Development And Application Of Mine Roof Monitoring And Early Warning System Based On Wireless Sensors

This project is one of the important sub-projects of Shanxi Province’s Science and Technology Major Project "State-of-the-art Coal Mine Major Production Equipment Condition Monitoring and Life Cycle Management System Development"(20131101029).It is proposed for achieving the safety monitoring and disaster early warning of mine roofs.Based on the actual requirements of both the underground roof monitoring in coal mines and China’s 2025 smart coal mines,this paper develops the wireless roof-based monitoring and early warning system which can acquire and storage and upload the roof’s delamination and stress signals,and forewarn roof disasters.The main contents of the study are:By consulting a large amount of relevant literature and investigating the status of on-site monitoring of the mine roof,the feasibility and necessity of the application of wireless transmission technology in the mine roof monitoring and early warning were analyzed.Based on the actual installation and operation requirements of the mine,the overall system design program was formulated and determined.The structure composition and function of mine roof monitoring and early warning system are presented based on wireless sensing.The whole system consists of a host computer,a CAN to Ethernet module,multiple relay devices,and dozens of low power consumption wireless roof monitoring devices.Together they form a real-time roof condition monitoring and early warning system based on the field wireless network.Among them,wired transmission is used between the host computer and the CAN-to-Ethernet module,and between the module and the relay device,and wireless transmission is used to connect the relay device and the mine roof monitoring device.Under the full consideration of the explosion-proof requirements of underground instruments and meters and the low power consumption requirements of wireless devices,a low power wireless roof condition monitoring device hardware circuit and a top board repeater device based on a low power microcontroller MSP430F1611 as the main controller were developed Hardware circuit.In addition to the main controller,the device mainly includes hardware circuits such as a power conversion module,a display module,a multi-parameter signal acquisition module,a data storage module,a Bluetooth communication module,and a CAN communication module.They provide a means to control power consumption in multiple ways from the hardware.Using the combination of software and hardware,a mine roof monitoring device program with low power consumption and wireless sensing characteristics was written.It mainly includes the main program,power management program,OLED screen display program,multi-channel signal acquisition program,external FLASH storage program,clock read and write and parameter power-down storage program,light trigger and physical key identification program,and Bluetooth communication program.In addition,according to the requirements of data conversion and transmission,a repeater program was written,which mainly includes an OLED screen display program,an external physical key program,a Bluetooth data transceiver program,and a CAN transceiver-based data transceiver program.The hardware and software functions realize the low-power operation and wireless data transmission of multiple monitoring sensors on the mine roof,which not only extends the continuous monitoring time of the roof after an unexpected power outage,but also reduces the blindness of the mine in responding to unexpected accidents.By analyzing the advantages and disadvantages of intelligent algorithms and mathematical models such as neural networks in mine roof prediction and early warning,combined with the roof feature information that can be given by the monitoring system developed in this paper,a mine roof warning model based on the autoregressive moving average model was developed and PC software that integrates monitoring and early warning.Based on the historical roof monitoring data of a mine in Shanxi Jincheng Coal Group,the reliability and effectiveness of the autoregressive moving average model for dynamic early warning of the roof of the mine were verified and the dynamic evaluation and early warning of roof were realized.After the joint debugging of the individual functions of the various units and the overall system functions was carried out in the laboratory and the workshop of the Jincheng Coal Group Technology Research Institute,all kinds of functions in system is versified to meet the expected requirements of the design.The debugging results also show that the system can accurately complete the acquisition,storage,upload and the early warning realizes the orderly transmission of data under the wireless network,effectively improves the continuity of roof monitoring after the communication line is accidentally cut off,which improves the monitoring of the mine roof.Reliability also provides a basis for further analysis and prediction of roof dynamics.