基于高精度时间数据的加速器故障分析样机设计

Design of accelerator failure analysis system prototype based on high precision time data

高性能的加速器对运行的可靠性和稳定性提出了更高的要求,而加速器庞大的设备数量、极高的设备精度及性能导致对外部干扰非常敏感。为实现加速器长期、高效、可靠的运行,故障快速定位、诊断和恢复对现代加速器控制系统至关重要。目前,在加速器运行过程中,常规保存的历史数据可以判断和处理大部分一般故障。但对于类似高频、束测元件等快电子学引发的瞬态故障,由于常规方式保存的历史数据时间粒度不够,导致无法对这类快速故障过程进行有效分析。因此,有必要通过技术手段完整地记录故障发生时刻前后一段时间设备的状态及参数,保存高真实的现场“快照”。本文设计了一种基于高时间相关性和高时间分辨率的加速器故障分析系统,并进行了样机实现。该样机基于事件定时系统实现了同步精度好于16 ns的全局时间戳,采用同步触发的方式进行数据获取,并利用EPICS 7的规范类型进行数据组装和发布。样机实验结果表明,利用获取到的高精度时间数据,可区分不同设备发生故障的先后顺序,验证了故障分析系统的可行性。

[Background]High-performance accelerators have higher requirements for operational reliability and stability.By analyzing the historical data that is routinely saved during accelerator operation,most failures can be judged.However,when some rapid failure processes occur,due to the insufficient granularity of the historical data stored conventionally,it is impossible to effectively analyze such rapid failure processes.When a failure occurs in a particle accelerator,fast acquisition techniques are needed to collect large amounts of data from various devices with precise timestamps.The failure occurrent process can be rapidly reconstructed by using these data to locate and judge the root cause of the failure.In order to obtain data accurately when a failure occurs,hardware devices with data cache function can be used at the front-end devices,and data can be locked and obtained in the synchronous trigger mode.That is,after receiving the synchronous trigger signal,data in the cache area of the front-end hardware device can be locked,and then read and stored.[Purpose]This study aims to design a failure analysis system prototype based on the event-timing technique.[Methods]Two core parts of the prototype were implemented:global highprecision timestamp implementation and data assembly and acquisition analysis.As one of the key factors,the global high-precision time stamping of failure data was applied to analyzing failure causes.Based on a high-performance rubidium atomic clock and the event-timing system,high-precision time stamps were implemented in this prototype with synchronization accuracy better than 16 ns to provide global high-precision time stamps for time data.Structured data based on the normative type of EPICS 7 was adopted for assembling and publishing the data.Essential information,including the system name,the subsystem name,the device name,the device card number,the data sampling frequency,the event timestamp,and the latched data,was obtained from the structured data.[Results]The prototype experiment results show that the failure sequence of different equipment can be distinguished by the obtained high-precision time data,confirming the high feasibility of our proposed failure analysis system.[Conclusions]The prototype designed in this study meets the requirements for rapid failure analysis of particle accelerators.And this prototype will be applied to the CSNS accelerator in the near future.In addition,it can also be applied to EPICS-based and event-timing based accelerator control systems.