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Publications (10 of 76) Show all publications
Lucchese, R. (2019). A study of fine and coarse actuation capabilities in air-cooled server racks: control strategies and cost analysis. IEEE Transactions on Control Systems Technology
Open this publication in new window or tab >>A study of fine and coarse actuation capabilities in air-cooled server racks: control strategies and cost analysis
2019 (English)In: IEEE Transactions on Control Systems Technology, ISSN 1063-6536, E-ISSN 1558-0865Article in journal (Refereed) Submitted
Keywords
Data center thermal management, Server thermal models, Controlled air-cooling
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-75914 (URN)
Available from: 2019-09-09 Created: 2019-09-09 Last updated: 2019-09-18
Lucchese, R. & Johansson, A. (2019). ColdSpot: A thermal supervisor aimed at server rooms implementing a raised plenum cooling setup. In: : . Paper presented at ACC. IEEE conference proceedings
Open this publication in new window or tab >>ColdSpot: A thermal supervisor aimed at server rooms implementing a raised plenum cooling setup
2019 (English)Conference paper (Refereed)
Place, publisher, year, edition, pages
IEEE conference proceedings, 2019
Keywords
Data center thermal supervisor, Energy efficient cooling, Perforated tile flow model, ColdSpot
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-75910 (URN)
Conference
ACC
Available from: 2019-09-09 Created: 2019-09-09 Last updated: 2019-09-09
Lucchese, R. (2019). Controlled Direct Liquid Cooling of Data Servers. IEEE Transactions on Control Systems Technology
Open this publication in new window or tab >>Controlled Direct Liquid Cooling of Data Servers
2019 (English)In: IEEE Transactions on Control Systems Technology, ISSN 1063-6536, E-ISSN 1558-0865Article in journal (Refereed) Accepted
Place, publisher, year, edition, pages
IEEE, 2019
Keywords
Controlled liquid cooling, Direct liquid cooling, Data server thermal management, Heat recovery
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-75905 (URN)
Available from: 2019-09-09 Created: 2019-09-09 Last updated: 2019-09-18
Lucchese, R. & Johansson, A. (2019). On energy efficient flow provisioning in air-cooled data servers. Control Engineering Practice, 89, 103-112
Open this publication in new window or tab >>On energy efficient flow provisioning in air-cooled data servers
2019 (English)In: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 89, p. 103-112Article in journal (Refereed) Published
Abstract [en]

This study considers how to efficiently manage the thermal state of data servers by provisioning their cooling airflow dynamically. It introduces a thermal network framework that is tailored to capture the temperature dynamics of the on-board thermal inertiae. On top of this modeling, it devises LeakageCooling, a novel flow provisioning controller that balances the temperature dependent leakage dissipation within the electronic chips and the power consumed by the local fans to produce the cooling airflow. The prediction capabilities of the proposed modeling and the overall control performance are assessed over several relevant experimental scenarios on an Open Compute Windmill V2 server.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Server thermal models, Server thermal management, Controlled flow provisioning, Controlled data center cooling
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-75057 (URN)10.1016/j.conengprac.2019.05.019 (DOI)000477785800009 ()2-s2.0-85066323953 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-27 (johcin)

Available from: 2019-06-27 Created: 2019-06-27 Last updated: 2019-09-09Bibliographically approved
Lucchese, R. & Johansson, A. (2019). On server cooling policies for heat recovery: exhaust air properties of an Open Compute Windmill V2 platform. In: : . Paper presented at CCTA. IEEE conference proceedings
Open this publication in new window or tab >>On server cooling policies for heat recovery: exhaust air properties of an Open Compute Windmill V2 platform
2019 (English)Conference paper (Refereed)
Place, publisher, year, edition, pages
IEEE conference proceedings, 2019
Keywords
Server thermal management, Server exhaust heat properties, Data center heat recovery
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-75909 (URN)
Conference
CCTA
Available from: 2019-09-09 Created: 2019-09-09 Last updated: 2019-09-09
Atta, K., Johansson, A. & Gustafsson, T. (2017). Accuracy Improvement of Extremum Seeking Control. IEEE Transactions on Automatic Control, 62(4), 1952-1958, Article ID 7498657.
Open this publication in new window or tab >>Accuracy Improvement of Extremum Seeking Control
2017 (English)In: IEEE Transactions on Automatic Control, ISSN 0018-9286, E-ISSN 1558-2523, Vol. 62, no 4, p. 1952-1958, article id 7498657Article in journal (Refereed) Published
Abstract [en]

In this work, we present a modification for theclassic and phasor extremum seeking control algorithms in orderto improve the accuracy by removing or reducing the convergenceerror. The modulation signals were replaced by a sum of sinusoidsin order to remove the equilibrium shift in the controlled variableof the averaged system. The convergence error is calculated as afunction of the number of sinusoids used in the modulation signal.A simulation example is presented to illustrate the improvement.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2017
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-62395 (URN)10.1109/TAC.2016.2584184 (DOI)000399033000031 ()2-s2.0-85018485239 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-29 (rokbeg)

Available from: 2017-03-10 Created: 2017-03-10 Last updated: 2018-07-10Bibliographically approved
Atta, K., Johansson, A. & Gustafsson, T. (2016). On the stability analysis of phasor and classic extremum seeking control (ed.). Paper presented at . Systems & control letters (Print), 91, 55-62
Open this publication in new window or tab >>On the stability analysis of phasor and classic extremum seeking control
2016 (English)In: Systems & control letters (Print), ISSN 0167-6911, E-ISSN 1872-7956, Vol. 91, p. 55-62Article in journal (Refereed) Published
Abstract [en]

In this work we present a semi-global practical asymptotic stability analysis for phasor extremum seeking control with a general non-linear dynamic system. With the same technique applied to the classic band pass filter algorithm, we present a more relaxed (less constrained) semi-global practical asymptotic stability condition compared to earlier work. The results are based on a non approximated averaging for both control techniques.

National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-12684 (URN)10.1016/j.sysconle.2016.02.007 (DOI)000375630000009 ()2-s2.0-84961794725 (Scopus ID)bd90bbac-c727-44bd-93c0-26f1097bb9b3 (Local ID)bd90bbac-c727-44bd-93c0-26f1097bb9b3 (Archive number)bd90bbac-c727-44bd-93c0-26f1097bb9b3 (OAI)
Note
Validerad; 2016; Nivå 2; 20160318 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Atta, K., Birk, W., Hostettler, R. & Johansson, A. (2016). Phasor extremum seeking control with adaptive perturbation amplitude. In: 2016 IEEE 55th Conference on Decision and Control, CDC 2016: . Paper presented at 55th IEEE Conference on Decision and Control, CDC 2016, Las Vegas, United States, 12-14 December 2016 (pp. 7069-7074). Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), Article ID 7799358.
Open this publication in new window or tab >>Phasor extremum seeking control with adaptive perturbation amplitude
2016 (English)In: 2016 IEEE 55th Conference on Decision and Control, CDC 2016, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2016, p. 7069-7074, article id 7799358Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, we propose a perturbation amplitude adaption scheme for phasor extremum seeking control based on the plant's estimated gradient. By using phasor extremum seeking instead of classical extremum seeking, the problem of algebraic loops in the controller formulation is avoided. Furthermore, a stability analysis for the proposed method is provided, which is the first stability analysis for extremum seeking controllers using adaptive amplitudes. The proposed method is illustrated using numerical examples and it is found that changes in optimum can be tracked accurately while the steady-state perturbations can be reduced significantly.

Place, publisher, year, edition, pages
Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2016
Series
IEEE Conference on Decision and Control, E-ISSN 0743-1546
National Category
Signal Processing
Research subject
Signal Processing
Identifiers
urn:nbn:se:ltu:diva-61868 (URN)10.1109/CDC.2016.7799358 (DOI)000400048107044 ()2-s2.0-85010747991 (Scopus ID)9781509018376 (ISBN)
Conference
55th IEEE Conference on Decision and Control, CDC 2016, Las Vegas, United States, 12-14 December 2016
Available from: 2017-02-08 Created: 2017-02-08 Last updated: 2017-12-15Bibliographically approved
Sayyaddelshad, S., Johansson, A., Darouach, M. & Gustafsson, T. (2016). Robust state estimation and unknown inputs reconstruction for a class of nonlinear systems: multiobjective approach (ed.). Paper presented at . Automatica, 64, 1-7
Open this publication in new window or tab >>Robust state estimation and unknown inputs reconstruction for a class of nonlinear systems: multiobjective approach
2016 (English)In: Automatica, ISSN 0005-1098, E-ISSN 1873-2836, Vol. 64, p. 1-7Article in journal (Refereed) Published
Abstract [en]

We consider a novel method to design H-infinity observers for a class of uncertain nonlinear systems subject to unknown inputs. First, the main system dynamics are rewritten as an augmented system with state vector including both the state vector of the main system and the unknown inputs. Then, we design a H-infinity reduced-order observer to estimate both state variables and unknown inputs simultaneously. Based on a Lyapunov functional, we derive a sufficient condition for existence of the designed observer which requires solving a nonlinear matrix inequality. To facilitate the observer design, the achieved condition is formulated in terms of a set of linear matrix inequalities (LMI). By extending the proposed method to a multiobjective optimization problem, the maximum bound of the uncertainty and the minimum value of the disturbance attenuation level are found. Finally, the proposed observer is illustrated with an example.

Keywords
Information technology - Automatic control, Informationsteknik - Reglerteknik
National Category
Control Engineering
Research subject
Control Engineering
Identifiers
urn:nbn:se:ltu:diva-3452 (URN)10.1016/j.automatica.2015.10.051 (DOI)000368967000001 ()2-s2.0-84951753244 (Scopus ID)14661358-2de9-42eb-87e4-fc5c24c5d160 (Local ID)14661358-2de9-42eb-87e4-fc5c24c5d160 (Archive number)14661358-2de9-42eb-87e4-fc5c24c5d160 (OAI)
Note
Validerad; 2015; Nivå 2; 20151027 (salsay)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Atta, K., Johansson, A. & Gustafsson, T. (2015). Extremum seeking control based on phasor estimation (ed.). Paper presented at . Systems & control letters (Print), 85, 37-45
Open this publication in new window or tab >>Extremum seeking control based on phasor estimation
2015 (English)In: Systems & control letters (Print), ISSN 0167-6911, E-ISSN 1872-7956, Vol. 85, p. 37-45Article in journal (Refereed) Published
Abstract [en]

We present an extremum seeking control algorithm based on the estimation of the phasor of the perturbation frequency in the output of the plant. The phasor estimator is based on a continuous time Kalman filter, which is reduced into a variable gain observer by explicitly solving the special case of the Riccati equation. Local stability of the proposed al- gorithm for general non-linear dynamic systems using averaging and singular perturbations is presented for the single input case. The advantage of the presented algorithm is that it can be used on plants with large and even variable phase lag.

National Category
Control Engineering
Research subject
Control Engineering; Intelligent industrial processes (AERI)
Identifiers
urn:nbn:se:ltu:diva-10781 (URN)10.1016/j.sysconle.2015.08.010 (DOI)000364884300006 ()2-s2.0-84944041663 (Scopus ID)9a49e75c-e3e9-47ab-8626-7390e4551bd6 (Local ID)9a49e75c-e3e9-47ab-8626-7390e4551bd6 (Archive number)9a49e75c-e3e9-47ab-8626-7390e4551bd6 (OAI)
Note
Validerad; 2015; Nivå 2; 20150908 (tgu)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8893-4809

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