Study On The Key Algorithms Of Underground Personnel Positioning Based On Dead Reckoning

With national attention on mine safety, personnel positioning technology of coal mine has also been a rapid development. Underground personnel positioning technology can provide accurate location information of workers and plays a crucial role in determining a plan for helping workers trapped underground quickly and efficiency. Now most of underground personnel positioning system are based on location technology infrastructure, which requires installation of the system facilities in advance, with high cost and limited range.In this paper, personal navigation algorithm based on dead reckoning has been developed, which can enable autonomous positioning without the help of outside information, and is easy to use and cost low. The algorithm is mainly in-depth study of the pedometer algorithm and heading angle solver algorithm. Because pedestrians body sway can affect the gyroscope,so this paper chose an adaptive pedometer algorithm based on accelerometer, whose parameters can be automatically set up. UAV attitude solver algorithm-Gradient descent algorithm and multi-axis complementary filtering algorithm based on Mahony were taken into the pedestrians heading solver. Gradient descent algorithm combined the rotation quaternion obtained by the idea of gradient descent when the error function got the minimum number and the rotation quaternion calculated by gyroscope to get the heading angle. Multi-axis complementary filtering algorithm based on Mahony combined mutual compensation long-term effectiveness of accelerometer and magnetometer and accuracy of gyroscope in a short time to achieve attitude update and get the direction of pedestrians. At the sometimes, this paper made the complementary filter better for a smaller amount of calculation and higher stability.In the end, this paper did a simulation for gradient descent algorithm and improved multi-axis complementary filtering algorithm in Mat lab and gave a comparison from the estimation accuracy of the algorithm and computing time according to the simulation result. Finally the results indicated that improved multi-axis complementary filtering algorithm can do a better result in the underground heading angle solver.