1 code implementation • 10 Sep 2023 • Muhammad Umar B. Niazi, Michelle S. Chong, Amr Alanwar, Karl H. Johansson
When a strategic adversary can attack multiple sensors of a system and freely choose a different set of sensors at different times, how can we ensure that the state estimate remains uncorrupted by the attacker?
no code implementations • 18 Apr 2023 • John Cao, Muhammad Umar B. Niazi, Matthieu Barreau, Karl Henrik Johansson
The proposed sensor fault detection and isolation (s-FDI) method applies to a general class of nonlinear systems.
no code implementations • 7 Apr 2023 • Muhammad Umar B. Niazi, Karl H. Johansson
In this paper, we present an observer design approach for estimating the state of nonlinear systems, without requiring any parameterization of the system's nonlinearities.
1 code implementation • 15 Nov 2022 • Muhammad Umar B. Niazi, Amr Alanwar, Michelle S. Chong, Karl Henrik Johansson
This paper considers the problem of set-based state estimation for linear time-invariant (LTI) systems under time-varying sensor attacks.
1 code implementation • 10 Nov 2022 • Mahsa Farjadnia, Amr Alanwar, Muhammad Umar B. Niazi, Marco Molinari, Karl Henrik Johansson
By using the past noisy input-output data in the learning phase, we propose a novel method to over-approximate reachable sets of an unknown nonlinear system.
no code implementations • 10 Nov 2022 • Zishuo Li, Muhammad Umar B. Niazi, Changxin Liu, Yilin Mo, Karl H. Johansson
At each time step, the local estimates of sensors are fused by solving an optimization problem to obtain a secure estimation, which is then followed by a local detection-and-resetting process of the decentralized observers.
1 code implementation • 4 Oct 2022 • Muhammad Umar B. Niazi, John Cao, Xudong Sun, Amritam Das, Karl Henrik Johansson
Designing Luenberger observers for nonlinear systems involves the challenging task of transforming the state to an alternate coordinate system, possibly of higher dimensions, where the system is asymptotically stable and linear up to output injection.
no code implementations • 8 Nov 2021 • Amr Alanwar, Muhammad Umar B. Niazi, Karl H. Johansson
The offline phase utilizes past input-output data to estimate a set of possible coefficients of the polynomial system.