基于模糊理论的数控机床液压系统故障树分析

摘要

以某数控机床液压系统为研究对象,针对其故障发生概率具有模糊性和不确定性的特点,将模糊理论引入故障树分析中,采用三角型模糊数来描述底事件发生概率.通过分析该系统故障发生的机理,建立了该系统的模糊故障树,在定性分析的基础上进行定量计算,得到了基本事件的模糊重要度这项可靠性指标,为系统的可靠性评估、故障诊断以及维修决策提供了理论依据.%In this paper, fuzzy theory is introduced into the fault tree analysis for machine hydraulic systems to characterize the fuzziness and uncertainty of occurrence probability.The triangular fuzzy numbers are utilized to qualify the probability of basic events.The fuzzy fault tree can be constructed according to failure modes of systems.In addition, quantitative computing can be performed based on qualitative analysis subsequently.Fuzzy importance measure of each basic event can be further computed which can provide a theoretical basis for system reliability assessment, fault diagnosis and maintenance.