Search Results for author: Henrik Sandberg

Found 26 papers, 3 papers with code

On well-posedness of the leak localization problem in parallel pipe networks

no code implementations15 Mar 2024 Victor Molnö, Henrik Sandberg

In this work, we contribute to the development of such a theory by introducing an example water network structure with parallel pipes that is tractable for analytical treatment.

Electrical Fault Localisation Over a Distributed Parameter Transmission Line

no code implementations20 Oct 2023 Daniel Selvaratnam, Amritam Das, Henrik Sandberg

Motivated by the need to localise faults along electrical power lines, this paper adopts a frequency-domain approach to parameter estimation for an infinite-dimensional linear dynamical system with one spatial variable.

Complexity reduction for resilient state estimation of uniformly observable nonlinear systems

no code implementations18 Apr 2023 Junsoo Kim, Jin Gyu Lee, Henrik Sandberg, Karl H. Johansson

As a result, although a portion of measurements are compromised, they can be locally identified and excluded from the state estimation, and thus the true state can be recovered.

The Fundamental Limitations of Learning Linear-Quadratic Regulators

no code implementations27 Mar 2023 Bruce D. Lee, Ingvar Ziemann, Anastasios Tsiamis, Henrik Sandberg, Nikolai Matni

We present a local minimax lower bound on the excess cost of designing a linear-quadratic controller from offline data.

valid

Modeling and Analysis of a Coupled SIS Bi-Virus Model

no code implementations23 Jul 2022 Sebin Gracy, Philip E. Paré, Ji Liu, Henrik Sandberg, Carolyn L. Beck, Karl Henrik Johansson, Tamer Başar

We establish a sufficient condition and multiple necessary conditions for local exponential convergence to the boundary equilibrium (i. e., one virus persists, the other one dies out) of each virus.

How are policy gradient methods affected by the limits of control?

no code implementations14 Jun 2022 Ingvar Ziemann, Anastasios Tsiamis, Henrik Sandberg, Nikolai Matni

We study stochastic policy gradient methods from the perspective of control-theoretic limitations.

Policy Gradient Methods

Green Routing Game: Strategic Logistical Planning using Mixed Fleets of ICEVs and EVs

no code implementations1 Apr 2022 Hampei Sasahara, György Dán, Saurabh Amin, Henrik Sandberg

Each player faces the cost of delayed delivery (due to charging requirements of EVs) and a pollution cost levied on the ICEVs.

Leakage Localization in Water Distribution Networks: A Model-Based Approach

no code implementations31 Mar 2022 Ludvig Lindstrom, Sebin Gracy, Sindri Magnusson, Henrik Sandberg

Finally, assuming the existence of a single leak, for a network comprising of more than one pipe and assuming that the network has a tree structure, we provide a systematic procedure for determining the leak location, the leak exponent, and the leak constant

Single Trajectory Nonparametric Learning of Nonlinear Dynamics

no code implementations16 Feb 2022 Ingvar Ziemann, Henrik Sandberg, Nikolai Matni

Given a single trajectory of a dynamical system, we analyze the performance of the nonparametric least squares estimator (LSE).

counterfactual

Regret Lower Bounds for Learning Linear Quadratic Gaussian Systems

no code implementations5 Jan 2022 Ingvar Ziemann, Henrik Sandberg

TWe establish regret lower bounds for adaptively controlling an unknown linear Gaussian system with quadratic costs.

A Bayesian Nash equilibrium-based moving target defense against stealthy sensor attacks

no code implementations12 Nov 2021 David Umsonst, Serkan Sarıtaş, György Dán, Henrik Sandberg

We present a moving target defense strategy to reduce the impact of stealthy sensor attacks on feedback systems.

Experimental evaluation of sensor attacks and defense mechanisms in feedback systems

no code implementations5 Nov 2021 David Umsonst, Henrik Sandberg

In this work, we evaluate theoretical results on the feasibility of, the worst-case impact of, and defense mechanisms against a stealthy sensor attack in an experimental setup.

Multi-Layer SIS Model with an Infrastructure Network

no code implementations20 Sep 2021 Philip E. Pare, Axel Janson, Sebin Gracy, Ji Liu, Henrik Sandberg, Karl H. Johansson

We develop a layered networked spread model for a susceptible-infected-susceptible (SIS) pathogen-borne disease spreading over a human contact network and an infrastructure network, and refer to it as a layered networked susceptible-infected-water-susceptible (SIWS) model.

Finite sample guarantees for quantile estimation: An application to detector threshold tuning

1 code implementation25 May 2021 David Umsonst, Justin Ruths, Henrik Sandberg

A detector threshold that provides an acceptable false alarm rate is equivalent to a specific quantile of the detector output distribution.

Anomaly Detection

A Model Randomization Approach to Statistical Parameter Privacy

no code implementations22 May 2021 Ehsan Nekouei, Henrik Sandberg, Mikael Skoglund, Karl H. Johansson

To ensure parameter privacy, we propose a filter design framework which consists of two components: a randomizer and a nonlinear transformation.

Geometrical Characterization of Sensor Placement for Cone-Invariant and Multi-Agent Systems against Undetectable Zero-Dynamics Attacks

no code implementations10 May 2021 Jianqi Chen, Jieqiang Wei, Wei Chen, Henrik Sandberg, Karl H. Johansson, Jie Chen

Undetectable attacks are an important class of malicious attacks threatening the security of cyber-physical systems, which can modify a system's state but leave the system output measurements unaffected, and hence cannot be detected from the output.

Asymptotic Security by Model-based Incident Handlers for Markov Decision Processes

no code implementations24 Mar 2021 Hampei Sasahara, Henrik Sandberg

This study investigates general model-based incident handler's asymptotic behaviors in time against cyber attacks to control systems.

Decision Making

Data-Driven Set-Based Estimation using Matrix Zonotopes with Set Containment Guarantees

1 code implementation26 Jan 2021 Amr Alanwar, Alexander Berndt, Karl Henrik Johansson, Henrik Sandberg

We propose a method to perform set-based state estimation of an unknown dynamical linear system using a data-driven set propagation function.

On Uninformative Optimal Policies in Adaptive LQR with Unknown B-Matrix

no code implementations18 Nov 2020 Ingvar Ziemann, Henrik Sandberg

After defining the intrinsic notion of an uninformative optimal policy in terms of a singularity condition for Fisher information we obtain local minimax regret lower bounds for such uninformative instances of LQR by appealing to van Trees' inequality (Bayesian Cram\'er-Rao) and a representation of regret in terms of a quadratic form (Bellman error).

Power Injection Attacks in Smart Distribution Grids with Photovoltaics

no code implementations11 Nov 2020 Martin Lindström, Hampei Sasahara, Xingkang He, Henrik Sandberg, Karl Henrik Johansson

We study the worst-case attack strategy of a power injection attack against the physical layer of a smart distribution grid with a high penetration of photovoltaic resources.

Privacy Preserving Set-Based Estimation Using Partially Homomorphic Encryption

1 code implementation19 Oct 2020 Amr Alanwar, Victor Gassmann, Xingkang He, Hazem Said, Henrik Sandberg, Karl Henrik Johansson, Matthias Althoff

The set-based estimation has gained a lot of attention due to its ability to guarantee state enclosures for safety-critical systems.

Cryptography and Security Robotics

Disconnection-aware Attack Detection and Isolation with Separation-based Detector Reconfiguration

no code implementations23 Sep 2020 Hampei Sasahara, Takayuki Ishizaki, Jun-ichi Imura, Henrik Sandberg

In accordance with the disconnection, the equipped attack detection unit should be reconfigured to maintain its detection capability.

How to Secure Distributed Filters Under Sensor Attacks

no code implementations11 Apr 2020 Xingkang He, Xiaoqiang Ren, Henrik Sandberg, Karl H. Johansson

The resilience of the secured filter with detection is verified by an explicit relationship between the upper bound of the estimation error and the number of detected attacked sensors.

On the confidentiality of controller states under sensor attacks

no code implementations8 Jan 2020 David Umsonst, Henrik Sandberg

We derive conditions for when the attacker is able to perfectly estimate the controller's state.

Cannot find the paper you are looking for? You can Submit a new open access paper.