基于FTA和模糊集理论的设备可靠性研究

应用模糊故障树（模糊集合论和故障树相结合）分析的方法研究了CXT设备Handler模块的可靠性。以Handler失效为顶事件，建立此模块的系统故障树，并采用上行法定性分析找出该故障树的最小割集。传统故障树定量分析时需要得到各底事件的概率精确值，而实践中，由于底事件的发生概率具有随机性和模糊性，难以获得精确的概率值，为克服传统故障树这一不足，引入模糊数（通常采用对称三角模糊数）来表示底事件的发生概率，并且按照模糊逻辑门的运算法则定量计算，从而得到故障树顶事件及各中间事件的发生概率（亦为区间数），最终找出了Handler的薄弱环节并计算出Handler的系统不可靠度。

Researches on Equipment Reliability Based on FTA and Fuzzy Set Theory

The reliability of Handler module in CXT using fuzzy fault tree analysis method is researched,which combines the traditional fault tree analysis method with fuzzy sets theory. The system＇s fault tree is built, which considers Handler＇s failure as top event. Then its minimum cut sets are obtained by adopting the ascending method （qualitative analysis）. However, the traditional fault tree analysis must have exact probability of every basic event, which is hard to achieve in real word because of uncertainty and fuzziness of basic event itself and other factors. In order to overcome this defect, The Fuzzy Number （ symmetrical triangular fuzzy number） is introduced into traditional fault tree analysis method. Fuzzy Number from fuzzy set theory is used to describe the probability of basic event. After the probabilities of the top and every middle event are quantitatively calculated, the Handler＇s unreliability is clear and its weak link is confirmed.