Flight Design Research Articles

Flight design and dynamics analysis of a new water-air UAV

In the field of UAV research, water-air amphibious is an important direction. If water-air amphibious is realized, the UAV will no longer be restricted by the space field, and can realize various functions in the three domains of water, land and air more flexibly and freely to complete various flight and exploration missions. Therefore, this paper designs the model and flight algorithm of a new type of water-air amphibious variable wing UAV, and verifies the dynamic analysis of the relevant flight components of the UAV.

The reachable regions construction for the inelastic anisotropic billiards

Modern methods of the ballistic design of space flights (entry of a spacecraft with non-zero aerodynamic quality into the planet’s atmosphere, carrying out gravity assist maneuvers around planets) are associated with the need to calculate a lot of trajectories (i.e. of the phase beams). For their effective use and determination of dynamically admissible reachability regions, it is necessary to identify and study the structure of accompanying singularities of the phase parameters and to construct the corresponding adequate and adaptive models. In this sense, the analogy of the motion of these systems with the singular motion of billiard systems turns out to be very fruitful. First of all, we are talking about anisotropic billiards with dissipation taken into account. In this work, we set and described the model problems about the flat stones skipping on the surface of the water (the ricochets) and an inelastic ball analogue which is bouncing or rolling on an imperfect surface in the presence of a side deviation effect. The main indicatrices types classification for the singular reflection from the plane surface is carried out. Model problems of the ricocheting pebble on the surface of the water surface and the inelastic ball bouncing or rolling on an imperfect surface in the presence of a side bouncing effect also the attainability region problem of the atmospheric entry are posed and described. The configurations of their maximum reachable regions are described

LOW-COST 3D MODELLING TO INTEGRATE AN EXISTING KARTING CIRCUIT INTO A SIMULATOR USING AERIAL PHOTOGRAMMETRY WITH DRONES

Vehicle simulators are widely used devices in disciplines such as Formula 1, design of commercial vehicles, military or civil flights, etc. They enable the evaluation of several aspects of a vehicle during the design phase. Driving simulators are composed of a hardware, with which a driver interacts, and a software that contains the mathematical model of the car and the track, being also the responsible for solving the physics between both parties. An important part of this set is the interaction with the circuit where the car should run, especially if it is a real track-based model. In this work a method is proposed for modeling a circuit that involves a low economic cost its integration into a professional simulator located in the Automotive Intelligence Centre – AIC, Amorebieta, Basque Country, Spain. The 3D model presented corresponds to the Vilariño Motorsport Circuit (Olaberria), obtained by aerial photogrammetry with a drone achieving a resolution of 3.4 mm / px) and a maximum error of 50 mm being also a fast and low-cost method with respect to capture systems with LIDAR. Keywords: Driving Simulator, Formula Student, Arial Photogrammetry, Virtual Environment

Approaches to aircraft flight tests at high angles of attack

Evaluation of aircraft characteristics at high angles of attack is one of the most important tasks when testing highly maneuverable aircraft. The paper presents a new methodology for flight tests of aircraft at high angles of attack based on information and computer technologies. The key points are the flight experiment design, the identification of aerodynamic coefficients at super-critical angles of attack, the use of mathematic models for the phenomena of aerodynamic hysteresis. Practical results in the field of testing aircraft at high and super-critical angles of attack are presented.

Model of auxiliary identification and technical diagnosis of space vehicles, rockets-rockets, running blocks with the function of error recognition of typical solutions

Problem statement. The concept of solving problems of identification and technical diagnostics of spacecraft (SC), launch vehicles (LV), upper stages (RB) under conditions of imperfect models and methods of their identification with a priori uncertainty of statistical relationships of controlled parameters is proposed. Goal. Increasing the reliability of technical diagnostics of spacecraft, launch vehicles and missile launchers under conditions of imperfect models and methods of their identification under destructive influences. Results. A commutative diagram of extended technical diagnostics of complex objects of rocket and space technology (SFBT), as well as a model of augmented identification and technical diagnosis of SFBT as a set of interrelated mathematical models of systems of an object and an object as a whole, control of their technical state, search for the location and causes of malfunctions, assuming the detection of signs of erroneous decisions of typical technical diagnostics and increasing its reliability in case of malfunctions. Practical significance. The idea of RCBT augmented identification and technical diagnostics of the RCBT with the function of recognizing errors of standard solutions is proposed as a basis for creating special software and mathematical support for standard and promising automated test complexes for the preparation of spacecraft, launch vehicles, RB during factory tests, tests at technical and launch complexes, as well as means spacecraft flight control centers during flight design tests and routine control.

Влияние отверстий в пористой поверхности земли на парящий полет насекомого

Aerodynamics of a flapping foil at low Reynolds number in close proximity to the ground in aperture effect are studied by numerical simulations based on the normal hovering motion mode. A vortex street is interestingly generated by both ground and aperture effects and the rotation of the foil. The study reveals that the aperture takes a force-reduction effect and a large enough aperture effectively can remove the ground force-enhancement effect produced when the foil is in close proximity to the ground. This paper provides an effective method of optimizing foil-flapping flight design of flying robotics over a porous plane.

Design of Flight Closed Loop Simulation System Based on Runge-Kutta Algorithm

To solve the problem that the function/performance of the module cannot be fully verified in the laboratory or in the field during the design stage of the airborne radar system, the paper proposes and designs an airborne flight closed-loop simulation system. The flight simulator, which is the core of the entire simulation system, uses the Runge-Kutta algorithm to solve the model and solve the 6-degree-of-freedom nonlinear model of the aircraft in real time, providing realistic aircraft movement data for the airborne radar system. The design builds a Matlab/Simulink simulation model and embeds it in simulation test software to run independently as a model component. The verification test of the closed-loop simulation system shows that the system can realize the real-time simulation of the entire flight environment and meet the design performance requirements.

Sex-related interannual plasticity in wing morphological design in Heliconius charithonia enhances flight metabolic performance.

Flight morphological variations and its consequences on animal performance are common in winged insects. In the butterfly Heliconius charithonia, sex-related differences in the wing morphological design have been described resulting in differences in foraging behavior, daily flight distances and flight aerodynamics. It has been suggested that these differences should be reflected in the metabolic capacities and energetic budgets associated with flight in both sexes. In this study, we analyzed the relationship between wing morphological variation and metabolic performance, flight aerodynamics and energetic reserves in females and males of Heliconius charithonia over two years. The results confirm the presence of wing shape sexual dimorphism, but also show an unexpected sex-related annual variation in wing shape, mirrored in the metabolic condition (resting metabolic rate) of individuals. However, contrary to expectation, intersexual variations in wing shape are not related to differences between the sexes in terms of flight aerodynamics, flight metabolic rates, or energetic reserves (carbohydrates, lipids and proteins). Our results indicate a considerable plasticity in H. charithonia wing shape, which we suggest is determined by a trade-off between environmental pressures and reproductive restriction of each sex, maintaining an optimum flight design. Finally, similarities in metabolic rates between young and older males and females in both years may be a consequence of the ability of Heliconius species to feed on pollen.

Aircraft Cabin Pressurization and Concern for Non-Arteritic Anterior Ischemic Optic Neuropathy.

BACKGROUND: Cabin pressurization is the process by which aircraft maintain a comfortable and safe environment for passengers flying at high altitudes. At high altitudes, most patients can tolerate changes in pressurization; however, passengers at high risk of hypoxia may experience ischemic events. The purpose of this study was to evaluate variations in pressurization of commercial aircraft at cruising altitude and describe its relevance in relation to patients with non-arteritic anterior ischemic optic neuropathy (NAION).METHODS: Altimeters were used to measure altitude and cabin altitude at cruising altitude aboard 113 commercial flights, including 53 narrow-body and 60 wide-body aircraft.RESULTS: Cabin altitude ranged from 4232 ft to 7956 ft at cruising altitudes ranging from 30,000 ft to 41,000 ft. The mean cabin altitude for all flights was 6309 876 ft. Narrow-body aircraft had a significantly higher mean cabin altitude (6739 829 ft) compared to wide-body aircraft (5929 733 ft). For all flights, the mean cruising altitude was 35,369 2881 ft with narrow-body aircraft cruising at a lower altitude of 34,238 2389 ft compared to wide-body aircraft at 36,369 2925 ft. Newer generation aircraft had a mean cabin altitude of 6066 837 ft, which was lower than the mean cabin altitude of older aircraft (6616 835 ft).DISCUSSION: Innovation in flight design has offered the ability for aircraft to fly at greater altitudes while maintaining lower cabin altitude. Those at high risk of hypoxia-induced complications may consider aircraft type when air travel is required.Nazarali S, Liu H, Syed M, Wood T, Asanad S, Sadun AA, Karanjia R. Aircraft cabin pressurization and concern for non-arteritic anterior ischemic optic neuropathy. Aerosp Med Hum Perform. 2020; 91(9):715719.

MORPHOLOGICAL ANALYSIS OF LANDSLIDES IN EXTREME TOPOGRAPHY BY UAS-SfM: DATA ACQUISITION, 3D MODELS AND CHANGE DETECTION

Abstract. Landslides are one major kind of natural disasters and geomorphological processes on Earth’s surface. Accurate geodetic observations are crucial for understanding morphological changes, providing a quantitative basis of further research in surface process and hazard management. In recent years, the development of UAVs and SfM technology enhance research to build high quality digital surface models of landforms with low budget and efficiency. In areas of extreme topography where landslides occur on steep slopes, however, it is required to specifically design the UAV-SfM workflow to keep the data quality. This study aims to use UAS-SfM workflow to develop a low-cost, efficient methodology to detect detailed morphological change of landslide morphology in extreme topography. The study focuses on examining results of different flight design and GCPs distribution geometry, which are important components in the workflow. In addition, we applied a mathematical model to compare point clouds to calculate volumetric change of the landslide with reduced distortion.

An At-Scale Tailless Flapping-Wing Hummingbird Robot. I. Design, Optimization, and Experimental Validation

Designing a hummingbird-inspired, at-scale, tail-less flapping-wing micro aerial vehicle (FWMAV) is a challenging task in order to achieve animallike flight performance under the constraints of size, weight, power, and actuation limitations. It is even more challenging to design such a vehicle with a pair of independently controlled wings equipped with a total of only two actuators. This article details a systematic solution for the design optimization and prototyping of such FWMAVs. The proposed solution covers the complete system models and analysis of wing-actuation dynamics, control authorities, body dynamics, mechanical limitations, and electrical constraints. Each subsystem, as well as the overall system, is experimentally validated. This comprehensive approach can facilitate the design of such FWMAVs with different optimization goals. To demonstrate the effectiveness of the proposed approach, in this article, we conduct three different design optimization tasks, which yield three different prototype systems: optimizing the lift-to-weight ratio, optimizing control bandwidth, and optimizing control authority. We first construct a vehicle with an optimized lift-to-weight ratio. Based on it, the other two platforms with different design optimization goals are presented for better flight performance. Flight tests were performed on each prototype to validate their flight performance and design goals. Compared to optimized control bandwidth, we demonstrate that the vehicle with optimized control authorities is significantly more capable in terms of flight performance. It shows sustained stable flight in both hovering and heavy load carrying (more than 60% of the vehicle's total weight), which is hard for the other two platforms to achieve.

Reducing systematic dome errors in digital elevation models through better UAV flight design

AbstractIt is well established that digital elevation models (DEMs) derived from unmanned aerial vehicle (UAV) images and processed by structure from motion may contain important systematic vertical errors arising from limitations in camera geometry modelling. Even when significant, such ‘dome’‐shaped errors can often remain unnoticed unless specific checks are conducted. Previous methods used to reduce these errors have involved: the addition of convergent images to supplement traditional vertical datasets, the usage of a higher number of ground control points, precise direct georeferencing techniques (RTK/PPK) or more refined camera pre‐calibration. This study confirms that specific UAV flight designs can significantly reduce dome errors, particularly those that have a higher number of tie points connecting distant images, and hence contribute to a strengthened photogrammetric network. A total of 22 flight designs were tested, including vertical, convergent, point of interest (POI), multiscale and mixed imagery. Flights were carried out over a 300 × 70 m2 flat test field area, where 143 ground points were accurately established. Three different UAVs and two commercial software packages were trialled, totalling 396 different tests. POI flight designs generated the smallest systematic errors. In contrast, vertical flight designs suffered from larger dome errors; unfortunately, a configuration that is ubiquitous and most often used. By using the POI flight design, the accuracy of DEMs will improve without the need to use more ground control or expensive RTK/PPK systems. Over flat terrain, the improvement is especially important in self‐calibration projects without (or with just a few) ground control points. Some improvement will also be observed on those projects using camera pre‐calibration or with stronger ground control. © 2020 John Wiley & Sons, Ltd.

Effects of Different Staircase Design Factors on Evacuation of Children from Kindergarten Buildings Analyzed via Agent-Based Simulation.

Staircase design is critical to the evacuation of children. Through an agent-based simulation, this study focused on the relationship between staircase design factors and evacuation efficiency in a multi-story kindergarten. A quantitative study was conducted on three critical architectural design factors: stair flight width, positional relationship, and design pattern of the juncture between the staircase and the corridor. The findings were as follows. (1) When the stair flight width ranges from 0.7 to 1.0 m, an increase in this width can improve evacuation efficiency significantly; when the width ranges from 1.1 to 1.4 m, evacuation efficiency is improved continuously, but an increase in this width range has a diminishing effect on evacuation efficiency; when the width is greater than 1.7 m, a further increase has an adverse effect on evacuation efficiency, because such a staircase space allows overtaking behaviors. (2) Under the same stair flight width conditions, evacuation efficiency is higher when the staircase and corridor are perpendicular to each other than when they are parallel, because the natural steering angle of the children was preserved during their evacuation. (3) The cut corner and rounded corner designs between the staircase and corridor improved evacuation efficiency and alleviated the congestion at bottleneck positions; the evacuation efficiency continued to rise with an increase in the cutting angle. These findings are expected to provide a useful reference for the evacuation design of kindergarten buildings and for emergency evacuation management.

Design and Verification of the Feet Design used for the “Heat Flow Property Package Instrument” (HP3) on-board the Mars Mission InSight

The HP3 instrument measures the thermal flux through the Martian crust using a penetration probe. Launched on the InSight mission in 2018, HP3 was deployed for penetration activities in the beginning of 2019. During initial operation, the instrument is vulnerable to slip, due to a combination of low system mass (3.3 kg on Earth), shocks delivered by the penetration probe’s action, and the possibility of an inclined attitude on the surface. An uncontrolled position change of the instrument on the surface can reduce the scientific output and even lead to a loss of the experiment if the probe’s supporting structure moves laterally. Naturally, the design of the feet has major impact on the total amount of slippage. A new design for the feet with a high slippage resistance capability at a low level of complexity and mass was developed for this instrument’s supporting structure. The design provides sufficient slippage resistance while fulfilling the challenging set of requirements for a Mars surface mission. The design was verified by test campaigns which emulate launch environments and operational behavior on Mars. This paper gives a detailed overview of the HP3 instrument itself, the relevant requirements, the complex different test campaigns and the final flight design.

Artificial Lumbered Flight for Autonomous Soaring

Soaring strategies are redefining the flight capabilities of small-class fixed-wing unmanned aerial vehicles. This paper presents an autonomous soaring strategy that exploits updraft energy independent of the classification of an updraft. The strategy employs an artificial lumbered flight algorithm (ALFA) that weighs near-field updraft velocity estimates and mission priorities in real time for navigation through a wind field. This work addresses the question of ALFA’s ability to handle classified and unclassified updrafts. Instead of explicitly considering the classification of the updraft, the ALFA measures updraft data along an aircraft’s flight path, estimates updraft data ahead of the aircraft, generates candidate flight paths ahead of the aircraft for evaluation, and then selects the best candidate flight path based on a reward function. This paper describes the structure of ALFA and the tuning processes used for the updraft estimator and the reward function. Flight results demonstrate the ALFA’s ability to harvest atmospheric energy from classified and unclassified updrafts. The results discuss several produced flight behaviors in more detail, examining the ALFA’s effectiveness when flying among classified updrafts. Finally, this paper concludes that harvesting energy from the atmosphere with real-time local decision making is practically feasible and suggests that autonomous flight design and control strategies for small-class fixed-wing aircraft will likely be driven by harvesting energy from the atmosphere.

A combined physical and DEM modelling approach to improve performance of rotary dryers by modifying flights design

To characterize the drying process in the Gol-E-Gohar pelletizing plant ball mill the material veiling profile (material showering) was studied by physical modeling and DEM. To simulate the trajectory of particles in the dryer in a reasonable period of time the GPU parallel processing was implemented in the DEM codes. After calibration of DEM parameters by using the model dryer, various flight designs were then employed in the simulation to find an appropriate veiling profile. It was found that by decreasing the release angle of flights from 70° to less than 40° the coverage of hot gas tunnel cross section by particles increases from 41.6% to 89.6%. The simulations also indicated that by changing the flight edge from the raised edge to the rectangular tooth-like type, the coverage of hot gas tunnel cross section could reach 97.1% and more uniform veiling profile could be obtained. Evaluation of the grinding performance over a period of 15 months showed an increase of 17 t/h in the throughput in the case of the new flights in mill No. 1 while for the same period, mill No.2 experienced a decrease of 7 t/h in the throughput with the original flights for the same feed.

Flight tests of the computational reconfigurable imaging spectrometer

We present the first flight data using a Computational Reconfigurable Imaging Spectrometer (CRISP) system. CRISP (Sullenberger et al., 2017) is a novel hyperspectral thermal imaging spectrometer that uses computational imaging to enable high sensitivity measurements (via spectral multiplexing) from smaller, noisier, and less-expensive components (e.g., uncooled microbolometers) making it useful on small space and air platforms with strict size, weight, and power requirements. In contrast to other multiplexing hyperspectral solutions (e.g Michelson interferometer), it does not require moving parts, allowing for a robust system without aggressive engineering solutions. We discuss flight system design and calibration. Spectra from ground targets and gaseous species are compared to performance expectations. We successfully demonstrate the ability to extract airborne longwave infrared (8–12 μm) imagery and spectra from an uncooled camera-based CRISP system.

Spatial Audio Cueing Aids Pilot Navigation during Simulated Helicopter Flight in Degraded Visual Environments

Aviation mishaps resulting from degraded visual environments (DVEs) represent a significant loss in military personnel and aircraft every year. DVEs can be caused by any type of environmental condition (e.g., sand, snow, fog) that obstructs the pilot’s vision, and can cause spatial disorientation. The current study was a tri-service effort exploring the implementation of spatial audio cueing to aid pilot navigation in DVEs. Directional cueing (i.e., indicating the location of target waypoints) was achieved by spatializing an auditory stimulus. Pilots performed multiple flight maneuvers in a full-motion UH-60 Black Hawk flight simulator at the U.S. Army Aeromedical Research Laboratory. Performance was assessed by measures of error, completion time, and failure rate. Findings from this study provide information on sensory cueing display design for helicopter flight in DVEs.

Research on Structural Design of Land and Space Inspection Robot

The quadrotor is an aircraft that can take off and land vertically, and it is often used for target search and tracking of tasks. In order to further enhance the flexibility and endurance of the drone, a land and air inspection robot is designed. The land and air inspection robot is combined by a drone and a smart car. While driving, if the obstacle is not the case, the robot uses the landline equipment, otherwise, the rotor is used. The motion simulation analysis is carried out through 3D modeling to achieve optimal mechanical design. Through flight design calculation, the self-anti-jamming flight algorithm is obtained. According to the actual measurement, the design of the land and air inspection robot can achieve the expected results, and it can be widely used in the inspection tasks of factory monitoring, anti-terrorism, search and rescue, forest fire prevention and other occasions.

Formation flight design for a LISA-like gravitational wave observatory via Cascade optimization

Laser Interferometer Space Antenna (LISA) is a project to detect and measure gravitational waves. The project has three spacecraft flying in a formation of near equilateral triangle in a heliocentric orbit trailing Earth. Many sources of perturbations cause the configuration to deviate from the nominal. This paper studies the formation design problem for a LISA-like mission by considering ephemeris-based dynamics. This type of mission is well-known for addressing several strict mission requirements under the realistic dynamics. The problem is formulated as optimizing multiple mission performance indices. It is observed that some indices are correlated with each other, whereas some indices have different sensitivities with respect to the semi-major axis. Therefore, the problem is transformed into a two-step cascade single-objective optimization, in which the optimal solution of the first optimization problem is fed to the second optimization as initial value. In addition, the major perturbing celestial bodies are picked up to make a simplified but accurate enough dynamics to speed up the optimization. Numerical examples verify the analysis and show the effectiveness of the optimization procedure. The influences of mission lifetime and spatial scales on the optimal solutions are also presented.