Underground coal mine accurate positioning method without clock synchronization

Abstract

The invention provides an underground coal mine accurate positioning method without clock synchronization. An underground mine tunnel serves as a one-dimensional channel for analysis; a system structure of positioning substations+ positioning cards is adopted; by utilizing known distance between substations, adjacent substations carry out ranging communication with each positioning card respectively, and the positioning initiating substation finishes ranging and positioning calculation without any timing and data operation of the positioning cards; and distance between each personnel positioning card and the substations can be accurately obtained by utilizing the known distance between substations, and thus accurate positioning is realized. When the accurate positioning method is implemented, clock synchronization is not needed between the substations and between the substations and the positioning cards, and clock and crystal oscillator offset errors of a positioning device can be eliminated. The accurate positioning method is simple in realization process, fast in positioning speed and high in real-time performance, and has a wide popularization value.

Description

technical field [0001] The invention relates to a coal mine underground accurate positioning method without clock synchronization, and the method relates to the fields of radio communication, distance measurement and positioning technology and the like. Background technique [0002] The "Notice of the State Administration of Work Safety and the National Coal Mine Safety Supervision Bureau on the Construction and Improvement of the "Six Major Systems" for Underground Coal Mine Safety and Avoidance" (An Jian Zong Meizhuang [2010] No. 146) requires the construction and improvement of the coal mine underground personnel positioning system. Give full play to the role of the underground personnel positioning system in personnel management and emergency rescue work. "Priority should be given to products with advanced technology, stable performance, and high positioning accuracy to ensure that the dynamic distribution of underground personnel and the number of personnel in the minin...

AI Technical Summary

Problems solved by technology

Time of Arrival positioning TOA requires strict synchronization between the positioning card and substations, and between substations

Time difference of arrival (TDOA) positioning does not require synchronization between the positioning card and substations, but strict synchronization between substations is required. System synchronization is difficult, crystal oscillator stability is high, and the cost is high, especially for identification cards.

At present, the number of positioning systems based on radio frequency identification technology (RFID) is the largest in actual use in mines. The use of RFID has the following problems: the positioning accuracy is limited by the distribution density of readers, and only regional positioning can be achieved, and accurate positioning with an error of several meters cannot be achieved; Limited by the reading and writing speed of RFID, it cannot handle the situation that many people pass through the card reading system at the same time, and it is easy to miss reading

However, the transmission loss model of wireless signals is greatly affected by the environment, so the general RSSI positioning system often has to rely on increasing the density of anchor nodes and using a global optimization algorithm to control the positioning error in one direction, but the underground environment is mostly a linear environment composed of tunnels. Field strength data in other directions on the plane cannot be obtained, so when there are other factors affecting wireless signal transmission such as large metal obstructions in the tunnel, the positioning error is large

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