基于多值决策图的温储备系统可靠性建模方法

温储备系统是冷储备与热储备系统的推广,在实际中有广泛应用。针对不可修温储备系统的可靠性建模问题,已有基于多值决策图(MDD)的系统可靠性建模方法。该方法以系统中的单元故障为建模对象,分别构建故障级MDD与系统级MDD,进而获得系统可靠度的解析表达式。然而,该表达式中不同维度积分相互混杂,计算给定时刻的系统可靠度需要首先梳理系统可靠度的表达式,以利用数值方法求解其中的积分。为实现系统可靠度的程序化计算,在已有研究基础上提出将系统级MDD按故障数分解为一系列子决策图,通过对MDD中边的概率重新赋值获得每一子决策图的发生概率,得到系统可靠度的规范形式,形成一套完整的系统可靠度计算方法。 

Multi-valued decision diagram based reliability modeling of warm standby systems

As a generalization of cold and hot standby technique, warm standby has been widely used in the system design. This paper focuses on the reliability modeling of warm standby systems and extends a multi-valued decision diagram (MDD) based system reliability modeling approach. By concentrating on the failures in the system, the existing method first constructed the failure level MDD and system MDD, and then obtained the analytical expression for the system reliability based on the system MDD. However, the system reliability expression is a mixture of integrals of different dimensions, which requires some manual rearrangement to calculate the system reliability at given time. Based on the existing work, we suggest an MDD splitting procedure after obtaining the system level MDD and a reassignment for the probabilities of the edges in the system MDD. With this extension, the numerical value for the system reliability at any given time can be easily obtained and the MDD based reliability evaluation approach for warm standby systems is completed.