1. System diagnostics

System diagnostics meet a direct and fast-growing demand from manufacturers. A fault must be rapidly detected, its source localized and its cause identified, to enable control algorithms and/or operators to ensure process continuity, stability and safety [1] .

In general, in order to determine the operating conditions of a system, and whether or not it is in a normal operating mode, it is necessary to define a set of indicators enabling the state of the system to be analyzed. It is then possible to say that a system has a fault if one or more elements of this set do not correspond to the pre-established values supposed to represent the so-called "normal" behavior of the process. In such an approach, two main families of methodologies can be distinguished: on the one hand, model-based...