关键词: 多模型切换, 工况判断, 高斯混合模型, 平方预报误差, 多模型预测控制

Abstract: Aiming at problems appearing in model switching of multi-model predictive control,a multi-model switching method based on recognition of operating conditions was presented,and the variations of dynamic characteristics in the process reflected by measurable variables were adopted.Firstly,Gaussian mixture model(GMM)was used to classify historical data into several operating conditions. Then the load vector matrix and the predictive models were built based on the data of different operating conditions. Lastly,the predictive model was chosen according to squared prediction error(SPE)of the principal component analysis(PCA)model.This method was implemented in controlling the coil outlet temperature(COT)in an ethylene pyrolysis furnace.The simulation results showed that the stable and balanced control of multiple COTs were realized by the presented method,and the matched operating condition could be easily found by comparing SPE of different PCA models when the operating condition of the system varied.Meanwhile,the corresponding predictive model was selected,with which the problem of switching lag among predictive models when the dynamic characteristics of the system changed was resolved.

Key words: multi-model switching method, operating condition, Gaussian mixture model, squared prediction error, multi-model predictive control