A fiber grating high-speed sensing system for pressure detection

Abstract

The application relates to the technical field of optical fiber sensing and pressure monitoring, and discloses a fiber grating high-speed sensing system for pressure detection. The system comprises a light source module, a sensor module and a detection, collection and demodulation module. The light source module is based on an MG-Y tunable laser and outputs high-speed linear scanning light; the sensor module is composed of a pressure conduction device, a pressure testing device, a temperature compensation device, a sealed shell and a fixing structure, and converts the measured pressure and environmental temperature change into optical signals with different wavelength drift characteristics; the detection, collection and demodulation module adopts high-speed photoelectric detection and a double-FPGA processing unit to synchronously collect and real-timely demodulate the reflected spectrum. The application is collaboratively designed through a pressure conversion structure and an MG-Y high-speed sweep frequency demodulation platform, high-precision, high-stability and high-speed real-time detection of pressure signals are realized, different ranges can be expanded by changing the thickness of the pressure diaphragm, and long-term creep drift is reduced through an oxygen-free glue welding fixing mode.

Description

Technical Field

[0001] This invention relates to the field of fiber optic sensing and pressure monitoring technology, specifically to a high-speed fiber optic grating sensing system for pressure detection. Background Technology

[0002] Pressure testing is widely used in pressure pipelines, hydraulic systems, storage and transportation equipment, and process industrial plants. The test results directly affect equipment safety, process stability, and fault early warning capabilities. Existing pressure testing solutions mostly employ pressure transmitters, resistance strain gauges, or corrugated diaphragm pressure gauges, which suffer from problems such as susceptibility to electromagnetic interference, difficulty in long-term stable operation in flammable and explosive environments, limited long-distance transmission capabilities, and difficulties in multi-point networking. Furthermore, for scenarios with pulsating pressure or rapid pressure changes, there are limitations in sampling speed and real-time performance.

[0003] Fiber Bragg grating (FBG) sensors offer advantages such as immunity to electromagnetic interference, intrinsic safety, long-distance transmission capability, ease of cascading and multiplexing, and suitability for online monitoring, making them suitable for pressure condition monitoring. Existing mechanical fiber Bragg grating pressure sensors can convert external pressure into grating axial strain or displacement via a pressure diaphragm, but there is still room for improvement in areas such as range adaptability, long-term creep drift, and temperature cross-sensitivity.

[0004] On the other hand, the overall performance of the fiber grating demodulation system is limited by the stability of the swept frequency light source, the linearity of the driving wavelength, the signal-to-noise ratio of the reflected spectrum acquisition, and the calibration and demodulation algorithms.

[0005] Therefore, there is an urgent need to provide a system solution that integrates a highly stable pressure sensor head with a high-precision MG-Y high-speed sweep frequency demodulation platform to simultaneously address the issues of universal range adaptation, temperature compensation, long-term stability, and high-speed real-time demodulation for pressure sensors. Summary of the Invention

[0006] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a high-speed fiber optic grating sensing system for pressure detection, solving the problems of insufficient sensor versatility and stability, and limited real-time performance and accuracy of demodulation systems in the prior art.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: In a first aspect, the present invention provides a fiber optic grating high-speed sensing system for pressure detection, the system comprising a light source module, a sensor module, and a detection, acquisition, and demodulation module; The output of the light source module is connected in sequence to the input of the optical isolator and the optical circulator. The first port of the optical circulator is connected to the sensor module, and the second port of the optical circulator is connected to the detection, acquisition and demodulation module. The light source module is used to output scanning light signals covering the operating wavelength band of the fiber optic grating sensor; The sensor module converts the measured pressure and ambient temperature changes into fiber optic grating reflection signals with different center wavelength drift characteristics; The detection, acquisition, and demodulation module is used to perform photoelectric conversion, synchronous sampling, wavelength calibration, and demodulation processing on the reflected signal to obtain the measured pressure value after temperature compensation.

[0008] Preferably, in one possible implementation of the first aspect, the light source module includes an MG-Y tunable laser, a tunable drive current source, a temperature control unit, and a control unit; The tunable drive current source provides drive current to the main gain region, left and right gate regions, phase control region and semiconductor optical amplifier of the MG-Y tunable laser, respectively. The temperature control unit includes a semiconductor cooler, an NTC temperature sensor, and a PID closed-loop controller, which is used to perform closed-loop temperature control on the MG-Y tunable laser chip. The control unit is used to output linear scan or segmented scan control sequences.

[0009] Preferably, in one possible implementation of the first aspect, the tunable drive current source includes a DAC digital-to-analog converter, a multi-stage amplifier circuit, a sampling resistor, and a feedback adjustment circuit; The DAC digital-to-analog converter outputs an analog control voltage, which is then converted into the driving current required by each electrode of the MG-Y tunable laser through a multi-stage amplification circuit. The feedback adjustment circuit performs closed-loop correction on the drive circuit based on the output current detected by the sampling resistor.

[0010] Preferably, in one possible implementation of the first aspect, the sensor module includes a pressure transmitting device, a pressure testing device, a temperature compensation device, and a sealed housing; The pressure transmission device is provided with an external threaded interface or flange interface at the front end for connecting to the pressure system being measured, and an elastic pressure diaphragm at the rear end. The pressure testing device is connected to the pressure transmission device and is encapsulated with a force-measuring fiber optic grating and a temperature-compensating fiber optic grating. The sealed housing is connected to the pressure transmission device to achieve sealed protection for the internal components.

[0011] Preferably, in one possible implementation of the first aspect, the pressure transmission device converts the pressure of the measured medium into a change in the deflection at the center of the diaphragm via a pressure diaphragm, and the pressure testing device converts the change in the deflection at the center of the diaphragm into the axial compression of the force-measuring fiber optic grating. The diameter of the pressure diaphragm is fixed or limited to a predetermined range, and the equivalent consistency of the change in the center deflection of the diaphragm under different ranges is achieved by changing the thickness of the pressure diaphragm.

[0012] Preferably, in one possible implementation of the first aspect, the force-measuring fiber optic grating is in a pre-stretched state during assembly and is gradually compressed as the pressure increases; The force-measuring fiber optic grating and / or temperature-compensating fiber optic grating are mounted on the pressure testing device using oxygen-free adhesive welding or low-creep fixing methods to reduce long-term zero-point drift caused by colloidal creep.

[0013] Preferably, in one possible implementation of the first aspect, the temperature compensation device adjusts the sensitivity characteristics of the temperature compensation fiber grating by setting the packaging length, installation position, and thermal expansion coefficient of the compensation material, for temperature compensation during pressure demodulation.

[0014] Preferably, in one possible implementation of the first aspect, the detection, acquisition, and demodulation module includes a photodetector, a transimpedance amplifier circuit, a variable gain circuit, an ADC analog-to-digital converter circuit, a first FPGA, and a second FPGA. The photodetector is used to convert the reflected light signal from the sensor module into a current signal; The transimpedance amplifier circuit converts the current signal into a voltage signal; The variable gain circuit switches the amplification factor of the voltage signal according to the intensity of the reflected light, and amplifies the voltage signal. The ADC analog-to-digital conversion circuit synchronously samples the amplified voltage signal; The first FPGA is used for timing control of the MG-Y tunable laser drive; The second FPGA is used for data acquisition synchronization and demodulation calculation.

[0015] Preferably, in one possible implementation of the first aspect, the detection, acquisition, and demodulation module further includes a calibration unit and a storage unit; The calibration unit uses a reference grating, FP Etalon standard, gas absorption line or multi-wavelength meter to establish the mapping relationship between control current and output wavelength, and generates a lookup table stored in the storage unit. During real-time demodulation, the wavelength coordinates of the reflection spectrum are recovered based on the sampling point and trigger timing.

[0016] Preferably, in one possible implementation of the first aspect, the second FPGA performs the following demodulation step: Threshold filtering is applied to the acquired signal to remove background noise; Perform moving average or smoothing on the effective spectral peaks; The center wavelengths of the force-measuring fiber optic grating and the temperature-compensated fiber optic grating are determined using a demodulation algorithm within a local window. The pressure measurement results are output in real time based on the difference or ratio of the center wavelengths of the two components or a preset compensation model.

[0017] The beneficial effects of this invention are as follows: through the integrated design of the mechanical pressure transmission structure and the MG-Y high-speed sweep frequency demodulation platform, a complete system integration from pressure loading to wavelength demodulation is realized, which can not only meet the requirements of online detection, but also has the inherent advantages of anti-electromagnetic interference and long-distance transmission of fiber optic sensing systems. By simply changing the thickness of the pressure diaphragm, different measurement ranges can be adapted, reducing structural differences between products with different measurement ranges and improving the versatility and manufacturing consistency of the sensor head. By setting up a temperature-compensated fiber optic grating and its compensation structure, the pressure signal and temperature signal were separated, reducing the influence of ambient temperature on the pressure measurement results. By using oxygen-free adhesive welding to achieve a low-creep fixation method, the creep and zero-point drift caused by traditional gel encapsulation under long-term stress are reduced. By designing a high-precision tunable drive current source, a closed-loop temperature control system, dual FPGA high-speed synchronous acquisition, and lookup table calibration, the linearity, demodulation accuracy, and real-time response capability of the swept frequency light source are improved, making it suitable for synchronous high-speed demodulation in single-point or multi-point high-speed pressure monitoring systems. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This application provides a structural diagram of a fiber Bragg grating high-speed sensing system for pressure detection.

[0020] Figure 2 This application provides a structural diagram of a light source module in a fiber Bragg grating high-speed sensing system for pressure detection.

[0021] Figure 3 This application provides a structural diagram of a sensor module in a fiber Bragg grating high-speed sensing system for pressure detection.

[0022] Figure 4 This application provides a structural diagram of a detection, acquisition, and demodulation module in a fiber Bragg grating high-speed sensing system for pressure detection.

[0023] Figure 5This application provides a schematic diagram of a high-speed demodulation process in a fiber Bragg grating high-speed sensing system for pressure detection.

[0024] Figure 6 This application provides a graph showing the relationship between wavelength change and measured pressure value and fitted pressure value in a fiber optic grating high-speed sensing system for pressure detection.

[0025] Reference numerals: 100-light source module, 110-optical isolator, 120-optical circulator, 200-sensor module, 300-detection, acquisition and demodulation module; 101-MG-Y tunable laser, 102-tunable drive current source, 103-temperature control unit, 104-control unit; 210-Pressure transmission device, 211-Pressure diaphragm, 220-Pressure testing device, 221-Force measuring fiber optic grating, 222-Temperature compensation fiber optic grating, 230-Temperature compensation device, 240-Sealed housing, 250-Fixed structure; 310 - Photodetector, 320 - Transimpedance amplifier circuit, 330 - Variable gain circuit, 340 - ADC analog-to-digital converter circuit, 350 - First FPGA, 360 - Second FPGA, 370 - Calibration unit, 380 - Storage unit. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1: As Figure 1 As shown, this invention provides a high-speed fiber Bragg grating sensing system for pressure detection, comprising a light source module 100, a sensor module 200, and a detection, acquisition, and demodulation module 300. The light source module 100 is connected to the sensor module 200 via an optical isolator 110 and an optical circulator 120. The reflected light generated by the sensor module 200 is introduced into the detection, acquisition, and demodulation module 300 via the optical circulator 120. The detection, acquisition, and demodulation module 300 recovers the center wavelengths of the force-measuring fiber Bragg grating 221 and the temperature-compensated fiber Bragg grating 222 based on the reflection spectrum, and outputs the real-time pressure through high-speed demodulation after compensation calculation.

[0028] The light source module 100 includes an MG-Y tunable laser 101, a tunable drive current source 102, a temperature control unit 103, and a control unit 104. The structural diagram of the light source module 100 is shown below. Figure 2 As shown.

[0029] The tunable drive current source 102 provides drive current to the main gain region, left and right gate regions, phase control region, and semiconductor optical amplifier of the MG-Y tunable laser 101, and includes a DAC digital-to-analog converter, a multi-stage amplifier circuit (including a non-inverting amplifier stage and a power amplifier stage), a sampling resistor, and a feedback adjustment circuit. The DAC outputs an analog control voltage, which is converted into the drive current required by each electrode of the MG-Y tunable laser 101 by the multi-stage amplifier circuit. Preferably, the DAC is a 14-bit high-speed DAC. The feedback adjustment circuit performs closed-loop correction of the drive circuit based on the output current detected by the sampling resistor. The control unit 104 outputs control words to each electrode of the MG-Y tunable laser 101 according to a preset wavelength scan table, so that the left and right gates, phase region, and semiconductor optical amplifier change in a set order to achieve full-range linear scanning or segmented scanning. The temperature control unit 103 includes a semiconductor cooler, an NTC temperature sensor, and a PID closed-loop controller to maintain the temperature stability of the MG-Y tunable laser 101 chip during operation.

[0030] In this embodiment, the scanning light output from the light source module 100 enters the optical circulator 120 after passing through the optical isolator 110, and is then injected into the sensor module 200 by the optical circulator 120. Because of the optical isolator 110, the impact of reflected light signal feedback on the operational stability of the MG-Y tunable laser 101 can be effectively suppressed.

[0031] The sensor module 200 includes a pressure transmitting device 210, a pressure testing device 220, a temperature compensation device 230, a sealed housing 240, and a fixing structure 250. A structural diagram of the sensor module 200 is shown below. Figure 3 As shown.

[0032] The pressure transmission device 210 has an external threaded interface or flange interface at its front end for connection to the pressure system being measured, preferably with an M20×1.5 external thread, for connection to a pipeline installation interface; its rear end has an elastic pressure diaphragm 211, preferably with a diaphragm diameter of approximately 12 mm. The pressure testing device 220 is threadedly connected to the pressure transmission device 210 and encapsulates a force-measuring fiber optic grating 221 and a temperature-compensating fiber optic grating 222. The sealed housing 240, after being connected to the pressure transmission device 210, forms a sealed protective cavity, and the fixing structure 250 is used for field installation.

[0033] When the pressure of the medium inside the pipeline acts on the pressure diaphragm 211, a deflection change occurs at the center of the diaphragm. The pressure testing device 220 converts the deflection change into the axial compression of the force-measuring fiber Bragg grating 221, causing a shift in the Bragg center wavelength of the force-measuring fiber Bragg grating 221. The temperature-compensating fiber Bragg grating 222 is positioned at a location affected by temperature but not directly affected by pressure. Through the design of the length, stiffness, and thermal expansion coefficient of the material of the temperature compensation device 230, the temperature-compensating fiber Bragg grating 222 primarily reflects temperature changes.

[0034] The diameter of the pressure diaphragm is fixed or limited to a predetermined range. To ensure the versatility of the sensor under different ranges, the equivalent consistency of the change in the diaphragm center deflection under different ranges is achieved by changing the thickness of the pressure diaphragm. In this embodiment, the range adjustment is achieved only by changing the thickness of the pressure diaphragm 211, while keeping the diameter of the pressure diaphragm 211, the force transmission path of the pressure testing device 220, and the pre-stretching conditions of the force-measuring fiber optic grating 221 consistent. A preferred example is that, under ranges of 0.5 MPa, 2 MPa, 20 MPa, 30 MPa, and 70 MPa, diaphragm thicknesses of approximately 0.33 mm, 0.53 mm, 1.08 mm, 1.22 mm, and 1.60 mm can be selected, respectively, so that the change in the diaphragm center deflection is maintained within a predetermined range of approximately 0.02 mm.

[0035] During assembly, the temperature-compensated fiber optic grating 222 is installed on the pressure testing device 220 using oxygen-free adhesive welding or low-creep fixing methods to reduce long-term zero-point drift caused by adhesive creep. The force-measuring fiber optic grating 221 is preferably pre-stretched first and then installed on the pressure testing device 220 using oxygen-free adhesive welding or other low-creep fixing methods. In this way, the grating remains stretched under zero pressure and is gradually compressed as the pressure increases, which can reduce the long-term drift caused by creep in traditional UV adhesive or epoxy adhesive encapsulation.

[0036] The detection, acquisition, and demodulation module 300 includes a photodetector 310, a transimpedance amplifier circuit 320, a variable gain circuit 330, an ADC analog-to-digital converter circuit 340, a first FPGA 350, a second FPGA 360, a calibration unit 370, and a storage unit 380. A structural diagram of the detection, acquisition, and demodulation module 300 is shown below. Figure 4 As shown.

[0037] The photodetector 310 receives reflected light from the optical circulator 120 and converts it into a weak current signal; the transimpedance amplifier circuit 320 converts the current signal into a voltage signal; the variable gain circuit 330 selects an appropriate amplification factor according to the signal strength to amplify the voltage signal and expand its dynamic range; the ADC analog-to-digital converter circuit 340 synchronously samples the amplified voltage signal. The first FPGA 350 is responsible for the power-on timing, scan triggering, and synchronization signal output of the MG-Y tunable laser 101; the second FPGA 360 is responsible for ADC sampling synchronization, data buffering, high-speed center wavelength demodulation, and communication with the host computer.

[0038] In this embodiment, the transimpedance amplifier circuit 320 is constructed using a high-speed, low-noise operational amplifier, coupled with a compensation capacitor and a power supply filter network; the variable gain circuit 330 can use an analog switch to switch the feedback resistor to achieve multiple gain levels. The second FPGA 360 monitors the amplitude of the digital signal output by the ADC analog-to-digital converter circuit 340 in real time. If it detects that the signal amplitude is too low or saturated, it sends a gain switching command to the variable gain circuit 330 to control the internal analog switch to switch the feedback resistor, thereby achieving adaptive multi-level gain selection and expanding the dynamic range of the system.

[0039] The calibration unit 370 is used to establish the mapping relationship between the control current and the output wavelength using a reference grating, FP Etalon standard, gas absorption line or multi-wavelength meter, and generate a lookup table stored in the storage unit 380. During real-time demodulation, the wavelength coordinates of the reflection spectrum are recovered based on the sampling point and trigger timing.

[0040] Example 2: Figure 5 As shown, the present invention provides a calibration and demodulation method in a fiber optic grating high-speed sensing system for pressure detection.

[0041] Before system use, wavelength calibration is performed first. Control unit 104 controls the MG-Y tunable laser 101 to perform a traversal scan within a predetermined current range. Reference wavelength points are collected through calibration unit 370 to establish a mapping relationship between the MG-Y tunable laser 101's drive control current and output wavelength, generating a lookup table and writing it to storage unit 380. Demodulation is performed through the second FPGA 360 or a host computer communicating with the second FPGA 360. In this embodiment, when performing high-speed center wavelength demodulation, the second FPGA 360 calls the data from storage unit 380 for real-time scanning calculations, thereby outputting a high-precision real-time pressure value. During real-time detection, the second FPGA 360 recovers the wavelength coordinates corresponding to the sampling points according to the scan trigger timing and the lookup table to meet the high-speed demodulation requirements.

[0042] The second FPGA 360 performs threshold filtering on the sampled data to remove background noise and invalid data; it performs moving average or other smoothing processing on the effective spectral peaks; it establishes local windows near the initial values ​​of each spectral peak, and uses quadratic polynomial interpolation, peak fitting, or correlation algorithms to obtain the center wavelengths of the force-measuring fiber optic grating 221 and the temperature-compensating fiber optic grating 222. Based on the difference, ratio, or preset compensation model of the center wavelengths of the force-measuring fiber optic grating 221 and the temperature-compensating fiber optic grating 222, it outputs the pressure measurement results in real time. In this embodiment, the center wavelength drift of the force-measuring fiber optic grating 221 is set as follows: The center wavelength drift of temperature-compensated fiber grating 222 is The calibrated pressure value Calculated using the following model:

[0043] in, The pressure sensitivity coefficient of the force grating. This is the temperature compensation coefficient. This is the zero-point correction value. For the calibration of a single pressure sensor head, it can also be based on the wavelength change. A univariate pressure fitting model is established using standard pressure data. This example demonstrates this. Taking the loading / unloading calibration data as an example, a quadratic polynomial fitting can be used to obtain... Figure 6 .

[0044] Example 3: This invention provides a high-speed fiber Bragg grating sensing system for pressure detection, which also includes array expansion. This invention is not limited to a single sensor head. Multiple sensor modules 200 can be connected in series or parallel along the same optical fiber, and each force-measuring fiber Bragg grating 221 and temperature-compensating fiber Bragg grating 222 has a non-overlapping or grouped operating wavelength range. By adding wavelength division multiplexers, optical switches, or multi-channel detection circuits, distributed high-speed pressure monitoring at multiple measurement points can be achieved.

[0045] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A high-speed fiber Bragg grating sensing system for pressure detection, characterized in that, The system includes a light source module, a sensor module, and a detection, acquisition, and demodulation module; The output of the light source module is connected in sequence to the input of the optical isolator and the optical circulator. The first port of the optical circulator is connected to the sensor module, and the second port of the optical circulator is connected to the detection, acquisition and demodulation module. The light source module is used to output scanning light signals covering the operating wavelength band of the fiber optic grating sensor; The sensor module converts the measured pressure and ambient temperature changes into fiber optic grating reflection signals with different center wavelength drift characteristics; The detection, acquisition, and demodulation module is used to perform photoelectric conversion, synchronous sampling, wavelength calibration, and demodulation processing on the reflected signal to obtain the measured pressure value after temperature compensation.

2. The fiber optic grating high-speed sensing system for pressure detection as described in claim 1, characterized in that, The light source module includes an MG-Y tunable laser, a tunable drive current source, a temperature control unit, and a control unit; The tunable drive current source provides drive current to the main gain region, left and right gate regions, phase control region and semiconductor optical amplifier of the MG-Y tunable laser, respectively. The temperature control unit includes a semiconductor cooler, an NTC temperature sensor, and a PID closed-loop controller, which is used to perform closed-loop temperature control on the MG-Y tunable laser chip. The control unit is used to output linear scan or segmented scan control sequences.

3. The fiber optic grating high-speed sensing system for pressure detection as described in claim 2, characterized in that, The tunable drive current source includes a DAC digital-to-analog converter, a multi-stage amplifier circuit, a sampling resistor, and a feedback adjustment circuit; The DAC digital-to-analog converter outputs an analog control voltage, which is then converted into the driving current required by each electrode of the MG-Y tunable laser through a multi-stage amplification circuit. The feedback adjustment circuit performs closed-loop correction on the drive circuit based on the output current detected by the sampling resistor.

4. The fiber optic grating high-speed sensing system for pressure detection as described in claim 1, characterized in that, The sensor module includes a pressure transmission device, a pressure testing device, a temperature compensation device, and a sealed housing; The pressure transmission device is provided with an external threaded interface or flange interface at the front end for connecting to the pressure system being measured, and an elastic pressure diaphragm at the rear end. The pressure testing device is connected to the pressure transmission device and is encapsulated with a force-measuring fiber optic grating and a temperature-compensating fiber optic grating. The sealed housing is connected to the pressure transmission device to achieve sealed protection for the internal components.

5. A fiber optic grating high-speed sensing system for pressure detection as described in claim 4, characterized in that, The pressure transmission device converts the pressure of the measured medium into a change in the deflection at the center of the diaphragm through a pressure diaphragm, and the pressure testing device converts the change in the deflection at the center of the diaphragm into the axial compression of the force-measuring fiber optic grating. The diameter of the pressure diaphragm is fixed or limited to a predetermined range, and the equivalent consistency of the change in the center deflection of the diaphragm under different ranges is achieved by changing the thickness of the pressure diaphragm.

6. A fiber optic grating high-speed sensing system for pressure detection as described in claim 4 or 5, characterized in that, The force-measuring fiber optic grating is in a pre-stretched state during assembly and is gradually compressed as the pressure increases; The force-measuring fiber optic grating and / or temperature-compensating fiber optic grating are mounted on the pressure testing device using oxygen-free adhesive welding or low-creep fixing methods to reduce long-term zero-point drift caused by colloidal creep.

7. A fiber optic grating high-speed sensing system for pressure detection as described in claim 4, characterized in that, The temperature compensation device adjusts the sensitivity of the temperature compensation fiber grating by setting the packaging length, installation position, and thermal expansion coefficient of the compensation material, and is used for temperature compensation during pressure demodulation.

8. A fiber optic grating high-speed sensing system for pressure detection as described in claim 1, characterized in that, The detection, acquisition, and demodulation module includes a photodetector, a transimpedance amplifier circuit, a variable gain circuit, an ADC analog-to-digital converter circuit, a first FPGA, and a second FPGA. The photodetector is used to convert the reflected light signal from the sensor module into a current signal; The transimpedance amplifier circuit converts the current signal into a voltage signal; The variable gain circuit switches the amplification factor of the voltage signal according to the intensity of the reflected light, and amplifies the voltage signal. The ADC analog-to-digital conversion circuit synchronously samples the amplified voltage signal; The first FPGA is used for timing control of the MG-Y tunable laser drive; The second FPGA is used for data acquisition synchronization and demodulation calculation.

9. A fiber optic grating high-speed sensing system for pressure detection as described in claim 8, characterized in that, The detection, acquisition, and demodulation module also includes a calibration unit and a storage unit; The calibration unit uses a reference grating, FP Etalon standard, gas absorption line or multi-wavelength meter to establish the mapping relationship between control current and output wavelength, and generates a lookup table stored in the storage unit. During real-time demodulation, the wavelength coordinates of the reflection spectrum are recovered based on the sampling point and trigger timing.

10. A fiber optic grating high-speed sensing system for pressure detection as described in claim 8 or 9, characterized in that, The second FPGA performs the following demodulation steps: Threshold filtering is applied to the acquired signal to remove background noise; Perform moving average or smoothing on the effective spectral peaks; The center wavelengths of the force-measuring fiber optic grating and the temperature-compensated fiber optic grating are determined using a demodulation algorithm within a local window. The pressure measurement results are output in real time based on the difference or ratio of the center wavelengths of the two components or a preset compensation model.

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