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Journal articles on the topic 'Fixed Wing MAVs'
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1
Watkins, A., M. Thompson, M. Shortis, R. Segal, M. Abdulrahim, and J. Sheridan. "An overview of experiments on the dynamic sensitivity of MAVs to turbulence." Aeronautical Journal 114, no. 1158 (August 2010): 485–92. http://dx.doi.org/10.1017/s0001924000003973.
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Abstract Aspects of the turbulent wind environment Micro Air Vehicles (MAVs) experience when flying outdoors were replicated in a large wind tunnel. An overview of the facility, instrumentation and initial flight tests is given. Piloting inputs and aircraft accelerations were recorded on fixed and rotary wing MAVs and for some tests, measurements of the approach flow (u,v,w sampled at 1,250Hz at four laterally disposed upstream locations) were made. The piloting aim was to hold straight and level flight in the 12m wide × 4m high × ~50m long test section, while flying in a range of turbulent conditions. The Cooper-Harper rating system showed that a rotary craft was less sensitive to the effects of turbulence compared to the fixed wing craft and that while the fixed wing aircraft was relatively easy to fly in smooth air, it became extremely difficult to fly under high turbulence conditions. The rotary craft, while more difficult to fly per. se., did not become significantly harder to fly in relatively high turbulence levels. However the rotary craft had a higher mass and MOI than the fixed wing craft and further work is planned to understand the effects of these differences.
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Lin, Jih‐Lung, Chin‐Yi Wei, and Chi‐Yu Lin. "Design and testing of fixed‐wing MAVs." Aircraft Engineering and Aerospace Technology 79, no. 4 (July 10, 2007): 346–51. http://dx.doi.org/10.1108/00022660710758213.
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Aboelezz, Ahmed, Yunes Elqudsi, Mostafa Hassanalian, and Ahmed Desoki. "WIND TUNNEL CALIBRATION, CORRECTIONS AND EXPERIMENTAL VALIDATION FOR FIXED-WING MICRO AIR VEHICLES MEASUREMENTS." Aviation 23, no. 4 (February 17, 2020): 104–13. http://dx.doi.org/10.3846/aviation.2019.11975.
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The increase in the number of Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs), which are used in a variety of applications has led to a surge in low Reynolds number aerodynamics research. Flow around fixedwing MAVs has an unusual behavior due to its low aspect ratio and operates at low Reynolds number, which demanded to upgrade the used wind tunnel for this study. This upgrade enables measuring the small aerodynamics forces and moment of fixed-wing MAVs. The wind tunnel used in this work is upgraded with a state of art data acquisition system to deal with the different sensors signals in the wind tunnel. For accurate measurements, the sting balance, angle sensor, and airspeed sensor are calibrated. For validation purposes, an experiment is made on a low aspect ratio flat plate wing at low Reynolds number, and the measured data are corrected and compared with published results. The procedure presented in this paper for the first time gave a detailed and complete guide for upgrading and calibrating old wind tunnel, all the required corrections to correct the measured data was presented, the turbulence level correction new technique presented in this paper could be used to estimate the flow turbulence effect on the measured data and correct the measured data against published data.
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Trittler, M., T. Rothermel, and W. Fichter. "Visual Servoing Based Landing Approach Controller for Fixed-Wing MAVs." IFAC Proceedings Volumes 46, no. 19 (2013): 200–205. http://dx.doi.org/10.3182/20130902-5-de-2040.00024.
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Trittler, M., W. Fichter, and A. Schöttl. "Return Strategies for Fixed-Wing MAVs After Loss of GPS." IFAC Proceedings Volumes 46, no. 19 (2013): 254–59. http://dx.doi.org/10.3182/20130902-5-de-2040.00083.
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Mohamed, Abdulghani, Kevin Massey, Simon Watkins, and Reece Clothier. "The attitude control of fixed-wing MAVS in turbulent environments." Progress in Aerospace Sciences 66 (April 2014): 37–48. http://dx.doi.org/10.1016/j.paerosci.2013.12.003.
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Hota, Sikha, and Debasish Ghose. "Waypoint-Based Trajectory Planning of Fixed-Wing MAVs in 3D Space." Journal of Intelligent & Robotic Systems 86, no. 1 (October 1, 2016): 95–113. http://dx.doi.org/10.1007/s10846-016-0415-3.
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Goszczyński, Jacek A., Maciej Lasek, Józef Pietrucha, and Krzysztof Sibilski. "ANIMALOPTERS-TOWARDS A NEW DIMENSION OF FLIGHT MECHANICS." TRANSPORT 17, no. 3 (June 30, 2002): 108–16. http://dx.doi.org/10.3846/16483840.2002.10414023.
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Recently, it has been recognised that flapping wing propulsion can be more efficient than conventional propellers if applied to very small-scale vehicles, so-called MAVs (micro air vehicles). Extraordinary possibilities of such objects, particularly in the context of special missions, are discussed. Flapping flight is more complicated than flight with fixed or rotating wings. Therefore, there is a need to understand the mechanisms of force generation by flapping wings in a more comprehensive way. The paper describes the current work on flapping wing conducted by the Flying amp;Swimming Puzzle Group. The key to understand the mechanisms of flapping flight is the adequate physical and mathematical modelling; modelling problems of flow and motion are emphasised. Sample calculations illustrating current capabilities of the method have been performed. The effect of feathering amplitude, flapping amplitude, and phase shifting on the MAV&s control effectiveness has been examined. It has been discovered that the parameters mentioned above can be considered as control parameters of “flapping wing” MAVs, especially in lateral direction. Research programmes for the construction of MAYs concentrate on understanding the mechanisms of animal flight and on creating smart structures which would enable flight in micro-scale.
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Cosyn, P., and J. Vierendeels. "Design of fixed wing micro air vehicles." Aeronautical Journal 111, no. 1119 (May 2007): 315–26. http://dx.doi.org/10.1017/s0001924000004565.
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Abstract The paper describes the methodology and computational design strategies used to develop a series of fixed wing micro air vehicles (MAVs) at the Ghent University. The emphasis of the research is to find an optimal MAV-platform that is bound to geometrical constraints but superior in its performance. This requires a multidisciplinary design optimisation but the challenges are mainly of aerodynamic nature. Key areas are endurance, stability, controllability, manoeuvrability and component integration. The highly three-dimensional low Reynolds number flow, the lack of experimental databases and analytical or empirical models of MAV-aerodynamics required fundamental research of the phenomena. This includes the use of a vortex lattice method, three-dimensional CFD-computations and a numerical propeller optimisation method to derive the forces and their derivatives of the MAV and propeller for performance and stability-related optimisation studies. The design method leads to a simple, stable and robust flying wing MAV-platform that has the agility of a fighter airplane. A prototype, the UGMAV25, was constructed and flight tests were performed. The capabilities of the MAV were tested in a series of successful flight manoeuvres. The UGMAV15, a MAV with a span of 15cm, is also developed to test flight-qualities and endurance at this small scale. With the current battery technology, a flight-time of at least one hour is expected.
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Sibilski, Krzysztof, Mirosław Nowakowski, Dariusz Rykaczewski, Paweł Szczepaniak, Andrzej Żyluk, Anna Sibilska-Mroziewicz, Michał Garbowski, and Wiesław Wróblewski. "Identification of Fixed-Wing Micro Aerial Vehicle Aerodynamic Derivatives from Dynamic Water Tunnel Tests." Aerospace 7, no. 8 (August 13, 2020): 116. http://dx.doi.org/10.3390/aerospace7080116.
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A micro air vehicle (MAV) is a class of miniature unmanned aerial vehicles that has a size restriction and may be autonomous. Fixed-wing MAVs are very attractive for outdoor surveillance missions since they generally offer better payload and endurance capabilities than rotorcraft or flapping-wing vehicles of equal size. This research paper describes the methodology applying indicial function theory and artificial neural networks for identification of aerodynamic derivatives for fixed-wing MAV. The formulation herein proposed extends well- known aerodynamic theories, which are limited to thin aerofoils in incompressible flow, to strake wing planforms. Using results from dynamic water tunnel tests and indicial functions approach allowed to identify MAV aerodynamic derivatives. The experiments were conducted in a water tunnel in the course of dynamic tests of periodic oscillatory motion. The tests program range was set at high angles of attack and a wide scope of reduced frequencies of angular movements. Due to a built-in propeller, the model’s structure test program was repeated for a turned-on propelled drive system. As a result of these studies, unsteady aerodynamics characteristics and aerodynamic derivatives of the micro-aircraft were identified as functions of state parameters. At the Warsaw University of Technology and the Air Force Institute of Technology, a “Bee” fixed wings micro aerial vehicle with an innovative strake-wing outline and a propeller placed in the wing gap was worked. This article is devoted to the problems of identification of aerodynamic derivatives of this micro-aircraft. The result of this research was the identification of the aerodynamic derivatives of the fixed wing MAV “Bee” as non-linear functions of the angle of attack, and reduced frequency. The identification was carried out using the indicial function approach.
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Ferdaus, Md Meftahul, Sreenatha G. Anavatti, Matthew A. Garratt, and Mahardhika Pratama. "Development of C-Means Clustering Based Adaptive Fuzzy Controller for a Flapping Wing Micro Air Vehicle." Journal of Artificial Intelligence and Soft Computing Research 9, no. 2 (April 1, 2019): 99–109. http://dx.doi.org/10.2478/jaiscr-2018-0027.
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Abstract Advanced and accurate modelling of a Flapping Wing Micro Air Vehicle (FW MAV) and its control is one of the recent research topics related to the field of autonomous MAVs. Some desiring features of the FW MAV are quick flight, vertical take-off and landing, hovering, and fast turn, and enhanced manoeuvrability contrasted with similar-sized fixed and rotary wing MAVs. Inspired by the FW MAV’s advanced features, a four-wing Nature-inspired (NI) FW MAV is modelled and controlled in this work. The Fuzzy C-Means (FCM) clustering algorithm is utilized to construct the data-driven NIFW MAV model. Being model free, it does not depend on the system dynamics and can incorporate various uncertainties like sensor error, wind gust etc. Furthermore, a Takagi-Sugeno (T-S) fuzzy structure based adaptive fuzzy controller is proposed. The proposed adaptive controller can tune its antecedent and consequent parameters using FCM clustering technique. This controller is employed to control the altitude of the NIFW MAV, and compared with a standalone Proportional Integral Derivative (PID) controller, and a Sliding Mode Control (SMC) theory based advanced controller. Parameter adaptation of the proposed controller helps to outperform it static PID counterpart. Performance of our controller is also comparable with its advanced and complex counterpart namely SMC-Fuzzy controller.
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Galinski, Cezary. "INFLUENCE OF MAV CHARACTERISTICS ON THEIR APPLICATIONS." Aviation 9, no. 4 (December 31, 2005): 16–23. http://dx.doi.org/10.3846/16487788.2005.9635913.
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Micro Air Vehicles (MAVs) are an emerging class of unmanned flying vehicles envisaged for direct reconnaissance easy in handling and transport even by single operator. Teams all over the world are developing several different configurations. Each of the configurations exhibits a different set of characteristics. On the other hand, MAVs are expected to serve many different applications and fulfil requirements that sometimes exclude each other. This paper presents the most important characteristics and constraints of fixed wing airplanes, rotary aircraft, and entomopters and show how they fit certain requirements.
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Wang, Jue. "Design and Fabrication of a Flapping-Wing Robot Based on Slider-Crank Mechanism." International Journal of Electrical and Computer Engineering Research 2, no. 2 (June 15, 2022): 11–21. http://dx.doi.org/10.53375/ijecer.2022.264.
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Tailless Flapping-Wing Micro Air Vehicles (FW-MAVs) have gained more attention recently because they utilize energy more efficiently compared to fixed-wing aircraft and rotorcrafts. FW-MAVs could be used commercially to explore confined spaces with insufficient air or serve as surveillance robots. However, due to their use of unsteady aerodynamics and small size, the research and design process is very complicated. In this paper, I propose a flight mechanism for a light-weighted, two-winged, hummingbird-inspired flapping-wing robot. Five versions of the robot were built; each version improved upon the issues of the previous one. Calculations were performed to optimize the stroke amplitude and the transmission ratio of the gears. Four groups of control experiments were conducted to investigate the relationship between different factors (voltage, motor type, wing area, and the number of veins) and the robot’s lift, which was monitored by a pressure sensor. I analyzed the results from the experiments and built a final version of the robot based on a slider-crank mechanism. The main structure of the final version is made of three 3mm carbon fiber boards, and the wings are made of 0.025mm PET (polyethylene terephthalate) material, reinforced by three carbon fiber rods: two 0.5mm ones across the membrane and a 1mm one at the leading edge. The robot weighs 16.3g and can produce enough lift to overcome its gravity under 9V with an off-board power source by exhibiting an upward trend during a tethered flight test.
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Suzuki, Kosuke, Keisuke Minami, and Takaji Inamuro. "Lift and thrust generation by a butterfly-like flapping wing–body model: immersed boundary–lattice Boltzmann simulations." Journal of Fluid Mechanics 767 (February 20, 2015): 659–95. http://dx.doi.org/10.1017/jfm.2015.57.
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AbstractThe flapping flight of tiny insects such as flies or larger insects such as butterflies is of fundamental interest not only in biology itself but also in its practical use for the development of micro air vehicles (MAVs). It is known that a butterfly flaps downward for generating the lift force and backward for generating the thrust force. In this study, we consider a simple butterfly-like flapping wing–body model in which the body is a thin rod and the rectangular rigid wings flap in a simple motion. We investigate lift and thrust generation of the model by using the immersed boundary–lattice Boltzmann method. First, we compute the lift and thrust forces when the body of the model is fixed for Reynolds numbers in the range of 50–1000. In addition, we estimate the supportable mass for each Reynolds number from the computed lift force. Second, we simulate free flights when the body can only move translationally. It is found that the expected supportable mass can be supported even in the free flight except when the mass of the body relative to the mass of the fluid is too small, and the wing–body model with the mass of actual insects can go upward against the gravity. Finally, we simulate free flights when the body can move translationally and rotationally. It is found that the body has a large pitch motion and consequently gets off-balance. Then, we discuss a way to control the pitching angle by flexing the body of the wing–body model.
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Kellogg, J., C. Bovais, R. Foch, H. McFarlane, C. Sullivan, J. Dahlburg, J. Gardner, et al. "The NRL micro tactical expendable (MITE) air vehicle." Aeronautical Journal 106, no. 1062 (August 2002): 431–42. http://dx.doi.org/10.1017/s000192400009223x.
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AbstractThe US Naval Research Laboratory (NRL) is developing technologies that will enable Navy-relevant missions with the smallest practical Micro Air Vehicles (MAVs). The NRL Micro Tactical Expendable (MITE) air vehicle is a result of this research. MITE is a hand-launched, dual-propeller, fixed-wing air vehicle, with a 25cm chord and a wingspan of 25–47cm, depending on payload weight. Vehicle gross weight is 130–350g. Miniature autopilot systems, based on visual imaging techniques, are being developed for MITE. These will be used in conjunction with conventional autopilot sensors to allow the MITE to fly autonomously. This paper provides an overview of the MITE development, including aerodynamic design considerations, electric propulsion, and vision-based autopilot research. Also presented is a rationale for the development of control laws that can direct the behavior of large groups of MAVs or other vehicle agents. Dubbed ‘physicomimetics,’ this process can bring about the self-assembly of complex MAV formations, though individual MAVs have minimal onboard processing power and limited local sensing capabilities.
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Villarreal Valderrama, José Francisco, Luis Takano, Eduardo Liceaga-Castro, Diana Hernandez-Alcantara, Patricia Del Carmen Zambrano-Robledo, and Luis Amezquita-Brooks. "An integral approach for aircraft pitch control and instrumentation in a wind-tunnel." Aircraft Engineering and Aerospace Technology 92, no. 7 (June 13, 2020): 1111–23. http://dx.doi.org/10.1108/aeat-10-2019-0193.
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Purpose Aircraft pitch control is fundamental for the performance of micro aerial vehicles (MAVs). The purpose of this paper is to establish a simple experimental procedure to calibrate pitch instrumentation and classical control algorithms. This includes developing an efficient pitch angle observer with optimal estimation and evaluating controllers under uncertainty and external disturbances. Design/methodology/approach A wind tunnel test bench is designed to simulate fixed-wing aircraft dynamics. Key elements of the instrumentation commonly found in MAVs are characterized in a gyroscopic test bench. A data fusion algorithm is calibrated to match the gyroscopic test bench measurements and is then integrated into the autopilot platform. The elevator-angle to pitch-angle dynamic model is obtained experimentally. Two different control algorithms, based on model-free and model-based approaches, are designed. These controllers are analyzed in terms of parametric uncertainties due to wind speed variations and external perturbation because of sudden weight distribution changes. A series of experimental tests is performed in wind-tunnel facilities to highlight the main features of each control approach. Findings With regard to the instrumentation algorithms, a simple experimental methodology for the design of optimal pitch angle observer is presented and validated experimentally. In the context of the platform design and identification, the similitude among the theoretical and experimental responses shows that the platform is suitable for typical pitch control assessment. The wind tunnel experiments show that a fixed linear controller, designed using classical frequency domain concepts, is able to provide adequate responses in scenarios that approximate the operation of MAVs. Research limitations/implications The aircraft orientation observer can be used for both pitch and roll angles. However, for simultaneousyaw angle estimation the proposed design method requires further research. The model analysis considers a wind speed range of 6-18 m/s, with a nominal operation of 12 m/s. The maximum experimentally tested reference for the pitch angle controller was 20°. Further operating conditions may require more complex control approaches (e.g. scheduling, non-linear, etc.). However, this operating range is enough for typical MAV missions. Originality/value The study shows the design of an effective pitch angle observer, based on a simple experimental approach, which achieved locally optimum estimates at the test conditions. Additionally, the instrumentation and design of a test bench for typical pitch control assessment in wind tunnel facilities is presented. Finally, the study presents the development of a simple controller that provides adequate responses in scenarios that approximate the operation of MAVs, including perturbations that resemble package delivery and parametric uncertainty due to wind speed variations.
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V, Somashekar. "A Computational Investigation of Unsteady Aerodynamics of Insect-Inspired Fixed Wing Micro Aerial Vehicle’s 2D Airfoil." Advances in Aerospace Engineering 2014 (June 17, 2014): 1–7. http://dx.doi.org/10.1155/2014/504049.
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A Micro air vehicle (MAV) is defined as class of unmanned air vehicle (UAV) having a linear dimension of less than 15 centimeters and a mass of less than 100 grams with flight speeds of 6 to 12 meters per second. MAVs fall within a Reynolds number (Re) range of 50,000 and 120,000, in which many causes of unsteady aerodynamic effects are not fully understood. The research field of low Reynolds number aerodynamics is currently an active one, with many defence organizations, universities, and corporations working towards a better understanding of the physical processes of this aerodynamic regime. In the present work, it is proposed to study the unsteady aerodynamic analysis of 2D airfoil using CFD software and Xfoil panel code method. The various steps involved in this work are geometric modelling using CATIA V5R17, meshing using ICEM CFD, and solution and postprocessing through FLUENT. The finite control volume analysis and Xfoil panel code method has been carried out to predict aerodynamic characteristics such as lift coefficients, drag coefficients, moment coefficients, pressure coefficients, and flow visualization. The lift and drag coefficients were compared for all the simulations with experimental results. It was observed that for the 2D airfoil, lift and drag both compared well for the midrange angle of attack from −10 to 15 degree AOA.
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Manoj Kumar, Vedulla, and Chin-Cheng Wang. "Active Flow Control of Flapping Airfoil Using Openfoam." Journal of Mechanics 36, no. 3 (December 13, 2019): 361–72. http://dx.doi.org/10.1017/jmech.2019.46.
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ABSTRACTThe concept of the fixed wing Micro Air Vehicles (MAVs) has received increasing interest over the past few decades, with the principal aim of carrying out the surveillance missions. The design of the flapping wing MAVs still is in infancy stage. On the other hand, there has been increasing interest over the flow control using plasma actuators in worldwide. The aim of this research is to study the flow control of a flapping airfoil with and without plasma actuation in OpenFOAM. The OpenFOAM CFD platform has been used to develop our own plasma solver. For the plasma induced turbulence in the flow regime, k-ε turbulence model was adopted to address the interaction between plasma and fluid flows. For the plasma-fluid interaction, we use reduced-order modelling to solve the plasma induced electric force. A two dimensional NACA0012 flapping airfoil without plasma actuation study has been benchmarked with previous published literature. We have not only focused on the active flow control but also analyzed the important parameter reduced frequency at different values, those are 0.1, 0.05 and 0.025. Reduced frequency (κ) is very important parameter of an airfoil in the unsteady motion. Our major contribution is testing the several reduced frequencies with the plasma actuation. The positive and beneficial effects of the plasma actuator for all cases have been observed. From the observed results, the flapping with plasma actuation at reduced frequency of 0.1 showed the 14.285 percent lift improvement and the 16.19 percent drag reduction than the flapping without plasma actuation at the respective dynamic stall angles. The maximum lift coefficient is increased with the increase in reduced frequency. In overall, plasma actuators are effective in the flow control of a flapping airfoil. In future, the combination of the flapping with plasma actuators will be a promising application to boast the maneuverability of MAVs.
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Sudhakar, S., A. Chandankumar, and L. Venkatakrishnan. "Influence of propeller slipstream on vortex flow field over a typical micro air vehicle." Aeronautical Journal 121, no. 1235 (November 17, 2016): 95–113. http://dx.doi.org/10.1017/aer.2016.114.
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ABSTRACTAn experimental study has been carried out to explore the effect of propeller-induced slipstream on the vortex flow field on a fixed-wing Micro Air Vehicle (MAV). Experiments were conducted at a freestream velocity of 10 m/s, corresponding to a Reynolds number based on a root chord of about 1.6 × 105. Surface flow topology on the surface of the MAV wing at propeller-off and propeller-on conditions was captured using surface oil flow visualisation at four angles of incidence. The mean off-body flow over the MAV was documented in the four spanwise planes at different chord position using Stereoscopic Particle Image Velocimetry (SPIV) technique at angle-of-attack of 24° for both conditions. The oil flow visualisation showed minimal differences in flow patterns for propeller-off and propeller-on conditions at 10° and 15° incidence. The small asymmetry between port and starboard side observed at 20° during the propeller-off condition became significantly pronounced at 24°. The fuselage stub which is necessary for housing the motor of the propeller was seen to have a significant effect on the flow symmetry at large incidences that can occur when the MAV encounters sudden vertical gusts. Switching on the propeller restored the symmetry at both incidences. SPIV measurements were carried out at the incidence of 24° which exhibited the highest asymmetry. The off-body data shows the re-establishment of symmetry during propeller-on condition owing to the increase in the magnitude of spanwise and vertical velocities as a result of the propeller slipstream. The findings emphasise the importance of considering the propeller flow and design of the motor housing while evaluating the aerodynamics of low-aspect-ratio MAVs.
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Jiang, Tieying, Xiangsen Ma, Chengwei Yang, and Yukun Mao. "Influence Degree Analysis of Landing Points of Small-sized Fixed-wing Gliding UAV in Short Range." Journal of Physics: Conference Series 2281, no. 1 (June 1, 2022): 012003. http://dx.doi.org/10.1088/1742-6596/2281/1/012003.
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Abstract Enhancing the landing accuracy and reducing landing point dispersion of Unmanned Aerial Vehicles (UAVs) with fixed wings is critical for expanding the applications of UAVs in complex terrains. Faced with the requirement for arresting recovery for UAV landings in short range, a UAV with fixed wings is chosen as the research basis. The landing strategy for UAVs has been modified by the addition of wing flaps, dynamic compensation control, and ultrasonic sensors, among other things. Additionally, the simulation model validated the feasibility of the modified landing-recovery strategy. The Monte Carlo method is used to analyze the influence of interference sources, such as constant wind, gust, positioning error, airspeed measurement, mass, air density, processing and assembly, and control error, on landing point dispersion. Simulation results indicate that the modified landing strategy can significantly improve the short landing performance for small-sized UAVs with fixed wings.
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Sommerfeld, Markus, Martin Dörenkämper, Jochem De Schutter, and Curran Crawford. "Scaling effects of fixed-wing ground-generation airborne wind energy systems." Wind Energy Science 7, no. 5 (September 12, 2022): 1847–68. http://dx.doi.org/10.5194/wes-7-1847-2022.
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Abstract. While some airborne wind energy system (AWES) companies aim at small, temporary or remote off-grid markets, others aim at utility-scale, multi-megawatt integration into the electricity grid. This study investigates the scaling effects of single-wing, ground-generation AWESs from small- to utility-scale systems, subject to realistic 10 min, onshore and offshore wind conditions derived from a numerical mesoscale Weather Research And Forecasting (WRF) model. To reduce computational cost, vertical wind velocity profiles are grouped into 10 clusters using k-means clustering. Three representative profiles from each cluster are implemented into a nonlinear AWES optimal control model to determine power-optimal trajectories. We compare the effects of three different aircraft masses and two sets of nonlinear aerodynamic coefficients for aircraft with wing areas ranging from 10 to 150 m2 on operating parameters and flight trajectories. We predict size- and mass-dependent AWES power curves, annual energy production (AEP) and capacity factors (cf) and compare them to a quasi-steady-state reference model. Instantaneous force, tether-reeling speed and power fluctuations as well as power losses associated with tether drag and system mass are quantified.
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Muhammed, Manaf, and Muhammad Shakeel Virk. "Ice Accretion on Rotary-Wing Unmanned Aerial Vehicles—A Review Study." Aerospace 10, no. 3 (March 8, 2023): 261. http://dx.doi.org/10.3390/aerospace10030261.
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Ice accretion on rotary-wing unmanned aerial vehicles (RWUAVs) needs to be studied separately from the fixed-wing UAVs because of the additional flow complexities induced by the propeller rotation. The aerodynamics of rotatory wings are extremely challenging compared to the fixed-wing configuration. Atmospheric icing can be considered a hazard that can plague the operation of UAVs, especially in the Arctic region, as it can impose severe aerodynamic penalties on the performance of propellers. Rotary-wing structures are more prone to ice accretion and ice shedding because of the centrifugal force due to rotational motion, whereby the shedding of the ice can lead to mass imbalance and vibration. The nature of ice accretion on rotatory wings and associated performance degradation need to be understood in detail to aid in the optimum design of rotary-wing UAVs, as well as to develop adequate ice mitigation techniques. Limited research studies are available about icing on rotary wings, and no mature ice mitigation technique exists. Currently, there is an increasing interest in research on these topics. This paper provides a comprehensive review of studies related to icing on RWUAVs, and potential knowledge gaps are also identified.
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Huang, Jiafeng, Hyeung-Sik Choi, Mai The Vu, Dong-Wook Jung, Ki-Beom Choo, Hyun-Joon Cho, Phan Huy Nam Anh, et al. "Study on Position and Shape Effect of the Wings on Motion of Underwater Gliders." Journal of Marine Science and Engineering 10, no. 7 (June 28, 2022): 891. http://dx.doi.org/10.3390/jmse10070891.
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A typical structure of an underwater glider (UG) includes a pair of fixed wings, and the hydrodynamic force driving the glider forward as descending or ascending in the water is generated primarily by the fixed wings. In this paper, a simplified glider motion model was established to analyze the dynamics in an easier way, and whose simulation results do not differ from the original one. Also, in the paper, the effects of the wing position and wing shape on the UG to the motion were studied. Since no direct analytic approach cannot be performed, the case study of the effects of six different wing positions and three wing shapes on gliding performances which are gliding speed, gliding angle and gliding path were performed through computer simulation. The simulation results revealed that when the fixed wing is located far from the buoyancy center to the tail end, more traveling range is achieved with less energy. Also, effect of the shape difference of the wings were analyzed. Shape changes did not show much difference on the travelling performance of the UG. In addition to these, the transient mode of the UG was studied. To control this, the PID controller for the position of the mass shifter and piston were applied. By application of the PID controller to the linearized dynamics equations, it was shown that the transient behavior of the UG was quickly and steadily controlled.
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Müller, Johannes Alexander, Mostafa Yasser Mostafa Khalil Elhashash, and Volker Gollnick. "Electrical Launch Catapult and Landing Decelerator for Fixed-Wing Airborne Wind Energy Systems." Energies 15, no. 7 (March 29, 2022): 2502. http://dx.doi.org/10.3390/en15072502.
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This paper presents a (pre)feasibility study of the rail-based ultra-short launch and landing system ElektRail for fixed-wing airborne wind energy systems, such as Ampyx Power. The ElektRail concept promises airborne mass reductions through the elimination of landing gear as well as decreased landing stresses and ground stability requirements, opening possibilities for improved aerodynamics through a single fuselage configuration. Initially designed for operating fixed-wing drones from open fields, the ElektRail concept had to be significantly shortened for application in an airborne wind energy (AWE) context. This shorter size is required due to the much more limited space available at AWE sites, especially on offshore platforms. Hence, a performance enhancement using the integration of a bungee launching and landing system (BLLS) was designed and a system dynamics model for the launch and landing was derived. The results demonstrated the possibility for the ElektRail to be shortened from 140 m to just 19.3 m for use with an optimised tethered aircraft with a mass of 317 kg. A system length below 20 m indicates that an enhanced ElektRail launch and landing concept could be viable for airborne wind energy operations, even with relatively low-tech bungee cord boosters. Linear motor drives with a long stator linear motor actuator could potentially shorten the system length further to just 15 m, as well as provide better control dynamics. An investigation into improved AWE net power outputs due to reduced airborne mass and aerodynamic improvements remains to be conducted.
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Tang, Hui, Yulong Lei, Xingzhong Li, and Yao Fu. "Numerical investigation of the aerodynamic characteristics and attitude stability of a bio-inspired corrugated airfoil for MAV or UAV applications." Energies 12, no. 20 (October 22, 2019): 4021. http://dx.doi.org/10.3390/en12204021.
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In this study, two-dimensional (2D) and three-dimensional (3D) numerical calculations were conducted to investigate the aerodynamic characteristics, especially the unsteady aerodynamic characteristics and attitude stability of a bio-inspired corrugated airfoil compared with a smooth-surfaced airfoil (NACA2408 airfoil) at the chord Reynolds number of 4000 to explore the potential applications of non-traditional, corrugated dragonfly airfoils for micro air vehicles (MAVs) or micro-sized unmanned aerial vehicles (UAVs) designs. Two problem settings were applied to our numerical calculations. First, the airfoil was fixed at a constant angle of attack to analyze the aerodynamic characteristics and the hydrodynamic moment. Second, the angle of attack of airfoils was passively changed by the fluid force to analyze the attitude stability. The current numerical solver for the flow field around an unsteady rotating airfoil was validated against the published numerical data. It was confirmed that the corrugated airfoil performs (in terms of the lift-to-drag ratio) much better than the profiled NACA2408 airfoil at low Reynolds number R e = 4000 in low angle of attack range of 0 ∘ – 6 ∘ , and performs as well at the angle of attack of 6 ∘ or more. At these low angles of attack, the corrugated airfoil experiences an increase in the pressure drag and decrease in shear drag due to recirculation zones inside the cavities formed by the pleats. Furthermore, the increase in the lift for the corrugated airfoil is due to the negative pressure produced at the valleys. It was found that the lift and drag in the 2D numerical calculation are strong fluctuating at a high angle of attacks. However, in 3D simulation, especially for a 3D corrugated airfoil with unevenness in the spanwise direction, smaller fluctuations and the smaller average value in the lift and drag were obtained than the results in 2D calculations. It was found that a 3D wing with irregularities in the spanwise direction could promote three-dimensional flow and can suppress lift fluctuations even at high angles of attack. For the attitude stability, the corrugated airfoil is statically more unstable near the angle of attack of 0 ∘ , has a narrower static stable range of the angle of attack, and has a larger amplitude of fluctuations of the angle of attack compared with the profiled NACA2408 airfoil. Based on the Routh–Hurwitz stability criterion, it was confirmed that the control systems of the angle of attack passively changed by the fluid force for both two airfoils are unstable systems.
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Rizvi, S. M. Danish, Shahzor Ahmad, Khurram Khan, Azhar Hasan, and Ammar Masood. "Deep Learning Approach for Fixed and Rotary-Wing Target Detection and Classification in Radars." IEEE Aerospace and Electronic Systems Magazine 37, no. 3 (March 1, 2022): 32–42. http://dx.doi.org/10.1109/maes.2021.3140064.
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Skulstad, Robert, Christoffer Syversen, Mariann Merz, Nadezda Sokolova, Thor Fossen, and Tor Johansen. "Autonomous net recovery of fixed- wing UAV with single-frequency carrier-phase differential GNSS." IEEE Aerospace and Electronic Systems Magazine 30, no. 5 (May 2015): 18–27. http://dx.doi.org/10.1109/maes.2015.7119821.
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Dief, Tarek N., Uwe Fechner, Roland Schmehl, Shigeo Yoshida, Amr M. M. Ismaiel, and Amr M. Halawa. "System identification, fuzzy control and simulation of a kite power system with fixed tether length." Wind Energy Science 3, no. 1 (May 17, 2018): 275–91. http://dx.doi.org/10.5194/wes-3-275-2018.
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Abstract. In wind energy research, airborne wind energy systems are one of the promising energy sources in the near future. They can extract more energy from high altitude wind currents compared to conventional wind turbines. This can be achieved with the aid of aerodynamic lift generated by a wing tethered to the ground. Significant savings in investment costs and overall system mass would be obtained since no tower is required. To solve the problems of wind speed uncertainty and kite deflections throughout the flight, system identification is required. Consequently, the kite governing equations can be accurately described. In this work, a simple model was presented for a tether with a fixed length and compared to another model for parameter estimation. In addition, for the purpose of stabilizing the system, fuzzy control was also applied. The design of the controller was based on the concept of Mamdani. Due to its robustness, fuzzy control can cover a wider range of different wind conditions compared to the classical controller. Finally, system identification was compared to the simple model at various wind speeds, which helps to tune the fuzzy control parameters.
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Tobalske, B., and K. Dial. "Flight kinematics of black-billed magpies and pigeons over a wide range of speeds." Journal of Experimental Biology 199, no. 2 (February 1, 1996): 263–80. http://dx.doi.org/10.1242/jeb.199.2.263.
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To investigate how birds that differ in morphology change their wing and body movements while flying at a range of speeds, we analyzed high-speed (60 Hz) video tapes of black-billed magpies (Pica pica) flying at speeds of 4-14 m s-1 and pigeons (Columba livia) flying at 6-20 m s-1 in a wind-tunnel. Pigeons had higher wing loading and higher-aspect-ratio wings compared with magpies. Both species alternated phases of steady-speed flight with phases of acceleration and deceleration, particularly at intermediate flight speeds. The birds modulated their wingbeat kinematics among these phases and frequently exhibited non-flapping phases while decelerating. Such modulation in kinematics during forward flight is typical of magpies but not of pigeons in the wild. The behavior of the pigeons may have been a response to the reduced power costs for flight in the closed wind-tunnel relative to those for free flight at similar speeds. During steady-speed flight, wingbeat frequency did not change appreciably with increasing flight speed. Body angle relative to the horizontal, the stroke-plane angles of the wingtip and wrist relative to the horizontal and the angle describing tail spread at mid-downstroke all decreased with increasing flight speed, thereby illustrating a shift in the dominant function of wing flapping from weight support at slow speeds to positive thrust at fast speeds. Using wingbeat kinematics to infer lift production, it appeared that magpies used a vortex-ring gait during steady-speed flight at all speeds whereas pigeons used a vortex-ring gait at 6 and 8 m s-1, a transitional vortex-ring gait at 10 m s-1, and a continuous-vortex gait at faster speeds. Both species used a vortex-ring gait for acceleration and a continuous-vortex gait or a non-flapping phase for deceleration during flight at intermediate wind-tunnel speeds. Pigeons progressively flexed their wings during glides as flight speed increased but never performed bounds. Wingspan during glides in magpies did not vary with flight speed, but the percentage of bounds among non-flapping intervals increased with speed from 10 to 14 m s-1. The use of non-flapping wing postures seemed to be related to the gaits used during flapping and to the aspect ratio of the wings. We develop an 'adverse-scaling' hypothesis in which it is proposed that the ability to reduce metabolic and mechanical power output using flap-bounding flight at fast flight speeds is scaled negatively with body mass. This represents an alternative to the 'fixed-gear' hypothesis previously suggested by other authors to explain the use of intermittent flight in birds. Future comparative studies in the field would be worthwhile, especially if instantaneous flight speeds and within-wingbeat kinematics were documented; new studies in the laboratory should involve simultaneous recording of wing kinematics and aerodynamic forces on the wing.
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Wu, Jiang Hao, and Mao Sun. "Floquet stability analysis of the longitudinal dynamics of two hovering model insects." Journal of The Royal Society Interface 9, no. 74 (April 4, 2012): 2033–46. http://dx.doi.org/10.1098/rsif.2012.0072.
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Because of the periodically varying aerodynamic and inertial forces of the flapping wings, a hovering or constant-speed flying insect is a cyclically forcing system, and, generally, the flight is not in a fixed-point equilibrium, but in a cyclic-motion equilibrium. Current stability theory of insect flight is based on the averaged model and treats the flight as a fixed-point equilibrium. In the present study, we treated the flight as a cyclic-motion equilibrium and used the Floquet theory to analyse the longitudinal stability of insect flight. Two hovering model insects were considered—a dronefly and a hawkmoth. The former had relatively high wingbeat frequency and small wing-mass to body-mass ratio, and hence very small amplitude of body oscillation; while the latter had relatively low wingbeat frequency and large wing-mass to body-mass ratio, and hence relatively large amplitude of body oscillation. For comparison, analysis using the averaged-model theory (fixed-point stability analysis) was also made. Results of both the cyclic-motion stability analysis and the fixed-point stability analysis were tested by numerical simulation using complete equations of motion coupled with the Navier–Stokes equations. The Floquet theory (cyclic-motion stability analysis) agreed well with the simulation for both the model dronefly and the model hawkmoth; but the averaged-model theory gave good results only for the dronefly. Thus, for an insect with relatively large body oscillation at wingbeat frequency, cyclic-motion stability analysis is required, and for their control analysis, the existing well-developed control theories for systems of fixed-point equilibrium are no longer applicable and new methods that take the cyclic variation of the flight dynamics into account are needed.
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Garg, P. K. "Characterisation of Fixed-Wing Versus Multirotors UAVs/Drones." Journal of Geomatics 16, no. 2 (October 31, 2022): 152–59. http://dx.doi.org/10.58825/jog.2022.16.2.44.
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Drones are Unmanned Aerial Vehicles (UAVs) that do not carry a human operator, fly remotely or autonomously, and carry lethal or non-lethal payloads. Advances in fabrication, navigation, remote control capabilities, and power storage systems have made possible the development of a wide range of drones. The most popular ones are fixed-wing and multirotor drones. They have several advantages and disadvantages and can be deployed quickly to obtain very high resolution imagery/point cloud data. With sophisticated computer vision, robotics and data, and low cost digital cameras, it is possible to get centimeter-level resolution and accuracy. Advances in technology have made the increased uses of drones for various applications. The uses of UAVs/drones are increasing allowing 2D and 3D maps to be created and used for creation of 3D maps and digital elevation models (DEMs). This paper describes in details about the two broad categories of UAVs; fixed-wing and multirotor UAVs. Their salient characteristics along with advantages and disadvantages are also given. It also provides insights to the users for selection of right kind of UAV.
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URSU, Stefan. "Development of dielectric elastomeric actuators for morphing wings." INCAS BULLETIN 13, no. 2 (June 4, 2021): 163–73. http://dx.doi.org/10.13111/2066-8201.2021.13.2.15.
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In the last decades, wing morphing structures have aroused great interest due to their capability to improve the aerodynamic efficiency of modern aircraft. DE actuators, also known as “artificial muscles” due to their ability to exhibit large actuation strains at high voltages, are suitable candidates for morphing applications. This paper focuses on the research and development of miniature dielectric elastomeric actuators for variable-thickness morphing wings. A conical elastomeric actuation configuration has been proposed, consisting of a VHB4910 dielectric membrane preloaded with a spring mechanism and constrained to a rigid circular ring. The mini-actuators are developed to be fixed in an actuation array, mounted to the wing skin. This new electromechanical actuation system is designed to be integrated on thin airfoil wings, where conventional morphing structures cannot be used, because of restricted mass and space requirements. By controlling the thickness distribution using the proposed actuators, we may be able to maintain and delay the location of the laminar-turbulent transit towards the trailing edge, promoting laminar flow over the wing surface. Experimental models and prototypes will be developed in the next phase of the research project for further investigations.
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Saputra, Hendra, and Armada Armada. "Pembuatan peta photo udara Desa Wonosari menggunakan UAV Fixed Wing." Unri Conference Series: Community Engagement 2 (December 30, 2020): 423–31. http://dx.doi.org/10.31258/unricsce.2.423-431.
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Wonosari Village has natural resources such as agriculture, plantations and tourism. Plantation sector such as oil palm and rubber. In the tourism sector, Wonosari Village has forest areas that are wide enough to be used as an attraction for the village, such as natural forests, outbound places, as campsites, and reservoirs/lakes. To maximize this potential, it takes careful and comprehensive planning. Large-scale aerial images maps are a solution to serve as guidelines in determining and policymakers. In these activities, the method used is the use of UAV Fixed Wing. The results are in the form of orthophoto aerial imagery with an area of 1577 hectares. The advantage of aerial photo maps is the real appearance of objects with high resolution. The village government can use this aerial photo map to determine village administrative boundaries, “rukun tetangga” and “rukun warga” boundaries, guidelines in making master plans as well as supporting data in determining village profiles.
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Rehak, M., and J. Skaloud. "FIXED-WING MICRO AERIAL VEHICLE FOR ACCURATE CORRIDOR MAPPING." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences II-1/W1 (August 27, 2015): 23–31. http://dx.doi.org/10.5194/isprsannals-ii-1-w1-23-2015.
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In this study we present a Micro Aerial Vehicle (MAV) equipped with precise position and attitude sensors that together with a pre-calibrated camera enables accurate corridor mapping. The design of the platform is based on widely available model components to which we integrate an open-source autopilot, customized mass-market camera and navigation sensors. We adapt the concepts of system calibration from larger mapping platforms to MAV and evaluate them practically for their achievable accuracy. We present case studies for accurate mapping without ground control points: first for a block configuration, later for a narrow corridor. We evaluate the mapping accuracy with respect to checkpoints and digital terrain model. We show that while it is possible to achieve pixel (3-5 cm) mapping accuracy in both cases, precise aerial position control is sufficient for block configuration, the precise position and attitude control is required for corridor mapping.
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Ferchow, Julian, Stephanie Vogt, Matthias Schibli, and Mirko Meboldt. "Dust-resistant microthermal mass-flow pitot-tube for fixed-wing drones (UAV)." Procedia CIRP 100 (2021): 409–14. http://dx.doi.org/10.1016/j.procir.2021.05.096.
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Zheng, Jingzhong, Maria Sergeevna Selezneva, Jianfeng Yi, and Liangliang Zhu. "Attitude control of a moving mass-actuated fixed-wing UAV based on LADRC." Journal of Physics: Conference Series 2472, no. 1 (May 1, 2023): 012045. http://dx.doi.org/10.1088/1742-6596/2472/1/012045.
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Abstract This paper concerns attitude control of a moving mass-actuated fixed-wing unmanned aerial vehicle (MFUAV). Unlike conventional roll motion of UAV, which is controlled by ailerons, this MFUAV uses the movement of mass block inside the wing to generate roll moment. It is difficult to design a suitable attitude controller for it due to the strong non-linearity and coupling of the MFUAV dynamics. Linear active disturbance rejection control (LADRC) proved to be a simple and effective alternative to conventional PID control. LADRC is able to eliminate disturbances with the help of extended state observer (ESO) and does not depend on the accurate mathematical models of particular systems. Finally, simulation results show that the attitude tracking control of MFUAV is well achieved with robustness. This shows that the designed method is easy to adapt and implement during the actual flight of the MFUAV.
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Lehmkühler, K., K. C. Wong, and D. Verstraete. "Methods for accurate measurements of small fixed wing UAV inertial properties." Aeronautical Journal 120, no. 1233 (November 2016): 1785–811. http://dx.doi.org/10.1017/aer.2016.105.
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ABSTRACTTwo methods have been compared for the determination of the inertial properties of a small, fixed-wing un-manned aerial vehicle. The first method uses the standard single degree of freedom pendulum method and the second method implements a novel, potentially easier, 3 degrees of freedom pendulum method, which yields the entire inertia tensor from a single swing test. Both methods are using system identification of the pendulum motion to estimate the inertial properties. Substantial corrections (up to 25%) have to be applied to the experimental results. These corrections are caused by the acceleration of the pendulum being immersed in the surrounding air, also called the added mass effect. It has been found that the methods presented in literature to determine the corrections for full-scale aircraft do not give the correct results for the small-scale un-manned aerial vehicle under consideration. The only feasible, cost-effective method to generate these corrections utilise swing tests with a geometrically similar object of known inertial properties. It has also been found that the corrections are unique with respect to the experimental methods. Several benchmarking methods, including the innovative use of static and dynamic wind-tunnel test data, give high confidence in the results.
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Tobalske, Bret W. "Evolution of avian flight: muscles and constraints on performance." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1704 (September 26, 2016): 20150383. http://dx.doi.org/10.1098/rstb.2015.0383.
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Competing hypotheses about evolutionary origins of flight are the ‘fundamental wing-stroke’ and ‘directed aerial descent’ hypotheses. Support for the fundamental wing-stroke hypothesis is that extant birds use flapping of their wings to climb even before they are able to fly; there are no reported examples of incrementally increasing use of wing movements in gliding transitioning to flapping. An open question is whether locomotor styles must evolve initially for efficiency or if they might instead arrive due to efficacy. The proximal muscles of the avian wing output work and power for flight, and new research is exploring functions of the distal muscles in relation to dynamic changes in wing shape. It will be useful to test the relative contributions of the muscles of the forearm compared with inertial and aerodynamic loading of the wing upon dynamic morphing. Body size has dramatic effects upon flight performance. New research has revealed that mass-specific muscle power declines with increasing body mass among species. This explains the constraints associated with being large. Hummingbirds are the only species that can sustain hovering. Their ability to generate force, work and power appears to be limited by time for activation and deactivation within their wingbeats of high frequency. Most small birds use flap-bounding flight, and this flight style may offer an energetic advantage over continuous flapping during fast flight or during flight into a headwind. The use of flap-bounding during slow flight remains enigmatic. Flap-bounding birds do not appear to be constrained to use their primary flight muscles in a fixed manner. To improve understanding of the functional significance of flap-bounding, the energetic costs and the relative use of alternative styles by a given species in nature merit study. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’.
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Ross, Samuel A., Amanda E. White, Adam Andresen, Shah Saud Alam, and Christopher Depcik. "Martian Combustion-Powered Fixed-Wing UAVs: An Introductory Investigation and Analysis." Aerospace 9, no. 8 (August 16, 2022): 447. http://dx.doi.org/10.3390/aerospace9080447.
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The Martian topography needs to be investigated in greater detail for human habitations, and this can be accomplished faster using unmanned aerial vehicles (UAVs). In this regard, the RQ-11B Raven appears suitable for remote sensing and topography-mapping applications on Mars, due to its popularity in surveillance and reconnaissance applications on Earth. As a result, this study investigates the flight of this UAV in the Martian atmosphere with the assumptions that it employs an NACA S7012 airfoil and its electric propulsion technology is replaced with a four-stroke oxy-methane fueled Saito FG-11 internal combustion engine (ICE). This ICE is estimated to supply 367.8 W resulting in an engine speed of 6891 revolutions per minute. Based on this speed, the UAV must fly at least 72 m/s (Re = 18,100) at a 5° angle of attack to support flight under calm conditions. To achieve this speed will be difficult; thus, a weather balloon or German V1-style launch system should be employed to launch the UAV successfully. Furthermore, the UAV must operate below 165 m/s (Re = 41,450) to prevent transonic conditions. Finally, the vehicle’s fuel and oxidizer tanks can be refueled using an in situ methane and oxygen production system, enabling its sustainable use on Mars.
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Dorrington, G. E. "Performance of non-rigid airships operating in the neutral buoyancy condition." Aeronautical Journal 111, no. 1116 (February 2007): 89–103. http://dx.doi.org/10.1017/s0001924000001792.
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AbstractThe feasibility of using neutrally-buoyant (or fully-buoyant) airships for passenger and cargo transportation is investigated. The drag coefficients of rigid and non-rigid airships are deduced from flight data. Comparisons are made with empirical drag formulas and previous wind tunnel data. Some general trends for airship drag are derived. The mass breakdown of non-rigid airships with hull volumes up to 35,000m3is analysed using parametric equations. The maximum feasible airspeed and useful load carrying capacity of projected airships are calculated. ‘Specific productivity’ is found to be lower than values achievable with fixed-wing aircraft, but ‘fuel-specific productivity’ is found to be competitive, confirming results of a previous NASA study. The use of gaseous hydrogen and fuel cells is briefly discussed.
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Demircali, Anil, and Huseyin Uvet. "A STUDY OF UNMANNED GLIDER DESIGN, SIMULATION, AND MANUFACTURING." CBU International Conference Proceedings 5 (September 24, 2017): 1064–70. http://dx.doi.org/10.12955/cbup.v5.1072.
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This paper describes a mini unmanned glider's design, simulation, and manufacturing with a wing-folding mechanism. The mini-glider is designed for the CANSAT 2016 competition, which has the theme of a Mars glider concept with atmosphere data acquisition. The aim is to facilitate transportation and to land it to the destination point. Having a light and compact design is important since it is a glider without an engine and it uses power only for the transmission of sensory data. The glider is produced with a wingspan which is 440 mm, and its longitudinal distance is 304 mm. The wings can be packaged in a fixed size container whose dimensions are 125 mm in diameter and 310 mm in height. The glider's weight is only 144 gr, and it can increase up to 500 gr with maximum with payload. The mechanism, which includes springs and neodymium magnets for wing-folding, is capable of being ready in 98 ms for gliding after separation from its container. The mini-glider is capable of telemetry, communications, and other sensory operations autonomously during flight.
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Dalwadi, Nihal, Dipankar Deb, and Stepan Ozana. "Dual Observer Based Adaptive Controller for Hybrid Drones." Drones 7, no. 1 (January 11, 2023): 48. http://dx.doi.org/10.3390/drones7010048.
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A biplane quadrotor (hybrid vehicle) benefits from rotary-wing and fixed-wing structures. We design a dual observer-based autonomous trajectory tracking controller for the biplane quadrotor. Extended state observer (ESO) is designed for the state estimation, and based on this estimation, a Backstepping controller (BSC), Integral Terminal Sliding Mode Controller (ITSMC), and Hybrid Controller (HC) that is a combination of ITSMC + BSC are designed for the trajectory tracking. Further, a Nonlinear disturbance observer (DO) is designed and combined with ESO based controller to estimate external disturbances. In this simulation study, These ESO-based controllers with and without DO are applied for trajectory tracking, and results are evaluated. An ESO-based Adaptive Backstepping Controller (ABSC) and Adaptive Hybrid controller (AHC) with DO are designed, and performance is evaluated to handle the mass change during the flight despite wind gusts. Simulation results reveal the effectiveness of ESO-based HC with DO compared to ESO-based BSC and ITSMC with DO. Furthermore, an ESO-based AHC with DO is more efficient than an ESO-based ABSC with DO.
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Qiu, Xiaoqi, Mingen Zhang, Wuxing Jing, and Changsheng Gao. "Dynamics and Adaptive Sliding Mode Control of a Mass-Actuated Fixed-Wing UAV." International Journal of Aeronautical and Space Sciences 22, no. 4 (March 5, 2021): 886–97. http://dx.doi.org/10.1007/s42405-020-00344-w.
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Şugar-Gabor, Oliviu, and Andreea Koreanschi. "Design of Supercritical Low-Reynolds-Number Airfoils for Fixed-Wing Flight on Mars." Journal of Aerospace Engineering 33, no. 5 (September 2020): 04020052. http://dx.doi.org/10.1061/(asce)as.1943-5525.0001166.
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Tobalske, B. W., W. L. Peacock, and K. P. Dial. "Kinematics of flap-bounding flight in the zebra finch over a wide range of speeds." Journal of Experimental Biology 202, no. 13 (July 1, 1999): 1725–39. http://dx.doi.org/10.1242/jeb.202.13.1725.
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It has been proposed elsewhere that flap-bounding, an intermittent flight style consisting of flapping phases interspersed with flexed-wing bounds, should offer no savings in average mechanical power relative to continuous flapping unless a bird flies 1.2 times faster than its maximum range speed (Vmr). Why do some species use intermittent bounds at speeds slower than 1.2Vmr? The ‘fixed-gear hypothesis’ suggests that flap-bounding is used to vary mean power output in small birds that are otherwise constrained by muscle physiology and wing anatomy to use a fixed muscle shortening velocity and pattern of wing motion at all flight speeds; the ‘body-lift hypothesis’ suggests that some weight support during bounds could make flap-bounding flight aerodynamically advantageous in comparison with continuous flapping over most forward flight speeds. To test these predictions, we studied high-speed film recordings (300 Hz) of wing and body motion in zebra finches (Taenopygia guttata, mean mass 13.2 g, N=4) taken as the birds flew in a variable-speed wind tunnel (0–14 m s-1). The zebra finches used flap-bounding flight at all speeds, so their flight style was unique compared with that of birds that facultatively shift from continuous flapping or flap-gliding at slow speeds to flap-bounding at fast speeds. There was a significant effect of flight speed on all measured aspects of wing motion except percentage of the wingbeat spent in downstroke. Changes in angular velocity of the wing indicated that contractile velocity in the pectoralis muscle changed with flight speed, which is not consistent with the fixed-gear hypothesis. Although variation in stroke-plane angle relative to the body, pronation angle of the wing and wing span at mid-upstroke showed that the zebra finch changed within-wingbeat geometries according to speed, a vortex-ring gait with a feathered upstroke appeared to be the only gait used during flapping. In contrast, two small species that use continuous flapping during slow flight (0–4 m s-1) either change wingbeat gait according to flight speed or exhibit more variation in stroke-plane and pronation angles relative to the body. Differences in kinematics among species appear to be related to wing design (aspect ratio, skeletal proportions) rather than to pectoralis muscle fiber composition, indicating that the fixed-gear hypothesis should perhaps be modified to exclude muscle physiology and to emphasize constraints due to wing anatomy. Body lift was produced during bounds at speeds from 4 to 14 m s-1. Maximum body lift was 0.0206 N (15.9 % of body weight) at 10 m s-1; body lift:drag ratio declined with increasing air speed. The aerodynamic function of bounds differed with increasing speed from an emphasis on lift production (4–10 m s-1) to an emphasis on drag reduction with a slight loss in lift (12 and 14 m s-1). From a mathematical model of aerodynamic costs, it appeared that flap-bounding offered the zebra finch an aerodynamic advantage relative to continuous flapping at moderate and fast flight speeds (6–14 m s-1), with body lift augmenting any savings offered solely by flap-bounding at speeds faster than 7.1 m s-1. The percentage of time spent flapping during an intermittent flight cycle decreased with increasing speed, so the mechanical cost of transport was likely to be lowest at faster flight speeds (10–14 m s-1).
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Albuquerque, Wendell, Parviz Ghezellou, Kwang-Zin Lee, Quintus Schneider, Phillip Gross, Tobias Kessel, Bodunrin Omokungbe, et al. "Peptidomics as a Tool to Assess the Cleavage of Wine Haze Proteins by Peptidases from Drosophila suzukii Larvae." Biomolecules 13, no. 3 (February 28, 2023): 451. http://dx.doi.org/10.3390/biom13030451.
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Thermolabile grape berry proteins such as thaumatin-like proteins (TLPs) and chitinases (CHIs) promote haze formation in bottled wines if not properly fined. As a natural grapevine pest, the spotted-wing fly Drosophila suzukii is a promising source of peptidases that break down grape berry proteins because the larvae develop and feed inside mature berries. Therefore, we produced recombinant TLP and CHI as model thermolabile wine haze proteins and applied a peptidomics strategy to investigate whether D. suzukii larval peptidases were able to digest them under acidic conditions (pH 3.5), which are typically found in winemaking practices. The activity of the novel peptidases was confirmed by mass spectrometry, and cleavage sites within the wine haze proteins were visualized in 3D protein models. The combination of recombinant haze proteins and peptidomics provides a valuable screening tool to identify optimal peptidases suitable for clarification processes in the winemaking industry.
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Demircali, Ali, and Huseyin Uvet. "Mini Glider Design and Implementation with Wing-Folding Mechanism." Applied Sciences 8, no. 9 (September 3, 2018): 1541. http://dx.doi.org/10.3390/app8091541.
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This paper describes a mini unmanned glider’s design, simulation, and manufacturing with a novel wing-folding mechanism. The mini-glider is designed for CanSat competition, which has a theme of a Mars glider concept with atmosphere data acquisition. The aim is to facilitate the transportation of the glider and to land it on the destination point by following strict rules. Having a light and compact design is important since it uses power for the transmission of sensory data only. Dimensions of the glider is produced with a wingspan that is 440 mm and a length of 304 mm. The wings can be stowed in a fixed size container that has a diameter of 125 mm and a height of 310 mm. Its weight is only 144 g and it can increase up to 500 g maximum with a payload. The mechanism, which includes springs and neodymium N48 grade magnets for a wing-folding system, is capable of being ready in 98 ms for gliding after separating from its container. The mini-glider is capable of telemetering, communicating, and conducting other sensory operations autonomously during the flight.
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CHIO, SHIH-HONG. "VBS RTK GPS-ASSISTED SELF-CALIBRATION BUNDLE ADJUSTMENT FOR AERIAL TRIANGULATION OF FIXED-WING UAS IMAGES FOR UPDATING TOPOGRAPHIC MAPS." Boletim de Ciências Geodésicas 22, no. 4 (December 2016): 665–84. http://dx.doi.org/10.1590/s1982-21702016000400038.
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Unmanned Aircraft Systems (UASs) can collect high resolution and high quality images for local mapping. If the highly accurate GPS flying trajectory of a UAS is collected, it can support bundle adjustment aerial triangulation (AT) of UAS images and reduce the demands on ground control points (GCPs). This study installs a Trimble BD970 GNSS OEM on a fixed-wing UAS for capturing highly accurate GPS data by using a Virtual Base Station (VBS) RTK GPS technique for AT. Meanwhile, the GPS antenna-camera offset is resolved by stripwise linear drift parameters introduced in GPS observation equations, while performing bundle adjustment for AT. Additionally, self-calibration bundle adjustment is used in VBS RTK GPS-assisted AT to solve incomplete camera parameters calibrated by a close-range photogrammetric approach. The results show that the AT accuracy of fixed-wing UAS images collected with a 24 mm focal-length Canon EOS 5D Mark II camera at a flying height of 550 m above ground level is 0.21 m in planimetry and 0.22 m in height using two cross strips with two full GCPs at each corner of the block. The RMSE of check points from stereoscopic viewing can reach 0.27 m in planimetry and 0.24 m in height. The test results show that the accuracy of VBS RTK GPS-assisted bundle adjustment with self-calibration for the AT of fixed-wing UAS image can be used for updating local 1/5000 topographic maps in Taiwan.
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Ismailov, Kuat K. "Determination of aerodynamic characterisitcs of fixed-wing unmanned aerial vehicle by analytical techniques." Vestnik Tomskogo gosudarstvennogo universiteta. Matematika i mekhanika, no. 78 (2022): 112–24. http://dx.doi.org/10.17223/19988621/78/9.
Full textAbstract:
This paper presents a theoretical study of quick methods for determining the aerodynamic characteristics of fixed-wing unmanned aerial vehicles (UAVs). The purpose of the research is to create tools for aircraft shape optimization problems. The developed analytical techniques allow one to determine aerodynamic lift and drag coefficients as well as the efficiency characteristics based on the aircraft general characteristics. Other properties that can be derived are the wing shape parameters, the take-off mass, the structural mass, and the required characteristics of the propulsion and power supply system according to the specified flight performance characteristics. The use of these techniques for discrete points with aerodynamic characteristics obtained numerically or experimentally allows one to extrapolate the results to the entire range of operating angles of attack. As a result, the stages of conceptual and preliminary design of UAVs can be passed in a shorter span of time. Two UAVs have been designed in Tomsk State University with the use of the proposed techniques. The first is the preliminary designed UAV Prototype-2E; the second is the Prototype-2T UAV, which has been fully designed and then manufactured. The data calculated with these techniques on a SKIF Cyberia supercomputer in Tomsk State University are compared with the results of numerical simulations implemented in OpenFOAM and ANSYS Fluent. Good agreement of the results is revealed.
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Hu, Yu Lin, Lei Shi, and Hao Ming Liu. "Using Dynamic Reactive Power Compensation Equipments to Enhance Low Voltage Ride-Through Capability of Fixed Speed Asynchronous Wind Farms." Applied Mechanics and Materials 291-294 (February 2013): 481–89. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.481.
Full textAbstract:
This paper presents wind energy conversion model, drive shaft’s dual-mass model and generator’s transient mathematical model for the transient analysis of fixed speed asynchronous wind generators, and analyzes the transient characteristics of the wind generators under the condition of low voltage fault. The control principles of two dynamic reactive power compensation equipments as static var compensator (SVC) and static synchronous compensator (STATCOM) are introduced. Take a wind farm consists of fixed speed asynchronous wind generators as an example, the two compensation equipments are simulated in PowerFactory/DIgSILENT to compare the effort of them on enhancing the low voltage ride-through capability of the wind farm.