Low-power Roof Separation Monitoring System Based On ZigBee

As the largest country in the coal production, mining accidents often occurs in China, especially the roadway roof accident. It’s very important and necessary to monitor the roof separation. Roof separation indicator is an important equipment of roof monitoring. However, the monitoring data of roof is still depends on manual reading in China. Based on this problem, a novel roof separation monitoring system based on Zig Bee technology is proposed. The system can realize automatic transportation of separation data, thereby ensure personnel safe in coal mine.Using wireless sensor network and selecting the ZigBee technology for the wireless communication protocol of the subject, the monitoring system of roof separation based on Zig Bee is proposed. The data collecting nodes, routing nodes and sink nodes based on CC2530, CAN repeaters based on PIC18F258 and CAN-Ethernet based on LPC2378 are designed. Software design of system, which is based on the Zig Bee2007 stack, making the nodes to achieve the function of MANET(mobile ad hoc network), collecting and sending dates at regular time, nixietube displaying,alarming when over limitation and so on.On the basis of the analysis of energy consumption of roof separation indicator and the overall network, using of switching effect of Holzer element to improve the problem of displacement sensor working without dormancy. Combining with S-MAC protocol which can adaptive duty cycle ratio, Zig Bee MAC layer is improved.Simulation results show that the improved MAC protocol greatly decrease the energy consumption.