Optical fiber grating array intelligent vibration positioning and temperature monitoring system

Abstract

The invention relates to the technical field of a weak grating on-line monitoring system, in particular to an optical fiber grating array intelligent vibration positioning and temperature monitoring system. The system includes a swept source, an optical circulator, an optical fiber, identical weak grating arrays, an elimination optical fiber end face reflection device, an optical fiber transmission optical cable, a signal demodulation unit, a computer and a display screen, wherein the swept source is connected to the first port of the optical circulator, the second port of the optical circulator is connected to the head ends of the weak gratings of the identical weak grating arrays through the optical fiber, the tail end of the weak grating is connected with the elimination optical fiber end face reflection device, and the third port of the optical circulator is connected with the optical fiber transmission optical cable, the optical fiber transmission optical cable is connected to thesignal demodulation unit, the signal demodulation unit is connected to the computer, the computer is connected to the display screen, the optical fiber is fixed on a measured medium through a specially-made optical fiber clamp, and the identical weak grating arrays are uniformly distributed on the measured medium, and the temperature and vibration sensing points are customized by a temperature sensing unit and a vibration sensing unit according to monitoring requirements.

Description

technical field [0001] The invention relates to the technical field of weak grating on-line monitoring systems, in particular to an optical fiber grating array intelligent vibration positioning and temperature monitoring system. Background technique [0002] In terms of rail, the development of my country's rail transit industry is becoming stronger and stronger. It not only facilitates people's travel but also promotes the development of my country's economy, especially my country's high-speed rail, which has become a symbolic symbol of my country internationally. With the speeding up of trains and the efficiency of train operation, the safety performance of trains has attracted more attention, especially in the aspects of real-time tracking of trains, intelligent positioning and identification and monitoring of track occupancy. In terms of pipelines, pipeline systems are widely used in social development and people's lives, but the annual economic losses caused by pipeline...

AI Technical Summary

Problems solved by technology

[0003] At present, the monitoring methods of tracks, pipelines, building perimeters, etc. have: 1. The monitoring method introduced in the Chinese patent (patent No. 200710175343.1) "vehicle operation monitoring system based on fiber gratings" is to use fiber grating sensors, and the cost is high. Moreover, the distance between the sensors is large, and the occupancy of the track cannot be accurately identified. The clamp that fixes the sensor on the track destroys the mechanical structure of the rail, which poses a great safety hazard to the train operation; 2. Chinese patent (patent number 201610365373.8) "a The monitoring method introduced in "A Sound Wave Pipeline Leakage Monitoring System" is to install sound wave leakage monitors at the head end and the end of the pipeline respectively, collect the leakage signal of the pipeline, and then carry out data transmission, processing and alarm

However, the sensor described in the summary of the invention is an electrical sensor, which is susceptible to electromagnetic interference and does not have an explosion-proof function. It is difficult to form a network for this type of sensor. In addition, the measurement using this electrical sensor has low sensitivity and high temperature resistance , poor corrosion resistance and other shortcomings; 3. Wu Huijuan (Wu Huijuan, etc., a new fiber grating fence fire prevention and intrusion synchronous early warning system, Acta Photonica Sinica, 2011, 40(11): 1671-1676) proposed a new type of fiber grating fence fire protection Intrusion synchronous early warning system, the entire monitoring system hangs FBG fiber grating sensors on the perimeter fence or buries them underground, so as to use the collected signal change trends and characteristics to judge the occurrence of fire or intrusion, and give an alarm

However, the monitoring system described in the content of the invention has low monitoring accuracy, low spatial resolution, and a very limited number of sensor multiplexing, resulting in high system costs

[0004] At present, the traditional monitoring technologies for rails, pipelines, and building perimeters are all based on electronic technology. Therefore, when using these technologies or equipment, they are susceptible to interference from electromagnetic fields, external environments, and weather. Problems existing in existing electronic equipment, people have successively researched monitoring systems based on optical fiber sensing technologies such as temperature, pressure, and tension, but the use of distributed identical weak grating smart arrays has not been seen in vibration positioning and temperature monitoring related reports

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