An interferometric fiber optic sensor demodulation device

Abstract

The utility model discloses a signal demodulation technical field's interference type optical fiber sensor demodulation device, including PXle backplane, its characterized in that: PXle backplane's output end electricity is connected the input of main control module, and PXle backplate is used for receiving and will receive the electric signal send to main control module, the integrated connection data acquisition module and clock module on main control module, clock module's output end electricity is connected signal generator's input. The utility model discloses a demodulation unit is set to divide optical fiber sensor signal's transmission speed and sends to PXle backplate, can effectively reduce the transmission rate of optical fiber sensor signal and sampling rate, and simultaneously through the integration logic operation module on PXle backplate, and logic operation module can output the optical fiber sensor signal after logic operation demodulation, reduce demodulation data volume, reduce the calculation complexity and storage demand of filter and demodulation simultaneously, effectively avoid information loss, can reduce the power consumption and cost.

Description

Technical Field

[0001] This utility model relates to the field of signal demodulation technology, specifically an interferometric fiber optic sensor demodulation device. Background Technology

[0002] Interferometric fiber optic sensors, based on the phenomenon of light interference, typically consist of a laser, optical fiber, interferometer structure, and photodetector. When light propagates through the fiber, the measured physical quantity causes changes in the fiber's refractive index, length, or geometry, leading to a phase change in the light wave. This phase change forms interference fringes through the interferometer, and the photodetector detects the intensity changes of these fringes. Finally, signal processing yields the numerical value of the measured physical quantity. However, existing interferometric fiber optic sensor demodulation devices have high sampling rates, resulting in large data volumes. This also increases the computational complexity and storage requirements for filtering and demodulation, and makes them prone to information loss, further increasing power consumption and cost. Utility Model Content

[0003] The purpose of this invention is to provide an interferometric fiber optic sensor demodulation device. By setting the demodulation unit to demodulate the transmission speed of the time-division fiber optic sensor signal and sending it to the PXle backplane, the transmission rate and sampling rate of the fiber optic sensor signal can be effectively reduced. At the same time, by integrating a logic operation module on the PXle backplane, the amount of demodulated data can be reduced, and the computational complexity and storage requirements of filtering and demodulation can be reduced, effectively avoiding information loss.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] An interferometric fiber optic sensor demodulation device includes a PXle backplane. The output of the PXle backplane is electrically connected to the input of a main control module. The PXle backplane receives and transmits received electrical signals to the main control module. The main control module integrates a data acquisition module and a clock module. The output of the clock module is electrically connected to the input of a signal generator for synchronous operation of the carrier signal and data acquisition. The signal generator generates a carrier signal. The data acquisition module outputs pulse signals to the fiber optic sensor and the signal generator. The data acquisition module integrates an analog-to-digital converter (ADC). The ADC acquires a segment of the fiber optic sensor signal each time a pulse signal is output, converts it into a digital signal, and sends it to a demodulation unit. The demodulation unit is built into the data acquisition module and is used to determine the transmission speed of the time-division fiber optic sensor signal and send it to the PXle backplane. The PXle backplane integrates a logic operation module, which outputs the demodulated fiber optic sensor signal after logic operation.

[0006] As a further embodiment of this utility model: the data acquisition module is provided in multiple ways, and each of the multiple data acquisition modules includes several analog acquisition units, which are used to repeatedly trigger the acquisition of fiber optic sensor signals.

[0007] As a further embodiment of this utility model: the output terminal of the main control module is electrically connected to a touch display screen, which is used to set the parameters to be received or demodulated and to display waveforms.

[0008] As a further embodiment of this utility model: the logic operation module includes a first multiplier and a second multiplier, the output of the first multiplier is connected to a first low-pass filter (LPF), and the output of the second multiplier is connected to a second low-pass filter.

[0009] As a further embodiment of this utility model: the output terminals of both the first low-pass filter and the second low-pass filter are connected to a divider, and the output terminal of the divider is connected to an arctangent operator.

[0010] As a further embodiment of this utility model: the output terminals of the first low-pass filter and the second low-pass filter are both connected to the input terminal of the complex number operator, the output terminal of the complex number operator is connected to the input terminal of the sampling module, the output terminal of the sampling module is connected to the input terminal of the differential square root module, and the output terminal of the differential square root module is connected to the arctangent operator.

[0011] As a further aspect of this invention: the arctangent operator is used to output the demodulated fiber optic sensor signal.

[0012] As a further aspect of this invention, the frequency of the pulse signal is 200kHz.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] In this invention, by setting the demodulation unit to demodulate the transmission speed of the time-division fiber optic sensor signal and sending it to the PXle backplane, the transmission rate and sampling rate of the fiber optic sensor signal can be effectively reduced. At the same time, by integrating a logic operation module on the PXle backplane, the logic operation module can output the fiber optic sensor signal after logic operation demodulation, reducing the amount of demodulated data, while reducing the computational complexity and storage requirements of filtering and demodulation, effectively avoiding information loss, and reducing power consumption and cost. Attached Figure Description

[0015] Figure 1 This is a circuit diagram of the demodulation module of this utility model;

[0016] Figure 2 This is a logic operation module diagram of the first embodiment of the present invention;

[0017] Figure 3This is a logic operation module diagram of the second embodiment of this utility model. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Example 1:

[0020] Please see Figures 1-2 In this embodiment of the present invention, an interferometric fiber optic sensor demodulation device includes a PXle backplane. The output of the PXle backplane is electrically connected to the input of a main control module. The PXle backplane is used to receive and send the received electrical signals to the main control module. The main control module integrates a data acquisition module and a clock module. The output of the clock module is electrically connected to the input of a signal generator for synchronous operation of the carrier signal and data acquisition. The signal generator is used to generate a carrier signal. The data acquisition module is used to output pulse signals to the fiber optic sensor and the signal generator. The data acquisition module integrates an analog-to-digital converter. The analog-to-digital converter acquires a segment of fiber optic sensor signal and converts it into a digital signal each time a pulse signal is output, and then sends it to the demodulation unit. The demodulation unit is built into the data acquisition module. The demodulation unit is used to demodulate the transmission speed of the time-division fiber optic sensor signal and send it to the PXle backplane. The PXle backplane integrates a logic operation module, which is used to output the fiber optic sensor signal after logic operation demodulation.

[0021] In this embodiment, eight data acquisition modules are configured, forming a 32-channel high-speed acquisition system. Each of the eight modules includes four analog acquisition units, which are used to repeatedly trigger the acquisition of fiber optic sensor signals. By setting up four analog acquisition channels, a segment of signal can be acquired each time a pulse signal is generated. After the signal is digitized, it is sent to the demodulation unit for demodulation processing. Each high-speed analog signal is time-divided into eight 200kS / s low-speed signals, corresponding to the eight sensor signals on the fiber optic cables. The four analog acquisition channels acquire a total of 32 200kS / s signals. These 32 signals are demodulated on the FPGA to obtain sound / vibration signals.

[0022] Preferably, the output of the main control module is electrically connected to a touch display screen, which is used to set the received or demodulated parameters and display waveforms.

[0023] In this embodiment, the main control module is a Windows x86 computer with several network ports installed on it, which are used to forward data to other devices.

[0024] Preferred, such as Figure 2 As shown, the logic operation module includes a first multiplier and a second multiplier. The output of the first multiplier is connected to a first low-pass filter, and the output of the second multiplier is connected to a second low-pass filter.

[0025] Preferably, the outputs of both the first low-pass filter and the second low-pass filter are connected to a divider, and the output of the divider is connected to an arctangent operator.

[0026] Preferably, the arctangent operator is used to output the demodulated fiber optic sensor signal. When the logic operation module is working, the one high-speed fiber optic sensor signal is converted into eight low-speed fiber optic sensor signals after time-division multiplexing. Four high-speed acquisitions (250MSps) yield 32 low-speed data (200kSps). Each data channel is processed by a synchronous arctangent operator to obtain 32 sound / vibration signals. The demodulated signal can further reduce the sampling rate. The 32 demodulated data channels are transmitted to the main control module through the PCIe bus interface. The eight high-speed acquisition modules have a total of 256 signals. Assuming each signal is 20kSps, the total data volume is 32*8*20k*4byte=20.48MB / s.

[0027] Example 2:

[0028] Please see Figure 3 In this embodiment of the present invention, an interferometric fiber optic sensor demodulation device includes a PXle backplane. The output of the PXle backplane is electrically connected to the input of a main control module. The PXle backplane is used to receive and send the received electrical signals to the main control module. The main control module integrates a data acquisition module and a clock module. The output of the clock module is electrically connected to the input of a signal generator for synchronous operation of the carrier signal and data acquisition. The signal generator is used to generate a carrier signal. The data acquisition module is used to output pulse signals to the fiber optic sensor and the signal generator. The data acquisition module integrates an analog-to-digital converter. The analog-to-digital converter acquires a segment of fiber optic sensor signal and converts it into a digital signal each time a pulse signal is output, and then sends it to the demodulation unit. The demodulation unit is built into the data acquisition module. The demodulation unit is used to demodulate the transmission speed of the time-division fiber optic sensor signal and send it to the PXle backplane. The PXle backplane integrates a logic operation module, which is used to output the fiber optic sensor signal after logic operation demodulation.

[0029] In this embodiment, there are 8 data acquisition modules, which together form a 32-channel high-speed acquisition system. Each of the 8 data acquisition modules includes 4 analog acquisition units, which are used to repeatedly trigger the acquisition of fiber optic sensor signals.

[0030] Preferably, the output of the main control module is electrically connected to a touch display screen, which is used to set the received or demodulated parameters and display waveforms.

[0031] In this embodiment, the main control module is a Windows x86 computer with several network ports installed on it, which are used to forward data to other devices.

[0032] Preferably, the logic operation module includes a first multiplier and a second multiplier, the output of the first multiplier is connected to a first low-pass filter (LPF), and the output of the second multiplier is connected to a second low-pass filter.

[0033] Preferably, the outputs of the first low-pass filter and the second low-pass filter are both connected to the input of the complex number operator, the output of the complex number operator is connected to the input of the sampling module, the output of the sampling module is connected to the input of the differential square root module, and the output of the differential square root module is connected to the arctangent operator, R=I+jQ, where I is the baseband in-phase component, Q is the quadrature component, and R is the complex signal of the fiber optic sensor signal.

[0034] Preferably, the arctangent operator is used to output the demodulated fiber optic sensor signal.

[0035] In this embodiment, four consecutive sampling points are multiplied pairwise after passing through a low-pass filter to obtain the square root of the difference. Finally, an arctangent demodulation algorithm is applied. Since the square root operation is performed on four consecutive points, the data volume is reduced to 1 / 4, approximately 5 MB / s.

[0036] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. An interferometric fiber optic sensor demodulation device, comprising a PXle backplane, characterized in that: The output of the PXle backplane is electrically connected to the input of the main control module. The PXle backplane is used to receive and send the received electrical signals to the main control module. The main control module integrates a data acquisition module and a clock module. The output of the clock module is electrically connected to the input of a signal generator for synchronous operation of the carrier signal and data acquisition. The signal generator is used to generate a carrier signal. The data acquisition module is used to output pulse signals to the fiber optic sensor and the signal generator. The data acquisition module integrates an analog-to-digital converter. The analog-to-digital converter acquires a segment of fiber optic sensor signal each time a pulse signal is output, converts it into a digital signal, and sends it to the demodulation unit. The demodulation unit is built into the data acquisition module. The demodulation unit is used to decode the transmission speed of the time-division fiber optic sensor signal and send it to the PXle backplane. The PXle backplane integrates a logic operation module, which is used to output the fiber optic sensor signal after logic operation demodulation.

2. The interferometric fiber optic sensor demodulation device according to claim 1, characterized in that: The data acquisition module is configured in multiple ways, and each data acquisition module includes several analog acquisition units, which are used to repeatedly trigger the acquisition of fiber optic sensor signals.

3. The interferometric fiber optic sensor demodulation device according to claim 2, characterized in that: The output of the main control module is electrically connected to a touch display screen, which is used to set the parameters to be received or demodulated and to display waveforms.

4. The interferometric fiber optic sensor demodulation device according to claim 3, characterized in that: The logic operation module includes a first multiplier and a second multiplier. The output of the first multiplier is connected to a first low-pass filter, and the output of the second multiplier is connected to a second low-pass filter.

5. The interferometric fiber optic sensor demodulation device according to claim 4, characterized in that: The outputs of both the first and second low-pass filters are connected to a divider, and the output of the divider is connected to an arctangent operator.

6. The interferometric fiber optic sensor demodulation device according to claim 4, characterized in that: The outputs of the first and second low-pass filters are both connected to the input of the complex number operator. The output of the complex number operator is connected to the input of the sampling module. The output of the sampling module is connected to the input of the differential square root module. The output of the differential square root module is connected to the arctangent operator.

7. The interferometric fiber optic sensor demodulation device according to claim 5 or 6, characterized in that: The arctangent operator is used to output the demodulated fiber optic sensor signal.

8. The interferometric fiber optic sensor demodulation device according to claim 7, characterized in that: The frequency of the pulse signal is 200kHz.

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