Quantization noise testing device and method for optical fiber interferometer system

Abstract

The invention provides an optical fiber interferometer system quantization noise testing device and method, and the method comprises the steps: setting an analog interference signal of a signal processing board card to control an analog interference signal outputted by a DA module, and enabling the analog interference signal to be collected by an AD module; and the analog interference signal acquired by the AD module is input into the adjusting module to obtain the phase power spectrum density of the quantized noise of the data acquisition board card. According to the scheme provided by the invention, the optical fiber interferometer system can be optimized by modifying the input simulation interference signal parameters according to the measurement result, and the minimum system quantization noise is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of optical fiber sensing observation, and in particular relates to a device and method for testing quantization noise of an optical fiber interferometer system. Background Art

[0002] The improvement of traditional electromechanical sensor observation performance faces major challenges. Its measurement sensitivity is limited by the circuit thermal noise of the electrical sensor, and the measurement dynamic range is limited by the number of acquisition bits and accuracy of the digital-to-analog converter in the data acquisition device. Therefore, it is necessary to develop new technologies and devices to break through the limitations of sensor observation performance. In recent years, the development of fiber optic sensing technology has gradually matured and has unique advantages in long-distance monitoring. Fiber optic sensing uses the principle of fiber optic interference, with the wavelength of light as the reference, and the interference fringe demodulation and subdivision as a method of measuring displacement to replace the traditional electronic displacement conversion device, eliminating the thermal noise generated by the self-heating of the electronic circuit inside the traditional electromechanical sensor. The limitation on the measurement resolution has achieved high sensitivity, high resolution, broadband, and large dynamic range sensing.

[0003] The fiber interferometer system usually includes three parts: light source, fiber interferometer optical path, and photoelectric detection and acquisition demodulation circuit. Therefore, the total system noise is also composed of three parts: light source noise, fiber interferometer optical path noise, and circuit noise. Among them, circuit noise includes photoelectric shot noise, circuit thermal noise, quantization noise, etc. The data acquisition board of the analog-to-digital conversion module and the digital-to-analog module in the fiber interferometer is an important part of the acquisition demodulation circuit. Its main function is to realize the mutual conversion between analog signals and digital signals. Quantization noise is caused by the digital characteristics of the AD module and the DA module. In the process of analog-to-digital conversion, due to the accuracy of analog-to-digital conversion, there is a difference between the converted digital quantity and the actual analog quantity, which brings errors to the final demodulation signal of the system. The difference between the digital quantity and the analog quantity is called quantization error, and the noise variance calculated by the root mean square is the quantization noise. Sometimes it is necessary to consider the impact of its noise on the system.

[0004] Therefore, how to provide a fiber interferometer system quantization noise testing device and method has become a technical problem that urgently needs to be solved in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a device and method for testing quantization noise of a fiber interferometer system.

[0006] According to a first aspect of the present invention, there is provided a fiber interferometer system quantization noise test device, comprising a signal processing board and a data acquisition board;

[0007] The analog interference signal of the signal processing board is input to the DA module of the data acquisition board; the DA module of the data acquisition board is connected to the AD module of the data acquisition board; the AD module is connected to the adjustment module of the signal processing board.

[0008] According to a second aspect of the present invention, a method for testing quantization noise of a fiber interferometer system is provided, comprising the device for testing quantization noise of a fiber interferometer system according to the first aspect of the present invention, and the method specifically comprises:

[0009] The analog interference signal output by the DA module is controlled by setting the analog interference signal of the signal processing board, and collected by the AD module; the analog interference signal collected by the AD module is then input into the adjustment module to obtain the phase power spectrum density of the quantization noise of the data acquisition board.

[0010] Optionally, the simulated interference signal is:

[0011] Where A is the amplitude of the simulated interference signal, Ccos(ωt) represents the added carrier signal, C is the amplitude of the carrier, and ω represents the angular frequency. represents the frequency of the carrier signal, represents the calibration signal, B represents the amplitude of the calibration signal, Represents the frequency of the calibration signal.

[0012] Optionally, the step of inputting the analog interference signal collected by the AD module into the adjustment module to obtain the phase power spectrum density of the quantization noise of the data acquisition board includes:

[0013] The analog interference signal collected by the AD module is demodulated with high precision by the adjustment module of the signal processing board using the phase generation carrier demodulation method to obtain the phase information of the analog interference signal collected by the AD module, and then the phase power spectral density of the quantization noise of the data acquisition board is obtained.

[0014] Optionally, in order to ensure that the test noise of the quantization noise test device is the system self-noise, environmental factors are isolated from the fiber interferometer system and the quantization noise test device thereof.

[0015] Optionally, isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof includes:

[0016] The fiber optic interferometer system is placed in a sealed cabin for measurement.

[0017] Optionally, isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof further comprises:

[0018] Place the quantization noise test device on the optical air-floating platform.

[0019] Optionally, isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof further comprises:

[0020] The fiber interferometer system and its quantization noise test device are isolated from vibration and sound waves.

[0021] Optionally, isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof further comprises:

[0022] Thermal shielding of fiber interferometer systems and their quantization noise test setup.

[0023] Optionally, the heat shielding of the fiber interferometer system and the quantization noise testing device thereof comprises:

[0024] The ambient temperature variation of the optical fiber interferometer system and the quantization noise test device thereof is less than 0.1° C. / 1h.

[0025] The beneficial effects brought by the present invention are as follows:

[0026] It can be seen from the above scheme that the embodiment of the present invention provides a fiber interferometer system quantization noise testing device and method, which has the following beneficial effects: by modifying the input analog interference signal parameters, the fiber interferometer system can be optimized according to the measured results to obtain the minimum system quantization noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a fiber interferometer system quantization noise testing device provided according to an embodiment. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] According to a first aspect of the present invention, Figure 1 As shown, a fiber interferometer system quantization noise test device is provided, including a signal processing board and a data acquisition board;

[0030] The analog interference signal of the signal processing board is input to the DA module of the data acquisition board; the DA module of the data acquisition board is connected to the AD module of the data acquisition board; the AD module is connected to the adjustment module of the signal processing board.

[0031] According to a second aspect of the present invention, a method for testing quantization noise of a fiber interferometer system is provided, including the device for testing quantization noise of a fiber interferometer system according to the first embodiment. The method specifically includes:

[0032] The analog interference signal output by the DA module is controlled by setting the analog interference signal of the signal processing board, and collected by the AD module; the analog interference signal collected by the AD module is then input into the adjustment module to obtain the phase power spectrum density of the quantization noise of the data acquisition board.

[0033] In some embodiments, the simulated interference signal is:

[0034] Where A is the amplitude of the simulated interference signal, Ccos(ωt) represents the added carrier signal, C is the amplitude of the carrier, and ω represents the angular frequency. represents the frequency of the carrier signal, represents the calibration signal, B represents the amplitude of the calibration signal, Represents the frequency of the calibration signal.

[0035] In some embodiments, the step of inputting the analog interference signal collected by the AD module into the adjustment module to obtain the phase power spectrum density of the quantization noise of the data acquisition board includes:

[0036] The analog interference signal collected by the AD module is demodulated with high precision by the adjustment module of the signal processing board using the phase generation carrier demodulation method to obtain the phase information of the analog interference signal collected by the AD module, and then the phase power spectral density of the quantization noise of the data acquisition board is obtained.

[0037] In some embodiments, in order to ensure that the test noise of the quantization noise test device is the system self-noise, environmental factors are isolated from the fiber interferometer system and the quantization noise test device thereof.

[0038] The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof includes:

[0039] The fiber optic interferometer system is placed in a sealed cabin for measurement.

[0040] The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof also includes:

[0041] Place the quantization noise test device on the optical air-floating platform.

[0042] The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof also includes:

[0043] The fiber interferometer system and its quantization noise test device are isolated from vibration and sound waves.

[0044] The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof also includes:

[0045] Thermal shielding of fiber interferometer systems and their quantization noise test setup.

[0046] The heat shielding of the optical fiber interferometer system and the quantization noise test device thereof comprises:

[0047] The ambient temperature variation of the optical fiber interferometer system and the quantization noise test device thereof is less than 0.1° C. / 1h.

[0048] In summary, the solution provided by the embodiment of the present invention can optimize the fiber interferometer system according to the measured results by modifying the input analog interference signal parameters to obtain the minimum system quantization noise.

[0049] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A fiber interferometer system quantization noise test device, characterized in that: include: Signal processing board and data acquisition board; The analog interference signal of the signal processing board is input to the DA module of the data acquisition board; The DA module of the data acquisition board is connected to the AD module of the data acquisition board; and the AD module is connected to the adjustment module of the signal processing board.

2. A method for testing quantization noise of a fiber interferometer system, characterized in that: The optical fiber interferometer system quantization noise testing device according to claim 1, wherein the method specifically comprises: The analog interference signal output by the DA module is controlled by setting the analog interference signal of the signal processing board, and collected by the AD module; the analog interference signal collected by the AD module is then input into the adjustment module to obtain the phase power spectrum density of the quantization noise of the data acquisition board.

3. The fiber interferometer system quantization noise testing method according to claim 2, characterized in that: The simulated interference signal is: Where A is the amplitude of the simulated interference signal, Ccos(ωt) represents the added carrier signal, C is the amplitude of the carrier, and ω represents the angular frequency. represents the frequency of the carrier signal, represents the calibration signal, B represents the amplitude of the calibration signal, Represents the frequency of the calibration signal.

4. The method for testing quantization noise of a fiber interferometer system according to claim 2, characterized in that: The step of inputting the analog interference signal collected by the AD module into the adjustment module to obtain the phase power spectrum density of the quantization noise of the data acquisition board comprises: The analog interference signal collected by the AD module is demodulated with high precision by the adjustment module of the signal processing board using the phase generation carrier demodulation method to obtain the phase information of the analog interference signal collected by the AD module, and then the phase power spectral density of the quantization noise of the data acquisition board is obtained.

5. The fiber interferometer system quantization noise testing method according to claim 2, characterized in that: In order to ensure that the test noise of the quantization noise test device is the system self-noise, environmental factors are isolated from the fiber interferometer system and its quantization noise test device.

6. The method for testing quantization noise of a fiber interferometer system according to claim 5, characterized in that: The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof includes: The fiber optic interferometer system is placed in a sealed cabin for measurement.

7. The method for testing quantization noise of a fiber interferometer system according to claim 6, characterized in that: The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof also includes: Place the quantization noise test device on the optical air-floating platform.

8. The method for testing quantization noise of a fiber interferometer system according to claim 7, characterized in that: The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof also includes: The fiber interferometer system and its quantization noise test device are isolated from vibration and sound waves.

9. The method for testing quantization noise of a fiber interferometer system according to claim 8, characterized in that: The isolating environmental factors from the fiber interferometer system and the quantization noise test device thereof also includes: Thermal shielding of fiber interferometer systems and their quantization noise test setup.

10. The fiber interferometer system quantization noise testing method according to claim 9, characterized in that: The heat shielding of the optical fiber interferometer system and the quantization noise test device thereof comprises: The ambient temperature variation of the optical fiber interferometer system and the quantization noise test device thereof is less than 0.1° C. / 1h.

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