Base Station Synchronization Method Suitable for Underground Coal Mine

Abstract

The invention discloses a base station synchronization method suitable for an underground coal mine, which comprises the following steps that: a positioning label sends a first data message to a distance measurement base station, the distance measurement base station receives the first data message, updates the system time of the distance measurement base station according to the current system time of the positioning label contained in the first data message, and returns a second data message to the positioning label; and the positioning tag receives the second data message, updates the system time of the positioning tag according to the updated system time of the ranging base station, and broadcasts and sends a third data message to all the base stations in the coverage area of the positioning tag, so that all the base stations in the coverage area execute time synchronization work. According to the invention, the positioning label can be used as a relay, time synchronization is carried out on two base stations which cannot be directly reached by radio frequency, the realization of time division multiplexing is ensured, and then the large capacity of the whole positioning systemis realized; in addition, the base stations are not actively synchronized, the whole system period is distributed to the tags for positioning, and the maximization of the system load is ensured.

Description

technical field [0001] The invention relates to the technical field of underground base station positioning in coal mines, in particular to a base station synchronization method suitable for underground coal mines. Background technique [0002] Due to the special environment of the coal mine underground area, the ToF ranging mode is usually used for distance measurement between the positioning tag and the base station. At first glance, there is no need for time synchronization between the base stations (generally only in the TDoA positioning method, the base station is required) High-precision synchronization (better than 1 nanosecond)). However, the synchronization here is not related to ranging and positioning, but is proposed based on the large capacity of the system. [0003] Because there will be a large number of labels at the same position in the system to be positioned. If the tags are allowed to work freely, due to the increase in the number of positioning tags, t...

AI Technical Summary

Problems solved by technology

Each level of synchronization occupies different time slices. In this case, a large number of time slices of the system will be used for time synchronization instead of label positioning, which directly leads to a decrease in system load.

[0007] In addition, in some occasions, the distance between two adjacent base stations is likely to exceed the radio frequency coverage, which leads to the inability to transmit the synchronization message and the synchronization failure.

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