由零件外观预测使用寿命的模糊集方法

Fuzzy Set Approach for Forecast working life by the Appearance of Parts

某机械产品中A零件受年龄及环境因素影响,直径发生变化,最终无法继续使用。针对这一问题,提出了由描述零件外观特征的自然语言预测零件使用寿命的模糊集方法。该方法在分析零件A的外观变化规律基础上,建立外观特征值与生理年龄之间联系:以生理年龄为论域,分别定义出各特征的隶属函数。并用升半正态模糊集和专家经验确立隶属函数组的参数,得到零件外观模糊集隶属函数。同时给出了自然语言转化为精确数的映射表,以便使用隶属函数组。由此便可计算出零件的生理年龄和预测其寿命。

The changing of the diameter of part A in mechanical products due to the influences of environment and age, and it would finally result in the uselessness of part A. For this problem, a fuzzy sets approach that forecasts the working life of part by the natural language that describes the characters of the appearance of part was proposed. Based on the basis of analyzed the change regularity of the appearance of Part A, the relation between the appearance eigenvalue and the physiological age of the part was built. Taking the physiological age of part A as example, the membership function of each eigenvalue was defined respectively. The parameter of the set of membership functions are confirmed by quasi-normal fuzzy sets and specialist抯 experiences, and the membership functions of the fuzzy sets of part appearance was obtained. The mapping table converted the natural language into the accurate data was provided in order to use the membership function sets conveniently. Then, the physiological age of the part can be calculated, and the working life of part can be forecasted.