Browsing by Author "Hlava, Jaroslav"

Now showing 1 - 6 of 6
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    Autonomous Vehicle Control based on HoloLens Technology and Raspberry Pi Platform: an Educational Perspective
    (ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2019-01-01) Moezzi, Reza; Krčmařík, David; Bahri, Haythem; Hlava, Jaroslav
    Localization and mapping is an essential part of an autonomous vehicle control. Microsoft HoloLens is a sophisticated augmented reality device using many advanced technologies. As such HoloLens has high appeal for young people and its use in teaching may increase the attractiveness of control classes. In this paper we describe how this device can be used in advanced control education for experiments with autonomous vehicles localization, mapping and control. Among other capabilities HoloLens can provide 3D position information by its spatial mapping feature. This facilitates the simultaneous localization and mapping (SLAM) problem. Furthermore, based on HoloLens position information the students can design vehicle longitudinal and lateral control systems and compare the performance achieved with different strategies such as PID and Model Predictive control. Example comparisons are given in this paper.
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    Control of Jet Flow Angle in Continuous Casting Process using an Electromagnetic Brake
    (ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2019-01-01) Abouelazayem, Shereen; Glavinic, Ivan; Wondrak, Thomas; Hlava, Jaroslav
    The flow pattern in the mould of the continuous casting is an important factor in determining the quality of the steel slabs that are produced in the end of the process. Hence it can heavily influence manufacturing costs due to the scrap percentage. Electromagnetic actuators are frequently used in the continuous casting process to stabilize the flow in the mould and therefore produce higher quality of steel slabs. Usually they are used in open loop but their effect on the flow pattern may be much better directed if they are used as a part of closed loop control based on real time measurements. In this paper, a closed loop controller is proposed that adjusts the magnetic field of an electromagnetic brake using the real time measurement of the angle of the jet flowing from the Submerged Entry Nozzle (SEN). The angle is kept within a specific range by the controller in order to prevent a deeper jet impingement into the mould; this allows us to achieve the desirable double roll flow pattern, and to avoid the entrapment of slug. The controller is based on a model of the relationship between brake current and jet angle that was obtained using experimental data from a laboratory scale continuous casting plant.
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    Flow Control Based on Feature Extraction in Continuous Casting Process
    (MDPI, 2020-01-01) Abouelazayem, Shereen; Glavinić, Ivan; Wondrak, Thomas; Hlava, Jaroslav
    The flow structure in the mold of a continuous steel caster has a significant impact on the quality of the final product. Conventional sensors used in industry are limited to measuring single variables such as the mold level. These measurements give very indirect information about the flow structure. For this reason, designing control loops to optimize the flow is a huge challenge. A solution for this is to apply non-invasive sensors such as tomographic sensors that are able to visualize the flow structure in the opaque liquid metal and obtain information about the flow structure in the mold. In this paper, ultrasound Doppler velocimetry (UDV) is used to obtain key features of the flow. The preprocessing of the UDV data and feature extraction techniques are described in detail. The extracted flow features are used as the basis for real time feedback control. The model predictive control (MPC) technique is applied, and the results show that the controller is able to achieve optimum flow structures in the mold. The two main actuators that are used by the controller are the electromagnetic brake and the stopper rod. The experiments included in this study were obtained from a laboratory model of a continuous caster located at the Helmholtz-Zentrum Dresden Rossendorf (HZDR).
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    Implementation of X-Parameters Principle for Non-linear Vibroacoustic Membrane Using Two-Port Measurement
    (International Information and Engineering Technology Association, 2019-08-01) Moezzi, Reza; Hlava, Jaroslav; Vu, Trieu Minh
    X-parameters, a powerful solution to the simulation of nonlinear microwave components, can be used for other wave systems with distributed parameters. This paper introduces X-parameters to the acoustic field to deal with highly nonlinear large signals and boundary conditions. Firstly, an elastic membrane was selected to serve as the nonlinear boundary. Then, the equivalent electronic lumped model of the elastic membrane was established based on its nonlinear differential equation (NDE). The X-parameters of the model were determined by poly-harmonic distortion modelling. Then, an electrical analogy of the nonlinear system was established by two port method. The simulation and experimental results show that the properties of the elastic membrane were characterized well by the X-parameters.
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    Malý laboratorní servopohon pro výuku automatického řízení
    (Technická Univerzita v Liberci, 2006-01-01) Loos, Josef; Hlava, Jaroslav
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    Zvýšení kvality pramene na mykacím stroji
    (Technická univerzita v Liberci, 2003-01-01) Hlava, Jaroslav; Janeček, Bedřich; Janeček, Josef; Katedra řídící techniky
    Práce plánované v rámci širšího projektu „Zvýšení produkce mykacího stroje" na rok 2003 se měly soustředit v první řadě na problematiku modelování a regulace procesu průtahu. Vycházeje z prvních pokusů učiněných již v předchozím roce, měl být vytvořen spolehlivý matematický model a navržena regulace ústrojí. V návaznosti na to a na stavbu pracoviště umožňujícího pokusy s celým mykacím strojem pak mělo být přikročeno k identifikací mykacího stroje jako řízeného systému.