For the model plant mismatch (MPM) assessment of MPC systems, a correlation analysis method between the input and the disturbance (CAID) is proposed and is combined with model quality index (MQI) for its application in multivariable system. By deducing the input–output correlation coefficient variation law of adding independent variables in a function, the paper defines the CAID index of assessing the MPM. To realize the exact location of sub-model mismatch in multivariable system, the synthetical disturbance variable is constructed through principle component analysis (PCA), then it is used to define the synthetical CAID index of multivariable MPC system, and finally the decussation method combining synthetical CAID and MQI is presented. The proposed method is validated in Wood-Berry distillation process and an industrial air separate process.

针对MPC系统的模型工厂失配（MPM）评估，提出了一种输入与干扰（CAID）之间的相关分析方法，并将其与模型质量指标（MQI）相结合，用于多变量系统。通过推导在函数中添加自变量的输入输出相关系数变化规律，本文定义了评估MPM的CAID指数。为了实现子模型不匹配在多变量系统中的准确定位，通过主成分分析（PCA）构造了综合扰动变量，然后用它来定义多变量MPC系统的综合CAID指数，最后结合了显示了CAID和MQI。该方法在伍德-贝里蒸馏工艺和工业空气分离工艺中得到了验证。