Precise Positioning Of Moving Targets Under The Mine

The safety of personnel under coal mine is an important part of the coal mine safety production,and it is an important content of the underground safety management to understand and master the location information of the downhole personnel in real time.It is of great significance to improve the safety management of underground personnel,reduce the occurrence of accidents and speed up the search for the personnel after the accident,by using the existing Internet of things technology to realize the accurate positioning of the underground personnel.Therefore,the accurate positioning system of coal mine personnel plays an increasingly important role in coal mine safety production.Through the analysis of the characteristics of the coal mine underground environment,it is concluded that the wireless sensor network adopting ZigBee technology is more suitable for the personnel positioning system in the coal mine.Based on the location method,the location method based on distance measurement and distance independent localization method are deeply studied.In the location method based on distance measurement,the accuracy of distance values is very important.By comparing several common ranging methods,it is more convenient and feasible to use RSSI to range the distance in the underground ring coal mine.Through the analysis of the transmission and attenuation law of the downhole radio signal,the logarithm normal distribution model is used to calculate the distance.It is found that the sensitivity of the environment parameter n is very high,and the reasonable value of the location is directly related to the accuracy of the location.On the premise of reasonable parameters,an improved weighted centroid positioning algorithm based on RSSI is proposed.This algorithm can improve the positioning accuracy of the system to a certain extent.Considering the error of the measurement,the error source in the downhole personnel positioning system is analyzed in detail,and the corresponding correction scheme is proposed for the error.Combined with the positioning requirements of underground personnel,the whole framework of underground personnel positioning system is built,and the main functional modules of the system are designed and implemented.The software of the upper computer data processing and the location information acquisition node are developed and tested under the integrated environment of VS2010 and IAR Embedded Workbench.The operation results show that the system can meet the requirements of the location precision of the downhole personnel.