故障小修下瞬时可用度的波动分析

基于修理延迟下单部件三状态(工作、修理延迟、修理)可修系统的更新模型,提出了带有故障小修的三状态(工作、故障小修、修理)更新模型。运用简捷的方法把更新方程化为微分方程得到其解析表达式。结果显示模型的变化使得稳态可用度提升。使用一套波动理论,其中包括基础的波动定义和相关的波动判定引理。依此给出了瞬时可用度波动产生的条件。通过固定故障率,分析修复率对瞬时可用度波动的影响。同时结合实际背景,提供了抑制波动的方法,即控制平均修理时间小于平均故障时间的1/4。仿真结果与理论相一致。

Fluctuation analysis of instantaneous availability under minor repair

The renewal model of one-unit repairable system with three states (up,minor repair,repair) is put forward on the basis of the renewal model with three states (up,delay-repair,repair).The steady availability is improved in the new model.The renewal equation in the model is transformed into the ordinary differential equation to obtain the analytical expression of instantaneous availability.A novel set of fluctuation theory including the basic definition and decision lemma of fluctuation function is used to analyze the fluctuation of instantaneous availability,which gives conditions for fluctuation existence of instantaneous availability.Combined with the practical background,conditions are used to show the influence of different rates on fluctuation when fault rate is fixed,which provides the method of fluctuation suppression.The method is that mean to repair time is controlled to be less than a quarter of mean to failure time.Simulation results are in agreement with theoretical results.