T-S模糊故障树是由一系列具有IF-THEN规则的T-S逻辑门构成的故障树,可以解决复杂系统可靠性分析中故障多态、故障机理不明确、底事件失效率难以精确得知的问题。目前该方法主要分析系统中的功能故障问题。实际中,复杂多态系统内部很多故障常常会造成性能降级,出现多性能状态,进而系统在不同的故障状态下具有不同的性能可靠性。通过对T-S模糊故障树所表示的系统赋予性能变量及故障多态下的不同性能值,利用统计学中的期望思想,提出一种分析系统故障多态下的性能可靠性方法,以及已知某一底事件或中间事件在故障状态下分析系统性能可靠性的方法。通过对目前大型飞机上常用的航空电子交互式以太网(Avionics full duplex switched ethernet,AFDX)进行分析建树,利用该方法求解系统在多故障状态下的性能可靠性,进行了实例分析。
T-S fuzzy fault tree is a kind of fault tree constructed by a series of T-S gates with IF-THEN logic. This can solve the multi-state issue, uncertainty of failure mechanism, and that failure rate of the basic event is not accurately known in complex systems. Currently, this method mainly analyzes the system function failures. As a result, system has different performance reliability under different fault conditions. In practice, many of the internal failures of complex polymorphic systems often cause performance degradation, and multiple performance status appears. By using the expectation theory of statistics, giving performance variable for system and different performance values at different fault conditions, a method analyzing the performance reliability of a polymorphic system has been proposed. This method can also compute conditional expected performance reliability in condition of knowing the basic event's or middle event's failure. The performance reliability of avionics full duplex switched ethernet(AFDX), which is currently used on large aircraft, is analyzed by this method.