Fakulta elektrotechniky a informatiky / Faculty of Electrical Engineering and Informatics
Stálý URI pro tuto komunituhttps://hdl.handle.net/10195/3847
Práce obhájené před rokem 2008 jsou uloženy pouze v kolekci Vysokoškolské kvalifikační práce
Procházet
11 výsledky
Search Results
Článekpeer-reviewedpostprint Omezený přístup Generalized first-principle model of magnetic levitation(2023) Dušek, František; Tuček, Jiří; Novotný, Aleš; Honc, DanielSince its first demonstration more than a half century ago, magnetic levitation (MagLev) has gained eminent scientific attention from both the fundamental and applied points of view. In essence, MagLev shows highly nonlinear dynamics, described with nonlinear differential equations. Thus, in order to exploit the MagLev phenomenon, both mathematical models and control algorithms must be constructed. Frequently authors use simplifications of the model, and in doing so, limit the application of the MagLev model around a nominal operating point. In these simplified cases, the MagLev models may contain parameters that are not represented by proper physical quantities. Thus, in this work, we revised the issue of MagLev modelling from the first-principle approach. More specifically, we theoretically derived expressions for the interaction between the magnetic fields of the solenoid and a small magnetic object. The behaviour of the inductance on a distance from the solenoid was then described. The suggested MagLev modelling concept was verified experimentally, confirming the validity and correctness of the proposed MagLev mathematical model. The results presented here could thus be regarded as highly beneficial for formulating more complex MagLev designs exploitable in the field of model predictive control of the position of a levitating object.Článekpeer-reviewedpublished Otevřený přístup Simplified Energy Model and Multi-Objective Energy Consumption Optimization of a Residential House(MDPI, 2022) Mrázek, Michal; Honc, Daniel; Sanseverino, Eleonora Riva; Zizzo, GaetanoFeatured Application The potential application of the proposed model is a computationally inexpensive semi- or fully automated system for the optimization of operation in residential buildings in terms of energy consumption. Some analyses state that buildings contribute to overall energy consumption by 20-40%, which, in the context of the recent geopolitical energy crisis, makes them a critical issue to study. Finding solutions for better energy management in buildings can have a significant impact on the energy sector, thus reducing EU energy dependencies and contributing to the fulfillment of the REPowerEU goals. This paper focuses on proposing a simplified model of a residential house considering the main appliances, heating and cooling, a photovoltaic system, and electric vehicle recharging. Weather and solar irradiance forecasts are taken into account. The model predicts the energy demands of a house based on online weather forecasts and the desired indoor temperature. The article also focuses on the analysis of how weather forecast uncertainty affects energy demand prediction. This model can be used to better understand and predict the energy demand of either a single house or a set of houses. A multi-objective optimization approach that takes into account the preferences of users/inhabitants is developed to provide a compromise between the price paid for the electricity and temperature comfort. The authors plan to apply the proposed model to a residential house's real-time control system. The model will be tuned, its predictions will be tested, and it will be used for energy demand optimization.Článekpeer-reviewedpublished version Otevřený přístup Development of image procesing system for person detection(MM spektrum, 2020) Štursa, Dominik; Honc, Daniel; Doležel, PetrWith the rise of modern technology in computer science and engineering, as well as with the growing population in big cities around the world, many new approaches for person detection have become a very interesting and demanding topic. Person detection is a necessary building block for people monitoring systems and, therefore, various detection methods must be inspected comprehensively in order to select the one with the most suitable performance and accuracy. In this paper, a set of different image processing techniques applied to images captured from a high angle were used for people detection. To be more specific, selected feature extraction techniques, like edge detectors, local binary patterns, pixel intensities or histograms of oriented gradients, were used in combination with several classification algorithms. The combinations of each feature extractor and its best classifier were selected for performance comparison. As a result of the comparison, the most suitable image processing method for person detection in high angle image is presented at the end of the paper.Článekpeer-reviewedpostprint (accepted version) Otevřený přístup Calorimetric examination of suitability of calcium, cobalt and nickel nitrate hydrates for thermal energy storage(Springer, 2020) Honcová, Pavla; Sádovská, Galina; Binder, Lukáš; Košťál, Petr; Honc, DanielSelected nitrate hydrates were characterized using X-ray diffraction, helium pycnometer, Calvet-type calorimeter and simultaneous thermogravimetry coupled with differential scanning calorimeter. Melting and crystallization of all studied nitrate hydrates were observed by differential scanning calorimeter, and the supercooling (difference between melting temperature and crystallization temperature) was found to be more than 80, 14 and 37 degrees C for calcium nitrate tetrahydrate, cobalt and nickel nitrate hexahydrates, respectively. Those salts were mixed with selected nucleating agents to suppress supercooling and then tested under repeating of heating-cooling cycles. Calcium nitrate tetrahydrate showed reversible liquid-solid process with addition of CaO, Ca(OH)(2), BaO, Ba(OH)(2)center dot 8H(2)O, graphite and graphene, but the supercooling remains too high, and the enthalpy change significantly decreased. In the case of cobalt nitrate hexahydrate, the CaO, Ba(OH)(2)center dot 8H(2)O and graphite are the most effective nucleating agent in amount of 1 mass%. The supercooling of nickel nitrate hexahydrate was effectively reduced by addition of CaO, Sr(OH)(2) and graphite. The cobalt and nickel nitrates were tested with combination of two nucleating agents (1:1). The best results were obtained for composites with addition of 1 mass% of nucleating agent mixture consisting of both graphite and Ba(OH)(2)center dot 8H(2)O for cobalt nitrate hexahydrate, and CaO with Mg(OH)(2) for nickel nitrate hexahydrate.Článekpeer-reviewedpostprint Otevřený přístup Desired Terminal State Concept in Model Predictive Control: A Case Study(Hindawi limited, 2019) Dušek, František; Honc, DanielThe paper deals with an online optimization control method for dynamical processes called Model Predictive Control (MPC). It is a popular control method in industry and frequently treated in academic areas as well. The standard predictive controllers usually do not guarantee stability especially for the case of short horizons and large control error penalization. Terminal state is one way to ensure stability or at least increase the controller robustness. In the paper, deviation of the predicted terminal state from the desired terminal state is considered as one term of the cost function. Effect of the stability and control quality is demonstrated in the simulated experiments. The application area for online optimization methods is very broad including various logistics and transport problems. If the dynamics of the controlled processes cannot be neglected, the optimization problem must be solved not only for steady state but also for transient behaviour, e.g., by MPC.Článekpeer-reviewedpostprint Otevřený přístup Reduced order modelling and predictive control of multivariable nonlinear process(Indian Academy of Sciences, 2018) Abraham, Anuj; Pappa, N.; Honc, Daniel; Sharma, RahulIn this paper, an efficient model-predictive control strategy that can be applied to complex multivariable process is presented. A reduced order generalized predictive algorithm is proposed for online applications with reduction in complexity and time elapsed. The complex multivariable process considered in this work is a binary distillation column. The reduced order model is developed with a recently proposed hybrid algorithm known as Clustering Dominant Pole Algorithm and is able to compute the full set of dominant poles and their cluster centre efficiently. The controller calculates the optimal control action based on the future reference signals, current state and constraints on manipulated and controlled variables for a high-order dynamic simulated model of nonlinear multivariable binary distillation column process. The predictive control algorithm uses controlled auto-regressive integrated moving average model. The performance of constraint generalized predictive control scheme is found to be superior to that of the conventional PID controller in terms of overshoot, settling time and performance indices, mainly ISE, IAE and MSE.Článekpeer-reviewedpostprint Otevřený přístup Suppressing supercooling in magnesium nitrate hexahydrate and evaluating corrosion of aluminium alloy container for latent heat storage application(Springer, 2017) Honcová, Pavla; Pilař, Radim; Danielik, Vladimir; Soska, Peter; Sádovská, Galina; Honc, DanielThe repeating of heating/cooling cycle (75 times) simulating the heat energy storage in magnesium nitrate hexahydrate confirmed supercooling of 27 K, and thus many non-isostructural nucleating agents were tested in concentration of 1 mass% in four charge/discharge cycles. From the whole group, four promising nucleating salts were subjected to detailed study with addition of 0.5, 1, and 2 mass% of nucleating salt. The results show that the addition of Mg(OH)(2), BaO, MgO and Sr(OH)2 suppressed supercooling below 5 K during 50 melting/crystallization cycles. At the similar conditions (temperature range and repeating of heating and cooling), MNH and MNH with 0.5 mass% Mg(OH)(2) or Sr(OH)2 underwent corrosion tests in aluminium alloy tubes to discover applicability of this material for the containers or capsules for heat storage. The long-term contact (> 49 days) of aluminium alloy with melted heat storage material for 664 h provided information about suitability of alloy for storing of magnesium nitrate hexahydrate with nucleating agent.Článekpeer-reviewedpostprint Otevřený přístup Calorimetric study of calcium nitrate tetrahydrate and magnesium nitrate hexahydrate(Springer, 2016) Sádovská, Galina; Honcová, Pavla; Pilař, Radim; Oravova, Lucie; Honc, DanielThe heat capacity of calcium nitrate tetrahydrate, and magnesium nitrate hexahydrate were determined from 234.15 K to melting temperature with point of view of energy storage. Determined values were used for the calculation of entropy and Gibbs energy in the experimental temperature range. Melting point and enthalpy of fusion was determined for both substances. Moreover, the kinetics of solid-solid phase transformation for magnesium salt was studied under non-isothermal conditions by DSC and the process was described using autocatalytical model.Článekpeer-reviewedpostprint Otevřený přístup Kinetic study of dehydration of calcium oxalate trihydrate(Springer, 2016) Honcová, Pavla; Svoboda, Roman; Pilný, Petr; Sádovská, Galina; Barták, Jaroslav; Beneš, Ludvík; Honc, DanielThe dehydration of calcium oxalate trihydrate was studied using DSC method and open sample crucibles. The dehydration proceeds in two steps where first two molecules of water are released around 80 degrees of Celsius and consequently the last molecule of water is released at a temperature around 130 degrees of Celsius. The kinetic analysis of overlapping peaks was performed, and the apparent activation energy, pre-exponential factor, and kinetic exponents of kinetic model (reaction order model) were evaluated for both effects.Článekpeer-reviewedpostprint Omezený přístup Dynamic Behaviour of Differentially Steered Mobile Robot(2015) Dušek František; Honc Daniel; Sharma RahulThis article is aimed at obtaining a description of the behaviour of an ideal differentially steered drive system (mobile robot) and planar motion. The mathematical dynamic model describing the motion (speed and direction) of one robot’s point is created based on the first principles approach. The trajectory of this point is converted to trajectories of wheel contact points with the plane of motion. The dynamic behavior of motors and chassis, form of coupling between motors and wheels and basic geometric dimensions are taken into account. The resulting trajectory depends on the supply voltage of both drive motors. The dynamic model will be used for design and verification of a robot’s motion control in MATLAB / SIMULINK simulation environment.
