A Temperature Sensing System for Mine Safety Monitoring

A safety monitoring and sensing system technology, applied in the direction of physical/chemical change thermometers, thermometers, measuring heat, etc., can solve the problems of signal phase-frequency characteristics, frequency fluctuations, and difficulty in filtering out.

Inactive Publication Date: 2020-05-22
JILIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, on the one hand, the high-frequency component itself will affect the phase detection of the cosine wave (the position of the zero-crossing point changes); The electrical characteristics are equivalent to capacitance, and the voltage at both ends cannot jump, so the falling edge of the sawtooth wave cannot be infinitely short) and the elasticity of the optical fiber itself and many other factors, the frequency is variable, and it is difficult to filter out cleanly; and , when using a filter, in addition to affecting the amplitude-frequency characteristics of the output signal, it will also affect the phase-frequency characteristics of the signal at the same time, that is, the phase of the filter will be affected near the cut-off frequency, which is very important for relying on phase changes. Unfavorable for fiber optic sensors that measure temperature changes

Method used

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  • A Temperature Sensing System for Mine Safety Monitoring
  • A Temperature Sensing System for Mine Safety Monitoring
  • A Temperature Sensing System for Mine Safety Monitoring

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Embodiment 1 Overall structure of the present invention

[0029] like figure 1 Shown, the overall structure of the present invention has, pumping source 1 (the LC962U type pumping source of OCLARO company, central wavelength 980nm, the maximum single-mode output optical power is 750mW) and the first optical coupler 2 (OZ-OPTICS company produces The model is FUSED-12-1060-7 / 125-50 / 50-3U-3mm, the splitting ratio is 10:90 1×2 fiber optic coupler) connected to the input end, 90% output of the first optical coupler 2 The end is connected to the 980nm end of the optical wavelength division multiplexer 3, and the 1550nm end of the optical wavelength division multiplexer 3 (COMCORE company 980 / 1060nm single-mode fiber wavelength division multiplexer) is connected to the delay line adjustable optical fiber 12 (Sichuan Yuxingguang Technology Co., Ltd. Co., Ltd. VDL-40-15-S9-1-FA type motorized optical fiber delay line) is connected to one end, and the other end of the delay lin...

Embodiment 2

[0031] Embodiment 2 function conversion circuit

[0032] The structure of the function conversion circuit 29 is that one end of the capacitor C3 is connected to the pin 12 of the trigonometric function converter U1 and one end of the resistor R2, and the other end of the capacitor C3 is used as the input end of the function conversion circuit 29, which is recorded as the port ACOS_in , is connected with the output end of the differential amplifier circuit 28; the other end of the resistor R2 is grounded; the pins 2, 3, 4, 5, 8, 11, 13 of the trigonometric function converter U1 are grounded, and the pins 9, 10 are connected to the capacitor C2 One end is connected to -12V power supply, the other end of capacitor C2 is grounded; pin 6 of trigonometric function converter U1 is connected to pin 7, pin 16 is connected to +12V power supply and one end of capacitor C1, and the other end of capacitor C1 is grounded; The pin 1 of the trigonometric function converter U1 is connected to ...

Embodiment 3

[0033] Embodiment 3 Adaptive Amplitude Normalization Circuit

[0034] Because the amplitude of the signal output by the function conversion circuit 29 is relatively small, and is affected by multiple parameters in the optical path and the circuit, the size is indefinite, so the present invention designs an adaptive amplitude normalization circuit 30, which is used to convert the signal output by the function conversion circuit 29 The amplitude is normalized to the optimal size to further improve the accuracy of demodulation. The specific structure is that one end of the capacitor C11 is connected to one end of the resistor R21 and the pin 3 of the chip U2, the other end of the resistor R21 is grounded, and the other end of the capacitor C11 is used as the input end of the adaptive amplitude normalization circuit 30, which is recorded as the port ADAPT_in , is connected with the port ACOS_out of the function conversion circuit 29; the pin 1, the pin 7, the pin 8 and the pin 14 ...

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Abstract

The invention relates to a temperature sensing system for mine safety monitoring and belongs to the technical field of optical fiber sensors. Its main structure includes a pumping source (1), a first optical coupler (2), an optical wavelength division multiplexer (3) and the like. The invention uses a sinusoidal signal as a modulation signal, does not generate high-frequency interference, and has the characteristics of more reliable operation and high sensing precision.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensors, in particular to a temperature sensing system for mine safety monitoring. Background technique [0002] Fiber Bragg grating (FBG) is widely used in the field of sensing technology due to its advantages of anti-electromagnetic interference, chemical resistance, small transmission loss, small size and light weight, and easy mass production. At present, temperature sensors play an important role in safe production, especially in high-risk places such as mines, where temperature monitoring is crucial. However, most of the traditional temperature sensors are realized by the change of electrical signal, and the temperature sensor based on the change of electrical signal is greatly limited in practical application. Additional safety hazards, on the other hand, when used in harsh environments, they are greatly disturbed by the environment and the transmission is inconvenient. Due to the a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01K11/32G01K11/3206
CPCG01K11/32
Inventor 高博邱天莫思铭李凡余行霍佳雨张栋林旻
Owner JILIN UNIV
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