Raman fiber temperature sensing system and noise compensation method thereof

Abstract

The invention relates to the technical field of sensing, and discloses a raman fiber temperature sensing system and a noise compensation method thereof. According to the invention, the noise introduced during the wavelength division multiplexing step is considered to realize the data correction for the measurement result of a whole optical fiber section. According to the technical scheme of the invention, the ratio of the Stokes light to the anti-Stokes light at the same point of an acquisition optical fiber and under different measurement temperatures, and the ratio N0(T) are regarded as the product of a constant and a noise compensation function. After that, two temperature measurement reference sections are selected and a coefficient B is solved by means of the measurement data of the two reference sections. A temperature demodulation formula is obtained on each point of the optical fiber after the coefficient B is obtained. Furthermore, according to the method, in combination with an optical fiber distance loss coefficient, the more accurate data correction for the measurement result of the whole optical fiber section can be achieved.

Description

technical field [0001] The invention relates to the field of sensing technology, in particular to a Raman optical fiber temperature sensing system and a noise compensation method thereof. Background technique [0002] With the continuous development of the economy, in order to maximize the utilization of space, more and more enterprises choose to use three-dimensional warehouses to store their goods. The three-dimensional warehouse adopts multi-layer shelves, and the goods are placed in various positions on the shelves. The warehouse uses automatic material handling equipment for the inbound and outbound operations of the goods. The system structure has the characteristics of high mechanization and automation. Due to the large amount of goods in the three-dimensional warehouse, the fire load per unit area of ​​the warehouse is generally high, and dangerous chemicals are flammable, explosive, and corrosive, which will cause even greater losses after an accident. Different ha...

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Problems solved by technology

[0005] However, there are certain shortcomings in the temperature measurement technology based on Raman scattering. Since the intensity of scattered light generated by Raman scattering is extremely weak, anti-Stokes carrying temperature information is removed from the electrical signal converted by the avalanche photodiode (APD) inside the device. There are other noises in addition to the optical signal. At present, the cumulative average method is generally used to improve the signal-to-noise ratio, but the cumulative average only has a certain denoising effect on white noise, and it is difficult to solve the noise introduced by wavelength division multiplexing and other links; In addition, due to the influence of various environmental factors such as the bias voltage of the APD circuit and the operating temperature during the photoelectric conversion process of the detection signal, some errors are introduced after the optical signal is converted into an electrical signal, and this error is related to the intensity of the detected light.

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