基于BDD算法的航天测控系统任务可靠性建模与分析

Mission Reliability Modeling of Spaceflight TT&C System Based on BDD Algorithm and Relevant Analysis

提出了一种航天测控系统的层次化建模方法,以及测控任务可靠性二元决策图(BDD)分析算法。在模型底层描述了测控系统的结构和任务需求信息,模型顶层将测控资源与任务进行统一,将测控单元任务弧段切割成不同阶段,建立了任务可靠性的故障树模型。采用ITE算法将故障树模型转换为BDD模型,并给出了BDD模型的计算方法。最后,运用实例说明了方法的有效性,进行了测控任务可靠性的灵敏度分析,找出了系统的薄弱环节。

This paper proposes a hierarchical modeling approach and binary decision diagram（BDD）evaluating algorithm for the mission reliability analysis of spaceflight telemetry,tracking and command（TTC）system.The model describes the system structure at the lower level and mission information.At the upper level,components and missions are associated together.By cutting flight phase into many sections,the paper establishes a mission reliability model of fault tree.With if-thenelse（ITE）algorithm,the paper transforms fault trees into BDDs,and then expresses BDD evaluation algorithm.In the end,the paper illustrates the practicability and effectiveness of the approach with an example,analyzes the sensitivity of mission reliability and identifies the vulnerable points of system.