Publikace

informace pocházejí z univerzitní databáze V3S

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Ing. Stanislav Kušmírek, Ph.D.; doc. Ing. Bc. Vladimír Socha, Ph.D.; Ing. Tomáš Malich; doc. Ing. Luboš Socha, Ph.D. et Ph.D.; Ing. Karel Hylmar; Ing. Lenka Hanáková, Ph.D.
Publikováno:
2024, IEEE Access, 12, p. 109806-109821), ISSN 2169-3536
Anotace:
The increasing diversity of multirotor unmanned aerial vehicles (UAV) designs poses significant challenges in evaluating their flight characteristics and performance parameters. This is particularly true for commercially available UAVs whose control units do not provide users with data that could be used, for example, to estimate the operational and flight limits of the flight device itself. This study introduces the concept of a mountable device designed to track and assess the flight parameters of quadcopters, independent of the UAV's systems. Specifically, it involves independent monitoring of rotations, flight speed, air pressure, temperature, and drone orientation in space. The device validation involved real flight tests with the IRIS+ quadcopter using the Pixhawk control system, whose data were taken as a benchmark for validation. To demonstrate the applicability and benefits of such a device, the study also created a concept of an operational envelope for the drone, i.e. dependence of thrust on weight, angle of attack and speed. This concept was created using robotic simulation in the Gazebo environment. In the simulations, the IRIS+ device was used to simulate flights with different payload weights (0.9-2.9 lb, approximately 0.4-1.3 kg) and twenty flight speeds (1-20 ms-1), while simultaneously monitoring the angle of attack and motor revolutions (subsequently converted to thrust). The created operational envelope was subsequently validated using data from real flights. The overall results demonstrated the successful validation of the designed device and the accuracy of the measurement of critical flight parameters, with rotation measurement errors ranging between 100-200 RPM, angle of attack error at 4.25°, and altitude measurement error based on pressure at 0.56 m. Additionally, within this concept, the measurement of indicated airspeed was introduced, reflecting the expected flight speed values. In the context of validating the operational envelope, the results showed that the parameters of real flights fell within the predicted area of the created operational envelope for the IRIS+ drone. Independent monitoring devices like this can benefit operational limit determination and other testing purposes, especially for UAVs lacking data-sharing control units.
DOI:
Typ:
Článek v periodiku excerpovaném SCI Expanded

Autoři:
Ing. Karel Hylmar; Ing. Daniel Urban; doc. Ing. Bc. Vladimír Socha, Ph.D.
Publikováno:
2024, New Trends in Civil Aviation: Proceedings of the 24th International Conference on New Trends in Civil Aviation 2024, Praha, České vysoké učení technické v Praze), p. 247-251), ISBN 978-80-01-07181-6, ISSN 2694-7854
Anotace:
The propulsion systems of unmanned aircraft such as multicopters are very vulnerable to any kind of damage. Thus, the presented study introduces the possibility of using vibration sensing to determine the condition of the rotating propeller to detect possible damage or contamination. For the purpose of this study, a test stand was designed and a total of 3 different propeller damages were tested. These included minor and major damage to the tip of the propeller blade as well as disruption of the leading edge profile geometry. Propeller vibration was captured within the operating range of propeller (from 3 500 to 6000 RPM) in the axial X-axis and radial Y-axis. The measured data were processed by spectral analysis, i.e., by calculating the amplitude spectrum using a Fourier Transform. The outputs in the form of spectograms for each damage type and individual RPM were further processed by Principal Component Analysis (PCA). From the PCA, it was possible to identify the vibration frequency spectrum of the tested propeller and the individual damaged states.
DOI:
Typ:
Stať ve sborníku z prestižní konf.

Autoři:
Ing. Karel Hylmar; Bc. Karolína Šobrová; doc. Ing. Bc. Vladimír Socha, Ph.D.; Ing. Lenka Hanáková, Ph.D.; Umer Asgher, MSc., Ph.D.
Publikováno:
2024, Transportation Research Procedia, Amsterdam, Elsevier B.V.), p. 278-284), ISSN 2352-1465
Anotace:
Vertical take-off and landing unmanned aerial vehicles (VTOL UAVs) are becoming increasingly important in the modern aviation industry. With their growing use, it is essential to find solutions to newly emerging technical problems related to ensuring operational safety. One of these unresolved issues is the accumulation of ice on propeller blades during flight in adverse meteorological conditions. For VTOL UAVs, the propeller blades are the only lifting surfaces, and any disruption of their geometry by an ice layer can lead to the crash of the entire aircraft. A promising solution to this problem, currently being explored experimentally, is the use of hydrophobic coatings, which successfully delay or completely prevent the accumulation of ice. However, hydrophobic coatings currently lack sufficient durability and have a low ability to withstand normal operational wear and tear, causing them to lose their hydrophobic properties quickly. The primary goal of this work is to propose a concept and testing methodology that would allow propeller blades treated with hydrophobic coatings to be exposed to conditions as close as possible to operational wear and tear.
DOI:
Typ:
Stať ve sborníku z mezinár. konf.

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Publikováno:
2024, New Trends in Civil Aviation: Proceedings of the 24th International Conference on New Trends in Civil Aviation 2024, Praha, České vysoké učení technické v Praze), p. 147-152), ISBN 978-80-01-07181-6, ISSN 2694-7854
Anotace:
This study focuses on the influence of specific sound frequencies on pilot psychophysiological condition within a simulated cockpit environment. Conducted using a flight simulator, the study involved fifteen male pilots with an average of 175 flight hours. The experiment consisted of three key phases: a hearing test, a familiarization flight, and the experimental flight where specific sounds within the 498 Hz to 4000 Hz range were played at 64 dB. These sounds, typical of cockpit noise, were integrated into flight scenario to assess their physiological impact on pilots, monitored via electrocardiograms and focused on heart rate variability, respectively. Also, subjective data were collected using questionnaire. The results suggest, that the specific noise can negatively affect pilots' psychophysiological conditions, increase perceived workload and decrease comfort.
DOI:
Typ:
Stať ve sborníku z prestižní konf.

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Publikováno:
2024, New Trends in Civil Aviation: Proceedings of the 24th International Conference on New Trends in Civil Aviation 2024, Praha, České vysoké učení technické v Praze), p. 253-259), ISBN 978-80-01-07181-6, ISSN 2694-7854
Anotace:
The subject of this paper is validating the applicability of a wind wall as opposed to a wind tunnel in testing the performance parameters of a propeller propulsion unit. The primary focus is on unmanned aircraft, a sector experiencing continuous growth and integration into everyday life. This is closely tied to the development of new technologies, particularly in propulsion units, aiming for maximal efficiency and the associated reduction in energy consumption. However, current testing methods for these propulsion units are both costly and time-consuming. Additionally, when utilizing wind tunnels, constraints in terms of space availability pose further challenges. Consequently, verifying the performance parameters of propeller units becomes exceedingly difficult, if not impossible, for many manufacturers and institutions. The implementation of a wind wall would offer an affordable testing alternative, concurrently addressing space constraints when compared to a wind tunnel. This would facilitate further advancements in the realm of unmanned aircraft propulsion. In the presented study, two selected propellers were tested in flow created by wind wall. The acquired data were analysed and subsequently compared with relevant studies focusing on wind tunnel testing. The study's results indicate that the wind wall yields satisfactory results compared to the wind tunnel, suggesting its viability for use, at least in the initial stages of propeller propulsion unit development.
DOI:
Typ:
Stať ve sborníku z prestižní konf.

Autoři:
Ing. Daniel Urban; doc. Ing. Bc. Vladimír Socha, Ph.D.; Ing. Lenka Hanáková, Ph.D.; Ing. Karel Hylmar; Ing. Stanislav Kušmírek, Ph.D.
Publikováno:
2023, 2023 New Trends in Aviation Development (NTAD), Praha, IEEE Czechoslovakia Section), p. 262-269), ISBN 979-8-3503-7042-3, ISSN 2836-2756
Anotace:
Spatial orientation is very important during flight for the pilot and his ability to correctly perform several parallel tasks related to piloting, navigation and communication. In the event that the pilot loses his own spatial orientation, he must rely solely on the on-board instruments, increasing his workload and the likelihood that the pilot will make a mistake. Further, flight illusions are associated with the loss of spatial orientation and may cause the pilot to perceive inconsistent information about his or her position. Despite the fact that loss of spatial orientation may be commonly encountered by civilian pilots, they are not prepared for these situations as part of their practical training. Although full-flight simulators adapted to induce illusions can be utilized in this context, they are expensive and essentially unused in the training of civilian pilots. This has led to the proposal of a potentially usable and cost-effective technical solution that could be employed in inducing certain types of illusions. Therefore, the article specifically deals with the design of a rotary chair suitable for inducing vestibular nystagmus and the validation of this solution, along with an introduction to the practicality of this solution in the aviation training and research environment.
DOI:
Typ:
Stať ve sborníku z prestižní konf. (Scopus)

Autoři:
Ing. Daniel Urban; Ing. Stanislav Kušmírek, Ph.D.; doc. Ing. Bc. Vladimír Socha, Ph.D.; Ing. Lenka Hanáková, Ph.D.; Ing. Karel Hylmar; doc. Ing. Jakub Kraus, Ph.D.
Publikováno:
2023, Applied Sciences, 13 (5), ISSN 2076-3417
Anotace:
With the expanding electrification in all sectors of transport, it is necessary to look for new efficient solutions for propulsion systems for use in air transport. One of the approaches can be the use of electric ducted fans (EDFs), especially in, but not limited to, the case of unmanned aerial vehicles with vertical takeoff and landing. This concept has been known for several decades but has been used very little and therefore has been almost unexplored. This opens up opportunities for investigating the performance characteristics, electrical consumption or efficient thrust vectoring of EDFs with respect to their design and operational use. The presented study therefore deals with the influence of the EDF design change on its performance characteristics. These design changes mainly concerned the geometry of the cowling, i.e., reduction and increase of outlet cross section, and arrangement of fans, i.e., one- and two-rotor specification. The comparison was based on measuring of vertical thrust and power consumption during static testing. The results showed that the increasing outlet is the most suitable construction for the generation of vertical thrust during static testing, considering the specifically used EDF construction arrangement. Based on the findings, it can also be concluded that EDFs are a suitable option for use in unmanned aircraft as a competition to other propulsion systems.
DOI:
Typ:
Článek v periodiku excerpovaném SCI Expanded

Autoři:
Ing. Daniel Urban; Ing. Karel Hylmar; Ing. Stanislav Kušmírek, Ph.D.; Ing. Lenka Hanáková, Ph.D.; doc. Ing. Bc. Vladimír Socha, Ph.D.
Publikováno:
2023, 2023 International Conference on Military Technologies (ICMT), Vienna, IEEE Industrial Electronic Society), ISBN 979-8-3503-2568-3
Anotace:
The subject of this research is the development of ducted propulsion systems as replacements for traditional propeller propulsion systems intended for unmanned aircraft (UA). With the increasing number of operating UA and level of their automation, new possibilities for using UA in a number of applications are emerging. According to current legislation, one of the main limitations of the use of UA to date is the insufficient safety of UA operations over populated areas. Current UA equipped with propeller drive units do not achieve the required safety due to the rotating propeller blades. Ducted propulsion systems eliminate this shortcoming and provide other advantages that find their place mainly in conditions with space limitations. It is therefore necessary to find an optimal solution to these urban traffic problems. It is thus offered as a safety solution when operating in shared spaces near non-involved persons. The proposed specifications in this study are tested and the data subsequently compared with selected reference propeller drives from the point of view of energy consumption and generated thrust value. The aim of this study is to propose an optimal operational specification of the EDPS engine, suitable for UA operation from the point of view of better energy consumption and generated thrust compared to propellant systems. The results of the study prove that EDPS propulsion systems generate more thrust with lower total energy consumption than conventional propeller systems.
DOI:
Typ:
Stať ve sborníku z prestižní konf. (Scopus)

Autoři:
Ing. Karel Hylmar; doc. Ing. Bc. Vladimír Socha, Ph.D.; Ing. Stanislav Kušmírek, Ph.D.; Ing. Lenka Hanáková, Ph.D.; Ing. Daniel Urban; Ing. Miroslav Špák, Ph.D.
Publikováno:
2022, 2022 New Trends in Civil Aviation (NTCA), Praha, České vysoké učení technické v Praze), p. 115-122), ISBN 978-1-6654-5190-1
Anotace:
Vertical Take-off and Landing Unmanned Aerial Vehicles (VTOL UAVs) are operated at low flight levels, close to the ground, where they are exposed to meteorological conditions, which are difficult to predict and can cause severe degradation of their aerodynamic, performance and flight characteristics. Of these meteorological conditions, icing is one of the most dangerous for the operation of VTOL UAVs. Although icing poses significant safety and operational risks, it has not yet been taken into account in their operation and there are no certified and verified anti-icing and de-icing solutions against it. The aim of this work is to propose a concept together with testing methodology, which would allow to determine the influence of individual meteorological conditions of icing on selected performance characteristics of propulsion systems of VTOLUAVs. Testing and exposure of propulsion systems to icing conditions took place in the climatic chamber. Several series of measurements were performed in the climatic chamber, in which the propulsion systems were exposed to a temperature of 15, of −5, of −10 and of −15°C and a flow of super-cooled water droplets of 1.43 g/s. The mutual comparison of the performed measurements made it possible to determine the influence of individual conditions on the decrease of the thrust, the increase of the consumed electric current and the occurrence of vibrations.
DOI:
Typ:
Stať ve sborníku z prestižní konf.

Autoři:
Ing. Stanislav Kušmírek, Ph.D.; Ing. Tomáš Malich; doc. Ing. Bc. Vladimír Socha, Ph.D.; Ing. Lenka Hanáková, Ph.D.; Gavura, T.; Ing. Roman Matyáš, Ph.D.; Ing. Karel Hylmar
Publikováno:
2021, 2021 International Conference on Military Technologies (ICMT), Praha, IEEE Czechoslovakia Section), ISBN 978-1-6654-3724-0
Anotace:
New requirements for classifying unmanned aerial vehicles are forcing institutions as well as manufacturers to devise established procedures and methodologies for testing vehicles. A new possibility of dynamic testing of performance parameters of multicopters is offered in addition to conventional software modeling of flight characteristics and static tests in wind tunnels. This alternative is currently hampered by the problem of flight data collection. This work deals with the design of a complex measuring device specially designed for the testing of the flight characteristics of unmanned aerial vehicles. The proposed modular device provides the user with a flight record containing time-synchronized data showing the linear and angular accelerations achieved by the vehicle during flight, three-axis roll, flight altitude, magnetic course, multicopter speeds, and revolutions of each power unit separately. This work further defines the conditions imposed on the type of tested multicopter (load capacity) and the subsequent need for its balancing. The output of this work is to support the experimental research of dynamic quantification of multicopter performance properties during flight.
DOI:
Typ:
Stať ve sborníku z prestižní konf. (Scopus)

Autoři:
Ing. Stanislav Kušmírek, Ph.D.; doc. Ing. Bc. Vladimír Socha, Ph.D.; Ing. Lenka Hanáková, Ph.D.; Ing. Karel Hylmar; Ing. Roman Matyáš, Ph.D.; Kubový, P.
Publikováno:
2020, 2020 New Trends in Civil Aviation, Praha, IEEE Czechoslovakia Section), p. 129-133), ISBN 978-80-01-06726-0, ISSN 2694-7854
Anotace:
In recent years, drones have experienced rapid technological development. The new EU regulations, therefore, apply to both users as well as manufacturers of unmanned aerial vehicles. The mentioned legislation does not yet precisely define the testing methodology and methods of required parameters of each individual category of unmanned aerial vehicles. This study pays special attention to the possibility of dynamic indoor testing of multicopters. It raises the research question of the possibility of experimental determination of the pitch angle as a partial characterisation of a vehicle in flight with manual control of a multicopter against continuous airflow. A simplified wind tunnel generated the airflow with a lamella regulator. Three 10 minute experimental flights were performed against an airflow rate of 1.45 / 2.43 / 3.42 m/s. The task of an experienced pilot was to keep the multicopter in the middle of the airflow during hover manoeuvre. The flight data of the multicopter were recorded by an inertial motion capture (MoCap) system Inertia ProMove in the form of a quaternion and linear accelerations. The results of the study do not show an increase in the median value of the pitch angle of the quadcopter when manually maintaining the hover against the airflow rate in the wind tunnels. On the contrary, as expected, the correlation of the pitch quadcopter and forward linear acceleration was demonstrated. This pilot study presents a possible methodology for indoor testing of a partial aspect of the flight characteristics while drawing attention to the problem of such dynamic testing.
DOI:
Typ:
Stať ve sborníku z prestižní konf. (Scopus)