基于故障树的南极天文光学望远镜镜面除霜系统的可靠性分析

Fault Tree Analysis on Reliability of Mirror Defrosting System of Antarctica Astronomical Telescope

我国的南极天文光学望远镜目前架设在环境恶劣的南极冰穹A地区,观测时处于无人值守的状态。由于观测时部分光学镜面暴露在外部环境中,镜面表面的冰雪霜会降低光学系统的透光效率和反射效率。望远镜镜面除霜系统旨在降低或消除冰雪霜对光学系统的影响。基于故障树分析法建立了望远镜镜面除霜系统失效的故障分析树,通过对故障树的定性和定量分析,得到系统的最小割集和引起故障的各基本事件的结构重要度排序。结合实测结果,有效地找出系统的薄弱环节,对于提高系统的可靠性,改进和完善系统提供了理论指导。

In Antarctic optical telescope operating in Dome A, Antarctic, some mirrors are exposed to harsh environment when the telescope is observing. Frost snow and ice on the surface of the mirrors degrade the transmission and reflection of the optical system. Telescope mirror defrosting system is aimed to settle this problem. In this paper, a fault tree of the mirror defrosting system based on FTA （Fault Tree Analysis） is established to make sure the system works reliably. After qualitative and quantitative analysis of the fault tree, a minimal cut set of the system is obtained and the structure importance ranking of the basic events causing the fault appears. The analysis results show clearly the bottle neck of the system and point out the way to improve the reliability of the system theoretically.