Research on time synchronization algorithm of TTE multi-hop system based on IEEE1588 protocol

摘要

Accurate and precise frequency synchronization is an essential requirement for different areas in avionics system. Emerging practice for time synchronization is to utilize Time-triggered Ethernet(TTE) network which is peer-to-peer network since it is highly deterministic. However, for some situations, TTE network contains uncertain communication delay, such as the node of the TTE network has an external clock source or contains a controller other than the TTE controller etc. This problem can be overcome by applying IEEE1588v2 synchronization protocol to TTE network. In this paper, the feasibility and the synchronization error of the algorithm not only are analyzed theoretically but also are verified from the simulation point of view. Specifically, the first step is the construction of model of the clock offset and clock drift state space between master and slave clocks. Subsequently, the Kalman filter algorithm is used to estimate the clock offset and skew between master and slave clock and compensate for its. Lastly, the algorithm's performance is evaluated using simulation. In the simulation process, above method is applied to the TTE multi-hop system, considering the effect of timestamp accuracy on the synchronization effect. The result of this simulation shows that, the algorithm with the 1588 synchronization protocol on the TTE network has more accuracy and stability than without it, when the timestamp accuracy is microsecond or higher.