数控机床故障分析与可靠性评价技术的研究

针对传统数控机床可靠性建模时只考虑故障间隔时间而忽略故障性质的现象，提出兼顾机械故障和电气故障的混合威布尔分布模型，进而提高模型准确度.利用最大似然法来确定混合威布尔分布模型参数，用皮尔逊相关系数来确定数控机床各故障时间之间的关系.并通过K-S方法对模型进行检验， 最后确定其符合混合威布尔分布，并运用可靠性评定方法得出数控机床的平均无故障时间.

On the Fault Analysis and Reliability Evaluation of CNC Machine Tools

Aiming at the phenomenon that conventional CNC machine tools only consider the failure time interval but ignore the nature of faults， a mixed Weibull distribution model combining mechanical failures with electrical failures is proposed to further improve the accuracy of the model. The maximum likelihood method is used to determine the mixed Weibull distribution model parameters， and the Pearson correlation coefficient method is applied to determine the relationship of fault times for the CNC machine tool. The K-S method is used to verify the model and obtain the mixed Weibull distribution model at last， and the mean time between failures(MTBF)of the CNC machine tool is obtained by using the reliability evaluation method.