The Research Of Seismic Localization Algorithm In The Coal Bearing Seam

With the growth of the national economy, the demand for coal resources is increasing, while the safety problems in coal mine exploitation are urgent to be solved. Micro-seismic monitoring technology can timely and accurately monitor the position of an emergency, and require an effective micro-seismic localization algorithm as the guarantee. Micro-seismic location principle is the same as the earthquake’s, the former is used to locate a smaller area and requires relatively high positioning accuracy.Combined with the characteristics of the coal bearing strata:layered, complicated changes in the horizontal, this paper discusses micro-seismic locating algorithms based on the complex3D velocity model. Since the coal bearing seam may include low velocity zone, such as gas enrichment area or water area, which may block or slow down the propagation of the wave signal. It may divide the monitoring area of the coal seam into multiple of homogeneous regions, whose speed are not identical, then according to the calculation of the travel time tables based on Huygens’ principle, which is made by Podvin, can effectively circumvent the low velocity zone to ensure the accuracy of the location, then combining with the position of the sensors and giving the corresponding travel time table. Then this paper mainly introduces two micro-seismic location algorithm:the global search algorithm and simulated annealing algorithm. The two algorithms’essences build an objective function according to above travel time tables and first arrival times monitored by the sensors, and solve the extreme value of the objective function. The global search is similar to the exhaustive method, to search the entire solution space of all points, to find the extreme value. The smaller the particle size of the search is, the higher the accuracy of the algorithm is. The simulated annealing algorithm is an algorithm that performs a random walk in the solution space based on the Metropolis’s criterion. Its efficiency much higher than the former’s, and its accuracy is better. Finally the data simulations verify the accuracy and efficiency of the algorithms.