Design Of Monitoring System Based On ZigBee For Mine Roadway Roof Stress

Monitoring is an important part of the roof coal mine production safety, accuracy, timeliness and reliability of its data which is related to the current production safety, but also to the design of supporting future. In the light of problems of Implementation complexity, and larger stand-alone power in current roof monitoring, the paper designs of monitoring system based on ZigBee for coal roadway roof.The system consists of four parts dynamometer bolt, bolt stress meter, communication sub-station and the host computer. Bolt dynamometer is processing a pair of straight slot in a special bolt corresponding position. Strain gauges are pasted to the corresponding position in two straight groove. A corresponding set of strain gauges constitute a full bridge. The two groups of strain gauge distribute uniformly in the bolt dynamometer. The output signal of gauge bridge is sent to the strain gauges, strain gauges receives these analog signals, first amplified, A/D conversion and data processing, and stress data relay point to point manner (the strain gauge will be received stress data and their own stress data package once uploaded) uploaded to the communications sub-station, but also for local display as needed.ZigBee wireless communication is used between the strain gauge and communication sub-station and among the stain gauges. In the area of wireless communication to ZigBee, can be carried out by 485 serial communication interface. Strain gauges using a deep sleep-wake timing synchronization mechanisms to reduce system power consumption. The role of communication sub-station is to store data-forwarding data from strain gauges are transmitted to the host computer through Ethernet or 485. Communication sub-station can also be used to control management and data queries to other devices and manage all communications through the strain gauge model of human-computer interaction, including the display of data, store data, query data, system settings, and other functions. PC has the control and management, and query all sub-stations, export data reporting, real-time dynamic display of roof stress situation, see the historical curve, data backup and alarm logging functions. The system works in underground stress meter, the system hardware design of the safety measures have been taken to meet the requirements of the safety of mine (MA Center).Coal Research Institute Chongqing Branch of tests show that the system meets the requirements of each part. The field operation shows that, the system is stable and reliable, has achieved the design goal.