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Autonomous unmanned air vehicles (UAVs) are critical to current and future military, civil, and commercial operations. Despite their importance, no previous textbook has accessibly introduced UAVs to students in the engineering, computer, and science disciplines--until now. Small Unmanned Aircraft provides a concise but comprehensive description of the key concepts and technologies underlying the dynamics, control, and guidance of fixed-wing unmanned aircraft, and enables all students with an introductory-level background in controls or robotics to enter this exciting and important area. The authors explore the essential underlying physics and sensors of UAV problems, including low-level autopilot for stability and higher-level autopilot functions of path planning. The textbook leads the student from rigid-body dynamics through aerodynamics, stability augmentation, and state estimation using onboard sensors, to maneuvering through obstacles. To facilitate understanding, the authors have replaced traditional homework assignments with a simulation project using the MATLAB/Simulink environment. Students begin by modeling rigid-body dynamics, then add aerodynamics and sensor models. They develop low-level autopilot code, extended Kalman filters for state estimation, path-following routines, and high-level path-planning algorithms. The final chapter of the book focuses on UAV guidance using machine vision. Designed for advanced undergraduate or graduate students in engineering or the sciences, this book offers a bridge to the aerodynamics and control of UAV flight.

Aerial robots can autonomously collect temporal and spatial high‐resolution environmental data. This data can be utilized to develop mathematical ecology models to understand the impact of climate change on the habitat. In case of drone malfunction, the incorporated materials can threaten vulnerable environments. The recent introduction of transient robotics enables the development of biodegradable, environmental‐sensing drones capable of degrading in their environment. However, manufacturing methods for environmental‐sensing transient drones are rarely discussed. Herein, a manufacturing framework and material selection process featuring biopolymer‐based, high‐strength composite cryogels, and printed carbon‐based electronics for transient drones are highlighted. It is found that gelatin‐ and cellulose‐based cryogels mechanically outperform other biopolymer composites while having a homogeneous microstructure and high stiffness‐to‐weight ratio. The selected materials are used to manufacture a flying‐wing air‐frame, while the incorporated sensing skin is capable of measuring the elevons’ deflection angles as well as ambient temperature. It is demonstrated in the results how gelatin–cellulose cryogels can be used to manufacture lightweight transient drones, while printing carbon‐conductive electronics is a viable method for designing sustainable, integrated sensors. The proposed methods can be used to guide the development of lightweight and rapidly degrading robots, featuring eco‐friendly sensing capabilities. An interactive preprint version of the article can be found here: https://doi.org/10.22541/au.167506513.33779420/v1. Transient robots are biodegradable tools toward sustainable environmental monitoring in remote locations. Herein, manufacturing techniques are proposed to fabricate aerial robots from nonfossil, high‐performance, and lightweight biopolymer composite cryogels. By embodying inkjet‐printed carbon‐conductive sensors, proprioceptive and exteroceptive sensing capabilities can be added and the aerial robots data transmission and flightworthiness are demonstrated.

The current study presents a holistic technology evaluation and integration methodology for enhancing the aerodynamic efficiency and performance of a tactical, fixed-wing Blended-Wing-Body (BWB) Unmanned Aerial Vehicle (UAV) through the synergetic integration of several aerodynamic and performance-enhancing technologies. Based upon several individual technology investigations conducted in the framework of the EURRICA (Enhanced Unmanned aeRial vehicle platfoRm using integrated Innovative layout Configurations And propulsion technologies) research project for BWB UAVs, a structured Technology Identification, Evaluation, and Selection (TIES) is conducted. That is, a synergetic examination is made involving technologies from three domains: configuration layout, flow control techniques, and hybrid-electric propulsion systems. Six technology alternatives, slats, wing fences, Dielectric Barrier Discharge (DBD) plasma actuators, morphing elevons, hybrid propulsion system and a hybrid solar propulsion system, are assessed using a deterministic Multi-Attribute Decision Making (MADM) framework based on Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). Evaluation metrics include stall velocity (Vs), takeoff distance (sg), gross takeoff weight (GTOW), maximum allowable GTOW, and fuel consumption reduction. Results demonstrate that certain configurations yield significant improvements in low-speed performance and endurance, while the corresponding technology assumptions and constraints are, respectively, discussed. Notably, the configuration combining slats, morphing control surfaces, fences, and hybrid propulsion achieves the highest ranking under a performance-future synergy scenario, leading to over 25% fuel savings and more than 100 kg allowable GTOW increase. These findings provide quantitative evidence for the potential of several technologies in future UAV developments, even when a novel configuration, such as BWB, is used.

The article presents the results of preliminary studies of the parameters of the return flight trajectory of a rocket plane for suborbital tourist flights into space. The rocket plane is designed as a tailless vehicle and has an unconventional arrangement of control surfaces: elevons and side plates that can rotate. The main aim of the research presented in this paper is to investigate the dynamic stability of the rocket plane and the response to control in the return suborbital flight. The secondary objective is to study the behavior of the rocket plane with respect to the initial state of the return flight. The key parameters taken into account in this study are the Mach number and G-load. Moreover, a study of the trim condition, dynamic stability and response to control of a rocket plane in the low part of the stratosphere is presented. The tests were carried out using a numerical simulation of the flight of a rocket plane. Dynamic stability was determined on the basis of time history analysis, and the results were compared with the results obtained by solving the eigenvalues problem. The results revealed that the rocket plane should be equipped with a Stability Augmentation System to improve short period damping at supersonic speeds at moderate altitudes. It can also be concluded that the maximum load G and Ma do not occur at the same height of flight. In terms of the effectiveness of the control surfaces, they start working at an altitude of 55 km. Due to the speed regime, the obtained results can be useful in the design of such objects as rocket planes, highly maneuverable and supersonic aircraft.

Purpose The purpose of this research is a study into a mathematical approach of a tailless aircraft dynamic stability analysis. This research is focused on investigation of influence of elevons (elevator) on stability derivatives and consequently on the aircraft longitudinal dynamic stability. The main research question is to determine whether this impact should be taken into account on the conceptual and preliminary stage of the analysis of the longitudinal dynamic stability. Design/methodology/approach Aerodynamic coefficients and longitudinal stability derivatives were computed by Panukl (panel methods). The analysis of the dynamic stability of the tailless aircraft was made by the Matlab code and SDSA package. Findings The main result of the research is a comparison of the dynamic stability of the tailless aircraft for different approaches, with and without the impact of elevator deflection on the trim drag and stability derivatives. Research limitations/implications This paper presents research that mostly should be considered on the preliminary stage of aircraft design and dynamic stability analysis. The impact of elevons deflection on the aircraft moment of inertia has been omitted. Practical implications The results of this research will be useful for the further design of small tailless unmanned aerial vehicles (UAVs). Originality/value This research reveals that in case of the analysis of small tailless UAVs, the impact of elevons deflection on stability derivatives is bigger than the impact of a Mach number. This impact should be taken into consideration, especially for a phugoid mode.

In this paper we present a centralised flight-by-wire system based on μ -synthesis approach to the longitudinal flight motion of our experimental flying wing unmanned aerial vehicle (UAV), P15035 series. The challenge associated with our UAV is related to the fact that all motions of our UAV are controlled by two independently-actuated-ailerons namely elevons, together with its throttle. The scope of this research, nonetheless, falls within the area of elevon control based on the trimmed linear longitudinal flight modes obtained experimentally while throttle was set constant. The reason for considering μ -synthesis autopilot is to minimise the effects of uncertainty in modelling by maximising the amount of tolerable uncertainty within our system’s bandwidth as we aim to minimise the structure singular value μ of the corresponding robust performance associated with the uncertain systems. Second, it also provides flexibility in tunning due to the absence of partitioning model of MIMO system. Hence the entire autopilot was designed by keeping the system model as a whole. We also perform a comparative study with respect to well-known H ∞ mixed sensitivity autopilot. Our study indicates that the μ synthesis autopilot designed possesses better performances both in time and frequency domain as indicated by reasonably quick settling time in the absence of overshoot while still maintaining better robust stability margin.

This paper aims at studying the control surfaces of the STRATOFLY project reference aircraft, funded by the European Commission, under the framework of Horizon 2020 plan. The values of aerodynamic coefficients in a wide range of flow free-stream conditions are stored in the aircraft aerodynamic database. The research goal is to update a pre-existent database that was developed with fixed control surfaces using the six control surfaces deflection as input. Different Mach numbers determine different flow regimes: subsonic, transonic, supersonic, and hypersonic. In subsonic, transonic and low supersonic regimes a vortex-lattice solver is used to obtain the global coefficients assuming an unviscous flow on a simplified model. In hypersonic flow a build-up approach is applied: the control surfaces deflection contribution is developed by assuming a two-dimensional flow on the airfoil and by applying shock-expansion theory on the geometry. Then the paper analyses results showing stability and L/D results. The final paragraph focuses on trimmability at cruise Mach. No trimmed solution is obtainable to optimize the propulsive system. The solution proposed to solve this issue is to extend the four elevons: larger elevons are found to be able to trim the vehicle at the desired angle of attack.

Purpose This paper aims to present an aerothermodynamic analysis of a new concept of a small hypersonic airplane. Aerodynamics characteristics for different flow conditions encountered during the missions are analyzed. The effects of elevons deflection for pitch control and of the presence of engines on aerodynamic performances are also investigated for different flight conditions. The effects of boundary layer laminar–turbulent transition on aerodynamic heating are studied to preliminarily identify proper materials that can sustain the hypersonic phase. Design/methodology/approach Aerodynamic characteristics are predicted by means of the semi-empirical aerodynamic prediction code Missile DATCOM and computational fluid dynamics simulations. Computational fluid dynamics analysis is also performed to investigate aerodynamic heating phenomenon. Findings Major discrepancies between the results offered by the two methods have been registered in transonic regime, whereas in subsonic and super-hypersonic conditions, Missile DATCOM confirms to be a suitable tool for preliminary design steps. The results of the analysis show that for the identification of the materials that can sustain the hypersonic phase, the turbulent solution must be taken into account. Carbon fiber reinforced ceramics composite materials seem particularly well suited for the nose, wing and vertical tail leasing edges and control surfaces, while titanium alloys could be used for the rest of the vehicle surface. Originality/value This new concept of vehicle is designed both for point-to-point medium range hypersonic transportation and long duration suborbital space tourism missions, by integrating available technologies developed for aeronautical and space systems.

The modeling, stability, and control characteristics of a large scale highly flexible solar-powered UAV with distributed all-span multielevons were presented. A geometrically nonlinear intrinsic beam model was introduced to establish the structural/flight dynamics coupled equation of motion (EOM); based on it, the explicit decoupled linear flight dynamics and structural dynamics EOM were derived through mean axis theory. Undeformed, deformed, and flexible models were compared through trimming and modal analysis. Since the deformation of wing has increased the UAV’s moment of inertia about the pitch axis, the frequency of short period mode has obviously decreased for the deformed model. The serious coupling between short period mode and 1st bending mode also significantly influences the roots of short period mode of flexible model. So flexible model was the only one which is able to accurately estimate the flight dynamics behaviors and was selected as the later control model. Forty distributed elevons and LQG/LTR controller were employed to control the attitude and suppress the aeroelastic deformation of the UAV simultaneously. The dynamics performance, robustness, and simulation results show that they were suitable for large scale highly flexible solar-powered UAV.

Abstract The application of circulation control (CC) manoeuvre effectors to a tailless flight vehicle enables the possibility of providing control moments about three axes without the use of conventional control surfaces. Strong similarities exist between the use of split flap elevons and CC units used as trailing edge devices for the provision of three-axis control. Both control types can produce independent roll and pitching moments by lateral symmetric operation. Yawing moments can also be produced by simultaneous blowing from upper and lower CC slots increasing the local section axial force. An existing datasheet method for predicting the lift and pitching moment increments for plain flaps is modified to support some aspects of sizing CC devices; however, there are some significant gaps such as high fidelity models for the prediction of Coanda jet separation from the curved trailing edge, which require further research. A case study is presented in which the provision of three-axis control moments using CC is evaluated for a tailless 20 kg class gas-turbine-powered model aircraft. Wind tunnel experiments are used to demonstrate the validity of the aerodynamic design of the vehicle and the ability to produce control moments from CC sufficient to meet basic trim and manoeuvre requirements. The peak values of CC control gains achieved for δ CL/ δ Cμ is 20 and the control gain for δ CD/ δ Cμ for use as part of a ‘thrust’-based yaw control scheme from blowing from both upper and lower slots is low (∼0.5); however this is sufficient to trim the case study aircraft at 8° of sideslip at cruise conditions with 10 per cent mass flow bleed from the engine. For lateral symmetric operation of CC controls, the change in pitching moment with control lift increment has been shown to be similar for both CC and flaperon devices