2015/11/09 by Sérgio Pequito, Farshad Khorrami, Pequito, Sergio +5
Engineering · Computer Science · #Smart Grid Security and Resilience #Formal Methods in Verification #Petri Nets in System Modeling
paper · pdf · doi:10.48550/arxiv.1511.02963
This paper considers the analysis and design of resilient/robust\ndecentralized control systems. Specifically, we aim to assess how the pairing\nof sensors and actuators lead to architectures that are resilient to\nattacks/hacks for industrial control systems and other complex cyber-physical\nsystems. We consider inherent structural properties such as internal fixed\nmodes of a dynamical system depending on actuation, sensing, and\ninterconnection/communication structure for linear discrete time-invariant\ndynamical systems. We introduce the notion of resilient fixed-modes free system\nthat ensures the non-existence of fixed modes when the\nactuation-sensing-communication structure is compromised due to attacks by a\nmalicious agent on actuators, sensors, or communication components and natural\nfailures. Also, we provide a graph-theoretical characterization for the\nresilient structurally fixed modes that enables to capture the non-existence of\nresilient fixed modes for almost all possible systems' realizations.\nAdditionally, we address the minimum actuation-sensing-communication co-design\nensuring the non-existence of resiliently structurally fixed modes, which we\nshow to be NP-hard. Notwithstanding, we identify conditions that are often\nsatisfied in engineering settings and under which the co-design problem is\nsolvable in polynomial-time complexity. Furthermore, we leverage the structural\ninsights and properties to provide a convex optimization method to design the\ngain for a parametrized system and satisfying the sparsity of a given\ninformation pattern. Thus, exploring the interplay between structural and\nnon-structural systems to ensure their resilience. Finally, the efficacy of the\nproposed approach is demonstrated on a power grid example.\n