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  • 1.
    Atta, Khalid
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Guay, Martin
    Department of Chemical Engineering, Queens University, Kingston, ON.
    Fast proportional integral phasor extremum seeking control for a class of nonlinear system2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 5724-5730Article in journal (Refereed)
    Abstract [en]

    In this paper, we present a modification of the phasor extremum-seeking control for the fast optimization of a class of Wiener-Hammerstein nonlinear dynamical systems with a general strict unimodal nonlinearity. Based on the prior knowledge of the system’s relative order and number of non-minimum phase zeros, the proposed approach uses a high frequency perturbation signal and the phasor of the plant output to enable fast convergence of the overall system without the need for filters of the plant’s input and output. The extremum-seeking controller has two modes. In addition to the integral term, a proportional term is used to enable the application to very slow and integrating systems. Semi-global practical asymptotic stability analysis of the overall system to the unknown optimum is achieved. The effectiveness of the proposed approach is illustrated using numerical examples for different types of Wiener-Hammerstein systems.

  • 2.
    Bodin, Ulf
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Computer Science.
    Andersson, Ulf
    Dadhich, Siddharth
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Uhlin, Erik
    Volvo Construction Equipment.
    Marklund, Ulf
    Boliden AB.
    Häggström, Derny
    Oryx Simulations AB.
    Remote Controlled Short-Cycle Loading of Bulk Material in Mining Applications2015In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 48, no 17, p. 54-59Article in journal (Refereed)
    Abstract [en]

    High-capacity wireless IP networks with limited delays are nowadays being deployed in both underground and open-pit mines. This allows for advanced remote control of mining machinery with improved feedback to operators and extensive monitoring of machine status, wear and fatigue. Wireless connectivity varies however depending on channel impairments caused by obstacles, multi-path fading and other radio issues. Therefore remote control and monitoring should be capable of adapting their sending rates to handle variations in communications quality. This paper presents key challenges in advanced remote control and monitoring of working machines via high-capacity wireless IP networks in mining environments. We reason about these challenges in context of underground short-cycle load, haul and dump operation with large-volume built wheel-loaders and present a generic communication solution for an operator assistance concept capable of adapting to varying communication properties

  • 3.
    Castaño Arranz, Miguel
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Birk, Wolfgang
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    A Survey on Control Configuration Selection and New Challenges in Relation to Wireless Sensor and Actuator Networks2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 8810-8825Article in journal (Refereed)
    Abstract [en]

    This survey on Control Configuration Selection (CCS) includes methods based on relative gains, gramian-based interaction measures, methods based on optimization schemes, plantwide control, and methods for the reconfiguration of control systems. The CCS problem is discussed, and a set of desirable properties of a CCS method are defined. Open questions and research tracks are discussed, with the focus on new challenges in relation to the emerging area of Wireless Sensors and Actuator Networks.

  • 4.
    Fresk, Emil
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Ödmark, Kristoffer
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Ultra WideBand enabled Inertial Odometry for Generic Localization2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 11465-11472Article in journal (Refereed)
    Abstract [en]

    In this paper we will present a inertial odometry localization system, utilizing Ultra WideBand distance measurements for corrections, as a generic localization solution. The proposed scheme is evaluated in two different measurement schemes, one cyclic and one based on stochastic events, which has the strong merit of minimizing the sampling rate, while adhering to covariance constraints on the state, allowing the system to conform with RF regulations. The efficacy of the proposed scheme is evaluated in extended experimental evaluation on an hexacopter Unmanned Aerial Vehicle

  • 5.
    Guay, Martin
    et al.
    Department of Chemical Engineering, Queen's University, Kingston, ON, Canada.
    Atta, Khalid
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    A set-based model-free reinforcement learning design technique for nonlinear systems2018In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 51, no 18, p. 37-42Article in journal (Refereed)
    Abstract [en]

    In this study, we propose an extremum-seeking approach for the approximation of optimal control problems for unknown nonlinear dynamical systems. The technique combines a phasor extremum seeking controller with an reinforcement learning strategy. The learning approach is used to estimate the value function of an optimal control problem of interest. The phasor extremum seeking controller implements the approximate optimal controller. The approach is shown to provide reasonable approximations of optimal control problems without the need for a parameterization of the nonlinear control system. A simulation example are provided to demonstrate the effectiveness of the technique

  • 6.
    Hoseinie, Hadi
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Ghodrati, Behzad
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Galar, Diego
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Juuso, Esko
    University of Oulu, Control Engineering Group, Faculty of Technology, University of Oulu.
    Optimal Preventive Maintenance Planning for Water Spray System of Drum Shearer2015In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 48, no 17, p. 166-170Article in journal (Refereed)
    Abstract [en]

    Water spray system is one of the most important parts of rock cutting machines, especially the drum shearer. Field data shows that the maintenance of this system is time-consuming and causes major downtimes in the coal mines’ production process. Therefore, it is essential to find an optimum preventive maintenance task and intervals, to reduce the downtime and minimize the associated costs of the machine. In this paper, in order to suggest an optimum preventive maintenance plan, a parametric failure and reliability analysis was done on available data from an Iranian longwall coal mine over the two years. A reliability-based cost modelling was implemented to identify the optimum maintenance interval and frequencies of restoration for the water spray system. In the study, a cost rate function was introduced in which an as-good-as-new effectiveness for restoration actions is considered. The results of the analysis showed that the minimum maintenance cost per unit of time for the studied machine, $19.54/hour, will be achieved within a range of intervals i.e. T=136 hours to T=142 hours.

  • 7.
    Knorn, Steffi
    et al.
    Department of Engineering Sciences, Uppsala University, Sweden.
    Varagnolo, Damiano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Oliver-Chiva, Ernesto
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Melles, Reinhilde
    Department of Psychology and Neuroscience, Clinical Psychological Science, Behavioural Medicine, Maastricht Universitair Medisch Centrum, Maastricht, The Netherlands.
    Dewitte, Marieke
    Department of Psychology and Neuroscience, Clinical Psychological Science, Behavioural Medicine, Maastricht Universitair Medisch Centrum, Maastricht, The Netherlands.
    Data-driven modelling of pelvic floor muscles dynamics2018In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 51, no 27, p. 321-326Article in journal (Refereed)
    Abstract [en]

    This paper proposes individualized, dynamical and data-driven models that describe pelvic floor muscle responses in women that use vaginal dilation. Specifically, the models describe how the volume of an inflatable balloon inserted at the vaginal introitus dynamically affects the aggregated pressure exerted by the pelvic floor muscles of the person. The paper inspects the approximation capabilities of different model structures, such as Hammerstein-Wiener and NARX, for this specific application, and finds the specific model structures and orders that best describe the recorded measurement data. Hence, although the current dataset is drawn from a sample of healthy volunteers, this paper is an initial step towards better understanding women’s responses to vaginal dilation and facilitating individualised medical vaginal dilation treatment.

  • 8.
    Lucchese, Riccardo
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Olsson, Jesper
    Luleå University of Technology.
    Ljung, Anna-Lena
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Garcia-Gabin, Winston
    ABB Corporate Research, Västerås.
    Varagnolo, Damiano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Energy savings in data centers: A framework for modelling and control of servers’ cooling2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 9050-9057Article in journal (Refereed)
    Abstract [en]

    Aiming at improving the energy efficiency of air cooled servers in data centers, we devise a novel control oriented, nonlinear, thermal model of the servers that accounts explicitly for both direct and recirculating convective air flows. Instrumental to the optimal co-design of both geometries and cooling policies, we propose an identification methodology based on Computational Fluid Dynamics (CFD) for a generic thermal network of m fans and n electronic components. The performance of the proposed modelling framework is validated against CFD measurements with promising results. We formalize the minimum cooling cost control problem as a polynomially constrained Receding Horizon Control (RHC) and show, in-silico, that the resulting policy is able to efficiently modulate the cooling resources in spite of the unknown future computational and electrical power loads.

  • 9.
    Lucchese, Riccardo
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Varagnolo, Damiano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Average consensus via max consensus2015In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 48, no 22, p. 58-63Article in journal (Refereed)
    Abstract [en]

    Since intuition states that it is simple and fast to compute maxima over networks, we aim at understanding the limits of computing averages over networks through computing maxima. We thus build on top of max-consensus based networks’ cardinality estimation protocols a novel estimation strategy that infers averages through computing maxima of opportunely and locally generated random initial conditions. We motivate the max-consensus strategy explaining why it satisfies practical requirements, we characterize completely its statistical properties, and we analyze when and under which conditions it performs favorably against classical linear consensus strategies in static Cayley graphs

  • 10.
    Mansouri, Sina Sharif
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Karvelis, Petros
    Laboratory of Knowledge and Intelligent Computing, Department of Computer Engineering, Technological Educational Institute of Epirus.
    Georgoulas, Georgios
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Remaining Useful Battery Life Prediction for UAVs based on Machine Learning2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 4727-4732Article in journal (Refereed)
    Abstract [en]

    Unmanned Aerial Vehicles are becoming part of many industrial applications. The advancements in battery technologies played a crucial part for this trend. However, no matter what the advancements are, all batteries have a fixed capacity and after some time drain out. In order to extend the flying time window, the prediction of the time that the battery will no longer be able to support a flying condition is crucial. This in fact can be cast as a standard Remaining Useful Life prognostic problem, similarly encountered in many fields. In this article, the problem of Remaining Useful Life estimation of a battery, under different flight conditions, is tackled using four machine learning techniques: a linear sparse model, a variant of support vector regression, a multilayer perceptron and an advanced tree based algorithm. The efficiency of the overall proposed machine learning techniques, in the field of batteries prognostics, is evaluated based on multiple experimental data from different flight conditions.

  • 11.
    Modolo, V.
    et al.
    University of Padova, Padova, Italy.
    Varagnolo, Damiano
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Carli, L.
    University of Padova, Padova, Italy.
    Distributed formation control using robust asynchronous and broadcast-based optimization schemes2018In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 51, no 23, p. 385-390Article in journal (Refereed)
    Abstract [en]

    We consider the problem of letting a network of mobile agents distributedly track and maintain a formation while using communication schemes that are asynchronous, broadcasts based, and prone to packet losses. To this purpose we revisit and modify an existing distributed optimization algorithm that corresponds to a distributed version of the Newton Raphson (NR) algorithm. The proposed scheme uses then robust asynchronous ratio consensus algorithms as building blocks, and employs opportune definitions for the local cost functions to achieve the desired coordination objective. In our algorithm, indeed, we code the position of the to-be-followed target as the minimum of a shared global cost, and capture the desired inter-robots behaviors through dedicated distances-based potential barriers. We then check the effectiveness of the strategy using field tests, and verify that the scheme achieves the desired goal of introducing robustness to changes in the agents positions due to unexpected disturbances. More precisely, if an agent breaks the formation, then the update mechanism embedded in our scheme make that agent move back to a meaningful position as soon as some packets are successfully received by the misplaced agent. 

  • 12.
    Nikolakopoulos, George
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Gustafsson, Thomas
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Martinsson, Pär-Erik
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems. ProcessIT Innovations.
    Andersson, Ulf
    Mine Tek HB, Kiruna.
    A Vision of Zero Entry Production Areas in Mines2015In: IFAC-PapersOnLine, E-ISSN 2405-8963, Vol. 48, no 17, p. 66-68Article in journal (Refereed)
    Abstract [en]

    This industrial article aims in presenting a short roadmap on the identified activities and technologies needed towards the vision of zero entry production areas in Mines. This work has been performed in close cooperation with large mining companies in Europe as part of the Smart Mine of the Future Research, Development and Innovation Program and will present the most important areas that it is expected the robotic technology to have an impact on.

  • 13.
    Varagnolo, Damiano
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Knorn, Steffi
    Department of Engineering Sciences, Uppsala University.
    Melles, Reinhilde
    Department of Psychology and Neuroscience, Clinical Psychological Science, Behavioural Medicine, Maastricht Universitair Medisch Centrum, Maastricht.
    Dewitte, Marieke
    Department of Psychology and Neuroscience, Clinical Psychological Science, Behavioural Medicine, Maastricht Universitair Medisch Centrum, Maastricht.
    Qualitative modeling of pressure vs. pain relations in women suffering from dyspareunia2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 2043-2050Article in journal (Refereed)
    Abstract [en]

    Genital pain / penetration disorders affect a significant portion of the female population and diminish significantly the quality of life of the subjects. Treatments, that often consist in stretching opportunely the vaginal duct by means of opportune vaginal dilators, are known to be invasive, lengthy and uncomfortable. Designing better treatments (e.g., more efficient locations and levels of pressures) nonetheless requires understanding better how the pressure developed in the vaginal channel affects the patient and leads to subjective pain. Here we take a control-oriented approach to the problem, and aim at describing the dynamics of the pressure vs. pain mechanisms by means of opportune state space representations. In particular, we first collect and discuss the medical literature, that describes how the variables that are involved in the treatment of genital pain / penetration disorders with vaginal dilators, are logically related. After this we translate (and complete) this set of logical relations into a qualitative model that allows control oriented analyses of the dynamics. The obtained state space model is then proved to both mimic correctly what is expected from logical perspectives and reproduce behaviors measured in clinical settings.

  • 14. Wuthier, David
    et al.
    Kominiak, Dariusz
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Fresk, Emil
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Nikolakopoulos, George
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    A Geometric Pulling Force Controller for Aerial Robotic Workers2017In: IFAC-PapersOnLine, ISSN 1045-0823, E-ISSN 1797-318X, Vol. 50, no 1, p. 10287-10292Article in journal (Refereed)
    Abstract [en]

    The aim of this article is to establish a geometric, pulling force control scheme in order to enable the concept of Aerial Robotic Workers (ARWs), where the capabilities of the Unmanned Aerial Vehicles (UAVs) are enhanced by aerial manipulators in order to exert known pulling forces on the environment, with characteristic applications such as levers actuation, debris removal and safety assessments. The proposed novel approach consists of interfacing a cascaded position control scheme with a manipulation framework in such a way that the UAV, together with the manipulator are being controlled in a complete system The validity of the proposed scheme as well as the ability of the UAV to track a desired pulling force is validated through a real-world experiment.

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