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41	Systém pro haptickou odezvu a jeho spolehlivost / Haptic Feedback System and its Reliability Horpatzká, Michaela January 2019 (has links) This master thesis covers conceptual design of haptic feedback system and safety and reliability assessment. System is developed for aircraft categories UL2, EASA CS-LSA, EASA CS-VLA and EASA-CS-23. Conceptual design is divided into three parts. First is aimed on haptic system test with simulator. Second is conceptual design of haptic system for in-flight test. Third part contains safety and reliability assessment and summarizes problems of haptic system installation in real aircraft.
42	Neural Network Based Adaptive Control for Nonlinear Dynamic Regimes Shin, Yoonghyun 28 November 2005 (has links) Adaptive control designs using neural networks (NNs) based on dynamic inversion are investigated for aerospace vehicles which are operated at highly nonlinear dynamic regimes. NNs play a key role as the principal element of adaptation to approximately cancel the effect of inversion error, which subsequently improves robustness to parametric uncertainty and unmodeled dynamics in nonlinear regimes. An adaptive control scheme previously named composite model reference adaptive control is further developed so that it can be applied to multi-input multi-output output feedback dynamic inversion. It can have adaptive elements in both the dynamic compensator (linear controller) part and/or in the conventional adaptive controller part, also utilizing state estimation information for NN adaptation. This methodology has more flexibility and thus hopefully greater potential than conventional adaptive designs for adaptive flight control in highly nonlinear flight regimes. The stability of the control system is proved through Lyapunov theorems, and validated with simulations. The control designs in this thesis also include the use of pseudo-control hedging techniques which are introduced to prevent the NNs from attempting to adapt to various actuation nonlinearities such as actuator position and rate saturations. Control allocation is introduced for the case of redundant control effectors including thrust vectoring nozzles. A thorough comparison study of conventional and NN-based adaptive designs for a system under a limit cycle, wing-rock, is included in this research, and the NN-based adaptive control designs demonstrate their performances for two highly maneuverable aerial vehicles, NASA F-15 ACTIVE and FQM-117B unmanned aerial vehicle (UAV), operated under various nonlinearities and uncertainties. Uncertainties Nonlinear dynamic regimes Fighter aircraft High angle of attack Composite adaptive control Supermaneuverability Adaptive control Neural networks Nonlinear dynamic inversion Adaptive control systems Uncertainty Nonlinear control theory Neural networks (Computer science) Fighter planes Dynamics
43	Design, Modeling, Guidance And Control Of A Vertical Launch Surface To Air Missile Tekin, Raziye 01 September 2010 (has links) (PDF) The recent interests in the necessity of high maneuverability and vertical launching triggered namely the unconventional control design techniques that are effective at high angle of attack flight regimes. For most of missile configurations, this interest required thrust vector control together with conventional aerodynamic control. In this study, nonlinear modeling and dynamical analysis of a surface to air missile with both aerodynamic and thrust vector control is investigated. Aerodynamic force and moment modeling of the presented missile includes the challenging high angle of attack aerodynamics behavior and the so called hybrid control, which utilizes both tail fins and jet vanes as control surfaces. Thrust vector and aerodynamic control effectiveness is examined during flight envelope. Different autopilot designs are accomplished with hybrid control. Midcourse and terminal guidance algorithms are implemented and performed on target sets including maneuverable targets. A different initial turnover strategy is suggested and compared with standard skid-to-turn maneuver. Comparisons of initial roll with aerodynamic and thrust vector control are examined. Afterwards, some critical maneuvers and hybrid control ratio is studied with a real coded genetic algorithm. Rapid turnover for low altitude targets, intercept maneuver analysis with hybrid control ratio and lastly, engagement initiation maneuver optimization is fulfilled. TL Rockets 780-785.8
44	Konstrukce zkušebního zařízení pro testování adheze a hluku v kontaktu kola a kolejnice / Design of test rig for measurement of adhesion and noise in wheel-rail contact Gabriel, Tomáš January 2020 (has links) This master’s thesis is dedicated to the design of an experimental rig that allows investigation of causes for noise during tram’s passing of a track curve and the developement of means to mitigate this noise. The opening section of this thesis contains theoretical background for the tribological mechanics of wheel-rail contact with emphasis on the process of noise generation, followed by an overview of laboratory tst rigs with similar purpose. Design itself is centered around the implementation of the dynamic model of wheel-rail contact using real tram wheel. Resulting test rig allows measurement of the adhesion characteristic in tangential and lateral directions and recording of the generated noise while an angle of attack is set.
45	Stabilizační a autopilotní systém pro RC model letadla / Stability and autopilot system for airplane RC model Čamaj, Peter January 2014 (has links) The master thesis deals with design and realization of stabilizing and autopilot system, which is used in radio controlled model planes. The thesis contains a proposal of hardware platform, which is able to control the plane model based on data measured from a sensor system. Moreover, this thesis describes a software implementation of individual modules, which is measured the onboard values. The basic principles of stabilization and autonomous flight control are also summarized. In conclusion, the system is subjected to flight tests.
46	Predicting the Crosswind Performance of High Bypass Ratio Turbofan Engine Inlets Clark, Adam January 2016 (has links) No description available. Aerospace Engineering CFD jet engine inlet crosswind separation reattachment distortion IDC RANS Euler inviscid loading parameter pressure gradient aerodynamics nacelle angle of attack separation bubble aerodynamic loading pressure coefficient hysteresis
47	Low-Frequency Flow Oscillations on Stalled Wings Exhibiting Cellular Separation Topology Disotell, Kevin James January 2015 (has links) No description available. Aerospace Engineering Fluid Dynamics wing aerodynamics stall cells turbulent separated flows three-dimensional separation large-scale unsteadiness vortical wakes low-frequency flow oscillations time-resolved particle image velocimetry
48	Aerodynamics of the Maple Seed Desenfans, Philip January 2019 (has links) (PDF) Purpose - The paper presents a theoretical framework that describes the aerodynamics of a falling maple (Acer pseudoplatanus) seed. --- Methodology - A semi-empirical method is developed that provides a ratio stating how much longer a seed falls in air compared to freefall. The generated lift is calculated by evaluating the integral of two-dimensional airfoil elements using a preliminary falling speed. This allows for the calculation of the definitive falling speed using Blade Element Momentum Theory (BEMT); hereafter, the fall duration in air and in freefall are obtained. Furthermore, the input-variables of the calculation of lift are transformed to require only the length and width of the maple seed. Lastly, the method is applied to two calculation examples as a means of validation. --- Findings - The two example calculations gave percentual errors of 5.5% and 3.7% for the falling speed when compared to measured values. The averaged result is that a maple seed falls 9.9 times longer in air when released from 20 m; however, this result is highly dependent on geometrical parameters which can be accounted for using the constructed method. --- Research limitations - Firstly, the coefficient of lift is unknown for the shape of a maple seed. Secondly, the approximated transient state is yet to be verified by measurement. --- Originality / Value - The added value of this report lies in the reduction of simplifications compared to BEMT approaches. In this way a large amount of accuracy is achieved due to the inclusion of many geometrical parameters, even though simplicity is maintained. This has been accomplished through constructing a simple three-step method that is fundamental and essentially non-iterative. ddc:620 info:eu-repo/classification/ddc/629.13 Aerodynamik Ahorn Auftrieb Strömungsabriss Aerodynamics Maple Lift (Aerodynamics) Stalling (Aerodynamics) Aerodynamisches Profil Anstellwinkel Freier Fall Bergahorn Samen Evolutionsbiologie Aerofoils Angle of attack (Aerodynamics) Acer pseudoplatanus Seeds Evolution (Biology) Blade Element Momentum Theory BEMT free fall post-stall chord twist camber autorotation
49	Predicting Drag Polars For Micro Air Vehicles Luke, Mark Elden 03 November 2003 (has links) (PDF) Drag polars for three Micro Air Vehicles (MAVs) were measured at Reynolds numbers of 70,000, 50,000, 30,000, and 10,000 and compared to predictions generated using the classical approach. The MAVs tested had different configurations and aspect ratios varying from 1.2 to 1.6 and ratios of wetted surface area to planform area from 2.6 to 3.9. A force balance was used to measure the lift and drag on the MAVs at angles of attack ranging from -5 degrees (or -10 degrees) to 10 degrees. The force balance allowed the MAVs to rotate in the pitching axis. The MAV angle of attack was set using an elevator installed on the MAV and controlled using a standard radio control used by RC plane enthusiasts. Uncertainty analysis performed on the data showed the uncertainty for high Reynolds numbers was dominated by velocity uncertainty, and uncertainty for the lower Reynolds numbers was dominated by uncertainty in the force measurements. Agreement between measured and predicted drag polars was good with the measured drag never being more than two times the predicted drag. For the majority of the tests, the drag coefficients followed the expected Reynolds number trend: increasing with decreasing Reynolds number. Micro Air Vehicle MAV low Reynolds number drag polar predicted vs. measured wind tunnel force balance Cfe equivalent skin friction coefficient e0 oswald efficiency CL minD lift coefficient drag coefficient drag polar prediction angle of attack wetted surface area ratio wing loading aspect ratio parasite drag coefficient drag due to lift aerodynamics Mechanical Engineering
50	Railway curve squeal: Statistical analysis of train speed impact on squeal noise Asplund, Ruben January 2024 (has links) No description available. ml operation maintenance railway maintenance railway curve machine learning statistics railway train passenger train x60 squeal noise curve squeal squealing noise squeal wheel squeal squealing programming system development computer engineering data visualization data preprocessing industrial computer systems matlab python vibration vibrations vibration signals signals and systems filtering signal processing computer systems communication system infrastructure technology infrastructure track t-test z-test random forest xgboost feature importance speed detection band-pass filter script yaw angle angle of attack decision tree gbdt filter temperature humidity dew point curve radius cloud accelerometers sensors track rail statistical analysis acoustics sound ai artificial intelligence gradient boosting decision trees curve software development drift underhåll järnvägsunderhåll järnvägskurva maskininlärning statistik järnväg tåg x60 skrikljud snäva kurvor kurvradie kurvskrik hjulskrik programmering systemutveckling datateknik data industriella datorsystem matlab python vibration signaler vibrations signaler signaler och system filtrering signalbehandling datorsystem kommunikationssystem infrastrukturteknik infrastruktur spår t-test z-test random forest Södertälje band-pass filter hastighets detektion attackvinkeln anfallsvinkel IMx SKF temperatur fuktighet daggpunkt accelerometer järnvägskurvskrik tåg hastighetens statistisk analys akustik ljud ai kurva kurvor mjukvaruutveckling artificiell intelligens Infrastructure Engineering Infrastrukturteknik Signal Processing Signalbehandling Communication Systems Kommunikationssystem Computer Systems Datorsystem

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