面向工业应用的低成本高可靠光纤时间传递系统

Low-cost and high-reliability fiber-optic time transfer system for Industry 4.0

文章提出了一种基于电子计数法的多站点分布式光纤时间传递系统方案,阐述了系统原理、误差来源。实验搭建了一个发射端下设1km、2km和3km的三个相互独立互不干扰接收端的分布式光纤传递系统,连续一周钟差测试结果与理论分析的±4ns时间同步精度相吻合。该方案中的时间间隔测量和时间延迟均在FPGA中实现,结合SFP光模块可进行单板集成,具有精度较高、成本低廉、可靠性好、灵活易操作等特点,可满足工业时间同步应用需求。

In this paper, a distributed multi-access optical time transfer scheme based on the electronic counting method is proposed with the corresponding principle and error sources of the system being described. Experimentally, a distributed fiber-optic time transfer system with one local station connecting three independent remote stations by the 1km, 2km and 3km fiber links respectively is demonstrated.The measured time differences lasting for one week illustrate that the time synchronization accuracy better than ±4ns can be realized, which is consist with the theoretical analysis. In our scheme, the time interval measurement and time delay compensation are realized in a single FPGA, and can be integrated with SFP optical modules. This scheme has the characteristics of high precision, low cost, good reliability, great flexibility and easy operation, and it is quite suitable for industrial applications where synchronized time signals are required.