Fault detection and isolation of hybrid system using diagnosers that combine discrete and continuous dynamics

In this paper, a design methodology and implementation architecture for diagnosers in the framework of hybrid systems is proposed. The design methodology is based on the hybrid automata model that represents the system behaviour by means of the interaction of continuous dynamics and discrete events. The architecture is composed by means of modules which realize the mode recognition and diagnostic tasks both based on residuals generated using models. Both tasks interact each other since the diagnosis module adapts accordingly to the current mode of the hybrid system. The mode recognition task involves detecting the mode change and identification by determining the set of residuals that are consistent with the current mode of the hybrid system. On the other hand, the diagnostic task involves detecting and isolating the fault by identifying the fault that can explain the set of residuals that are observed as inconsistent. As an application case study to illustrate the proposed fault diagnosis for hybrid systems a piece of the Barcelona sewer network is used.