Method and device for time synchronization and maintaining based on frequency deviation estimation

Abstract

The invention provides a method and a device for time synchronization and maintaining based on frequency deviation estimation. The method includes firstly, synchronizing time of a slave clock and a master clock and calculating a frequency deviation initial value R0 of the master clock and the slave clock; and secondly, estimating the corresponding time of the slave clock to the master clock at the moment t according to the calculated frequency deviation initial value R0, calculating the synchronization time measured value Ts of the slave clock at the moment t, determining whether synchronizing time or not according to the error of the master clock time and the synchronization time measured value Ts, if yes, synchronizing time of the slave clock and the master clock, and if not, acquiring N new master clock counts and slave clock counts to recalculating a frequency deviation value R based on the N new master clock counts and slave clock counts. By means of the method and the device for time synchronization and maintaining based on frequency deviation estimation, a distributive system can be more accurate in clock synchronization and more convenient in operation.

Description

technical field [0001] The invention relates to a method and device for realizing time synchronization and maintenance among multiple computers in a distributed network environment, in particular to a time synchronization and maintenance method and device based on frequency deviation estimation. Background technique [0002] Time unification is one of the most basic requirements of computer application systems. In a network-based distributed system, it is necessary to establish a standard time unification system or a common time reference to achieve system time unification. Otherwise, these applications are very difficult to work together and run well. [0003] For two free-running clocks, due to reasons such as the frequency division deviation of the crystal oscillator and the clock timer, each clock runs at a different speed, which eventually causes a deviation between the clocks. Therefore, time synchronization includes two parts of work: (1) Realize time difference syn...

AI Technical Summary

Problems solved by technology

[0005] There are following disadvantages in the existing time synchronization technology: when calculating the count of the slave clock, the local time of the slave clock is used, if time adjustment occurs at this time, the accuracy of the count will be affected; the crystal oscillator frequency of the clock will be affected by external factors ( Temperature, humidity) due to the influence of jumps, there may be a frequency jump between the two clock synchronizations, resulting in a discrepancy between the calculated interval time and the actual value, affecting the adjustment of the frequency; if the network environment is not good, causing the master-slave If the network communication between the clocks loses packets, or even the network between the master and slave clocks is interrupted, the slave clock will not be able to adjust the frequency and maintain time; it will not be able to deal with network jitter and clock frequency jumps in real time, which will affect the accuracy of time synchronization, etc.

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