基于滑模控制的IEEE1588时钟同步算法研究

Research on IEEE1588 clock synchronization algorithmbased on sliding mode control

针对IEEE1588时钟同步过程中存在时钟频率漂移问题,提出了一种基于滑模控制的新型时钟同步算法。首先根据主从时钟偏差与漂移的递推关系,建立系统状态空间模型;然后运用滑模控制缩小时钟偏差与时钟漂移;最后结合滑动平均滤波对实验过程中的频率抖动和随机误差进行优化。结果表明,基于滑模控制的时钟同步算法可有效抑制时钟漂移引起的时钟偏差线性增长,将时钟偏差控制在1μs以下,从而实现亚微秒级网络对时。相比传统IEEE1588协议同步方法,所提方法提供了更高的同步精度。

Aiming at the problem of clock frequency drift in IEEE1588 clock synchronization process, a novel clock synchronization algorithm based on sliding mode control is proposed. Firstly, the state space model of the system is established according to the recurrence relationship between master-slave clock offset and drift. Then, the sliding mode control is used to reduce the clock skew and clock drift. Finally, the frequency jitter and random error in the experimental process are optimized by sliding average filter. The results show that the clock synchronization algorithm based on sliding mode control can effectively restrain the linear growth of clock skew caused by clock drift, and control the clock skew below 1 μs, thus, realizing sub microsecond network time synchronization. Compared with the traditional IEEE1588 protocol synchronization method, the proposed method provides higher synchronization accuracy.