Algorithm research and simulation experiment of underground positioning with GRPM

It is very difficult for miners to escape or be rescued using the existing mining positioning system without electricity and any network.GRPM is the abbreviation of Geomagnetic and Radio Positioning Method, which is a new active underground positioning method by radio frequency initial positioning and geomagnetism fine positioning, suitable for emergency escape.This study analyzes the high-precision geomagnetic data in underground roadway, which follow a " daily variation" rule with the continuous and regional abrupt change. The geometrical reference simulation is constructed by piecewise linear method, nearest neighbor method and cubic surface interpolation method, and the matching positioning simulation is carried with MSD, HD and NPROD model.The results prove that the piecewise linear interpolation method is suitable for the construction of geometrical reference, fast fitting, high precision, accord with the roadway magnetic distribution.The NPROD model is suitable for the dynamic positioning with a quick calculating speed and a 2/3 mesh precision, and satisfies the requirement of accurate positioning.