航天用时间触发网络系统同步性的故障分析

确定性网络的同步性在航天电子系统中至关重要。为保证确定性网络在发生故障的情况下也能正常的进行时间同步，本文采用spaceVPX标准中典型的双星拓扑交换结构配置基于时间触发以太网协议的可容错系统。针对此架构，使用以太网的航天系统中发生故障的单容错结构进行了仿真，模拟了几种时间同步协议控制帧异常的情况：协议控制帧包括冷启动帧、冷启动应答帧、集成帧从故障交换机的端口发送到网络中的一个终端系统后对于时间触发网络的同步网络所产生的影响。仿真结果表明，故障交换机会逐渐延长处于正常工作的终端系统的启动时间，进而不利于整个确定网络系统的同步过程，但是如果设置不同协议控制帧的周期超过一定的数值后，单点故障不会影响双冗余系统的启动时间。

Fault Analysis of Synchronization of Aerospace Time-Triggered Network System

The synchronization of deterministic networks is very important in aerospace electronic systems. In order to ensure the normal time synchronization of deterministic network in case of failure, this paper adopts the typical double star topology switching structure in spaceVPX standard to configure a fault-tolerant system based on time triggered Ethernet protocol. Aiming at this architecture, the single fault-tolerant structure in the aerospace system using Ethernet is simulated, and the exceptions of several time synchronization protocol control frames are simulated: the protocol control frame includes cold start frame, cold start response frame The impact of the integrated frame sent from the port of the faulty switch to a terminal system in the network on the synchronization network of the time triggered network. The simulation results show that the fault switch will gradually prolong the start-up time of the terminal system in normal operation, which is not conducive to the whole synchronization process of the network system. However, if the period of different protocol control frames exceeds a certain value, the single point of fault will not affect the start-up time of the dual redundant system.