2020 |
Jin Gyu Lee / Junsoo Kim / Hyungbo Shim Fully distributed resilient state estimation based on distributed median solver Journal Article In: IEEE Transactions on Automatic Control, vol. 65, no. 9, pp. 3935-3942, 2020, ISSN: 0018-9286. Abstract | Links | BibTeX | Tags: Analytical redundancy, Attack detection, Attack resilience, Blended dynamics, Cyber-physical systems, Heterogeneous multi-agents, Resilient state estimation, Strong coupling @article{Lee20b, In this article, we present a scheme of fully distributed resilient state estimation for linear dynamical systems under sensor attacks. The proposed state observer consists of a network of local observers, where each of them utilizes local measurements and information transmitted from the neighbors. As a fully distributed scheme, it does not necessarily collect a majority of sensing data for the sake of attack identification, whereas the compromised sensors are eventually identified by the distributed network and excluded from the observers. For this, the overall network (not the individual local observer) is assumed to have redundant sensors and assumed to be connected. The proposed scheme is based on a novel design of a distributed median solver, which approximately recovers the median value of local estimates. |
2019 |
Chanhwa Lee / Hyungbo Shim / Yongsoon Eun On Redundant Observability: From Security Index to Attack Detection and Resilient State Estimation Journal Article In: IEEE Transactions on Automatic Control, vol. 64, no. 2, pp. 775-782, 2019. Abstract | Links | BibTeX | Tags: Attack detection, Cyber-physical system, Resilient state estimation @article{LeeShimEun19, The security of control systems under sensor attacks is investigated. Redundant observability is introduced, explaining existing security notions including the security index, attack detectability, and observability under attacks. Equivalent conditions between redundant observability and existing notions are presented. Based on a bank of partial observers utilizing Kalman decomposition and a decoder exploiting redundancy, an estimator design algorithm is proposed enhancing the resilience of control systems. This scheme substantially improves computational efficiency utilizing far less memory. |
Junsoo Kim / Chanhwa Lee / Hyungbo Shim / Yongsoon Eun / Jin Heon Seo Detection of Sensor Attack and Resilient State Estimation for Uniformly Observable Nonlinear Systems having Redundant Sensors Journal Article In: IEEE Transactions on Automatic Control, vol. 64, no. 3, pp. 1162-1169, 2019, ISBN: 0018-9286. Abstract | Links | BibTeX | Tags: Attack detection, Cyber-physical system, Resilient state estimation @article{KimLeeShimEunSeo19, This paper presents a detection algorithm for sensor attacks and a resilient state estimation scheme for a class of uniformly observable nonlinear systems. An adversary is supposed to corrupt a subset of sensors with the possibly unbounded signals, while the system has sensor redundancy. We design an individual high-gain observer for each measurement output so that only the observable portion of the system state is obtained. Then, a nonlinear error correcting problem is solved by collecting all the information from those partial observers and exploiting redundancy. A computationally efficient, on-line monitoring scheme is presented for attack detection. Based on the attack detection scheme, an algorithm for resilient state estimation is provided. The simulation results demonstrate the effectiveness of the proposed algorithm. |
List of English Publication
2020 |
Fully distributed resilient state estimation based on distributed median solver Journal Article In: IEEE Transactions on Automatic Control, vol. 65, no. 9, pp. 3935-3942, 2020, ISSN: 0018-9286. |
2019 |
On Redundant Observability: From Security Index to Attack Detection and Resilient State Estimation Journal Article In: IEEE Transactions on Automatic Control, vol. 64, no. 2, pp. 775-782, 2019. |
Detection of Sensor Attack and Resilient State Estimation for Uniformly Observable Nonlinear Systems having Redundant Sensors Journal Article In: IEEE Transactions on Automatic Control, vol. 64, no. 3, pp. 1162-1169, 2019, ISBN: 0018-9286. |