A fiber Bragg grating tilt sensor for posture monitoring of hydraulic supports in coal mine working face

Abstract

Hydraulic supports are indispensable equipment in coal mining face. In order to establish an intelligent monitoring system for posture monitoring of hydraulic supports and realize posture monitoring of hydraulic supports online, the posture monitoring system structure of two columns shield hydraulic supports is established in theory. Then, the kinematics model of the hydraulic supports is analyzed and the fiber Bragg grating tilt sensor is designed. Besides, a method of error compensation for tilt monitoring is proposed. What’s more, the performance test is carried out. The test results indicated that the linear relationship between angles and the FBG center wavelength was good with an angular sensitivity of 32.4 pm/(°) and a linear fitting coefficient of 0.9992 in the range from −30° to 30°, and the repeatability of the FBG tilt sensor was superior. Finally, posture monitoring programs of the hydraulic supports is designed to test the performance of the FBG tilt sensor. The engineering monitoring instance is displayed, and the reliability of the hydraulic support monitoring system based on optical fiber sensing technology is analyzed, and the dynamic state of the hydraulic support posture during production process of the working face is obtained. Furthermore, such a posture monitoring system can be extensively used for quasi-distributed measurement and long-term online monitoring of other types of hydraulic supports such as four-column chock-shield hydraulic supports and standing supports.