研究了一种光纤布拉格光栅顶板离层传感器，其具有结构简单、安装方便、成本较低等优点。光纤传感器自身不带电，适合应用在煤矿生产环境，传感器内部由机械结构组成，通过机械联动实现了传感器测量位移的转换，便于采用钢丝绳与顶板固定，同时也为实际应用中改变量程和灵敏度提供了便利。传感器使用了3个光栅，其多光栅的设计满足了对多点实时监测的需求，也提供了一种温度补偿的方法，在多个温度下的实验结果验证了该传感器具有可靠的线性系数，精度可以在±2 mm之内，量程可达300 mm。

设计了一种新型的矿用光纤光栅风速传感器, 利用差压原理实现风速转化, 由波纹管、等强度悬臂梁和双光纤光栅组成差分敏感机构, 并通过算法进一步进行温度补偿, 有效克服了温度交叉敏感问题, 提高了应变测量的灵敏度。文中推导了光纤光栅中心波长变化量与风速的关系, 同时对敏感机构进行了水压模拟试验, 得到传感器敏感机构的灵敏度为0.703 pm/Pa, 与理论值具有很好的吻合度; 对风速传感器样机进行风洞试验测试, 结果表明风速在0.2~20 m/s的情况下, 传感器测量误差可基本控制在±0.3 m/s以内, 并具有良好的线性关系。

Based on the principle of the fiber Bragg grating, a new type of fiber-optic pressure sensor for axial force measurement of transformer winding is designed, which is designed with the structure of bending plate beam, the optimization of the packaging process, and material of the sensor. Through the calibration experiment to calibrate the sensor, the field test results of the Taikai transformer factory show that the sensitivity of the sensor is 0.133 pm/kPa and the repeatability error is 2.7% FS. The data of the fiber-optic pressure sensor in different positions maintain consistent and repeatable, which can meet the requirement of the real-time monitoring of the axial force of transformer winding.

In order to monitor the process of surface subsidence caused by mining in real time, we reported two types of fiber Bragg grating (FBG) based sensors. The principles of the FBG-based displacement sensor and the FBG-based micro-seismic sensor were described. The surface subsidence monitoring system based on the FBG sensing technology was designed. Some factual application of using these FBG-based sensors for subsidence monitoring in iron mines was presented.

This paper presents the development of a cost-effective precision fiber Bragg grating (FBG) interrogation system using long-wavelength vertical-cavity surface-emitting laser (VCSEL). Tuning properties of a long-wavelength VCSEL have been studied experimentally. An approximately quadratic dependence of its wavelength on the injection current has been observed. The overall design and key operations of this system including intensity normalization, peak detection, and quadratic curve fitting are introduced in detail. The results show that the system achieves an accuracy of 1.2 pm with a tuning range of 3 nm and a tuning rate of 1 kHz. It is demonstrated that this system is practical and effective by applied in the FBG transformer temperature monitoring.

Spontaneous combustion of the coal mine goaf is one of the main disasters in the coal mine. The detection technology based on symbolic gas is the main means to realize the spontaneous combustion prediction of the coal mine goaf, and ethylene gas is an important symbol gas of spontaneous combustion in the coal accelerated oxidation stage. In order to overcome the problem of current coal ethylene detection, the paper presents a mine optical fiber multi-point ethylene concentration sensor based on the tunable diode laser absorption spectroscopy. Based on the experiments and analysis of the near-infrared spectrum of ethylene, the system employed the 1.62 μm (DFB) wavelength fiber coupled distributed feedback laser as the light source. By using the wavelength scanning technique and developing a stable fiber coupled Herriot type long path gas absorption cell, a ppm-level high sensitivity detecting system for the concentration of ethylene gas was realized, which could meet the needs of coal mine fire prevention goaf prediction.

The fiber Bragg grating (FBG) strain sensors were used for on-line monitoring of the stress variation of the lined wall in the gateway retained along the goaf of No. 3203 coal mining face in Dongtan Mine. The results showed that the FBG strain sensor with the wide measuring range could measure the stress variation accurately during the support process of the gateway retained along the goaf and could provide the basis to further optimize the support structure and to determine the support plan of the gateway retained along the goaf. The FBG micro-seismic sensors were used in Xinglong Mine to detect the micro-seismic signal. The signals were well received and analyzed to determine the location and energy level of the source of the micro-seismic event warning. The FBG sensors and detecting system show a significant potential for micro-seismic detection and geological disasters detection.