The invention discloses a monitoring index switching based multi-operating-mode process monitoring method and
system. The method includes: acquiring normal data in different operating
modes to serve as a training sample set; obtaining a
hidden Markov model on the basis of the training sample set, and acquiring
control limits corresponding to monitoring indexes of the
hidden Markov model; respectively establishing
statistical pattern analysis models of corresponding operating
modes on the basis of training samples of each operating mode, and acquiring
control limits corresponding to monitoring indexes of each
statistical pattern analysis model; computing operating mode vectors on the basis of process data acquired in real time, and further computing differential operating mode vectors; computing corresponding real-time monitoring indexes according to norms of the differential operating mode vectors, and comparing the real-time monitoring indexes with the
control limits corresponding to the monitoring indexes of the corresponding models so as to monitor running states of the operating
modes. The method has the advantages that the process data are acquired in real time, reliability in monitoring is guaranteed, data in each operating mode need not to obey
Gaussian distribution, and applicability is higher.