source signal, and acquiring an intensity electric signal by the photoelectric detector according to the second light source signal;
s304, analyzing the spectrum electric signal and the intensity electric signal through a data analysis end to obtain strain information and frequency information.
In the above embodiment, the light source generator 10 generates an initial light source, the initial light source is transmitted through the optical path transmitter 20, information related to vibration and strain is obtained from the grating sensor array, the light after the information is obtained is divided into two paths by the optical coupler, the strain information and the vibration information are respectively analyzed from the two paths of light by the charge coupler 30 and the photodetector 40, and finally the strain information and the vibration information are transmitted to the data analysis terminal 50 for processing, and the strain information and the frequency information are analyzed from the two paths of light.
Compared with an interference vibration measurement system, a time delay optical fiber is omitted, the system structure is simpler, complicated interference arm matching steps are omitted, addressing inquiry of each grating is completed by using a pulse light source, the position of the grating is conveniently and accurately searched and positioned in the measurement process, and the problems that the anti-noise performance is poor and the system robustness is not high in the traditional interference type optical fiber vibration measurement system are solved.
Referring to fig. 4, fig. 4 is a wavelength diagram of an embodiment of a central wavelength of a grating provided by the present invention, in some embodiments of the present invention, an optical path transmitter transmits an initial light source signal generated by a light source generator to obtain a reflected light signal, including:
amplifying and filtering the initial light source signal to obtain an acquired light signal;
fixing the grating sensing array on a structural body, and applying a preset stress to the structural body;
and transmitting the collected optical signals to a grating sensing array, and collecting the spectrum signals and the intensity signals to obtain reflected optical signals.
In the above embodiment, when the distributed weak grating sensor array is fixed on the structure, a certain pre-stress is applied to the structure to drive the structure to move, when the structure is strained, the grating is driven to deform, and when the structure vibrates, each part of the optical fiber starts to vibrate back and forth in the direction perpendicular to the chord length under the action of external force. In the whole process, pulse light is input into the distributed weak grating sensing array and then reflected back to the optical circulator, and reflected light with spectrum signals and intensity signals can be obtained.
In some embodiments of the present invention, emitting the pulsed light signal to the grating sensor array, and collecting the spectrum signal and the intensity signal to obtain a series of reflected pulsed light signals includes:
based on the grating sensing array, the pulse optical signals are reflected by the grating to obtain reflected optical signals;
by collecting the reflected light signals, the spectrum information and the intensity information are respectively obtained.
In the above embodiment, when the pulsed light passes through the distributed weak grating sensing array, the grating deformation and the optical fiber vibration in the distributed weak grating sensing array will affect the drift and the left-right shift of the central wavelength of the pulsed light, and the pulsed light can be recorded when passing through the distributed weak grating sensing array.
In some embodiments of the present invention, the charge-coupled device obtaining a spectral electrical signal from a first light source signal and the photodetector obtaining an intensity electrical signal from a second light source signal comprises:
the charge coupler converts the first reflected optical signal into a spectral electrical signal;
the photodetector converts the second reflected light signal into an electrical intensity signal.
In the above embodiment, the charge-coupled device 30 is used to convert the optical signal reflected by the grating into an electrical signal, so as to facilitate processing of the spectral information reflected by the grating, and ensure that the central wavelength of the grating is within the operating range of the charge-coupled device 30. And the photoelectric detector 40 is used for detecting the intensity information of the light reflected by the grating and converting the light intensity signal into an electric signal for demodulating the vibration frequency.
In some embodiments of the present invention, the analyzing the spectral electrical signal by the data analyzing end 50 to obtain the strain information includes:
the data analysis end 50 analyzes the spectrum electric signal to obtain a spectrum;
the data analysis end 50 determines the shift of the central wavelength according to the spectrum, and obtains strain information.
In the above embodiment, the reflected light converts the optical signal with the strain signal into an electrical signal through the CCD, then the electrical signal is sent to the data acquisition end, the data acquisition end performs data acquisition, and sends the acquired electrical signal to the data analysis end 50, and then the data analysis end 50 (PC end) demodulates the spectrum, and the measurement of the strain parameter is completed by observing the shift of the reflection peak center wavelength, that is, the strain information is analyzed.
In some embodiments of the present invention, the analyzing the intensity electrical signal by the data analysis end 50 to obtain the frequency information includes:
the data analysis end continuously collects the intensity electric signals and records the light intensity periodic variation caused by the left and right deviation of the central wavelength;
and the data analysis end performs Fourier demodulation on the light intensity periodic variation to obtain frequency information.
In the above embodiment, the reflected light converts the optical signal with the vibration signal into an electrical signal through the PD, and then sends the electrical signal to the data acquisition end, and the data acquisition end performs data acquisition, and sends the acquired electrical signal to the data analysis end 50, and then the data analysis end 50 (PC end) performs fourier demodulation, so as to obtain the frequency information of the vibration.
The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be considered as limiting the present application.
The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also within the scope of the present invention.
Claims (10)
1. A grating-based simultaneous strain and structure vibration measurement system, comprising: the device comprises a light source generator, a light path transmitter, a charge coupler, a photoelectric detector and a data analysis end; the light source generator is connected with the optical path transmitter, the optical path transmitter is respectively connected with the charge coupler and the photoelectric detector, and the charge coupler and the photoelectric detector are respectively connected with the data analysis end;
wherein the light source generator is used for generating an initial light source signal; the optical path transmitter is used for processing the initial light source signal to obtain a reflected light signal, and dividing the reflected light signal into a first light source signal and a second light source signal for transmission; the charge coupler is used for converting the first light source signal into a spectral electric signal; the photoelectric detector is used for converting the second light source signal into an intensity electric signal; the data analysis end is used for demodulating and analyzing the spectrum electric signal and the intensity electric signal.
2. The grating-based strain and structure vibration simultaneous measurement system of claim 1, wherein the optical path transmitter comprises a band pass filter, a light source amplifier, an optical circulator, a grating sensing array, and an optical coupler; the band-pass filter, the light source amplifier, the optical circulator and the grating sensing array are sequentially connected; the optical coupler is connected with the optical circulator;
the band-pass filter is used for filtering the initial light source signal to obtain an optical signal with a preset bandwidth; the light source amplifier is used for amplifying the preset bandwidth optical signal; the grating sensing array is used for transmitting the amplified preset bandwidth optical signal and sensing and collecting strain and vibration information; the optical coupler is used for dividing the preset bandwidth optical signal after information acquisition into a first light source signal and a second light source signal.
3. The grating-based simultaneous strain and structure vibration measurement system of claim 2, further comprising an FPGA module; the FPGA module is connected with the light source amplifier;
the FPGA module is used for controlling and recording the modulation process of the optical signal and carrying out addressing query on the grating.
4. The system for simultaneously measuring strain and vibration of a structure based on a grating of claim 2, further comprising a first data acquisition card and a second data acquisition card; the first data acquisition card is respectively and electrically connected with the charge coupler and the data analysis end; the second data acquisition card is respectively and electrically connected with the photoelectric detector and the data analysis end;
the first data acquisition card is used for acquiring the spectral electric signal and transmitting the spectral electric signal to the data analysis end; the second data acquisition card is used for acquiring the intensity electric signal and transmitting the intensity electric signal to the data analysis end.
5. A grating-based strain and structure vibration simultaneous measurement method, based on the grating-based strain and structure vibration simultaneous measurement system of any one of claims 1 to 4, comprising:
the light path transmitter transmits the initial light source signal generated by the light source generator to obtain a reflected light signal;
the optical path transmitter divides the reflected light signal into a first light source signal and a second light source signal;
the charge coupler acquires the spectrum electric signal according to the first light source signal, and the photoelectric detector acquires the intensity electric signal according to the second light source signal;
and analyzing the spectrum electric signal and the intensity electric signal through the data analysis end to obtain strain information and frequency information.
6. The method of claim 5, wherein the optical path transmitter transmits an initial light source signal generated by the light source generator to obtain a reflected light signal, and the method comprises:
filtering and amplifying the initial light source signal to obtain a pulse light signal;
fixing the grating sensing array on a structural body, and applying a preset stress to the structural body;
and transmitting the pulse light signal to the grating sensing array, and collecting a spectrum signal and an intensity signal to obtain a reflected light signal.
7. The method of claim 6, wherein the transmitting the collected light signal to the grating sensor array, collecting a spectrum signal and an intensity signal, and obtaining a reflected light signal comprises:
based on the grating sensing array, the pulse light signals are reflected by the grating to obtain reflected light signals;
and acquiring spectral information and intensity information of the reflected light signals respectively by collecting the reflected light signals.
8. The method of claim 5, wherein the step of acquiring the electrical spectral signal from the first light source signal and the electrical intensity signal from the second light source signal by the charge coupler and the photodetector comprises:
the charge coupler converts the first reflected optical signal into a spectral electrical signal;
the photodetector converts the second reflected light signal into an electrical intensity signal.
9. The method for simultaneously measuring strain and structural body vibration based on the grating as claimed in claim 5, wherein the analyzing the spectrum electric signal through the data analysis end to obtain strain information comprises:
the data analysis end analyzes the spectrum electric signal to obtain a spectrum;
and the data analysis end determines the drift of the central wavelength according to the spectrum to obtain strain information.
10. The method of claim 5, wherein analyzing the electrical intensity signal by the data analysis port to obtain frequency information comprises:
the data analysis end continuously collects the intensity electric signals and records the light intensity periodic variation caused by the left and right deviation of the central wavelength;
and the data analysis end performs Fourier demodulation on the light intensity periodic variation to obtain frequency information.
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