A High-Precision Dual-Frequency Magnetic Induction Through-the-Earth Positioning Method

Abstract

To achieve the high-precision through-the-earth positioning in mine rescue, we propose a dual-frequency magnetic induction positioning method. The dual-frequency transmitter underground is a loop energized coil. The receiver on the ground is a three-axis magnetic core coil. We first carry on the algebraic transformation to the expression of the dual-frequency positioning signal, and obtain the transceiver distance function that is not affected by the layered earth conductivity. Then, through the tilt angle of the receiver and the rotation matrices, we correct the receiver tilt. By the direction of the geomagnetic field, we correct the direction deviation of the receiver. Finally, we obtain the threedimensional coordinates of the transmitter by decomposition of the transceiver distance. The analysis and simulation results are as follows. The dual-frequency positioning method eliminates the positioning error caused by the path loss of the stratified earth media. The rotation matrices correct the error caused by the receiver tilt. When the receiver is close to the top of the transmitter, the positioning error can be reduced. By configuring proper transmitter parameters, we can maintain a balance between transmitter size and rescue efficiency.INDEX TERMS high-precision, dual-frequency, Magnetic induction, positioning, through-the-earth.