Research on shearer positioning experiment based on IMU and UWB at the end of underground coal mining working face

The long-term precision of shearer independent positioning device is an important research content of intelligent mining. The current shearer positioning accuracy is hard to meet the demands of automatic mining, and we established a fusion positioning model based on IMU/UWB, and proposed autonomous correction to compensate the drift error of inertial navigation device for the coal mine working face by using the fusion results of IMU/UWB to correct the position and posture of inertial positioning system. It can compensate the deviation of IMU in real time, and realize long-term high-precision autonomous cycle cutting of the shearer. To reduce the influence of uncertain measurement noise on the positioning results, we use variational Bayesian unscented Kalman filter (VB-UKF) technique to smooth the positioning results in order to further improve the fusion positioning accuracy. To verify the positioning accuracy of the mining face end, fusion positioning experiments are conducted in Taiyuan Heavy Machinery Co., Ltd on the ground and Shandong Energy Group coal mine working face in the underground, respectively. The experimental results demonstrate that, the accuracy of IMU/UWB fusion positioning is higher than that of the single UWB solution. After smoothing via the VB-UKF algorithm, the error in the x-axis and z-axis orientation of the IMU/UWB fusion localization for underground experiments decreased from 0.0102 m and 0.194 m to 0.082 m and 0.158 m, respectively, and the corresponding average accuracy improved by 19.6% and 18.6%. The error of the three pose angles is less than 2°, because the error extended Kalman filter compensates and modifies the IMU bias in the fusion localization model, which can effectively suppress the drift of the IMU posture angle. The underground field experiment proves the effectiveness of the positioning method of coal mining face end, which provides better reference and experience for the further application in underground coalmine by using IMU/UWB fusion positioning.