Observer gain effect in linear observer-based fault detection

Abstract

In linear observer-based fault detection methods, the observer gain plays an important role since it determines the time evolution of the residual sensitivity to a fault and therefore the minimum detectable fault at any time instant. In this chapter, the effect of the observer gain on the time evolution of the residual sensitivity to a fault is analyzed. Then, using these sensitivity studies, the minimum detectable fault time evolution has been established. Three types of faults are introduced: permanently detected, non-permanently detected, or just non-detected. Finally, an example based on a mineral grinding-classification process is used to illustrate the results derived.