冗余频率源无缝使用策略研究

Electronic information systems generate the reference frequency by redundant frequency standard in order to improve the reliability and stability. These systems require an external reference signal to assist in achieving the primary and backup links integrity monitoring. the real-time nature of this method is limited by external reference source and the accuracy of anomaly detection and isolation is limited by the noise of external compare link. We proposed an autonomous Integrity monitoring method based on the characteristics of redundant frequency standard. We monitoring the system autonomous by use intermediate oscillator of the measurement system as a third party criterion and Kalman filter model aided without increasing the system configuration and external reference. This method can improve the accuracy of the monitoring system for the monitoring of sudden failure, and improve the real-time and reliability. We explore the frequency variation of primary and backup links based on measurement and analysis, achieve real-time autonomous monitoring of the primary link via a new integrity self-monitoring algorithm, and improve the continuity and reliability of the protection system by the phase lock of output. We build an experimental system experimental to validate the new method based on the theoretical analysis and simulation, and develop the method of redundant frequency standard with Seamless Switchover.

为了提高电子信息系统的可靠性和稳定性，越来越多的系统采用主备冗余的方式来产生参考频率。这些系统通常需要借助外部参考信号来辅助实现主备链路的完好性监测，系统输出信号在主备切换前后不能保持连续，其频率和相位通常会发生突变甚至出现中断。 在对主备链路信号进行精密测量和分析的基础上，探索主备链路信号的变化规律，根据主备链路的特点，提出一种完好性自主监测方法。不需要外部参考信号，将测量系统中间振荡器的频率作为第三方判据，结合Kalman滤波器模型预测辅助算法，在不增加系统配置的条件下实现完好性的自主监测，提高监测的实时性和可靠性。 设计主备链路产生信号的精密控制方法，在不损失信号性能的前提下实现主备链路信号保持一致，提出输出锁相方法实现主备链路的无缝切换，为系统提供高可靠、稳定连续的参考时频信号。在理论分析和仿真试验的基础上，搭建实验系统，对新方法进行验证，最终制定切实可行的冗余频率源无缝使用策略。

冗余频率源是高精度电子系统的重要组成部分，负责为系统提供高精度时频参考信号。本项目主要研究了以多个高精度频率源为参考，产生高精度、稳定、可靠和连续的时频信号，重点解决了在多个参考频率源间进行切换的时候保证系统整体输出时频信号的频率和相位不发生跳变，提高系统输出信号的可靠性和连续性。. 经过三年的研究，取得了一系列研究进展。包括：1）通过精确测量主备链路产生信号之间的时差，对主备链路相位差和频率差进行数学建模；2）设计完成主备链路完好性自主监测方法，实现对主备链路输出信号的频率跳变、性能下降和缺失进行实时监测，并实现异常情况的隔离；3）设计实现主备链路的无缝切换方法，输出信号主备切换后频率和相位保持连续，频率波动小于1e-13，相位变化小于0.1ns；4）设计实现主备链路精密控制方法，控制主备链路产生信号保持一致；5）搭建完成多冗余频率源无缝使用策略实验系统。上述研究成果为我们进一步提高频率源输出信号的稳定性和可靠性奠定了基础。