Research Of Precision Positioning Algorithm Based On RSSI In Coal Mine Tunnel

As the complex of the electromagnetic environment and tunnel structure of the coal mine, it is very difficult to accurate locate the target object in the coal mine. The precise positioning technology will provide rescuers with the exact location information when mine tunnel suffered from natural disasters. With the development of the large data internet of things, wireless precise positioning has become the mainstream at present. However, there are still lots of shortcomings of localization technology, such as low positioning accuracy, high error and being vulnerable to environmental interference. In additional, the jitter and drift problems have limited the development of precision positioning for coal mine. Therefore, studying precision positioning algorithm and its application in coal mine have very important theoretical significance and application value.The paper proposes a precision RSSI positioning algorithm, which is shorted for Gaussian-a-RSSI Algorithm for coal mine. The path loss factor a and the environment parameter factorse were calculated by piecewise fitting method which based on Gaussian filter. The transmission mechanism of electromagnetic wave under the coal mine was tested in this paper. The experiment results show that the attenuation of the RSSI is proportional to the distance. According to the actual environment of the coal mine tunnel, the length of tunnel is over dozens of kilometers. The coal mine tunnel is divided into every 50 meters to locate the position. Based on the original RSSI localization algorithm, the RSSI value of the receive device was optimized by Gaussian filter. For the propagation model of Shadowing, the path loss factora and the environment parameter factorse were calculated by piecewise fitting method which combined with weighted least square method and the least squares curve fitting to built the signal transmission of the actual mine tunnel environment through a large number of measured data. With and,the signal transmission model of the actual environment was built and the distance between the anchor nodes and unknown nodes were calculated. The distance error parameter Dm was introduced in the positional elaboration phase. Locating node coordinates were estimated by the standard minimum mean square error iteration.Finally, precision positioning verification of the G- a-RSSI algorithm was tested with different typical layout of anchor nodes. The measurement error and the positioning error of the algorithm were in detail analyzed in theory. Compared with the RSSI algorithm which based on fixed path loss factor, the algorithm proposed inthis paper can improve positioning accuracy and reduce the error rate. The positioning accuracy is about 2 meters. The lateral error is 1.2 meters and the vertical error is 0.8 meters.