方差监测的自适应累积和车身质量控制图研究

摘要

针对车身制造质量检测工作量大、数据处理方式简单等特点,提出一种基于方差的改进累积和控制图(CUSUM)方法,用于监测车身制造质量的方差波动.其基本思想是对控制图参数k动态更新和迭代,并与方差波动量相联系,以便实时监测车身焊接尺寸过程方差的微小波动.通过对控制图的平均运行链长进行分析和实际案例研究,并与常规累积和控制图和指数加权移动平均控制图作对比,表明该方法对过程方差微小变异更为有效和敏感.%Considering the high workload and extremely simple data processing in body welding quality inspection,an adaptive CUSUM control chart for variance monitoring was proposed herein for body welding quality control,whose principle was adaptively updated the reference values to monitor small variances infinitely in the process of body welding.Evaluation instance results show that,compared with traditional CUSUM control chart and exponential weighted moving average(EWMA) control charts,the adaptive CUSUM control chart based on variance monitoring is more sensitive to the small abnormal variation fluctuation.