Design Of The Wireless Localization System Based On ZigBee Technology In Colliery

There are many coal mines in Shanxi province, due to the obsolete safety devices and backward establishments, when accidents occur, a lot of loss in person and property will appear. It is urgent to resolve the safety problem in colliery. Wire and wireless communication methods used in colliery home and international nowadays are unable to offer dynamic distribution and work conditions of the workers, so it is hard to carry out effective relief after disaster. The location information of the worker becomes more and more important in practice.This paper adopts ZigBee technology attached to Wireless Sensor Network to realize communication and localization in colliery after investigating localization system based on RFID(radio frequency identity distinguish) ad nRF2401.First, comparing with other two topologies, this paper adopts mesh topology with high robustness to form the wireless network in colliery.JN5139 module which has lower sleep current and wider communication scope produced by boccon company is applied to realize hardware scheme, after contrasting with other ZigBee chips on power consumption, cost, communication scope and MCU. Related software compiling environment Jennic CodeBlocks and download tool Jennic Flash Programmer are also introduced.Next, localization algorithms in WSN including range-based and range-free ones and two new algorithms which contains one based on arrival and leaving information of the beacon, the other using variance of RSSI(receive signal strength indicator)are studied. We adopt LQI (link quality indicator) which has higher resolution ratio contrasting with RSSI to estimate location, proposing localization algorithms based on 3 beacons in plane and 8 beacons in space.At last, this paper forms a consulting table which is used to transfer LQI to distance by some measuring data. The localization results based on 3 beacons in plane show in client interface based on VC++.