基于主元分析确定多变量系统控制极限的方法

Determining control limits of multivariate system based on principal component analysis

针对存在多个稳定状态的多变量统计过程控制的控制极限问题,提出先分析系统变量的历史数据得到其经验分布,确定该变量的不同稳定状态及对应的状态域;将数据样本按不同的状态分组标准化后,分别进行主元分析,得到不同稳定状态下的Hotellings T2及平方预测误差SPE(Q)控制极限。用本方法和普通主元分析法对某钢铁公司局部蒸汽管网的流量数据模拟监控的效果进行对比,表明本方法由于区分不同状态,确定的Hotellings T2及平方预测误差SPE(Q)控制极限更精确,能有效降低漏报警和误报警的概率。

Aiming at the control limits problem of Multivariate Statistical Process Control（MSPC）which had multiple stable states,Empirical Distribution Function（EDF）was obtained by analyzing historical data of system variables,and different stable states as well as corresponding state-domains of variables were determined.After standardizing data samples in different state groups,Hotelling＇s T2 and Squared Prediction Error（SPE）（Q）control limits in different states were obtained by using Principal Component Analysis（PCA）.Through comparison with traditional PCA in flow data monitoring for a steel corporation＇s local steam pipe network,the proposed method was more accurate on determining Hotelling＇s T2 and SPE（Q）control limits.It could reduce the probability of leaking alarm or false alarm effectively.