Downhole Accident Rescue Monitoring System Based On Distributed All - Fiber Vibration Sensing Technology

The yield of coal in our country lists top position in the world. But compared with other countries, the death rate in coal mine disasters in our country is rather high. It is because the locating devices in the mines are all electronic sensors at home and abroad, and they can hardly work normally after disasters. How to locate the survivors in the mine after disasters is the key to improve the security level in coal production and lower the death rate in disasters. Distributed fiber optic sensors can be applied to locate the survivors in the mine after disasters because of their original advantages, such as electromagnetic interference resistance, corrosion resistance, high sensitivity, and working without extra power supply.A monitoring system for locating survivors in the coal mine after disasters is designed in the article based on the distributed fiber optic vibration sensing system using white light interference technology. It uses only one optical fiber to realize the real distributed monitoring in the whole tunnel in the work site. It is hopeful to be applied successfully in the actual rescue action after coal mine disasters.The principle of the distributed fiber optic vibration sensing system (chapter2) is researched in the article. The hardware system (chapter3) including a stable laser source, a photo-electric transformation system with low noise and a high speed USB data acquisition system, and the software algorithm (chapter4) including phase reduction and locating recognition is designed. We make it compose a complete rescue monitoring system in cola mine disasters. Meanwhile, aiming at the needs of the special application environment and the features of the actual monitoring mode of the rescue monitoring system, the recognition algorithm of multi-point continuous perturbation based on gaussian kernel density estimation is proposed. With its support, the accuracy and the practicality of the system are better.In the actual test in the coal mine (chapter5), the system is stable and reliable. It can be installed and very easily. The results of multiple tests have good consistency. The error of the locating results in single-rescue and multi-rescue are all under30m. It has great practical application value.The innovations of the article are as followed:1. It is the first time to apply distributed fiber optic vibration sensing system to locate survivors in the mine after disasters, to improve the rescue rate of the survivors. The design of the monitoring system is finished. It resolves the problem lack of effective technology and devices in this field.2. Aiming at the needs of the application and the features of the actual monitoring mode of the system, the recognition algorithm of multi-point continuous perturbation based on gaussian kernel density estimation is proposed. The accuracy and the practicality of the system are improved further.