数控车床进给系统基于模糊理论的故障树分析

Fault tree analysis of ETC36 CNC lathe feed system based on fuzzy theory

摘要:

为解决ETC36数控车床进给系统在缺少可靠性试验数据和实际故障数据情况下的故障树分析问题,采用获取底事件模糊概率的专家语言评价方法,对进给系统进行基于模糊理论的故障树分析. 建立故障树并对其进行定性分析,得到ETC36数控车床进给系统的各种失效模式;采用专家语言评价方法,对故障树进行定量分析,获得顶事件发生的模糊概率,并与实际概率进行对比,得到相应的置信度水平λ为0.70,验证了专家语言评价方法的可行性和故障树建立的正确性;计算各底事件的模糊重要度,得到ETC36数控车床进给系统的具体薄弱环节,解决了ETC36数控车床进给系统在故障概率信息严重缺失下的故障树分析问题．

Abstract:

To get the fault tree analysis of ETC36 CNC lathe feed system under the condition of lack of actual failure data and reliability test data, and improve the reliability of ETC36 CNC lathe feed system, an expert language evaluation method is adopted to obtain the fuzzy probability of bottom events. Based on fuzzy theory, the fault tree is established and the qualitative analysis is carried out. Various failure modes of ETC36 CNC lathe feeding system are gotton. On the basis of using expert language evaluation method, a quantitative analysis of the fault tree is made and the fuzzy probability of top event is obtained. When compared the fuzzy probability of top event with the actual probability, the corresponding confidence level 0.70 is gotton that verifies the feasibility of language experts evaluation method and the correctness of the fault tree. The fuzzy importance degree of each bottom event is calculated, and the weak links of ETC36 CNC lathe feed system is overcome. To a certain extent, the fault tree analysis of ETC36 CNC lathe feed system under the serious lack of failure probability information is finished.