A new monitoring method for the between-mode transition of multimode processes

In practical industrial processes, the between-mode transition commonly exists. It is accepted that the transition has a closer association with its neighbouring modes than with the other modes in the multimode processes. Thus, this paper first separates the subspace based on the relationships between the transition and the features of its neighbouring modes. Then it models the local information of the transition in the remaining subspace. In this way, a complete monitoring structure is set up from cross-mode and inner-mode viewpoints. Moreover, the new monitoring method can be applied without special conditions. Both the three tank practical process and the Tennessee Eastman challenge problem have validated the effectiveness of the proposed method.