Research On UWB/IMU Joint Positioning System Under Mine

The accurate positioning in coal mine is one of the important parts in the construction of the 'intelligent coal mine'.With the advantages of high security,strong penetration ability and low cost,the UWB positioning technology has become the preferred positioning technology in the coal mine.However,in the non-line-of-sight environment,the positioning error of UWB signal is huge,which cannot meet the requirements of precise positioning.Aimming at the problems such as the low ranging efficiency of signal in the environment with serious non-line-of-sight,positioning error caused by multipath propagation and the deviation of the positioning result from the real traj ectory caused by the error accumulation of the inertial navigation system,We proposed an improved UWB/IMU joint location algorithm.By changing the transmission mode of the traditional bilateral ranging signals,the number of messages needed in the ranging process is reduced.In the same time,the ranging efficiency has been improved.During UWB signal transmission,Kalman-based interference cancellation algorithm and median filtering algorithm are used to preprocess the ranging signal.By eliminating outliers and multi-path interference signals in the ranging signal,the system's anti-interference ability is improved.We uses the weighted LM algorithm to solve the first location information of the pre-processed location information,and combines the positioning result with the position information calculated by Gaussian iteration to calculate the second location information in the way of weighted coefficient fusion.By combining the two algorithms,the error accumulation of inertial navigation system can be effectively avoided.The simulation results show that the improved joint positioning algorithm has an average positioning error of less than 21cm.In the same time it has the strong anti-multi-path interference ability,the closer positioning coordinates to the truth value and a higher positioning accuracy.Based on the DW1000 module and the JY901 module,we established a UWB/IMU joint positioning system,and carried out experimental verification in the actual mine roadway.The experimental environment was set up at the Shaanxi Key Laboratory of Coal Green Development and Geological Guarantee.Experimental verification shows that the positioning error of the positioning system in the static state is less than 11cm,and 16cm in the motion state.The experimental results show that the improved algorithm has high positioning accuracy and can meet the requirements of accurate positioning in the well.