Research And Design Of Coal Mine Roof Monitoring System Based On LoRa Technology

Coal,as one of the main energy sources in China,supports the development of China's industry,but accidents often occur in the process of coal mining.In coal mine production accidents,gas explosion,seepage roof fall and roadway collapse are three major accidents.Coal mine roadway collapse has great harm to mine safety production.Previously,most coal mines in China used mechanical and hydraulic observation instruments to monitor roof pressure in underground,which had low accuracy and efficiency.With the development of sensor and communication network,coal mine roof monitoring adopts wired communication mode for data transmission.The wired monitoring system connects various monitoring equipment through communication cable.This connection mode is not only difficult to wiring and complex to operate,but also easy to be broken in the mining process.The failure of local line may paralyse the whole monitoring system,resulting in the failure of local line.Data cannot be monitored and transmitted in real time.Most of the existing wireless roof monitoring systems are based on ZigBee wireless communication technology.Like Bluetooth,ZigBee technology is a short-distance,low-power wireless communication technology.It is mainly used for data transmission between various electronic devices with short distance and low power consumption.However,the bandwidth overhead of ZigBee protocol requires high bandwidth,which in turn affects the communication distance and environmental adaptability.In practical applications,the transmission power can be increased to increase the communication distance and enhance the penetration.However,such an approach will increase the power consumption in practical application,which leads to the frequent replacement of batteries.In view of the above situation,a low-power transmission information design schemebased on LoRa technology is proposed.LoRa has all the characteristics of low-power WAN,including low-power(long battery life),long-distance,anti-jamming and other advantages,and integrates forward error correction coding,digital signal processing and digital spread spectrum technology.The problems existing in the monitoring system of coal mine roof are analyzed and studied.The shortcomings of the monitoring system of coal mine roof are analyzed.Based on the actual production environment of coal mine,a new monitoring system of coal mine roof based on LoRa technology is developed.