基于模糊理论动车制动系统故障树可靠性分析

动车组制动系统在可靠性分析过程中存在故障数据的不确定性问题,主要表现为数据的来源不同和事件语义表述不同等,导致很难获取系统事件发生概率的精确数值。因此传统的故障树分析方法对于这类问题的处理不能得到符合现实条件的准确数据结果,故提出运用模糊数学理论将事件的发生概率进行模糊化处理,并结合专家信心指数法通过故障树分析模型计算得出制动系统底事件的模糊概率重要度,并根据各底事件在不同故障状态情况下的模糊概率重要度的大小,找出影响系统可靠性的薄弱环节。通过对兰新客专上运行的动车组制动系统进行分析,结果与动车组制动系统实际运行情况相符合,验证了算法的可行性和有效性。为根据该线路故障的特点制定相应的检修和维护策略给出了理论依据。

Fault Tree Reliability Analysis of EMU Braking System Based on Fuzzy Theory

In the process of reliability analysis, the uncertainty of the fault data of EMU( electric multiple units) brake system is mainly caused by the different sources of data and the different semantic expression of events, which makes it difficult to get the exact value of the probability of system events occurrence. Therefore, the traditional methods of fault tree analysis( FT A) cannot get the exact data from the actual conditions in the treatment of such problems. The fuzzy mathematical theory is adopt to fuzzy deal with the occurrence probability of events. Combined with the expert confidence index method, the fuzzy probability importance of the brake system bottom events is calculated by the FTA model. According to the value of the fuzzy probability importance in different breakdown conditions, the weak links that affect system reliability are found. Based on the analysis of EMU braking system on Lanzhou-Xinjiang railway dedicated line, the results are correspond to the actual operation conditions of EMU braking system, which verifies the feasibility and effectiveness of the algorithm. The theoretical basis is given for laying down the corresponding recondition and maintenance strategies based on the impact of the characteristics of the line on the fault.