Secure Diagnosability of Hybrid Dynamical Systems

Observability and diagnosability properties of a hybrid dynamical system are essential in characterizing the possibility of identifying the system’s hybrid state, and in particular the occurrence of some specific states that may correspond to a malfunctioning of the system due to a fault or an attack. Diagnosability has been extensively studied for Finite State Machines (FSMs). However, the results obtained for FSMs cannot, in general, be applied directly to hybrid systems where the discrete evolution interacts with the continuous one. In this chapter, we propose a formal definition of diagnosability for hybrid systems. Furthermore, motivated by the great importance of security issues for hybrid systems, we characterize the diagnosability property in the more general case where the available information may be corrupted by an external attacker. Finally, we establish sufficient conditions for a hybrid system to be diagnosable.