Enhancement of efficiency of search and rescue under falls of ground
M. A. Durmanov, Igor I. Maronchuk, Igor B. Shirokov · Gornyi Zhurnal · 2017
In mine accidents, miners are isolated in roadways by falls of ground from mine roof. It is possible to enhance efficiency of search and rescue of miners using radio technical equipment for detection and positioning of people. This study is aimed to design a radio technical system and to develop methods for fixing position of sufferers. The search equipment should be fitted with undamageable (wireless) communication channel to ensure mobility of the search, to use signals that can penetrate deeper in rock mass and to ensure the wanted accuracy and efficiency of the search. The search system implements the amplitude–different method and involves active beacon stations to be given to search subjects, activation device, control and computation system and three search devices to be given to rescuers. The activation device activates the beacon stations in its coverage area, the beacon stations emit signals at the unique frequencies that are taken by the search devices at three points; the search subject coordinates are fixed using the triangulation method and the subject is identified. The beacon station has a ferrite core coil that generates variable magnetic field picked by analog antennas of the search devices in accordance with the law of electromagnetic induction. Rock mass in coal mines is not magnetic, and the magnetic field propagates in rocks without extra attenuation. Based on that, knowing the behavior of the magnetic field attenuation in free space, it is possible to use the amplitude–difference method for finding the range to an object. In order to improve the range finding accuracy and to avoid remeasurement, the iteration algorithm of the ranging data correction has been developed.