A clock synchronization method for a vehicle detection system

Abstract

The invention relates to a clock synchronization method of a vehicle detection system. In the method, when the clock offsets of the node and the gateway node are not greater than the first allowable error during each synchronization within a preset time, the synchronization cycle is increased; When there is a clock offset greater than the first allowable error among the clock offsets of each synchronization within a time period, the synchronization period is reduced; the energy consumption of clock synchronization can be reduced without sacrificing clock synchronization accuracy by adopting the present invention.

Description

technical field [0001] The invention relates to a wireless sensor network (WSN, Wireless Sensor Network) technology, in particular to a clock synchronization method of a vehicle detection system. Background technique [0002] WSN, which integrates sensor technology, information processing technology and network communication technology, consists of a large number of sensor nodes distributed in physical space through an ad-hoc network, and uses different types of sensors built into the nodes to detect different surrounding environments, including temperature, humidity, movement, etc. Numerous physical phenomena such as target direction and speed. Clock synchronization is an important part of WSN applications. The data fusion detected by sensor nodes and its own positioning require the clocks between sensor nodes to be synchronized. [0003] The methods widely used in network clock synchronization mainly include Global Positioning System (GPS, Global Positioning System) and N...

AI Technical Summary

Problems solved by technology

GPS has a very high synchronization accuracy, but its cost is high and energy consumption is high, and the synchronization accuracy will be greatly affected in environments with obstacles such as buildings

NTP is a protocol for clock synchronization on the Internet. It can realize high-precision computer time calibration on the network, but it is computationally intensive and has a large computational overhead.

In WSN applications, the shape of sensor nodes is required to be as small as possible, and it is difficult to maintain after deployment. In addition, there are strict requirements on energy consumption, and low cost is required so that they can be deployed in large quantities. Obviously, GPS and NTP are used for WSN. Clock synchronization is not desirable

There are also a lot of research on clock synchronization in distributed systems, but these methods also do not consider the characteristics of wireless sensor networks and require a large resource overhead, so they are not suitable for clock synchronization of WSN

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