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Model Predictive Control in buildings with thermal and visual comfort constraints

Khosravi, M. (author), Huber, Benjamin (author), Decoussemaeker, Antoon (author), Heer, Philipp (author), Smith, Roy S. (author)

Model Predictive Control can cope with conflicting control objectives in building energy managements. In terms of user satisfaction, visual comfort has been proven in several studies to be a crucial factor, however thermal comfort is typically considered the only important aspect. Besides human well-being, visual comfort strongly impacts the...

journal article 2024

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The existence and uniqueness of solutions for kernel-based system identification

Khosravi, M. (author), Smith, Roy S. (author)

The notion of reproducing kernel Hilbert space (RKHS) has emerged in system identification during the past decade. In the resulting framework, the impulse response estimation problem is formulated as a regularized optimization defined on an infinite-dimensional RKHS consisting of stable impulse responses. The consequent estimation problem is...

journal article 2023

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Kernel-based identification with frequency domain side-information

Khosravi, M. (author), Smith, Roy S. (author)

This paper discusses the problem of system identification when frequency domain side-information is available. We mainly consider the case where the side-information is provided as the H_∞-norm of the system being bounded by a given scalar. This framework allows considering different forms of frequency domain side-information, such...

journal article 2023

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Guest Editorial: Introduction to IEEE Control Systems Letters Special Section on Multi-Agent Coordination for Energy Systems: From Model Based to Data-Driven Methods

Glielmo, Luigi (author), Grammatico, S. (author), Kebriaei, Hamed (author), Smith, Roy S. (author)

Editorial

contribution to periodical 2023

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Kernel-based Identification of Periodically Parameter-Varying Models of Power Kites

Yin, Mingzhou (author), Ozan, Defne E. (author), Iannelli, Andrea (author), Smith, Roy S. (author)

conference paper 2022

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An Adaptive Control Framework for Underactuated Switched Euler–Lagrange Systems

Roy, S. (author), Baldi, S. (author), Ioannou, Petros A. (author)

The control of underactuated Euler–Lagrange systems with uncertain and switched parameters is an important problem whose solution has many applications. The problem is challenging as standard adaptive control techniques do not extend to this class of systems due to structural constraints that lead to parameterization difficulties. This note...

journal article 2022

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Adaptive single-stage control for uncertain nonholonomic Euler-Lagrange systems

Tao, T. (author), Roy, S. (author), Baldi, S. (author)

This work introduces a new single-stage adaptive controller for Euler-Lagrange systems with nonholonomic constraints. The proposed mechanism provides a simpler design philosophy compared to double-stage mechanisms (that address kinematics and dynamics in two steps), while achieving analogous stability properties, i.e. stability of both original...

conference paper 2022

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A Switching Control Perspective on the Offshore Construction Scenario of Heavy-Lift Vessels

Ye, J. (author), Roy, S. (author), Godjevac, Milinko (author), Baldi, S. (author)

Position control for heavy-lift construction vessels is crucial for safe operation during offshore construction. During the various phases of a typical offshore construction assignment, considerable changes in the dynamics of the crane-vessel system occur. Operational hazard was reported if such interchanging dynamics are not properly handled...

journal article 2021

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A New Adaptive-Robust Design for Time Delay Control under State-Dependent Stability Condition

Roy, S. (author), Lee, Jinoh (author), Baldi, S. (author)

This brief proposes a new adaptive-robust formulation for time-delay control (TDC) under a less-restrictive stability condition. TDC relies on estimating the unknown system dynamics via the artificial introduction of a time delay, often referred to as time-delay estimation (TDE). In conventional TDC, the estimation error, called TDE error, is...

journal article 2021

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Electricity in the Air: Insights From Two Decades of Advanced Control Research and Experimental Flight Testing of Airborne Wind Energy Systems

Vermillion, Chris (author), Cobb, Mitchell (author), Fagiano, Lorenzo (author), Leuthold, Rachel (author), Diehl, Moritz (author), Smith, Roy S. (author), Wood, Tony A. (author), Rapp, S. (author), Schmehl, R. (author)

Airborne wind energy systems convert wind energy into electricity using tethered flying devices, typically flexible kites or aircraft. Replacing the tower and foundation of conventional wind turbines can substantially reduce the material use and, consequently, the cost of energy, while providing access to wind at higher altitudes. Because the...

review 2021

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Stable Adaptation in Multi-Area Load Frequency Control under Dynamically-Changing Topologies

Tao, T. (author), Roy, S. (author), Baldi, S. (author)

Multi-area load frequency control (LFC) selects and controls a few generators in each area of the power system in an effort to dampen inter-area frequency oscillations. To effectively dampen such oscillations, it is required to enhance and lower the control activity dynamically during operation, so as to adapt to changing circumstances....

journal article 2021

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Visualizing response to DNA damage in bacteria

Deb Roy, S. (author)

The basis of this thesis has been the curiosity, however modest, to understand how DNA replication happens in vivo, particularly during the onset of DNA damage and beyond. DNA damage is a recurring phenomenon, which a (bacterial) cell faces in its lifetime from the environment or even its inherent metabolism. While we understand much about...

doctoral thesis 2020

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The issue of transients in leakage-based model reference adaptive control of switched linear systems

Tao, T. (author), Roy, S. (author), Baldi, S. (author)

The literature has proven that attaining good transient behavior in leakage-based robust adaptive control of uncertain switched systems is intrinsically challenging. In fact, because the gains of the inactive subsystems must exponentially vanish during inactive times as an effect of leakage action, new learning transients will repeatedly...

journal article 2020

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Addressing Unmodeled Path-Following Dynamics via Adaptive Vector Field: A UAV Test Case

Fari, S. (author), Wang, X. (author), Roy, S. (author), Baldi, S. (author)

The actual performance of model-based path-following methods for unmanned aerial vehicles (UAVs) shows considerable dependence on the wind knowledge and on the fidelity of the dynamic model used for design. This study analyzes and demonstrates the performance of an adaptive vector field (VF) control law which can compensate for the lack of...

journal article 2020

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On adaptive sliding mode control without a priori bounded uncertainty

Roy, S. (author), Baldi, S. (author), Fridman, Leonid M. (author)

Adaptive Sliding Mode Control (ASMC) aims to adapt the switching gain in such a way to cope with possibly unknown uncertainty. In state-of-the-art ASMC methods, a priori boundedness of the uncertainty is crucial to ensure boundedness for the switching gain and uniformly ultimately boundedness. A priori bounded uncertainty might impose a...

journal article 2020

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On vanishing gains in robust adaptation of switched systems: A new leakage-based result for a class of Euler–Lagrange dynamics

Roy, S. (author), Kosmatopoulos, Elias B. (author), Baldi, S. (author)

In the presence of unmodelled dynamics and uncertainties with no a priori constant bounds, conventional robust adaptation strategies for switched systems cannot allow the control gains of inactive subsystems to remain constant during inactive intervals: vanishing gains are typically required in order to prove bounded stability. As a...

journal article 2020

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Towards structure-independent stabilization for uncertain underactuated Euler–Lagrange systems

Roy, S. (author), Baldi, S. (author)

Available control methods for underactuated Euler–Lagrange (EL) systems rely on structure-specific constraints that may be appropriate for some systems, but restrictive for others. A generalized (structure-independent) control framework is to a large extent missing, especially in the presence of uncertainty. This paper introduces an adaptive...

journal article 2020

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Experimental Validation of Path-Tracking Model Predictive Control for Fixed-Wing Power Kites

Ahbe, Eva (author), Stastny, Thomas (author), Dangel, Manuel (author), Siegwart, Roland (author), Smith, Roy S. (author)

conference paper 2019

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Observer-based robust control for dynamic positioning of large-scale heavy lift vessels

Ye, J. (author), Roy, S. (author), Godjevac, M. (author), Baldi, S. (author)

With the growing demand of large-scale heavy lift vessels in the deep-sea offshore construction works, high performance of Dynamic positioning (DP) systems is becoming ever crucial. However, current DP systems on board of heavy lift vessels do not consider model uncertainty (typically arising from mooring forces). In this paper, an observer...

journal article 2019

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Perceived relevance of automatic code inspection in end-user development: A study on VBA

Roy, S. (author), van Deursen, A. (author), Hermans, F.F.J. (author)

Microsoft VBA (Visual Basic for Applications) is a programming language widely used by end-user programmers, often alongside the popular spreadsheet software Excel. Together they form the popular Excel-VBA application ecosystem. Despite being popular, spreadsheets are known to be fault-prone, and to minimize risk of faults in the overall...

conference paper 2019