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RAMESH, P. S., i J. V. MURUGA LAL JEYAN. "Comparative Analysis of Fixed-Wing, Rotary-Wing and Hybrid Mini Unmanned Aircraft Systems (UAS) from the Applications Perspective". INCAS BULLETIN 14, nr 1 (7.03.2022): 137–51. http://dx.doi.org/10.13111/2066-8201.2022.14.1.12.
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Mini Unmanned Aircraft Systems (UAS) present distinct design challenges due to their man-portable, field-deployable profile. The implications of various unmanned aerial vehicle (UAV) design configurations for Mini UAS applications are discussed in this study. Fixed-wing, rotary-wing, and hybrid Mini UAS design configurations are analysed and compared based on performance parameters specified by various manufacturers to assess appropriateness for military and civil applications. Mini UAS designed for military applications can meet most requirements in the civil domain. However, the reverse is seldom feasible because of several restrictions imposed by combat conditions. Fixed-wing Mini UAS have significant limitations for military applications, primarily because of launch and recovery considerations. For civil applications, the fixed-wing configuration provides multiple advantages. The benefit of the rotary-wing configuration's compact size to overcome various battlespace restrictions for military applications does not translate to other performance parameters, and this is a serious limitation for its applications. The hybrid profile has significant design advantages that can be leveraged for both military and civil applications. The interrelation between design, end-use requirements and terrain restrictions presented in the paper provides an insight into the implications of the design configurations of Mini UAS for various applications.
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Xu, Ronghua, Sixiao Wei, Yu Chen, Genshe Chen i Khanh Pham. "LightMAN: A Lightweight Microchained Fabric for Assurance- and Resilience-Oriented Urban Air Mobility Networks". Drones 6, nr 12 (16.12.2022): 421. http://dx.doi.org/10.3390/drones6120421.
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Rapid advancements in the fifth generation (5G) communication technology and mobile edge computing (MEC) paradigm have led to the proliferation of unmanned aerial vehicles (UAV) in urban air mobility (UAM) networks, which provide intelligent services for diversified smart city scenarios. Meanwhile, the widely deployed Internet of drones (IoD) in smart cities has also brought up new concerns regarding performance, security, and privacy. The centralized framework adopted by conventional UAM networks is not adequate to handle high mobility and dynamicity. Moreover, it is necessary to ensure device authentication, data integrity, and privacy preservation in UAM networks. Thanks to its characteristics of decentralization, traceability, and unalterability, blockchain is recognized as a promising technology to enhance security and privacy for UAM networks. In this paper, we introduce LightMAN, a lightweight microchained fabric for data assurance and resilience-oriented UAM networks. LightMAN is tailored for small-scale permissioned UAV networks, in which a microchain acts as a lightweight distributed ledger for security guarantees. Thus, participants are enabled to authenticate drones and verify the genuineness of data that are sent to/from drones without relying on a third-party agency. In addition, a hybrid on-chain and off-chain storage strategy is adopted that not only improves performance (e.g., latency and throughput) but also ensures privacy preservation for sensitive information in UAM networks. A proof-of-concept prototype is implemented and tested on a micro-air–vehicle link (MAVLink) simulator. The experimental evaluation validates the feasibility and effectiveness of the proposed LightMAN solution.
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Wu, Yan, Dejin Kong, Qian Wang i Gang Li. "Performance Analysis of UAV-Assisted Hybrid FSO/RF Communication Systems under Various Weather Conditions". Sensors 23, nr 17 (3.09.2023): 7638. http://dx.doi.org/10.3390/s23177638.
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Nowadays, unmanned aerial vehicle (UAV) communication systems are commonly considered as one of the key enabling technologies for 6G. The hybrid free space optical (FSO)/radio frequency (RF) system has the advantages of both FSO and RF links to improve communication system performance, and the relay-assisted system adopts multi-hop transmission and cooperative diversity methods to extend communication coverage. Thus, a joint consideration of UAV-assistedUAV assisted relay in hybrid FSO/RF transmission is meaningful. In this paper, we aim to analyze the performance of UAV-assisted multi-hop parallel hybrid FSO/RF communication systems with and without pointing errors (PE) in terms of Bit Error Rate (BER) and outage probability. In our considered system, the FSO sub-link adopts the Exponential Weibull turbulence model and the RF sub-link suffers the Nakagami fading model. With these, new mathematical formulas of both BER and outage probability are derived under the UAV-assisted hybrid FSO/RF with different modulation methods. Through numerical evaluationnumerical simulations, the performances of UAV-assisted hybrid FSO/RF systems are analyzed under different weather conditions, modulation methods, optical receiver aperture, RF fading parameters, pointing errors, and relay structures. The results demonstrate that (1) compared to hybrid FSO/RF direct links, UAV-assisted hybrid FSO/RF systems can further improve system performance; (2) the performance of UAV-assisted hybrid FSO/RF systems varies with different relay structures; (3) large receiver aperture and RF fading parameters can further improve the communication performance of hybrid FSO/RF direct links and UAV-assisted hybrid FSO/RF systems.
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Gorodetskiy, A., i M. Grabovskiy. "Technological qualities of root crops and economic efficiency of growing sugar beet hybrids by the KWS company in the conditions of "Rasavske" Ltd. of Kaharlyk district, Kiev region". Agrobìologìâ, nr 2(142) (22.12.2018): 34–39. http://dx.doi.org/10.33245/2310-9270-2018-142-2-34-39.
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The paper deals with the results of research on the study of the technological traits changes in foreign hybrids root crops of the KWS company sugar beet enterprises under the influence of long-term storage and their economic efficiency. The conducted researches are especially relevant due to insufficiently studied issues of changes in the technological traits of the root crops of the newest hybrids during their storage in the crutches on the field or at the sugar factory. Estimation of new hybrids of sugar beet by regions of the Forest-steppe allows to predict the genetically determined degree of their plasticity and stability both in the yield and the quality. Hybrids with higher resistance to extreme temperatures are especially valuable. The researches were carried out during 2014–2015 at the "Rasavske" Ltd. of Kaharlyk district, Kyiv region. The sugar content in the root crops increased from 1.6% in the Alyona hybrid to 5.9 % in the Daria hybrid and 6.1 % in the Coryda hybrid, due to the loss of moisture during their prolonged storage. The content of soluble dry matter in the root crops increased from 1.7 % in the Alyona hybrid to 7.7 % in the Coryda hybrid for the same reason. The conducted calculations of cell juice quality showed that long-term storage resulted in the highest growth of this indicator by 8.2 % in the Cesaria hybrid and by 7.5 % in the Acatsia hybrid. In the Alyona hybrid, the growth rate of cell juice quality was only 0.8 %, while the Corida hybrid had the quality of the previous level. In the Olesya hybrid, this indicator decreased by 1.8 % compared with the previous determination period (October 10). The costs of growing root crops ranged from 17,859 to 20,726 UAH/ha. The highest profit was 17435 UAH/ha and the profitability level was 86.3 % for the Alyona hybrid, while the lowest economic efficiency figures were for the profit of 10,201 UAH/ha and the profitability level of 53.7 % in the Carmelite hybrid. The highest rates of the technological traits of root crops during the long-term storage of sugar beet were determined in the Alyona hybrid. The highest yield of root crops was in the Daria hybrid – 79.8 t/ha. According to the indicators of economic efficiency the Alona hybrid was the best in terms of profit (17,435 UAH/ha) and the profitability level of 86.3 %. Key words: sugar beet, hybrids, productivity, yield, sugar content, technological traits, profit, profitability level.
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Goh, Chi Yen, Chee Yen Leow i Rosdiadee Nordin. "Energy Efficiency of Unmanned Aerial Vehicle with Reconfigurable Intelligent Surfaces: A Comparative Study". Drones 7, nr 2 (31.01.2023): 98. http://dx.doi.org/10.3390/drones7020098.
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Unmanned aerial vehicles (UAVs) and reconfigurable intelligent surfaces (RIS) are the promising emerging technologies proposed for the 6th-Generation (6G) network to improve the capacity, reliability, and coverage of wireless communications. By integrating the UAV with RIS (RIS-UAV), the three-dimensional (3D) mobility of the UAV can be leveraged to establish strong line-of-sight links with the ground nodes, while the RIS intelligently reflect the signals toward the desired directions. However, the existing literature on RIS-UAV systems mainly assumes the use of passive elements, which suffers from the double path-loss problem. The use of active elements in RIS, which could improve the reflected link performance at the cost of increased energy consumption, has not been considered for the RIS-UAV system. Further, the energy efficiency of a RIS-UAV with active elements remains as an open direction because there is a need to investigate the feasibility of either an active or hybrid RIS-UAV implementation. This paper proposes active and hybrid RIS-UAVs and investigates the energy efficiencies of active and hybrid RIS-UAVs in comparison with existing passive RIS-UAVs and conventional UAV relays. The numerical results reveal that the proposed hybrid and active RIS-UAV relaying schemes can provide up to 14 times and 26 times improvement as compared to the passive RIS-UAV, respectively. As opposed to the active RIS-UAV that requires a larger power budget, half-duplex UAV relays that have a lower spectral efficiency, and full-duplex UAV relays that suffer from self-interference, the hybrid RIS-UAV emerges as a promising option to assist the ground communication system.
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Xia, Chuying, Xin Fu i Shijie Zhai. "Research on power configuration scheme of parallel hybrid oil-electric power system for tilt- rotor UAV". Journal of Physics: Conference Series 2478, nr 10 (1.06.2023): 102028. http://dx.doi.org/10.1088/1742-6596/2478/10/102028.
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Abstract The tilt-rotor UAV is a new type of unmanned aerial vehicle that has both the hovering capability of a rotary-wing UAV and the high-speed cruising flight capability of a fixed- wing UAV. Through the tilting system of the UAV, different working states can be switched: during the take-off and landing phases, the rotor axis is perpendicular to the ground, thus realizing aerial hovering, forward and backward flight and side flight. In the cruise flight phase, the rotor axis is perpendicular to the flight direction, thus achieving the flight attitude of a fixed-wing aircraft. The hybrid power system is a composite power system that combines fuel power with electrical power. By applying the oil-electric hybrid power system on the tilt-rotor UAV, it can combine the advantages of long range and long range of fuel power and low noise and pollution of electric power. In this paper, the tilt-rotor UAV parallel oil-electric hybrid power system power configuration scheme is studied. Firstly, the three operating modes of the oil-electric hybrid power system are introduced, including hybrid drive, drive charging and pure oil drive. The power requirements of the tilt-rotor UAV in vertical takeoff and landing, fixed-wing cruise and other flight phases are calculated, and the correspondence between the UAV flight status and the hybrid power system operation mode is established according to the working characteristics of the tilt-rotor UAV and the hybrid power system operation mode. The power configuration method for each flight phase is finally determined, and the process of the overall power configuration realization of the threshold value is described in detail.
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Radócz, László, Atala Szabó, András Tamás, Árpád Illés, Csaba Bojtor, Péter Ragán, Attila Vad, Adrienn Széles, Endre Harsányi i László Radócz. "Investigation of the Detectability of Corn Smut Fungus (Ustilago maydis DC. Corda) Infection Based on UAV Multispectral Technology". Agronomy 13, nr 6 (30.05.2023): 1499. http://dx.doi.org/10.3390/agronomy13061499.
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Corn smut fungus (Ustilago maydis [DC.] Corda) is a globally widespread pathogen affecting both forage and sweet maize hybrids, with higher significance in sweet maize. Remote sensing technologies demonstrated favorable results for disease monitoring on the field scale. The study focused on the changes in vegetation index (VI) values influenced by the pathogen. In this study, four hybrids, two forage maize and two sweet maize hybrids were examined. Artificial infection was carried out at three different doses: a low (2500 sporidium number/mL), medium (5000 sporidium number/mL) and high dose (10,000 sporidium number/mL) with a non-infected control plot for each hybrid. The experimental plots were monitored using a multispectral UAV sensor of five monochrome channels on three different dates, i.e., 7, 14 and 21 days after infection. Five different indices (NDVI, GNDVI, ENDVI, LCI, and NDRE) were determined in Quantum GIS 3.20. The obtained results demonstrated that the infection had a significant effect on the VI values in sweet maize hybrids. A high-dose infection in the Dessert R 73 hybrid resulted in significantly lower values compared to the non-infected hybrids in three indices (NDVI, LCI and GNDVI). In the case of the NOA hybrids, GNDVI and ENDVI were able to show significant differences between the values of the infection levels.
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Tomashuk, O. "Economic efficiency of growing corn hybrids for grain by different soil tillage technologies". Feeds and Feed Production, nr 87 (7.06.2019): 144–50. http://dx.doi.org/10.31073/kormovyrobnytstvo201987-22.
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The article presents indicators of the economic efficiency of various technologies for growing corn hybrids for grain. The results of a 3-year field trial in maize of various maturity groups grown in the right-bank Forest-Steppe under different soil tillage models are highlighted. The costs of corn grain production under conventional cultivation and deep tillage, which averages 10,330 UAH per hectare of cropping area is studied. The rate of expenditures clearly correlated with the rate of hybrid productivity. High net profit of 20,119 UAH per hectare is shown when planting mid-ripening hybrid «Adevei» using intensification of the technological process. For other hybrids, conditionally net income fluctuated at the rate of 17,000 UAH per hectare. It is established that during the cultivation of corn for grain according to conventional technology and No-till, hybrids «Adevei» and «LG 3232» were characterized by the best indicators of economic efficiency.
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Farid Danial Norazman, Ahmad Hamdan Ariffin, Mohd Rahmat Firman Sahifulddin i Irfan Abdul Rahim. "Investigation of Empennage Location Effect to the Unmanned Aerial Vehicle (UAV) Structure Characteristic". Journal of Advanced Research in Applied Mechanics 113, nr 1 (22.01.2024): 1–12. http://dx.doi.org/10.37934/aram.113.1.112.
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Over the past few decades, unmanned aerial vehicles, commonly known as UAVs, have been widely used in a number of consumer and military applications, such as surveillance, tracking, monitoring, and aerial photography. Fixed-wing and rotary UAVs are the two primary categories in UAV. Interestingly, the hybridization of fixed-wing and rotary UAV gives better performance in terms of energy consumption and the needs of runaway. Designing new hybrid fixed wing-rotary UAV or hybrid vertical take-off and landing (VTOL) is challenging especially to identify the critical location in the UAV and material selection. Therefore, the objective of this research is to study the effect of empennage location and material selection on the structural strength of a hybrid VTOL UAV. The SolidWorks software was employed to design a 3D model of the UAV with different empennage locations, as well as perform a simulation of the structural strength of fibre glass, carbon fibre and kenaf for the hybrid VTOL UAV. The simulation analysis presents stress (Von Mises). The results show that the fibre glass (4.342 N/m2) at top empennage gives the best performance as compared to other parameters. In conclusion, this study is necessary to give a better picture of structural strength of composite materials and best design location in hybrid VTOL UAV for future research.
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Shen, Xueqiang, Jiwei Fan i Haiqing Wang. "Design and Simulation of Eight-Rotor Unmanned Aerial Vehicle Based on Hybrid Control System". International Journal of Aerospace Engineering 2018 (5.12.2018): 1–10. http://dx.doi.org/10.1155/2018/5306125.
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In order to control the position and attitude of unmanned aerial vehicle (UAV) better in different environments, this study proposed a hybrid control system with backstepping and PID method for eight-rotor UAV in different flight conditions and designed a switching method based on altitude and attitude angle of UAV. The switched process of hybrid controller while UAV taking off, landing, and disturbance under the gust is verified in MATLAB/Simulink. A set of appropriate controllers always matches to the flight of UAV in different circumstances, which can speed up the system response and reduce the steady-state error to improve stability. The simulation results show that the hybrid control system can suppress the drift efficiently under gusts, enhance the dynamic performance and stability of the system, and meet the position and attitude of flight control requirements.
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Moisiienko, Vira, i Vasyl Bezkorovainyi. "ECONOMIC EVALUATION OF ELEMENTS OF WINTER RAPE CULTIVATION TECHNOLOGY IN THE CONDITIONS OF RIGHT-BANK FOREST-STEPPE". Agriculture and Forestry, nr 4 (35) (24.12.2024): 17–28. https://doi.org/10.37128/2707-5826-2024-4-2.
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In the global agricultural market, winter rapeseed (Brassica napus L.) retains its leading position as a valuable and profitable oilseed crop with wide food, fodder, technical and bioenergy use. The article presents the results of scientific research conducted during 2022–2024 on typical black soil in the Forest-Steppe zone of the Right-Bank Ukraine with winter rape. The yield of three mid-season hybrids of winter rape was determined, which influenced the indicators of economic efficiency of crop cultivation. The results indicate a high economic evaluation of winter rape hybrids - InVigor 1030, Exception and Mercedes. It was found that the production costs of growing and obtaining rapeseed seeds depend on mineral nutrition (44.4%), pesticides (25.1%), soil cultivation (11.5%), seed cost (7.0%), fungicidal plant protection (5.5%) and the pricing policy of the marketing year. The cost of production is significantly higher than the production costs of growing and harvesting. The highest conditional net profit was obtained from the hybrid Exception on plots with N140P40K40 (background) + Yara Vita Brassitrel Pro, 2.0 l/ha (VVSN 31), which is 41940 UAH/ha. The combination of mineral nutrition with fungicidal treatment of plants in the flowering phase (VVSN 65) with Piktor 0.5 l/ha provided 59370 UAH/ha of net profit, and Propuls 0.9 l/ha - 57780 UAH/ha. The InVigor 1030 hybrid with the application of mineral fertilizers at the rate of N140P40K40 (background) + Yara Vita Brassitrel Pro, 2.0 l/ha (VVSN 31) provided 41605 UAH/ha of conditional net profit, and in combination with spraying in the flowering phase (VVSN 65) with Piktor 0.5 l/ha - 59035 UAH/ha and Propuls 0.9 l/ha - 57445 UAH/ha. The highest level of profitability for the InVigor 1030 hybrid is 151.3%, for the Exception hybrid - 150.1% and for the Mercedes hybrid - 138.3%.
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Bai, Mingliang, Wenjiang Yang, Dongbin Song, Marek Kosuda, Stanislav Szabo, Pavol Lipovsky i Afshar Kasaei. "Research on Energy Management of Hybrid Unmanned Aerial Vehicles to Improve Energy-Saving and Emission Reduction Performance". International Journal of Environmental Research and Public Health 17, nr 8 (23.04.2020): 2917. http://dx.doi.org/10.3390/ijerph17082917.
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The rapid development of industry results in large energy consumption and a negative impact on the environment. Pollution of the environment caused by conventional energy sources such as petrol leads to increased demand for propulsion systems with higher efficiency and capable of energy-saving and emission reduction. The usage of hybrid technology is expected to improve energy conversion efficiency, reduce energy consumption and environmental pollution. In this paper, the simulation platform for the hybrid unmanned aerial vehicle (UAV) has been built by establishing the subsystem models of the UAV power system. Under the two chosen working conditions, the conventional cruise flight mission and the terrain tracking mission, the power tracking control and Q-Learning method have been used to design the energy management controller for the hybrid UAV. The fuel consumption and pollutant emissions under each working condition were calculated. The results show that the hybrid system can improve the efficiency of the UAV system, reduce the fuel consumption of the UAV, and so reduce the emissions of CO2, NOx, and other pollutants. This contributes to improving of environmental quality, energy-saving, and emission reduction, thereby contributing to the sustainable development of aviation.
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Li, Boya, Chenxi Wu, Jian Ding i Difeng Zhu. "A rapid unmanned aerial vehicle inspection path planning method based on hybrid heuristic algorithm". E3S Web of Conferences 522 (2024): 01014. http://dx.doi.org/10.1051/e3sconf/202452201014.
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The advancement of unmanned aerial vehicle (UAV) and remote sensing technologies has fueled interest in automatic UAV inspection path planning based on inspection tasks. However, traditional methods suffer from limitations such as manual operation, inability to find optimized paths, and lengthy time consumption. We propose a rapid UAV inspection path planning method using a hybrid heuristic algorithm in this paper. First, real-world data is abstracted into a graph. Then, a hybrid heuristic algorithm is proposed and used to determine an optimal inspection path considering the tasks and power parameters of the UAV. Finally, the total power consumption for the mission is computed to assess UAV battery capacity adequacy. Experimental results demonstrate the effectiveness of our method in terms of both performance and accuracy.
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Xuefeng Chen, Xuefeng Chen, Wan Tang Xuefeng Chen, Ximin Yang Wan Tang, Lingyun Zhou Ximin Yang i Liuhuan Li Lingyun Zhou. "PSO-VFA: A Hybrid Intelligent Algorithm for Coverage Optimization of UAV-Mounted Base Stations". 網際網路技術學刊 23, nr 3 (maj 2022): 487–95. http://dx.doi.org/10.53106/160792642022052303007.
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<p>When the number of outdoor wireless users surges and fixed base stations (BSs) can hardly accommodate high-load communication traffic, unmanned aerial vehicles (UAVs) carrying BSs can provide wireless communication services, and the location deployment of the UAV-mounted BSs directly influences the reliability of network communications. For the target area scenario where the UAVs uniformly cover user nodes, we propose a hybrid intelligent coverage algorithm called PSO-VFA to optimize the coverage of a fixed number of UAV-BSs. The PSO-VFA algorithm consists of two phases employing different intelligent algorithms. First, we adopt a particle swarm optimization (PSO) method for a global search of the coverage areas. Then, for local search, a virtual-repulsive-force-based firefly algorithm (VFA) is proposed in this paper to maximize the user coverage. In the VFA algorithm, the users are treated as the objects attracting the UAVs, and the virtual repulsive force is used for UAV location adjustment. Simulation results show that the proposed PSO-VFA hybrid algorithm has faster convergence and significantly increases the communication coverage of UAV-mounted BSs compared with individual intelligent algorithms such as VFA, PSO, genetic algorithm (GA), and simulated annealing (SA).</p> <p> </p>
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Krishnakumar, R., K. Senthil Kumar i T. Anand. "Design and Development of Vertical Takeoff and Horizontal Transition Mini Unmanned Aerial Vehicle". Advanced Materials Research 1016 (sierpień 2014): 436–40. http://dx.doi.org/10.4028/www.scientific.net/amr.1016.436.
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In recent years Unmanned Aerial Vehicles (UAV) has become a significant segment of the aviation industry. They can be chosen to be designed as fixed wing or Rotary wing type. Fixed-wing aircraft has the performance of fast forward movement, long range and superior endurance due to its gliding capabilities with no power. Unlike the fixed wing models, rotary wing mini-copters are able to fly in all directions, hover in a fixed position with minimal space for takeoff and landing. This makes them the perfect instrument for detailed inspection work or surveying. Implementing a hybrid UAV has the advantages of both fixed-wing and rotary wing UAV. This paper aims to brief on the design, development and testing of a hybrid tilt body UAV with four rotors. The hybrid vehicle comprises two units, an aerial unit and a ground unit. The aerial unit consists of an unmanned aircraft system. The ground unit consists of means to view and post-data processing of video/image sent by the UAV if it is used for aerial surveillance and control, navigate and guide the aircraft. To proceed, a novel hybrid UAV with capability of Vertical Take Off and Landing (VTOL) and horizontal flight is developed and its response during the transition from VTOL to horizontal flight is analyzed.
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Jianzhi, DENG, SONG Wenyan, YANG Guangjun, JIANG Feng i XIONG Neng. "Aircraft/Engine Integrated Design for an Air-superiority Unmanned Aerial Vehicle". Journal of Physics: Conference Series 2235, nr 1 (1.05.2022): 012060. http://dx.doi.org/10.1088/1742-6596/2235/1/012060.
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Abstract Aiming at the demand of efficient energy management for wide flight envelope of air-superiority unmanned aerial vehicle (UAV), an conceptual and preliminary design of air-superiority UAV with oil-electric hybrid power was proposed based on the idea of integrated aircraft and engine modelling. The evaluation model of the UAV aerodynamic performance and the thrust requirements of full flight envelope were determined, then the matching configuration of target turbofan engine was proposed. According to general design parameters of UAV, the simulation model and constraint relations for aircraft-engine integration performance calculation were established, parameters were optimized for typical multi-mission conditions, the tactical performance of future advanced air superiority UAV was predicted. The integrated design method of air superiority UAV upon hybrid electric turbofan can also be applied to improve the performance of UAVs in service, which established in this paper has good engineering practical value.
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Pierucci, Laura. "Hybrid Direction of Arrival Precoding for Multiple Unmanned Aerial Vehicles Aided Non-Orthogonal Multiple Access in 6G Networks". Applied Sciences 12, nr 2 (16.01.2022): 895. http://dx.doi.org/10.3390/app12020895.
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Unmanned aerial vehicles (UAV) have attracted increasing attention in acting as a relay for effectively improving the coverage and data rate of wireless systems, and according to this vision, they will be integrated in the future sixth generation (6G) cellular network. Non-orthogonal multiple access (NOMA) and mmWave band are planned to support ubiquitous connectivity towards a massive number of users in the 6G and Internet of Things (IOT) contexts. Unfortunately, the wireless terrestrial link between the end-users and the base station (BS) can suffer severe blockage conditions. Instead, UAV relaying can establish a line-of-sight (LoS) connection with high probability due to its flying height. The present paper focuses on a multi-UAV network which supports an uplink (UL) NOMA cellular system. In particular, by operating in the mmWave band, hybrid beamforming architecture is adopted. The MUltiple SIgnal Classification (MUSIC) spectral estimation method is considered at the hybrid beamforming to detect the different direction of arrival (DoA) of each UAV. We newly design the sum-rate maximization problem of the UAV-aided NOMA 6G network specifically for the uplink mmWave transmission. Numerical results point out the better behavior obtained by the use of UAV relays and the MUSIC DoA estimation in the Hybrid mmWave beamforming in terms of achievable sum-rate in comparison to UL NOMA connections without the help of a UAV network.
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Wu, H., Z. Wang, B. Ren, L. Wang, J. Zhang, J. Zhu i Z. He. "DESIGN AND EXPERIMENT OF A HIGH PAYLOAD FIXED WING VTOL UAV SYSTEM FOR EMERGENCY RESPONSE". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B3-2020 (22.08.2020): 1715–22. http://dx.doi.org/10.5194/isprs-archives-xliii-b3-2020-1715-2020.
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Abstract. With the development of UAV technologies, the advantages of hybrid VTOL UAV have been realized and taken in emergency response. But, former hybrid VTOL UAV is lack of capacities on payload and endurance, which restrict the integration of multiple sensors. In this paper, a high payload fixed wing VTOL UAV, which has 20 kg payload and more than 3 hours endurance, is used to design a UAV system for emergency response. Multiple sensors including an optronics pod, PhaseOne IXM-100 camera, high accuracy inertial navigation system and three-axis stable head are integrated with it. Based on this, specific processing software is developed to process the video data and image which could meet the requirements of emergency response in different stages. Experiment results shown that the precision of mosaic image is about 10m and the precision of orthoimage is about 1m. This work could be reference for the design and practice of UAV system with multiple sensors.
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Papadopoulos, C., S. Vlachos i K. Yakinthos. "Conceptual design of a fixed wing hybrid UAV UUV platform". IOP Conference Series: Materials Science and Engineering 1226, nr 1 (1.02.2022): 012028. http://dx.doi.org/10.1088/1757-899x/1226/1/012028.
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Abstract In this work, the conceptual design methodology of a hybrid Unmanned Aerial Vehicle (UAV) – Unmanned Underwater Vehicle (UUV) platform is presented. As the mission complexity and the need for interoperability between different platforms grows more demanding by the day, hybrid platforms are becoming an essential solution. Hybrid UAV-UUVs can operate seamlessly and repeatedly in both the aerial and underwater environments, something that numerous animal species already execute in an optimized way. The design methodology starts with the review of the few available prototypes, creating initial design trends and continues with analytical calculations. These calculations are based on aircraft design textbooks and are modified to take into account the special characteristics of a hybrid platform, such as the means of transition between the water and the air. A Blended Wing Body (BWB) layout configuration is selected for the numerous aerodynamic advantages that it offers. The analytical calculations are then validated with the use of high fidelity CFD calculations. The results from the conceptual design phase indicate that the proposed methodology for hybrid UAV-UUV configurations provides a good design accuracy. Finally, the outcome of this methodology, which is a hybrid UAV-UUV platform is potentially the answer to the operational gap for missions that include both underwater and aerial environments.
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Chai, Xiyuan, Xin Fu i Shijie Zhai. "Research on the Working Performance of UAV Hybrid Power System Based on Mission Profile". Journal of Physics: Conference Series 2478, nr 10 (1.06.2023): 102029. http://dx.doi.org/10.1088/1742-6596/2478/10/102029.
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Abstract Currently, UAVs can be divided into two main types based on the type of power unit, fuel-powered UAVs and electrically powered UAVs. Most drones that are generally smaller and lighter in weight are electrically powered; while larger drones are usually fuel-powered. Both have their advantages and disadvantages, with fuel-powered drones being highly polluting and noisy, while electric drones usually have a shorter range. Fuel-powered UAVs are noisy and polluting, while electrically powered UAVs are usually shorter. The hybrid system combines the advantages of both and reduces pollution while ensuring a longer range. In this paper, an oil-electric hybrid power system for a tilt-rotor UAV is studied, a mathematical model of the hybrid power system is built, and the performance of the hybrid power system is studied and analyzed based on the mission profile. The mission profile of the UAV is determined, and the UAV demand power curve under this mission profile is given. The overall performance of the oil-electric hybrid power system is simulated and calculated. The results show that the oil-electric hybrid power system meets the power demand of the tilt-rotor UAV under the mission profile given in this paper, and can work normally within the full envelope.
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Ali, Zain Anwar, i Han Zhangang. "Multi-unmanned aerial vehicle swarm formation control using hybrid strategy". Transactions of the Institute of Measurement and Control 43, nr 12 (19.04.2021): 2689–701. http://dx.doi.org/10.1177/01423312211003807.
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This study proposes a novel hybrid strategy for formation control of a swarm of multiple unmanned aerial vehicles (UAVs). To enhance the fitness function of the formation, this research offers a three-dimensional formation control for a swarm using particle swarm optimization (PSO) with Cauchy mutant (CM) operators. We use CM operators to enhance the PSO algorithm by examining the varying fitness levels of the local and global optimal solutions for UAV formation control. We establish the terrain and the fixed-wing UAV model. Furthermore, it also models different control parameters of the UAV as well. The enhanced hybrid algorithm not only quickens the convergence rate but also improves the solution optimality. Lastly, we carry out the simulations for the multi-UAV swarm under terrain and radar threats and the simulation results prove that the hybrid method is effective and gives better fitness function.
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Diem, P. G., P. H. Anh, Phu Khanh Nguyen, N. P. Hung i N. V. Hien. "A Hybrid Control Model to Develop the Trajectory-Tracking Controller for a Quadrotor UAV". Advanced Materials Research 1016 (sierpień 2014): 678–85. http://dx.doi.org/10.4028/www.scientific.net/amr.1016.678.
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A new hybrid model of control implementation is developed to realize trajectory-tracking controllers for quadrotor Unmanned Aerial Vehicles (UAV). This model is based on the Computational Fluid Dynamics (CFD) model and hybrid automata in order to accurately implement control parts of these vehicles, and can be applied to most standard quadrotor UAV platforms. The paper brings out step-by-step the controller development lifecycle for a quadrotor UAV, including the configuration and aerodynamic calculation model for the gathering preliminary inputs of the control application, the control analysis of dynamic model and general architecture, as well as the control design performed by specializing hybrid automata. The detailed design model is then converted into the implementation model by using open-source platforms in order to quickly simulate and realize the trajectory-tracking controller for this quadrotor UAV. Finally, this application was completely deployed and successfully taken on trial flights.
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Wang, Bohang, i Daobo Wang. "Robust Hybrid Control Algorithm for Tuning the Altitude and Attitude of Unmanned Aerial Vehicle". Journal of Robotics 2020 (25.01.2020): 1–8. http://dx.doi.org/10.1155/2020/2368273.
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In this article, a new and novel robust hybrid control algorithm is designed for tuning the parameters of unmanned aerial vehicle (UAV). The quadrotor type UAV mathematical model is taken to observe the effectiveness of our designed robust hybrid control algorithm. The robust hybrid control algorithm consists of H∞ based regulation, pole-placement and tracking (RST) controller along with mixed sensitivity function is applied to control the complete model of UAV. The selected rotor craft is under-actuated, nonlinear and multivariable behavior in nature along with six degrees of freedom (DOF). Due to all these aforementioned issues its stabilization is quite difficult as compared to fully actuated systems. For the tuning of nonlinear parameters of the UAV, we designed, robust hybrid control algorithm is used. Moreover, the performance of the designed controller is compared with robust controller. The validity and effectiveness of the designed controllers are simulated in MATLAB and Simulink, in which the designed controller shows better steady state behavior, robustness and converges quickly in specific amount of time as compared to robust controller.
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Salas-Marco, Joe, Hua Fan-Minogue, Adam K. Kallmeyer, Lawrence A. Klobutcher, Philip J. Farabaugh i David M. Bedwell. "Distinct Paths To Stop Codon Reassignment by the Variant-Code Organisms Tetrahymena and Euplotes". Molecular and Cellular Biology 26, nr 2 (15.01.2006): 438–47. http://dx.doi.org/10.1128/mcb.26.2.438-447.2006.
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ABSTRACT The reassignment of stop codons is common among many ciliate species. For example, Tetrahymena species recognize only UGA as a stop codon, while Euplotes species recognize only UAA and UAG as stop codons. Recent studies have shown that domain 1 of the translation termination factor eRF1 mediates stop codon recognition. While it is commonly assumed that changes in domain 1 of ciliate eRF1s are responsible for altered stop codon recognition, this has never been demonstrated in vivo. To carry out such an analysis, we made hybrid proteins that contained eRF1 domain 1 from either Tetrahymena thermophila or Euplotes octocarinatus fused to eRF1 domains 2 and 3 from Saccharomyces cerevisiae. We found that the Tetrahymena hybrid eRF1 efficiently terminated at all three stop codons when expressed in yeast cells, indicating that domain 1 is not the sole determinant of stop codon recognition in Tetrahymena species. In contrast, the Euplotes hybrid facilitated efficient translation termination at UAA and UAG codons but not at the UGA codon. Together, these results indicate that while domain 1 facilitates stop codon recognition, other factors can influence this process. Our findings also indicate that these two ciliate species used distinct approaches to diverge from the universal genetic code.
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Ullah, Saif, Khalid Hussain Mohammadani, Muhammad Asghar Khan, Zhi Ren, Reem Alkanhel, Ammar Muthanna i Usman Tariq. "Position-Monitoring-Based Hybrid Routing Protocol for 3D UAV-Based Networks". Drones 6, nr 11 (28.10.2022): 327. http://dx.doi.org/10.3390/drones6110327.
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Unmanned aerial vehicles (UAV) have emerged as prime technologies due to their compatible size and flexible architecture. UAV technology offers services in vast application such as inter-UAV communication, wireless sensors, and the future Internet of Things (IoT) due to its compatible architecture. A UAV’s speed varies while roaming, which may increase the risk of a connection failure. Various routing schemes have provided solutions to address this essential issue for three-dimensional (3D) UAV-based networks. The main category of UAV routing schemes is position-based routing schemes, which choose the best route based on the UAV’s location. However, position-based routing has the drawback that it depends on exact positioning and tracking. An efficient routing scheme can resolve the significant issue associated with UAV mobility in a 3D environment. This paper aims to address the issues of static preloaded location values by presenting a hybrid routing scheme named the Position-Monitor-based Hybrid Routing Protocol (PMHRP), which takes advantage of both geographic and topology-based routing protocols. The PMHRP establishes the shortest possible route based on a UAV’s Global Positioning System (GPS). Moreover, the proposed protocol utilizes the links for data forwarding. Furthermore, a disaster-based UAV scenario is adopted to provide connections to IoT devices. A detailed comparison analysis shows the proposed scheme’s extreme performance and results in up to 65% to 73% better packet delivery ratio (PDR) than batch mark schemes under standard 3D UAV scenarios. Compared to earlier work, the proposed scheme reduces the average delay by up to 68% to 75%. Further proposed routing schemes offer 70% to 72% more throughput than the existing routing schemes, and NRL (%) is 42% to 49% lower than the existing routing schemes. This happens because of the global routing information available at each UAV which is provided by the position head coordinator (PHC) UAV in the proposed work.
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Johnson, R. T., S. Squires, G. C. Elliott, G. L. Koch i A. J. Rainbow. "Xeroderma pigmentosum D-HeLa hybrids with low and high ultraviolet sensitivity associated with normal and diminished DNA repair ability, respectively". Journal of Cell Science 76, nr 1 (1.06.1985): 115–33. http://dx.doi.org/10.1242/jcs.76.1.115.
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Fusion between HeLa and fibroblasts from complementation group D xeroderma pigmentosum (XPD) followed by challenge with small doses of ultraviolet light (u.v.) results in the production of hybrid cells expressing either HeLa (HD1) or XPD-like (HD2) sensitivity to u.v. and related repair capacity. Assays used included unscheduled DNA synthesis (UDS), DNA break accumulation in the presence of inhibitors of DNA repair synthesis and host cell reactivation of irradiated adenovirus. Complementation assay in heterokaryons reveals limited ability of HD2 to restore UDS in XPD nuclei. We believe this complementation is more apparent than real since proliferating hybrids of HD2 and XPD parentage are without exception u.v.-sensitive and express limited excision repair. On the other hand hybrids between HD2 and XPC, XPE or XPF fibroblasts show true complementation resulting in a return to normal u.v. sensitivity and elevated repair ability.
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AbdElHamid, Amr, Peng Zong i Bassant Abdelhamid. "Advanced UAV Hybrid Simulator Model Based-on Dynamic Real Weather Data". International Journal of Modeling and Optimization 5, nr 4 (2015): 246–56. http://dx.doi.org/10.7763/ijmo.2015.v5.470.
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Alam, Mir Md Tasnim, Anita Simic Milas, Mateo Gašparović i Henry Poku Osei. "Retrieval of Crop Canopy Chlorophyll: Machine Learning vs. Radiative Transfer Model". Remote Sensing 16, nr 12 (7.06.2024): 2058. http://dx.doi.org/10.3390/rs16122058.
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In recent years, the utilization of machine learning algorithms and advancements in unmanned aerial vehicle (UAV) technology have caused significant shifts in remote sensing practices. In particular, the integration of machine learning with physical models and their application in UAV–satellite data fusion have emerged as two prominent approaches for the estimation of vegetation biochemistry. This study evaluates the performance of five machine learning regression algorithms (MLRAs) for the mapping of crop canopy chlorophyll at the Kellogg Biological Station (KBS) in Michigan, USA, across three scenarios: (1) application to Landsat 7, RapidEye, and PlanetScope satellite images; (2) application to UAV–satellite data fusion; and (3) integration with the PROSAIL radiative transfer model (hybrid methods PROSAIL + MLRAs). The results indicate that the majority of the five MLRAs utilized in UAV–satellite data fusion perform better than the five PROSAIL + MLRAs. The general trend suggests that the integration of satellite data with UAV-derived information, including the normalized difference red-edge index (NDRE), canopy height model, and leaf area index (LAI), significantly enhances the performance of MLRAs. The UAV–RapidEye dataset exhibits the highest coefficient of determination (R2) and the lowest root mean square errors (RMSE) when employing kernel ridge regression (KRR) and Gaussian process regression (GPR) (R2 = 0.89 and 0.89 and RMSE = 8.99 µg/cm2 and 9.65 µg/cm2, respectively). Similar performance is observed for the UAV–Landsat and UAV–PlanetScope datasets (R2 = 0.86 and 0.87 for KRR, respectively). For the hybrid models, the maximum performance is attained with the Landsat data using KRR and GPR (R2 = 0.77 and 0.51 and RMSE = 33.10 µg/cm2 and 42.91 µg/cm2, respectively), followed by R2 = 0.75 and RMSE = 39.78 µg/cm2 for the PlanetScope data upon integrating partial least squares regression (PLSR) into the hybrid model. Across all hybrid models, the RapidEye data yield the most stable performance, with the R2 ranging from 0.45 to 0.71 and RMSE ranging from 19.16 µg/cm2 to 33.07 µg/cm2. The study highlights the importance of synergizing UAV and satellite data, which enables the effective monitoring of canopy chlorophyll in small agricultural lands.
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Wang, Xiaodong, Yangming Guo, Nan Lu i Pei He. "UAV Cluster Behavior Modeling Based on Spatial-Temporal Hybrid Petri Net". Applied Sciences 13, nr 2 (5.01.2023): 762. http://dx.doi.org/10.3390/app13020762.
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Currently, we are facing an increasing trend in the use of unmanned aerial vehicles (UAV) in various activities, both civilian and military. The application of UAVs in the battlefield has received extensive attention amid a global new military revolution. A UAV cluster is a large and complex real-time feedback system that integrates a communication and sensor network, control system, calculation, and physical process. The heterogeneous UAVs conduct complex behaviors, which requires a comprehensive description and analysis of UAV cluster modeling. The integrated modeling of the heterogeneous UAV cluster is of great significance and value to test and verify the new combat mode. In this paper, we present a novel representation framework based on the Petri nets. We used a spatial-temporal hybrid Petri net to illustrate the discrete state and continuous process of a heterogeneous UAV cluster system, and effectively achieved the fusion of a physical and computational process and interaction event modeling in the cluster system. Finally, the formal verification of UAV cluster attack mission modeling was carried out by UPPAAL, suggesting the proposed modeling method is feasible and effective.
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Jung, Sunghun. "Development and Verification of Hybrid Power Controller Using Indoor HIL Test for the Solar UAV". Energies 13, nr 8 (24.04.2020): 2110. http://dx.doi.org/10.3390/en13082110.
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A hybrid power system (HPS) is developed for the photovoltaic (PV) powered and tethered multirotor unmanned aerial vehicle (UAV) based on the robot operating system (ROS) and verified using an indoor hardware-in-the-loop (HIL) test. All the processes, including a UAV flight mode change (i.e., takeoff, hovering, and landing) and power flow control (consisting of PV modules, a LiPo battery pack, and a UAV) are completely automated using a combination of Pixhawk 2.1 and the Raspberry Pi 3 Model B (RPi 3B). Once the indoor HIL test starts, (1) the UAV takes off and hovers with a preassigned 10 m altitude at a fixed point and keeps hovering until the voltage drops below 13.4 V ; (2) the UAV lands when the voltage drops below 13.4 V, and the hybrid power controller (HPC) starts to charge the LiPo battery pack using the energy from PV modules; and (3) the UAV takes off when the voltage of the battery pack becomes more than 16.8 V, and the procedure repeats from (1). A PV-powered and tethered multirotor UAV using the proposed HPS can fly more safely for a longer time, particularly in an urban area, and so it is competitive to the traditional multirotor type UAV in the sense of both the flight time and the surveillance mission performance.
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Zhao, Zhiheng, Weijie Chen i Cheng Yang. "An efficient hybrid aeroacoustic method to predict the noise of a ducted coaxial-rotor UAV". INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, nr 7 (30.11.2023): 1443–48. http://dx.doi.org/10.3397/in_2023_0216.
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Ducted coaxial-rotor UAV is a new concept UAV configuration. Compared with the traditional open rotor UAV, it has the advantages of higher safety, lower noise and smaller size, especially suitable for compact space and low noise scene applications. However, the complexity of the internal flow field caused by the presence of the duct makes it difficult to obtain accurate acoustic results by using the conventional aeroacoustic simulation methods. Based on the theory of duct acoustics and the theory of propeller noise, this paper presents an efficient calculation method of aeroacoustic source suitable for the configuration of a ducted UAV. The aeroacoustic source of a ducted coaxial-rotor UAV independently developed by the current research group is studied, and the duct acoustic mode components excited by the aeroacoustic source of the UAV are obtained. The results show that the distribution of the duct mode excited by the aeroacoustic source of the ducted UAV has a strong correlation with the number of propeller blades, and the main characteristic modes dominate the acoustic source of the UAV.
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Ali, Zain Anwar, Daobo Wang, Suhaib Masroor i M. Shafiq Loya. "Attitude and Altitude Control of Trirotor UAV by Using Adaptive Hybrid Controller". Journal of Control Science and Engineering 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/6459891.
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The paper presents an adaptive hybrid scheme which is based on fuzzy regulation, pole-placement, and tracking (RST) control algorithm for controlling the attitude and altitude of trirotor UAV. The dynamic and kinematic model of Unmanned Aerial Vehicle (UAV) is unstable and nonlinear in nature with 6 degrees of freedom (DOF); that is why the stabilization of aerial vehicle is a difficult task. To stabilize the nonlinear behavior of our UAV, an adaptive hybrid controller algorithm is used, in which RST controller tuning is performed by adaptive gains of fuzzy logic controller. Simulated results show that fuzzy based RST controller gives better robustness as compared to the classical RST controller.
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Wang, Yinyin, Lokeshkumar Kumar, Vijayanandh Raja, Hussein A. Z. AL-bonsrulah, Naveen Kumar Kulandaiyappan, Ashok Amirtharaj Tharmendra, Nagaraj Marimuthu i Mohammed Al-Bahrani. "Design and Innovative Integrated Engineering Approaches Based Investigation of Hybrid Renewable Energized Drone for Long Endurance Applications". Sustainability 14, nr 23 (3.12.2022): 16173. http://dx.doi.org/10.3390/su142316173.
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At present, surveillance is attracting attention in the field of UAV development. In particular, border surveillance plays a vital role in obtaining the required data around the border and for assisting in military operations. The primary function of this Hybrid UAV (VTOL and Fixed Wing) is to provide prerequisite data, captured during day/night surveillance, to the respective database. One of the primary problems that arise in border patrolling is the use of the UAV under different environmental conditions, thereby reducing its endurance firmly. In addition to the surveillance equipment, energy harvesting techniques are involved in solving the problem of endurance. The piezoelectric energy harvester and solar panels are added to harvest electrical energy in the UAV. Based on this application, the conceptual design of the Hybrid UAV, based on nature, was designed and investigated theoretically, as well as computationally. A series of analysis, which includes Computational Fluid Dynamics, Finite Element Analysis and Analytical approach, was used to determine the energy harvested from the energy harvester. This work confirms the proposed integrated engineering approach for the estimation of renewable energy, via PVEH patches, and the same approach is thus offered to researchers for subsequent applications. Additionally, a hybrid energy idea for newly developed drones was proposed in this work. This concept will be extensively used in the unmanned aircraft system sectors.
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Wang, Yi, i Ensheng Liu. "Virtual Reality Technology of Multi UAVEarthquake Disaster Path Optimization". Mathematical Problems in Engineering 2021 (10.03.2021): 1–9. http://dx.doi.org/10.1155/2021/5525560.
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China is a country with frequent earthquake disasters. After the occurrence of earthquake disasters, the key to disaster monitoring and rescue is to quickly obtain images of postdisaster areas. Unmanned aerial vehicle (UAV) path planning is the core of multi-UAV cooperative control. With the increasing popularity of UAVs, people with more complex living environments contact with UAVs more frequently, which also poses a challenge to the overall control of UAVs, making single UAV and even multi-UAV cooperative path planning become a hot research issue in recent years. The complexity of communication between aircraft in three-dimensional flight space and multidegree of freedom navigation makes multi-UAV cooperation more challenging. According to the research results at home and abroad, this paper takes multitarget tracking algorithm, ant colony algorithm, and hybrid particle swarm optimization algorithm as research methods. Based on virtual reality technology, by comparing the advantages and disadvantages of several algorithms, the research model of path optimization is established, and a multitarget detection method based on virtual reality technology is established. Through the analysis and improvement of multitarget tracking algorithm, ant colony algorithm, and hybrid particle swarm optimization algorithm, the path optimization problem of UAV after an earthquake based on virtual reality technology is studied. The results show that, compared with the previous research models, the overall optimization efficiency of UAV route is improved by 15%, which is more practical.
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LU, Nan, Xiaodong WANG, Zheng TANG i Pei HE. "Modeling method of unmanned aerial vehicle swarm behavior based on spatiotemporal hybrid Petri net". Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 40, nr 4 (sierpień 2022): 812–18. http://dx.doi.org/10.1051/jnwpu/20224040812.
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The more and more widely used UAV swarm operations have received great attention in the new global military revolution of informatization, and the integrated modeling of UAV swarms has great significance and value for the testing and verification of combat modes. Aiming at the modeling and simulation requirements of combat scenarios, taking the collaborative combat process of heterogeneous UAV swarms as the research object, starting from the modeling of a single UAV, on the basis of the formalization and mathematical description of the single combat process, this paper employs Petri nets based on the hybridization of time and space to describe the discrete states and continuous processes of heterogeneous UAV swarm systems, and effectively solves the problems of the fusion between physics and computing processes, and modeling of interactive events in swarm systems. UPPAAL is selected to formally verify the modeling of UAV swarm strike mission, which shows that the proposed modeling method is feasible and effective.
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Lu, Conghui, i Peng Chen. "Robust Channel Estimation Scheme for Multi-UAV MmWave MIMO Communication with Jittering". Electronics 12, nr 9 (4.05.2023): 2102. http://dx.doi.org/10.3390/electronics12092102.
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In unmanned aerial vehicle (UAV)-assisted millimeter-wave (mmWave) communications, the communication performance is significantly degraded by UAV jitter. We formulate a UAV-assisted mmWave channel model with hybrid beamforming for the impacts of UAV jitter. Then, we derive the distribution of angle of arrivals/departures (AOAs/AODs) with random fluctuation of the UAV attitude angle. We develop an iterative reweight-based robust scheme as the super-resolution AOAs/AODs estimation method. Specifically, we introduce the partially adaptive momentum (Padam) estimation method to optimize the objective function of the jittering UAV mmWave massive multi-input multioutput (MIMO) system. Finally, compared with existing channel estimation schemes, the proposed UAV mmWave channel estimation method can achieve robust super-resolution performance in AOAs/AODs and path gains estimation with numerical results. Therefore, the proposed channel estimation scheme is very suitable for UAV mmWave massive MIMO communications with jittering.
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Radócz, László, Csaba Juhász, András Tamás, Árpád Illés, Péter Ragán i László Radócz. "Multispectral UAV-Based Disease Identification Using Vegetation Indices for Maize Hybrids". Agriculture 14, nr 11 (7.11.2024): 2002. http://dx.doi.org/10.3390/agriculture14112002.
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In the future, the cultivation of maize will become more and more prominent. As the world’s demand for food and animal feeding increases, remote sensing technologies (RS technologies), especially unmanned aerial vehicles (UAVs), are developing more and more, and the usability of the cameras (Multispectral-MS) installed on them is increasing, especially for plant disease detection and severity observations. In the present research, two different maize hybrids, P9025 and sweet corn Dessert R78 (CS hybrid), were employed. Four different treatments were performed with three different doses (low, medium, and high dosage) of infection with corn smut fungus (Ustilago maydis [DC] Corda). The fields were monitored two times after the inoculation—20 DAI (days after inoculation) and 27 DAI. The orthomosaics were created in WebODM 2.5.2 software and the study included five vegetation indices (NDVI [Normalized Difference Vegetation Index], GNDVI [Green Normalized Difference Vegetation Index], NDRE [Normalized Difference Red Edge], LCI [Leaf Chlorophyll Index] and ENDVI [Enhanced Normalized Difference Vegetation Index]) with further analysis in QGIS. The gathered data were analyzed using R-based Jamovi 2.6.13 software with different statistical methods. In the case of the sweet maize hybrid, we obtained promising results, as follows: the NDVI values of CS 0 were significantly higher than the high-dosed infection CS 10.000 with a mean difference of 0.05422 *** and a p value of 4.43 × 10−5 value, suggesting differences in all of the levels of infection. Furthermore, we investigated the correlations of the vegetation indices (VI) for the Dessert R78, where NDVI and GNDVI showed high correlations. NDVI had a strong correlation with GNDVI (r = 0.83), a medium correlation with LCI (r = 0.56) and a weak correlation with NDRE (r = 0.419). There was also a strong correlation between LCI and GNDVI, with r = 0.836. NDRE and GNDVI indices had the correlation coefficients with a CCoeff. of r = 0.716. For hybrid separation analyses, useful results were obtained for NDVI and ENDVI as well.
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Santana, Dthenifer Cordeiro, Gustavo de Faria Theodoro, Ricardo Gava, João Lucas Gouveia de Oliveira, Larissa Pereira Ribeiro Teodoro, Izabela Cristina de Oliveira, Fábio Henrique Rojo Baio, Carlos Antonio da Silva Junior, Job Teixeira de Oliveira i Paulo Eduardo Teodoro. "A New Approach to Identifying Sorghum Hybrids Using UAV Imagery Using Multispectral Signature and Machine Learning". Algorithms 17, nr 1 (5.01.2024): 23. http://dx.doi.org/10.3390/a17010023.
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Using multispectral sensors attached to unmanned aerial vehicles (UAVs) can assist in the collection of morphological and physiological information from several crops. This approach, also known as high-throughput phenotyping, combined with data processing by machine learning (ML) algorithms, can provide fast, accurate, and large-scale discrimination of genotypes in the field, which is crucial for improving the efficiency of breeding programs. Despite their importance, studies aimed at accurately classifying sorghum hybrids using spectral variables as input sets in ML models are still scarce in the literature. Against this backdrop, this study aimed: (I) to discriminate sorghum hybrids based on canopy reflectance in different spectral bands (SB) and vegetation indices (VIs); (II) to evaluate the performance of ML algorithms in classifying sorghum hybrids; (III) to evaluate the best dataset input for the algorithms. A field experiment was carried out in the 2022 crop season in a randomized block design with three replications and six sorghum hybrids. At 60 days after crop emergence, a flight was carried out over the experimental area using the Sensefly eBee real time kinematic. The spectral bands (SB) acquired by the sensor were: blue (475 nm, B_475), green (550 nm, G_550), red (660 nm, R_660), Rededge (735 nm, RE_735) e NIR (790 nm, NIR_790). From the SB acquired, vegetation indices (VIs) were calculated. Data were submitted to ML classification analysis, in which three input settings (using only SB, using only VIs, and using SB + VIs) and six algorithms were tested: artificial neural networks (ANN), support vector machine (SVM), J48 decision trees (J48), random forest (RF), REPTree (DT) and logistic regression (LR, conventional technique used as a control). There were differences in the spectral signature of each sorghum hybrid, which made it possible to differentiate them using SBs and VIs. The ANN algorithm performed best for the three accuracy metrics tested, regardless of the input used. In this case, the use of SB is feasible due to the speed and practicality of analyzing the data, as it does not require calculations to perform the VIs. RF showed better accuracy when VIs were used as an input. The use of VIs provided the best performance for all the algorithms, as did the use of SB + VIs which provided good performance for all the algorithms except RF. Using ML algorithms provides accurate identification of the hybrids, in which ANNs using only SB and RF using VIs as inputs stand out (above 55 for CC, above 0.4 for kappa and around 0.6 for F-score). There were differences in the spectral signature of each sorghum hybrid, which makes it possible to differentiate them using wavelengths and vegetation indices. Processing the multispectral data using machine learning techniques made it possible to accurately differentiate the hybrids, with emphasis on artificial neural networks using spectral bands as inputs and random forest using vegetation indices as inputs.
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Alsadik, Bashar, Fabio Remondino i Francesco Nex. "Simulating a Hybrid Acquisition System for UAV Platforms". Drones 6, nr 11 (25.10.2022): 314. http://dx.doi.org/10.3390/drones6110314.
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Currently, there is a rapid trend in the production of airborne sensors consisting of multi-view cameras or hybrid sensors, i.e., a LiDAR scanner coupled with one or multiple cameras to enrich the data acquisition in terms of colors, texture, completeness of coverage, accuracy, etc. However, the current UAV hybrid systems are mainly equipped with a single camera that will not be sufficient to view the facades of buildings or other complex objects without having double flight paths with a defined oblique angle. This entails extensive flight planning, acquisition duration, extra costs, and data handling. In this paper, a multi-view camera system which is similar to the conventional Maltese cross configurations used in the standard aerial oblique camera systems is simulated. This proposed camera system is integrated with a multi-beam LiDAR to build an efficient UAV hybrid system. To design the low-cost UAV hybrid system, two types of cameras are investigated and proposed, namely the MAPIR Survey and the SenseFly SODA, integrated with a multi-beam digital Ouster OS1-32 LiDAR sensor. Two simulated UAV flight experiments are created with a dedicated methodology and processed with photogrammetric methods. The results show that with a flight speed of 5 m/sec and an image overlap of 80/80, an average density of up to 1500 pts/m2 can be achieved with adequate facade coverage in one-pass flight strips.
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De Wagter, C., B. Remes, E. Smeur, F. van Tienen, R. Ruijsink, K. van Hecke i E. van der Horst. "The NederDrone: A hybrid lift, hybrid energy hydrogen UAV". International Journal of Hydrogen Energy 46, nr 29 (kwiecień 2021): 16003–18. http://dx.doi.org/10.1016/j.ijhydene.2021.02.053.
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Anuar, Kaspul, Warman Fatra i Anita Susilawati. "PEMANFAATAN LIMBAH TANDAN KOSONG SAWIT (TKS) SEBAGAI MATERIAL ALTERNATIF DALAM PEMBUATAN BADAN WAHANA TERBANG TIPE FIXED WING ATHA MAPPER 2150". Jurnal Rekayasa Mesin 13, nr 2 (5.09.2022): 609–17. http://dx.doi.org/10.21776/jrm.v13i2.1161.
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To improve the application and use value of Palm Oil Empty Fruit Bunch (OPEFB) waste as a composite material, the research team conducted research related to the utilization OPEFB fiber as an alternative material to replace carbon fiber in the manufacture of fuselage of Unmaned Aerial Vehicle (UAV). The low price of OPEFB, low of specific density and it’s abundant availability are the basis of research to apply it’s fiber as material of UAV fuselage. This research begins with the processing of OPEFB into fiber through an alkali treatment process. Furthermore, the process of maleated natural rubber as a mixture of resin matrix. Afterward, the fuselage is molded use hybrid fiberglass-OPEFB fiber and resin epoxy that has been mixed with natural rubber. Fuselage of UAV is also molded with material of hybrid fiberglass-fibercarbon. Based on mass measurements, the fuselage of hybrid fiberglass-OPEFB fiber material and the fuselage of hybrid fiberglass-carbon fiber material have a mass of 510 grams and 540 grams respectively. For deflection measurement, fuselage of hybrid fiberglass-OPEFB fiber material has a maximum deflection as 2.01 mm, while the fuselage of hybrid fiberglass-fibercarbon material has a maximum deflection as 1.19 mm. In statis impact test, the two fuselage are able to withstand shock load.
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Lu, Ning, Yongzai Xi, Hongshan Zheng, Weidong Gao, Yongbo Li, Yu Liu, Zhiqiang Cui, Guixiang Liao i Junjie Liu. "Development of a Hybrid Fixed-Wing UAV Aeromagnetic Survey System and an Application Study in Chating Deposit". Minerals 13, nr 8 (16.08.2023): 1094. http://dx.doi.org/10.3390/min13081094.
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In recent years, the development of airborne magnetic survey technology based on unmanned aerial vehicles (UAVs) has been rapidly advancing. The commonly used systems are the fixed-wing UAV-based, multi-rotors UAV-based, and unmanned helicopters-based magnetic survey systems. And, a type of hybrid UAV that uses a vertical takeoff and landing (VTOL) and fixed-wing cruise mode is increasingly being used to carry airborne magnetic survey systems. To meet the requirements of most UAVs for small-sized and lightweight payloads, a miniature magnetic survey system was developed and integrated into a hybrid fixed-wing UAV and formed an aeromagnetic survey system. And, a peripheral mineral exploration test was conducted in a known porphyry copper–gold deposit in southeastern China using the system. By processing the collected magnetic data with 3D inversion of susceptibilities, potential ore-bearing intrusive rocks were quickly identified and delineated, providing clues for peripheral mineral exploration in the mining area.
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Giernacki, Wojciech, Sławomir Stępień, Marcin Chodnicki i Agnieszka Wróblewska. "Hybrid Quasi-Optimal PID-SDRE Quadrotor Control". Energies 15, nr 12 (13.06.2022): 4312. http://dx.doi.org/10.3390/en15124312.
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In the paper, a new cascade control system for an autonomous flight of an unmanned aerial vehicle (UAV) based on Proportional–Integral–Derivative (PID) and finite-time State-Dependent Riccati Equation (SDRE) control is proposed. The PID and SDRE controllers are used in a hybrid control system for precise control and stabilization, which is necessary to increase the drone’s flight stability and maneuver precision. The hybrid PID-SDRE control system proposed for the quadrotor model is quasi-optimal, since the suboptimal control algorithm for the UAV stabilization is used. The combination of the advantages of PID and SDRE control gives a significant improvement in the quality of control while maintaining the simplicity of the control system. Furthermore, the use of the suboptimal control technique provides the UAV attitude tracking in finite time. These remarks are drawn from a series of simulation tests conducted for the drone model.
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Tuyishimire, Emmanuel, Antoine Bagula i Adiel Ismail. "Clustered Data Muling in the Internet of Things in Motion". Sensors 19, nr 3 (24.01.2019): 484. http://dx.doi.org/10.3390/s19030484.
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This paper considers a case where an Unmanned Aerial Vehicle (UAV) is used to monitor an area of interest. The UAV is assisted by a Sensor Network (SN), which is deployed in the area such as a smart city or smart village. The area being monitored has a reasonable size and hence may contain many sensors for efficient and accurate data collection. In this case, it would be expensive for one UAV to visit all the sensors; hence the need to partition the ground network into an optimum number of clusters with the objective of having the UAV visit only cluster heads (fewer sensors). In such a setting, the sensor readings (sensor data) would be sent to cluster heads where they are collected by the UAV upon its arrival. This paper proposes a clustering scheme that optimizes not only the sensor network energy usage, but also the energy used by the UAV to cover the area of interest. The computation of the number of optimal clusters in a dense and uniformly-distributed sensor network is proposed to complement the k-means clustering algorithm when used as a network engineering technique in hybrid UAV/terrestrial networks. Furthermore, for general networks, an efficient clustering model that caters for both orphan nodes and multi-layer optimization is proposed and analyzed through simulations using the city of Cape Town in South Africa as a smart city hybrid network engineering use-case.
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Pai, Vinay U., i B. Sainath. "UAV Selection and Link Switching Policy for Hybrid Tethered UAV-Assisted Communication". IEEE Communications Letters 25, nr 7 (lipiec 2021): 2410–14. http://dx.doi.org/10.1109/lcomm.2021.3070197.
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Zhang, Chao, Zi Yang Zhen, Dao Bo Wang i Xin Yu Meng. "Optimal Control for Thrust Vectoring Unmanned Aerial Vehicle". Key Engineering Materials 439-440 (czerwiec 2010): 292–97. http://dx.doi.org/10.4028/www.scientific.net/kem.439-440.292.
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In this paper the application of linear quadratic (LQ) optimal control based techniques to a thrust vectoring unmanned aerial vehicle (TV-UAV) control problem is considered. A general nonlinear dynamic model of the TV-UAV is built, which is different from the common UAV. The longitudinal and lateral linearization models are derived in a benchmark flight state. Two thrust deflections are considered as control variables, associated with the rudder control variables. LQ optimal control method based multivariable control system is designed for the attitude stability control problem. Simulations of a nonlinear model described UAV is carried out, results of which show the superiority of the hybrid control strategy, and also show that the TV-UAV has better properties than the common UAV, in the aspects of anti-disturbance and control efficiency.
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Alanezi, Mohammed A., Abdulazeez F. Salami, Yusuf A. Sha’aban, Houssem R. E. H. Bouchekara, Mohammad S. Shahriar, Mohammed Khodja i Mostafa K. Smail. "UBER: UAV-Based Energy-Efficient Reconfigurable Routing Scheme for Smart Wireless Livestock Sensor Network". Sensors 22, nr 16 (17.08.2022): 6158. http://dx.doi.org/10.3390/s22166158.
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This paper addresses coverage loss and rapid energy depletion issues for wireless livestock sensor networks by proposing a UAV-based energy-efficient reconfigurable routing (UBER) scheme for smart wireless livestock sensor networking applications. This routing scheme relies on a dynamic residual energy thresholding strategy, robust cluster-to-UAV link formation, and UAV-assisted network coverage and recovery mechanism. The performance of UBER was evaluated using low, normal and high UAV altitude scenarios. Performance metrics employed for this analysis are network stability (NST), load balancing ratio (LBR), and topology fluctuation effect ratio (TFER). Obtained results demonstrated that operating with a UAV altitude of 230 m yields gains of 31.58%, 61.67%, and 75.57% for NST, LBR, and TFER, respectively. A comparative performance evaluation of UBER was carried out with respect to hybrid heterogeneous routing (HYBRID) and mobile sink using directional virtual coordinate routing (MS-DVCR). The performance indicators employed for this comparative analysis are energy consumption (ENC), network coverage (COV), received packets (RPK), SN failures detected (SNFD), route failures detected (RFD), routing overhead (ROH), and end-to-end delay (ETE). With regard to the best-obtained results, UBER recorded performance gains of 46.48%, 47.33%, 15.68%, 19.78%, 46.44%, 29.38%, and 58.56% over HYBRID and MS-DVCR in terms of ENC, COV, RPK, SNFD, RFD, ROH, and ETE, respectively. The results obtained demonstrated that the UBER scheme is highly efficient with competitive performance against the benchmarked CBR schemes.
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Donateo, Teresa, Claudia Lucia De Pascalis i Antonio Ficarella. "Synergy Effects in Electric and Hybrid Electric Aircraft". Aerospace 6, nr 3 (6.03.2019): 32. http://dx.doi.org/10.3390/aerospace6030032.
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The interest in electric and hybrid electric power system has been increasing, in recent times, due to the benefits of this technology, such as high power-to-weight ratio, reliability, compactness, quietness, and, above all, elimination of local pollutant emissions. One of the key factors of these technologies is the possibility to exploit the synergy between powertrain, structure, and mission. This investigation addresses this topic by applying multi-objective optimization to two test cases — a fixed-wing, tail-sitter, Vertical Take-off and Landing Unmanned Aerial Vehicle (VTOL-UAV), and a Medium-Altitude Long-Endurance Unmanned Aerial Vehicle (MALE-UAV). Cruise time and payload weight were selected as goals for the first optimization problem, while fuel consumption and electric endurance were selected for the second one. The optimizations were performed with Non-dominated Sorting Genetic Algorithm-II (NSGA-II) and S-Metric Selection Evolutionary Multiobjective Algorithm (SMS-EMOA), by taking several constraints into account. The VTOL-UAV optimization was performed, at different levels (structure only, power system only, structure and power system together). To better underline the synergic effect of electrification, the potential benefit of structural integration and multi-functionalization was also addressed. The optimization of the MALE-UAV was performed at two different levels (power system only, power system, and mission profile together), to explore the synergic effect of hybridization. Results showed that large improvements could be obtained, either in the first test case when, both, the powertrain design and the aircraft structure were considered, and in the optimization of the hybrid electric UAV, where the optimization of the aircraft flight path gave a strong contribution to the overall performances.
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Aires, Alysson Soares, Ademir Marques Junior, Daniel Capella Zanotta, André Luiz Durante Spigolon, Mauricio Roberto Veronez i Luiz Gonzaga. "Digital Outcrop Model Generation from Hybrid UAV and Panoramic Imaging Systems". Remote Sensing 14, nr 16 (17.08.2022): 3994. http://dx.doi.org/10.3390/rs14163994.
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The study of outcrops in geosciences is being significantly improved by the enhancement of technologies that aims to build digital outcrop models (DOMs). Usually, the virtual environment is built by a collection of partially overlapped photographs taken from diverse perspectives, frequently using unmanned aerial vehicles (UAV). However, in situations including very steep features or even sub-vertical patterns, incomplete coverage of objects is expected. This work proposes an integration framework that uses terrestrial spherical panoramic images (SPI), acquired by omnidirectional fusion camera, and a UAV survey to overcome gaps left by traditional mapping in complex natural structures, such as outcrops. The omnidirectional fusion camera produces wider field of view images from different perspectives, which are able to considerably improve the representation of the DOM, mainly where the UAV has geometric view restrictions. We designed controlled experiments to guarantee the equivalent performance of SPI compared with UAV. The adaptive integration is accomplished through an optimized selective strategy based on an octree framework. The quality of the 3D model generated using this approach was assessed by quantitative and qualitative indicators. The results show the potential of generating a more reliable 3D model using SPI allied with UAV image data while reducing field survey time and complexity.
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ISVORANU, Dragoș Daniel, Petrișor-Valentin PÂRVU i Octavian GRIGORE. "A HYBRID PROPULSION SYSTEM FOR UAS". SCIENTIFIC RESEARCH AND EDUCATION IN THE AIR FORCE 21, nr 1 (8.10.2019): 135–50. http://dx.doi.org/10.19062/2247-3173.2019.21.19.
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