Eleftherios Vlahakis

@kth.se

Division of Decision and Control Systems/Department of Intelligent Systems/School of Electrical Engineering and Computer Science
KTH Royal Institute of Technology

Eleftherios Vlahakis


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https://researchid.co/lefterisvl83

RESEARCH, TEACHING, or OTHER INTERESTS

Control and Systems Engineering, Electrical and Electronic Engineering, Computer Science, Decision Sciences
23

Scopus Publications

236

Scholar Citations

10

Scholar h-index

10

Scholar i10-index

Scopus Publications

  • Conformal Data-driven Control of Stochastic Multi-Agent Systems under Collaborative Signal Temporal Logic Specifications
    Eleftherios E. Vlahakis, Lars Lindemann, Dimos V. Dimarogonas
    Proceedings of the IEEE Conference on Decision and Control, 2025
  • State dependent disturbances in computation of forward reachable sets and minimal invariant sets
    Nikolaos Athanasopoulos, Eleftherios E. Vlahakis, Christopher Townsend, Sorin Olaru
    Proceedings of the IEEE Conference on Decision and Control, 2025
  • Efficient Coordination and Synchronization of Multi-Robot Systems under Recurring Linear Temporal Logic
    Davide Peron, Victor Nan Fernandez-Ayala, Eleftherios E. Vlahakis, Dimos V. Dimarogonas
    Proceedings IEEE International Conference on Robotics and Automation, 2025
  • AIMD-Inspired Switching Control of Computing Networks
    Eleftherios Vlahakis, Raphaël Jungers, Nikolaos Athanasopoulos, Seán McLoone
    IEEE Transactions on Control of Network Systems, 2024
    We consider the scheduling problem of requests entering a distributed computing network consisting of a set of noncooperative nodes, where a node is represented by a queue combined with a computing unit. Our interaction-free setup between nodes renders decentralized scheduling challenging, with most existing results focusing on centralized or static solutions. Inspired by congestion control, we propose a new average-based additive increase multiplicative decrease (AIMD) admission control policy, which requires minimal communication between individual nodes and an aggregator. The proposed admission policy infers a discrete-event model expressed as a positive, constrained switching system that is triggered whenever the queue of the aggregation point of requests vanishes. We show convergence of the proposed AIMD system under unknown, peak-bounded workload profiles by analyzing the spectrum of rank-one perturbations of symmetric matrices and the boundedness of the joint spectral radius of sets of symmetric matrices. Contrary to methods that address scheduling and resource allocation asynchronously or via a two-step approach, our AIMD-based scheme can tackle both tasks simultaneously. This is illustrated by proposing a decentralized resource allocation controller coupled with the scheduling scheme leading to a stable closed-loop control system that is guaranteed to avoid underutilization of resources and is tunable via the sets of AIMD parameters.
  • Distributed Sequential Receding Horizon Control of Multi-Agent Systems Under Recurring Signal Temporal Logic
    Eleftherios E. Vlahakis, Lars Lindemann, Dimos V. Dimarogonas
    2024 European Control Conference Ecc 2024, 2024
    We consider the synthesis problem of a multi-agent system under signal temporal logic (STL) specifications representing bounded-time tasks that need to be satisfied recurrently over an infinite horizon. Motivated by the limited approaches to handling recurring STL systematically, we tackle the infinite-horizon control problem with a receding horizon scheme equipped with additional STL constraints that introduce minimal complexity and a backward-reachability-based terminal condition that is straightforward to construct and ensures recursive feasibility. Subsequently, we decompose the global receding horizon optimization problem into agent-level programs the objectives of which are to minimize local cost functions subject to local and joint STL constraints. We propose a scheduling policy that allows individual agents to sequentially optimize their control actions while maintaining recursive feasibility. This results in a distributed strategy that can operate online as a model predictive controller. Last, we illustrate the effectiveness of our method via a multi-agent system example assigned a surveillance task.
  • Probabilistic Tube-based Control Synthesis of Stochastic Multi-Agent Systems under Signal Temporal Logic
    Eleftherios E. Vlahakis, Lars Lindemann, Pantelis Sopasakis, Dimos V. Dimarogonas
    Proceedings of the IEEE Conference on Decision and Control, 2024
    We consider the control design of stochastic discrete-time linear multi-agent systems (MASs) under a global signal temporal logic (STL) specification to be satisfied at a predefined probability. By decomposing the dynamics into deterministic and error components, we construct a probabilistic reachable tube (PRT) as the Cartesian product of reachable sets of the individual error systems driven by disturbances lying in confidence regions (CRs) with a fixed probability. By bounding the PRT probability with the specification probability, we tighten all state constraints induced by the STL specification by solving tractable optimization problems over segments of the PRT, and relax the underlying stochastic problem with a deterministic one. This approach reduces conservatism compared to tightening guided by the STL structure. Additionally, we propose a recursively feasible algorithm to attack the resulting problem by decomposing it into agent-level subproblems, which are solved iteratively according to a scheduling policy. We demonstrate our method on a ten-agent system, where existing approaches are impractical.
  • Conformal Prediction for Distribution-Free Optimal Control of Linear Stochastic Systems
    Eleftherios E. Vlahakis, Lars Lindemann, Pantelis Sopasakis, Dimos V. Dimarogonas
    IEEE Control Systems Letters, 2024
    We address an optimal control problem for linear stochastic systems with unknown noise distributions and joint chance constraints using conformal prediction. Our approach involves designing a feedback controller to maintain an error system within a prediction region (PR). We define PRs as sublevel sets of a nonconformity score over error trajectories, enabling the handling of joint chance constraints. We propose two methods to design feedback control and PRs: one through direct optimization over error trajectory samples, and the other indirectly using the S-procedure with a disturbance ellipsoid obtained from data. By tightening constraints with PRs, we solve a relaxed problem to synthesize a feedback policy. Our method ensures reliable probabilistic guarantees based on marginal coverage, independent of data size.
  • Distributionally Robust Control for Chance-Constrained Signal Temporal Logic Specifications
    Arash Bahari Kordabad, Eleftherios E. Vlahakis, Lars Lindemann, Dimos V. Dimarogonas, Sadegh Soudjani
    Proceedings of the IEEE Conference on Decision and Control, 2024
    We consider distributionally robust optimal control of stochastic linear systems under signal temporal logic (STL) chance constraints when the disturbance distribution is unknown. By assuming that the underlying predicate functions are Lipschitz continuous and the noise realizations are drawn from a distribution having a concentration of measure property, we first formulate the underlying chance-constrained control problem as stochastic programming with constraints on expectations and propose a solution using a distributionally robust approach based on the Wasserstein metric. We show that by choosing a proper Wasserstein radius, the original chance-constrained optimization can be satisfied with a user-defined confidence level. A numerical example illustrates the efficacy of the method.
  • Risk-Aware Real-Time Task Allocation for Stochastic Multi-Agent Systems under STL Specifications
    M. H. W. Engelaar, Z. Zhang, E. E. Vlahakis, D.V. Dimarogonas, M. Lazar, et al.
    Proceedings of the IEEE Conference on Decision and Control, 2024
    This paper addresses the control synthesis of heterogeneous stochastic linear multi-agent systems with realtime allocation of signal temporal logic (STL) specifications. Based on previous work, we decompose specifications into subspecifications on the individual agent level. To leverage the efficiency of task allocation, a heuristic filter evaluates potential task allocation based on STL robustness, and subsequently, an auctioning algorithm determines the definitive allocation of specifications. Finally, a control strategy is synthesized for each agent-specification pair using tube-based model predictive control (MPC), ensuring provable probabilistic satisfaction. We demonstrate the efficacy of the proposed methods using a multi-shuttle scenario that highlights a promising extension to automated driving applications like vehicle routing.
  • Quantifying Impact on Safety from Cyber-Attacks on Cyber-Physical Systems
    Eleftherios Vlahakis, Gregory Provan, Gordon Werner, Shanchieh Yang, Nikolaos Athanasopoulos
    IFAC Papersonline, 2023
  • Model-matching methods and distributed control of networks consisting of a class of heterogeneous dynamic agents
    Eleftherios E. Vlahakis, George D. Halikias
    International Journal of Control, 2022
  • Optimal Resource Scheduling and Allocation in Distributed Computing Systems
    Wei Ren, Eleftherios Vlahakis, Nikolaos Athanasopoulos, Raphael Jungers
    Proceedings of the American Control Conference, 2022
  • Modelling issues and aggressive robust load frequency control of interconnected electric power systems
    L. Dritsas, E. Kontouras, E. Vlahakis, I. Kitsios, G. Halikias, et al.
    International Journal of Control, 2022
  • Distributed Resource Autoscaling in Kubernetes Edge Clusters
    Dimitrios Spatharakis, Ioannis Dimolitsas, Eleftherios Vlahakis, Dimitrios Dechouniotis, Nikolaos Athanasopoulos, et al.
    Proceedings of the 2022 18th International Conference of Network and Service Management Intelligent Management of Disruptive Network Technologies and Services Cnsm 2022, 2022
  • AIMD scheduling and resource allocation in distributed computing systems
    Eleftherios Vlahakis, Nikolaos Athanasopoulos, Sean McLoone
    Proceedings of the IEEE Conference on Decision and Control, 2021
  • Distributed LQR design for identical dynamically coupled systems: Application to load frequency control of multi-area power grid
    Eleftherios E. Vlahakis, Leonidas D. Dritsas, George D. Halikias
    Proceedings of the IEEE Conference on Decision and Control, 2019
  • Temperature and concentration control of exothermic chemical processes in continuous stirred tank reactors
    Eleftherios Vlahakis, George Halikias
    Transactions of the Institute of Measurement and Control, 2019
  • Distributed Model Predictive Load Frequency Control of multi-area Power Grid: A Decoupling Approach
    Eleftherios E. Vlahakis, Leonidas D. Dritsas, George D. Halikias
    IFAC Papersonline, 2019
  • Distributed LQR design for a class of large-scale multi-area power systems
    Eleftherios Vlahakis, Leonidas Dritsas, George Halikias
    Energies, 2019
  • Distributed LQR-based Suboptimal Control for Coupled Linear Systems
    Eleftherios E. Vlahakis, Leonidas D. Dritsas, George D. Halikias
    IFAC Papersonline, 2019
  • Cooperative Distributed LQR Control for Longitudinal Flight of a Formation of Non-Identical Low-Speed Experimental UAV's
    Eleftherios E. Vlahakis, Efstathios Milonidis, George D. Halikias
    2018 Ukacc 12th International Conference on Control Control 2018, 2018
  • Distributed LQR Methods for Networks of Non-Identical Plants
    Eleftherios E. Vlahakis, George D. Halikias
    Proceedings of the IEEE Conference on Decision and Control, 2018
  • Model-Matching type-methods and Stability of Networks consisting of non-Identical Dynamic Agents⁎
    Eleftherios E. Vlahakis, George D. Halikias
    IFAC Papersonline, 2018

RECENT SCHOLAR PUBLICATIONS

  • Multi-Agent Temporal Logic Planning via Penalty Functions and Block-Coordinate Optimization
    EE Vlahakis, AB Kordabad, L Lindemann, P Sopasakis, S Soudjani, ...
    arXiv preprint arXiv:2602.17434 , 2026
    2026
  • Distribution-Free Stochastic MPC for Joint-in-Time Chance-Constrained Linear Systems
    L Vogel, A Carron, EE Vlahakis, DV Dimarogonas
    arXiv preprint arXiv:2512.10738 , 2025
    2025
  • Conformal data-driven control of stochastic multi-agent systems under collaborative signal temporal logic specifications
    EE Vlahakis, L Lindemann, DV Dimarogonas
    2025 IEEE 64th Conference on Decision and Control (CDC), 624-629 , 2025
    2025
    Citations: 4
  • State dependent disturbances in computation of forward reachable sets and minimal invariant sets
    N Athanasopoulos, E Vlahakis, C Townsend, S Olaru
    2025
    Citations: 2
  • Efficient coordination and synchronization of multi-robot systems under recurring linear temporal logic
    D Peron, VN Fernandez-Ayala, EE Vlahakis, DV Dimarogonas
    2025 IEEE International Conference on Robotics and Automation (ICRA), 10194 … , 2025
    2025
    Citations: 3
  • Data-driven distributionally robust control for interacting agents under logical constraints
    AB Kordabad, EE Vlahakis, L Lindemann, S Gros, DV Dimarogonas, ...
    arXiv preprint arXiv:2503.09816 , 2025
    2025
    Citations: 7
  • Data-Driven Distributionally Robust Control for Interacting Agents under Logical Constraints
    A Bahari Kordabad, EE Vlahakis, L Lindemann, S Gros, DV Dimarogonas, ...
    arXiv e-prints, arXiv: 2503.09816 , 2025
    2025
  • Probabilistic tube-based control synthesis of stochastic multi-agent systems under signal temporal logic
    EE Vlahakis, L Lindemann, P Sopasakis, DV Dimarogonas
    2024 IEEE 63rd Conference on Decision and Control (CDC), 1586-1592 , 2024
    2024
    Citations: 13
  • Risk-aware real-time task allocation for stochastic multi-agent systems under STL specifications
    MHW Engelaar, Z Zhang, EE Vlahakis, DV Dimarogonas, M Lazar, ...
    2024 IEEE 63rd Conference on Decision and Control (CDC), 8213-8218 , 2024
    2024
    Citations: 4
  • Conformal prediction for distribution-free optimal control of linear stochastic systems
    EE Vlahakis, L Lindemann, P Sopasakis, DV Dimarogonas
    IEEE Control Systems Letters 8, 2835-2840 , 2024
    2024
    Citations: 10
  • Distributed sequential receding horizon control of multi-agent systems under recurring signal temporal logic
    EE Vlahakis, L Lindemann, DV Dimarogonas
    2024 European Control Conference (ECC), 305-310 , 2024
    2024
    Citations: 6
  • Robust Invariant Sets for Systems Affected by State-Dependent Disturbance
    C Townsend, S Olaru, N Athanasopoulos, E Vlahakis
    2024
    Citations: 2
  • Distributionally Robust Control for Chance-Constrained Signal Temporal Logic Specifications
    A Bahari Kordabad, EE Vlahakis, L Lindemann, DV Dimarogonas, ...
    2024 IEEE 63rd Conference on Decision and Control (CDC), Milan, Italy, 1593-1598 , 2024
    2024
  • AIMD-inspired switching control of computing networks
    E Vlahakis, R Jungers, N Athanasopoulos, S McLoone
    IEEE Transactions on Control of Network Systems 11 (2), 683-695 , 2023
    2023
    Citations: 2
  • Quantifying Impact on Safety from Cyber-Attacks on Cyber-Physical Systems
    E Vlahakis, G Provan, G Werner, S Yang, N Athanasopoulos
    22nd IFAC World Congress Yokohama, Japan , 2023
    2023
    Citations: 11
  • Distributed resource autoscaling in kubernetes edge clusters
    D Spatharakis, I Dimolitsas, E Vlahakis, D Dechouniotis, ...
    2022 18th International Conference on Network and Service Management (CNSM … , 2022
    2022
    Citations: 19
  • Model-matching methods and distributed control of networks consisting of a class of heterogeneous dynamic agents
    EE Vlahakis, GD Halikias
    International Journal of Control 95 (8), 2066-2082 , 2022
    2022
  • Optimal resource scheduling and allocation in distributed computing systems
    W Ren, E Vlahakis, N Athanasopoulos, R Jungers
    2022 American Control Conference (ACC), 2327-2332 , 2022
    2022
    Citations: 5
  • Optimal Resource Scheduling and Allocation under Allowable Over-Scheduling
    W Ren, E Vlahakis, N Athanasopoulos, RM Jungers
    arXiv preprint arXiv:2204.00038 , 2022
    2022
  • Modelling issues and aggressive robust load frequency control of interconnected electric power systems
    L Dritsas, E Kontouras, E Vlahakis, I Kitsios, G Halikias, A Tzes
    International Journal of Control 95 (3), 753-767 , 2022
    2022
    Citations: 29

MOST CITED SCHOLAR PUBLICATIONS

  • Distributed LQR design for a class of large-scale multi-area power systems
    E Vlahakis, L Dritsas, G Halikias
    Energies 12 (14), 2664 , 2019
    2019
    Citations: 32
  • Modelling issues and aggressive robust load frequency control of interconnected electric power systems
    L Dritsas, E Kontouras, E Vlahakis, I Kitsios, G Halikias, A Tzes
    International Journal of Control 95 (3), 753-767 , 2022
    2022
    Citations: 29
  • Distributed resource autoscaling in kubernetes edge clusters
    D Spatharakis, I Dimolitsas, E Vlahakis, D Dechouniotis, ...
    2022 18th International Conference on Network and Service Management (CNSM … , 2022
    2022
    Citations: 19
  • Distributed LQR design for identical dynamically coupled systems: Application to Load Frequency Control of multi-area Power Grid
    EE Vlahakis, LD Dritsas, GD Halikias
    2019 IEEE 58th Conference on Decision and Control (CDC), 4471-4476 , 2019
    2019
    Citations: 16
  • Distributed LQR methods for networks of non-identical plants
    EE Vlahakis, GD Halikias
    2018 IEEE conference on decision and control (cdc), 6145-6150 , 2018
    2018
    Citations: 16
  • Probabilistic tube-based control synthesis of stochastic multi-agent systems under signal temporal logic
    EE Vlahakis, L Lindemann, P Sopasakis, DV Dimarogonas
    2024 IEEE 63rd Conference on Decision and Control (CDC), 1586-1592 , 2024
    2024
    Citations: 13
  • Temperature and concentration control of exothermic chemical processes in continuous stirred tank reactors
    E Vlahakis, G Halikias
    Transactions of the Institute of Measurement and Control 41 (15), 4274-4284 , 2019
    2019
    Citations: 13
  • Quantifying Impact on Safety from Cyber-Attacks on Cyber-Physical Systems
    E Vlahakis, G Provan, G Werner, S Yang, N Athanasopoulos
    22nd IFAC World Congress Yokohama, Japan , 2023
    2023
    Citations: 11
  • Distributed LQR-based suboptimal control for coupled linear systems
    EE Vlahakis, LD Dritsas, GD Halikias
    IFAC-PapersOnLine 52 (20), 109-114 , 2019
    2019
    Citations: 11
  • Conformal prediction for distribution-free optimal control of linear stochastic systems
    EE Vlahakis, L Lindemann, P Sopasakis, DV Dimarogonas
    IEEE Control Systems Letters 8, 2835-2840 , 2024
    2024
    Citations: 10
  • AIMD scheduling and resource allocation in distributed computing systems
    E Vlahakis, N Athanasopoulos, S McLoone
    2021 60th IEEE Conference on Decision and Control (CDC), 4642-4647 , 2021
    2021
    Citations: 9
  • Data-driven distributionally robust control for interacting agents under logical constraints
    AB Kordabad, EE Vlahakis, L Lindemann, S Gros, DV Dimarogonas, ...
    arXiv preprint arXiv:2503.09816 , 2025
    2025
    Citations: 7
  • Model-Matching type-methods and Stability of Networks consisting of non-Identical Dynamic Agents
    EE Vlahakis, GD Halikias
    IFAC-PapersOnLine 51 (23), 426-431 , 2018
    2018
    Citations: 7
  • Distributed sequential receding horizon control of multi-agent systems under recurring signal temporal logic
    EE Vlahakis, L Lindemann, DV Dimarogonas
    2024 European Control Conference (ECC), 305-310 , 2024
    2024
    Citations: 6
  • Distributed model predictive load frequency control of multi-area power grid: A decoupling approach
    EE Vlahakis, LD Dritsas, GD Halikias
    IFAC-PapersOnLine 52 (20), 205-210 , 2019
    2019
    Citations: 6
  • Optimal resource scheduling and allocation in distributed computing systems
    W Ren, E Vlahakis, N Athanasopoulos, R Jungers
    2022 American Control Conference (ACC), 2327-2332 , 2022
    2022
    Citations: 5
  • Cooperative distributed LQR control for longitudinal flight of a formation of non-identical low-speed experimental UAV's
    EE Vlahakis, E Milonidis, GD Halikias
    2018 UKACC 12th International Conference on Control (CONTROL), 295-300 , 2018
    2018
    Citations: 5
  • Conformal data-driven control of stochastic multi-agent systems under collaborative signal temporal logic specifications
    EE Vlahakis, L Lindemann, DV Dimarogonas
    2025 IEEE 64th Conference on Decision and Control (CDC), 624-629 , 2025
    2025
    Citations: 4
  • Risk-aware real-time task allocation for stochastic multi-agent systems under STL specifications
    MHW Engelaar, Z Zhang, EE Vlahakis, DV Dimarogonas, M Lazar, ...
    2024 IEEE 63rd Conference on Decision and Control (CDC), 8213-8218 , 2024
    2024
    Citations: 4
  • Distributed optimal and predictive control methods for networks of dynamic systems
    EE Vlahakis
    City, University of London , 2020
    2020
    Citations: 4