在固定时间抽样的可变抽样区间的单边控制图

The Control Charts of One Sided Variable Sampling Interval with Sampling at Fixed Times

根据文献 [1 ]在固定时间抽样的可变抽样区间 (VSIFT)的x控制图的模型设计标准差 (S)、极差(R)和不合格品数 (np)图。计算了VSIFTS图、R图和np图的发信号前的平均时间 ,并同固定抽样区间 (FSI)的常规S、R和np图作比较。所设计的VSIFTS、R和np图能缩短过程失控时间 。

Based on the model of x control chart in reference [1],the standard deviation,range and nonconforming number of the variable sampling interval control charts with sampling at fixed time,working out the average time of the signals for S,R and np charts in variable sampling intervals with sampling at fixed times.The author compares these charts with the fixed sampling interval S,R and np charts,and finds out that the process uncontrolled time can be shortened if using these charts.