截尾时间下数控机床可靠性分析的灰色模型法

Grey Model Method of CNC Machine Tool Reliability Analysis with Truncated Time

针对所收集数控机床的现场故障数据,采用灰色模型GM(1,1)的直接建模法对三参数威布尔分布模型进行估计,通过对比,考虑截尾时间和不考虑截尾时间所得模型参数的变化,说明了采用截尾时间进行分析时所得模型更加贴近实际。将故障数据用区间法划分,本文提出采用离散GM(1,1)建模法,对区间失效数进行预测。采用中点与失效数计算数控机床的平均无故障工作时间,通过与公式计算结果的对比,验证了该方法的准确性,可以在工程实践中进行运用。

In this paper,the failure data of the CNC machine tools of a domestic factory was collected and analyzed.And a 3-parameter Weibull distribution model was estimated by using grey model GM ( 1,1) direct modeling method.Consideration of the truncated time for analysis was better than without consideration of the data truncated time.The discrete GM ( 1,1) modeling method was used to predict interval number of failure by dividing the fault data into intervals.The midpoint and the failure number was conducted to numerically calculate the mean time between failures of CNC machine tools.The results can confirm the accuracy of the reliability analysis by contrast with formula calculation,and can be used in engineering practice.