Search Results for author: Vasileios Tzoumas

Found 15 papers, 4 papers with code

Safe Non-Stochastic Control of Control-Affine Systems: An Online Convex Optimization Approach

no code implementations28 Sep 2023 HongYu Zhou, Yichen Song, Vasileios Tzoumas

We study how to safely control nonlinear control-affine systems that are corrupted with bounded non-stochastic noise, i. e., noise that is unknown a priori and that is not necessarily governed by a stochastic model.

Collision Avoidance

Leveraging Untrustworthy Commands for Multi-Robot Coordination in Unpredictable Environments: A Bandit Submodular Maximization Approach

no code implementations28 Sep 2023 Zirui Xu, Xiaofeng Lin, Vasileios Tzoumas

MetaBSG leverages a meta-algorithm to learn whether the robots should follow the commands or a recently developed submodular coordination algorithm, Bandit Sequential Greedy (BSG) [1], which has performance guarantees even in unpredictable and partially-observable environments.

Safe Non-Stochastic Control of Linear Dynamical Systems

1 code implementation23 Aug 2023 HongYu Zhou, Vasileios Tzoumas

We study the problem of \textit{safe control of linear dynamical systems corrupted with non-stochastic noise}, and provide an algorithm that guarantees (i) zero constraint violation of convex time-varying constraints, and (ii) bounded dynamic regret, \ie bounded suboptimality against an optimal clairvoyant controller that knows the future noise a priori.

Collision Avoidance

Bandit Submodular Maximization for Multi-Robot Coordination in Unpredictable and Partially Observable Environments

1 code implementation22 May 2023 Zirui Xu, Xiaofeng Lin, Vasileios Tzoumas

We are motivated by the future of autonomy that involves multiple robots coordinating actions in dynamic, unstructured, and partially observable environments to complete complex tasks such as target tracking, environmental mapping, and area monitoring.

Efficient Online Learning with Memory via Frank-Wolfe Optimization: Algorithms with Bounded Dynamic Regret and Applications to Control

no code implementations2 Jan 2023 HongYu Zhou, Zirui Xu, Vasileios Tzoumas

In this paper, we enable projection-free online learning within the framework of Online Convex Optimization with Memory (OCO-M) -- OCO-M captures how the history of decisions affects the current outcome by allowing the online learning loss functions to depend on both current and past decisions.

Time Series Time Series Prediction

Online Submodular Coordination with Bounded Tracking Regret: Theory, Algorithm, and Applications to Multi-Robot Coordination

no code implementations26 Sep 2022 Zirui Xu, HongYu Zhou, Vasileios Tzoumas

We are motivated by the future of autonomy that involves multiple robots coordinating in dynamic, unstructured, and adversarial environments to complete complex tasks such as target tracking, environmental mapping, and area monitoring.

Safe Control of Partially-Observed Linear Time-Varying Systems with Minimal Worst-Case Dynamic Regret

no code implementations18 Aug 2022 HongYu Zhou, Vasileios Tzoumas

We present safe control of partially-observed linear time-varying systems in the presence of unknown and unpredictable process and measurement noise.

Outlier-Robust Estimation: Hardness, Minimally Tuned Algorithms, and Applications

no code implementations29 Jul 2020 Pasquale Antonante, Vasileios Tzoumas, Heng Yang, Luca Carlone

We extend ADAPT and GNC to the case where the user does not have prior knowledge of the inlier-noise statistics (or the statistics may vary over time) and is unable to guess a reasonable threshold to separate inliers from outliers (as the one commonly used in RANSAC).

object-detection Object Detection

Distributed Attack-Robust Submodular Maximization for Multi-Robot Planning

no code implementations2 Oct 2019 Lifeng Zhou, Vasileios Tzoumas, George J. Pappas, Pratap Tokekar

Since, DRM overestimates the number of attacks in each clique, in this paper we also introduce an Improved Distributed Robust Maximization (IDRM) algorithm.

Motion Planning

Graduated Non-Convexity for Robust Spatial Perception: From Non-Minimal Solvers to Global Outlier Rejection

4 code implementations18 Sep 2019 Heng Yang, Pasquale Antonante, Vasileios Tzoumas, Luca Carlone

In this paper, we enable the simultaneous use of non-minimal solvers and robust estimation by providing a general-purpose approach for robust global estimation, which can be applied to any problem where a non-minimal solver is available for the outlier-free case.

Pose Estimation

Outlier-Robust Spatial Perception: Hardness, General-Purpose Algorithms, and Guarantees

1 code implementation27 Mar 2019 Vasileios Tzoumas, Pasquale Antonante, Luca Carlone

First, we show that even a simple linear instance of outlier rejection is inapproximable: in the worst-case one cannot design a quasi-polynomial time algorithm that computes an approximate solution efficiently.

Pose Estimation

Resilient Non-Submodular Maximization over Matroid Constraints

no code implementations2 Apr 2018 Vasileios Tzoumas, Ali Jadbabaie, George J. Pappas

The objective of this paper is to focus on resilient matroid-constrained problems arising in control and sensing but in the presence of sensor and actuator failures.

Robot Navigation Scheduling

Resilient Active Information Gathering with Mobile Robots

no code implementations26 Mar 2018 Brent Schlotfeldt, Vasileios Tzoumas, Dinesh Thakur, George J. Pappas

In this paper, we provide the first algorithm, enabling the following capabilities: minimal communication, i. e., the algorithm is executed by the robots based only on minimal communication between them; system-wide resiliency, i. e., the algorithm is valid for any number of denial-of-service attacks and failures; and provable approximation performance, i. e., the algorithm ensures for all monotone (and not necessarily submodular) objective functions a solution that is finitely close to the optimal.

valid

Resilient Monotone Sequential Maximization

no code implementations21 Mar 2018 Vasileios Tzoumas, Ali Jadbabaie, George J. Pappas

In this paper, we provide the first scalable algorithm, that achieves the following characteristics: system-wide resiliency, i. e., the algorithm is valid for any number of denial-of-service attacks, deletions, or failures; adaptiveness, i. e., at each time step, the algorithm selects system elements based on the history of inflicted attacks, deletions, or failures; and provable approximation performance, i. e., the algorithm guarantees for monotone objective functions a solution close to the optimal.

Robot Navigation Scheduling +1

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