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Autonomous vehicles lane detection using particle filters
Věchet, Stanislav; Krejsa, Jiří; Chen, K.S.
2022 - anglický
Lane detection belongs among many others crucial tasks which an autonomous vehicles traveling in urban roads need to take care of. We present a lane detection method which uses particle filters combined with visual information from onboard camera to control the vehicles direction. Our initial experiments shows promising results as applied and tested in urban roads with focus on real-time data processing. Klíčová slova: mobile robot; signal processing; measurement Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Autonomous vehicles lane detection using particle filters

Lane detection belongs among many others crucial tasks which an autonomous vehicles traveling in urban roads need to take care of. We present a lane detection method which uses particle filters ...

Věchet, Stanislav; Krejsa, Jiří; Chen, K.S.
Ústav termomechaniky, 2022

Mobile Robot in the Elevator: What Floor Am i On?
Krejsa, Jiří; Věchet, Stanislav; Chen, K.S.; Havelka, M.; Černil, M.
2022 - anglický
Wheeled mobile robots in multiple stories buildings have to use elevator to access arbitrary floor of the building. To do so, the control system must be able to detect and access elevator controls and also determine on which floor the elevator stopped. The paper deals with the latter problem, using the fusion of relative floor change detected by onboard accelerometer and absolute floor number detected by the processing of elevator information screen panel image acquired by onboard camera. Bayesian filter is used for data fusion and convolution neural network for image processing. Field tests resulted in 97% correct detection. Klíčová slova: mobile robot; elevator floor determination; Bayesian filtering Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Mobile Robot in the Elevator: What Floor Am i On?

Wheeled mobile robots in multiple stories buildings have to use elevator to access arbitrary floor of the building. To do so, the control system must be able to detect and access elevator controls and ...

Krejsa, Jiří; Věchet, Stanislav; Chen, K.S.; Havelka, M.; Černil, M.
Ústav termomechaniky, 2022

Stress state rock mass monitoring ahead of longwall No. II/501/C, Mine Staszic-Wujek, PGG, Poland -Project RFCS DD-MET
Waclawik, Petr; Kukutsch, Radovan; Staš, Lubomír; Souček, Kamil; Vavro, Leona; Vavro, Martin; Kubina, Lukáš; Schuchová, Kristýna
2022 - anglický
For designing precisely the reinforcement of mine gate and reinforcing underground structures in general, knowing stress and deformation states in the rock massive in the immediate vicinity of these mine works as precisely as possible is absolutely decisive. In order to verify the rock mass stress state and its changes induced by longwall mining, the monitoring of rock mass stress changing in connection with the mine out of the coal seam No. 501, longwall face No. II/501/C in the Mine Staszic-Wujek, Poland, was suggested. The aim of the contractual research was the realisation and interpretation of the rock stress state monitoring using the CCBO (Compact Conical ended Borehole Overcoring method) and CCBM (Compact Conical ended Borehole Monitoring method) probes in the forefield of mentioned longwall face within geotechnical station. To verify stress monitoring, the survey of the state of the longwall gate was carried out using a pulse 3D scanner. The purpose was to capture deformation changes ahead of the advancing longwall face, specifically, at five stages in the ± 20 m section on each side from the installed geotechnical station. Klíčová slova: pre-mining stress; induced stress; 3D laser scanning Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Stress state rock mass monitoring ahead of longwall No. II/501/C, Mine Staszic-Wujek, PGG, Poland -Project RFCS DD-MET

For designing precisely the reinforcement of mine gate and reinforcing underground structures in general, knowing stress and deformation states in the rock massive in the immediate vicinity of these ...

Waclawik, Petr; Kukutsch, Radovan; Staš, Lubomír; Souček, Kamil; Vavro, Leona; Vavro, Martin; Kubina, Lukáš; Schuchová, Kristýna
Ústav geoniky, 2022

XXIV Czech-Polish seminar: Structural and ferroelectric phase transitions: Book of abstracts and program
Pokorný, Jan; Bubnov, Alexej; Janovská, Marie
2022 - anglický
This is the Book of Abstracts for the XXIV Czech-Polish Seminar (CPSEM-2022 conference) held in Harrachov (Czech Republic) on May 23 - 27, 2022. The special objective of the conference is expressed in the conference subtitle: Structural and Ferroelectric Phase Transitions. The continuous worldwide interest to this conference series is proving that it has a respected position within the series of International/European conferences covering all interdisciplinary field of the research related to structural and ferroelectric phase transitions. At the CPSEM-2022 conference there were about 100 participants from 10 countries delivered 8 tutorial lectures for early stage researchers, 8 invited lectures and selected 34 oral contributions. More than 55 posters were presented during two poster sessions. Klíčová slova: Czech-Polish seminar; structural and ferroelectric phase transition Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
XXIV Czech-Polish seminar: Structural and ferroelectric phase transitions: Book of abstracts and program

This is the Book of Abstracts for the XXIV Czech-Polish Seminar (CPSEM-2022 conference) held in Harrachov (Czech Republic) on May 23 - 27, 2022. The special objective of the conference is expressed in ...

Pokorný, Jan; Bubnov, Alexej; Janovská, Marie
Fyzikální ústav, 2022

Vibration mode shape extraction of bladed disk
Mekhalfia, Mohammed Lamine; Procházka, Pavel; Tchawou Tchuisseu, Eder Batista; Maturkanič, Dušan; Hodboď, Robert
2022 - anglický
This research paper deals with the experimental protocol followed to visualize the vibration mode shape of an aero-engine bladed disk. This study is based on a comparison between the numerical results obtained through Finite element methods (FEM) using ANSYS software and experimentally using the laser Doppler vibrometer. Therefore the bladed disk was transformed into a 3D virtual environment and structural analysis was performed. The results demonstrate a match between the numerical and the experimental one, this match offers the possibility for using the model for future studies. Klíčová slova: blade disk; mode shapes; laser doppler vibrometer Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Vibration mode shape extraction of bladed disk

This research paper deals with the experimental protocol followed to visualize the vibration mode shape of an aero-engine bladed disk. This study is based on a comparison between the numerical results ...

Mekhalfia, Mohammed Lamine; Procházka, Pavel; Tchawou Tchuisseu, Eder Batista; Maturkanič, Dušan; Hodboď, Robert
Ústav termomechaniky, 2022

Approaches to dynamical analysis of rotors with parameters of uncertain magnitudes
Zapoměl, Jaroslav; Kozánek, Jan; Košina, Jan; Cibulka, Jan
2022 - anglický
In many cases, the rotor configuration or loading characteristics are described by parameters of uncertain magnitude. Several procedures were developed to analyse such systems. This paper deals with the approach based on application of the fuzzy numbers. The investigated mechanical system is a rotor supported by hydrodynamic bearings. The parameters of its loading have uncertain values. Klíčová slova: rotors; uncertain parameters; fuzzy numbers approach Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Approaches to dynamical analysis of rotors with parameters of uncertain magnitudes

In many cases, the rotor configuration or loading characteristics are described by parameters of uncertain magnitude. Several procedures were developed to analyse such systems. This paper deals with ...

Zapoměl, Jaroslav; Kozánek, Jan; Košina, Jan; Cibulka, Jan
Ústav termomechaniky, 2022

Turbine blade linkages in reduced modal synthesis model
Pešek, Luděk; Šnábl, Pavel
2022 - anglický
The paper is the first stage of our modelling turbine blade linkages in reduced modal synthesis model. The modal synthesis method is used for the dynamic behaviour studies of turbine bladed wheels with frictional inter-blade linkages and in case of the microslips the stiffening effect of the linkages play an important role in wheel dynamics. The paper presents the first results of modal analysis of the wheel when springs were used to substitute the linkages in the modal synthesis model. Klíčová slova: bladed wheel; reduced model; tie-boss; shroud; stiffening Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Turbine blade linkages in reduced modal synthesis model

The paper is the first stage of our modelling turbine blade linkages in reduced modal synthesis model. The modal synthesis method is used for the dynamic behaviour studies of turbine bladed wheels ...

Pešek, Luděk; Šnábl, Pavel
Ústav termomechaniky, 2022

TM03000027-V6: ESC 3 - Posouzení vlivu na přesnost navigačních systémů GNSS - Evaluation of factors influencing the GNSS positioning accuracy
Urbář, Jaroslav; Suchánek, P.; Chum, Jaroslav
2022 - anglický
Technická zpráva o vlivu na přesnost navigačních systémů GNSS. Získaná data k ověření vlivu na přesnost navigačních systémů GNSS při výskytu MSTID v ionosféře. \n\nTechnical report analyzing the effect of MSTIDs on an accuracy of GNSS based positioning. The analysis should be performed based on experimentally obtained data.\n Klíčová slova: medium-scale traveling ionospheric disturbances (MSTIDs); Global Navigation Satellite System (GNSS); GADIOD; GNSS Plné texty jsou dostupné na vyžádání prostřednictvím repozitáře Akademie věd.
TM03000027-V6: ESC 3 - Posouzení vlivu na přesnost navigačních systémů GNSS - Evaluation of factors influencing the GNSS positioning accuracy

Technická zpráva o vlivu na přesnost navigačních systémů GNSS. Získaná data k ověření vlivu na přesnost navigačních systémů GNSS při výskytu MSTID v ionosféře. \n\nTechnical report analyzing the ...

Urbář, Jaroslav; Suchánek, P.; Chum, Jaroslav
Ústav fyziky atmosféry, 2022

Annular impinging jets and an active control of hysteretic effects
Devani, Yogendrasasidhar; Antošová, Zuzana; Trávníček, Zdeněk
2022 - anglický
An annular air jet with and without flow control was studied experimentally using flow visualization and measurements of the wall pressure and flow velocity by the Pitot and Prandtl probes and the hot-wire anemometer. To investigate flow control swirling effects, eight synthetic jets were generated from the annular nozzle center body.The experiments cover Reynolds numbers 4000–10000 (evaluated from the outer exit diameter of the annular nozzle). For Re<9000, the bistability and hysteresis were identified and two different flow field patterns (A and B) were found under the same boundary conditions. For A pattern, a small recirculation area (bubble) of separated flow is attached to the nozzle center body. For B pattern, a large recirculation area of separated flow bridges entire nozzle-to-wall distance. For higher Re > 9000, the bistability and hysteresis were not found.Flow control swirling effects causes suppression of the hysteresis. Moreover, weak flow control causes that the entire annular jet is forced into a precessing motion. Klíčová slova: annular jet; impinging jet; bistability; hysteresis Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Annular impinging jets and an active control of hysteretic effects

An annular air jet with and without flow control was studied experimentally using flow visualization and measurements of the wall pressure and flow velocity by the Pitot and Prandtl probes and the ...

Devani, Yogendrasasidhar; Antošová, Zuzana; Trávníček, Zdeněk
Ústav termomechaniky, 2022

Aeroacoustic Noise Source Investigation in the Case of the Blade Cascade
Procházka, Pavel P.; Antoš, Pavel; Šnábl, Pavel
2022 - anglický
The blade cascade consisted of five NACA 0010 profiles is examined in the framework of project dealing with nonlinear dynamic phenomenon related to stall flutter of flexible profiles with pitch degree of freedom in subsonic flow. Various angles of attack (AoA) of the cascade generates different (broadband) aeroacoustic noise. The goal of this article is to describe the existence of possible noise sources using two experimental methods – Particle Image velocimetry (PIV) and hot-wire (HW) anemometry. Klíčová slova: blade cascade; time-resolved PIV; HW anemometry; FFT Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Aeroacoustic Noise Source Investigation in the Case of the Blade Cascade

The blade cascade consisted of five NACA 0010 profiles is examined in the framework of project dealing with nonlinear dynamic phenomenon related to stall flutter of flexible profiles with pitch ...

Procházka, Pavel P.; Antoš, Pavel; Šnábl, Pavel
Ústav termomechaniky, 2022

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