一个可修的和可降级的控制系统可靠性和可行性

The Reliability and Performability of a Repariable and Degradable Control System

研究了一个可修的和可降级的控制系统的可靠性和可行性．该控制系统是由Ｌ（＝ｍ＋ｎ）个子系统构成的．其中有ｍ个子系统是两相同部件组成的温储备系统，另外ｎ个子系统是单部件系统．当其中某些子系统故障时，系统完成任务的能力有所下降，但系统仍可运行．当另一些子系统故障时，则系统故障．因此，它是一个可降级的系统．为了描述系统的这种性能，考虑了系统的可行性，该控制系统也是可修的．通过利用扩展Ｍａｒｋｏｖ更新过程的方法和概率论，得到了该控制系统的一些可靠性指标，比如可靠度Ｒ（ｔ），系统瞬时可用度Ａ（ｔ）和稳态可用度Ａ，系统首次故障的平均时间ＭＴＦＦ等．同时也求得了该系统的一些重要的可行性指标，如系统的瞬时性能可用度Ａｃ（ｔ）和稳态性能可用度Ａｃ。

The reliability and performability analysis of a repairable and degradable control system are discussed. The system is composed of L(=m+n) subsystems, in which m(>1) are two same units of warm-stand by subsystems and the others are simplex unit system. When some subsytems fail, the system is still able to operate, but its performance comes down. When one of the other subsystems fails, the system can't operate again, which means the system is fault. The control system is repairable if and only if the system is fault. By using the extended Markov renewal processes and probability theory, we get the system's reliability measures, such as reliability function R(t), system point-wise avaliability A(t) and steady state avaliability A, mean time to system first fault MTFF etc., and the system's performability measures such as System point-wise performance availability (or system mean computation ability at time t) A c (t) and steady state performance availability A c'  mean performance to system first fault MCFF etc.