基于SPC的计算机辅助监控系统的设计与实现

Design and Implementation of Computer Aided Monitoring System Based on SPC

指数加权移动平均(EWMA)控制图是针对传统的统计过程控制图对稳定过程出现小偏移无法及时发现而提出的。传统的统计过程控制图对于过程出现较大的波动能够及时地发现并给出报警,但是对于过程在稳定状态出现的小偏移却不能够及时地检测出来。EWMA控制图采取对过程已有的偏差加权的形式,将已有的偏差计入当前统计量,从而实现对过程出现的小偏差的检测报警功能。给出计算机实现EWMA的完整设计方案,用于构建过程的实时监控系统,监测过程的小偏移并及时报警。

Exponentially weighted moving average chart （EWMA） is designed to detect small drift in sta- tionary process. Most traditional statistical process control charts are able to detect large fluctu- ations. Their ability in discovering small fluctuations is very limited. By tracking the exponen- tially-weighted moving average, EWMA chart takes the previous drift into consideration and hence can be used to detect small shifts in the process. Provides an entire implementation of EWMA chart and uses it in an online monitoring system that can detect small shifts in the pro- cess system.