Coffee production and marketing is one of the main global commercial activities, but crop yields depend on several factors, among which plant health. The objective of this study was to evaluate the ...efficiency of spray droplet deposition in coffee crops grown in a mountain region, associated to the efficacy of the control of fungal diseases. The application efficiency, using an unmanned aerial vehicle (UAV), and the efficacy of the products applied were tested. Water-sensitive paper tags were used to analyze the application efficiency; agronomic efficiency, vegetative vigor, yield, and physiological parameters were used to determine the fungicide efficacy. Droplet coverage in the upper canopy layer using a pneumatic sprayer (28.70%) was 4.11-fold higher than that found in the same layer for application using a UAV (6.98%) at the rate of 15 L hasup.−1. The highest droplet depositions by using a UAV were found for the rate of 15 L hasup.−1: 1.60, 1.04, and 0.43 µL cmsup.−2 in the upper, middle, and lower layers, respectively; the deposition in the upper layer with application using a pneumatic sprayer was 42.67 µL cmsup.−2, and therefore, a 26.7-fold higher deposition. The results denote that the control of fungal diseases through fungicide applications using a UAV is efficient for mountain coffee crops.
Unmanned Aircraft Systemsdelivers a much needed introduction to UAV System technology, taking an integrated approach that avoids compartmentalising the subject. Arranged in four sections, parts 1-3 ...examine the way in which various engineering disciplines affect the design, development and deployment of UAS. The fourth section assesses the future challenges and opportunities of UAS.Technological innovation and increasingly diverse applications are two key drivers of the rapid expansion of UAS technology. The global defence budget for UAS procurement is expanding, and in the future the market for civilian UAVs is expected to outmatch that of the military. Agriculture, meteorology, conservation and border control are just a few of the diverse areas in which UAVs are making a significant impact; the author addresses all of these applications, looking at the roles and technology behind both fixed wing and rotorcraft UAVs.Leading aeronautical consultant Reg Austin co-founded the Bristol International Remotely Piloted Vehicle (RPV) conferences in 1979, which are now the longest-established UAS conferences worldwide. In addition, Austin has over 40 years' experience in the design and development of UAS. One of Austin's programmes, the 'Sprite UAV System' has been deployed around the world and operated by day and night, in all weathers.
The vertical air pollutant concentrations and their relationships with synoptic- and local-scale air movement have been studied. This study measured the vertical profiles of PMsub.2.5 and Osub.3 ...using an unmanned aerial vehicle during summer in South Korea and analyzed the characteristics of the measured profiles. To understand the impact of synoptic air movements, we generated and categorized the 48 h air trajectories based on HYSPLIT, and we analyzed how the vertical profiles varied under different categories of long-range transport. We found that the vertical PMsub.2.5 concentration has a positive gradient with altitude when more polluted air was transported from China or North Korea and has negative gradient when cleaner air was transported from the East Sea. Unlike PMsub.2.5, the Osub.3 concentration did not depend significantly on the long-range transport scenario because of the short photochemical lifetime of Osub.3 during summer. For local-scale air movements, we found no significant impact of local wind on the measured profiles.
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Recently, multi-UAV systems are attracting growing interests. It offers wide range of applications in civilian and military environment, carrying out dangerous missions that manned aircraft cannot ...offer. Currently, an important challenge is the collision avoidance algorithm. The idea is to use the collision avoidance algorithm to control the multi-UAV systems. This will guarantee the safety of the UAVs. The UAVs will complete the missions without colliding with any moving or static obstacles. This topic has motivated the development of various collision avoidance algorithms. In this paper, we proposed some improvements on the three-dimensional velocity obstacle algorithm proposed in Jenie et al. (J. Guid. Control Dyn. 39(10), 2312-2323 2016). Our improvements are threefold. First, we indicate the limitations of the original 3D collision avoidance method and present the modifications on the algorithm. Second, we develop the velocity obstacle method to be capable of handling cube obstacles in 3D space. Third, a real flight test is conducted to verify the effectiveness of the proposed three-dimensional velocity obstacle method. Keywords Three-dimensional collision avoidance * Three-dimensional velocity obstacle method * Unmanned aerial vehicles
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25.
Sense and avoid in UAS Angelov, Plamen; Angelov, Plamen
2012., 2012, 2012-04-30T00:00:00, 2012-03-06, 2012-03-16, Volume:
61
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There is increasing interest in the potential of UAV (Unmanned Aerial Vehicle) and MAV (Micro Air Vehicle) technology and their wide ranging applications including defence missions, reconnaissance ...and surveillance, border patrol, disaster zone assessment and atmospheric research. High investment levels from the military sector globally is driving research and development and increasing the viability of autonomous platforms as replacements for the remotely piloted vehicles more commonly in use.UAV/UAS pose a number of new challenges, with the autonomy and in particular collision avoidance, detect and avoid, or sense and avoid, as the most challenging one, involving both regulatory and technical issues.Sense and Avoid in UAS: Research and Applications covers the problem of detect, sense and avoid in UAS (Unmanned Aircraft Systems) in depth and combines the theoretical and application results by leading academics and researchers from industry and academia.Key features:Presents a holistic view of the sense and avoid problem in the wider application of autonomous systemsIncludes information on human factors, regulatory issues and navigation, control, aerodynamics and physics aspects of the sense and avoid problem in UASProvides professional, scientific and reliable content that is easy to understand, andIncludes contributions from leading engineers and researchers in the fieldSense and Avoid in UAS: Research and Applications is an invaluable source of original and specialised information. It acts as a reference manual for practising engineers and advanced theoretical researchers and also forms a useful resource for younger engineers and postgraduate students. With its credible sources and thorough review process, Sense and Avoid in UAS: Research and Applications provides a reliable source of information in an area that is fast expanding but scarcely covered.
Unmanning studies the conditions that create unmanned platforms in the United States through a genealogy of experimental, pilotless planes flown between 1936 and 1992. Characteristics often ...attributed to the drone—including machine-like control, enmity and remoteness—are achieved by displacements between humans and machines that shape a mediated theater of war. Rather than primarily treating the drone as a result of the war on terror, this book examines contemporary targeted killing through a series of failed experiments to develop unmanned flight in the twentieth century. The human, machine and media parts of drone aircraft are organized to make an ostensibly not human framework for war that disavows its political underpinnings as technological advance. These experiments are tied to histories of global control, cybernetics, racism and colonialism. Drone crashes and failures call attention to the significance of human action in making technopolitics that comes to be opposed to “man” and the paradoxes at their basis.
With the frequent occurrence of various disaster events, China has attached high importance to emergency rescue in recent years. Unmanned aerial vehicles (UAVs) are becoming more extensively used in ...emergency rescue, thanks to their flexibility, intellectuality, and safety in operation. It is therefore timely to evaluate UAV utilization in emergency rescue and explore the impediments to its further development in China. To date, UAVs have been mainly used for on-site monitoring and commanding, relay of communications, delivery of materials, disaster assessment, and life detection. Aerial emergency rescue is a vital component of the whole emergency rescue system in China. In the future, it is recommended that China take measures to boost UAV technical innovation and professional team development and promote the integrated application of manned aircraft and UAVs. Keywords: disasters, rescue scene, drone, technical innovation
With the frequent occurrence of various disaster events, China has attached high importance to emergency rescue in recent years. Unmanned aerial vehicles (UAVs) are becoming more extensively used in ...emergency rescue, thanks to their flexibility, intellectuality, and safety in operation. It is therefore timely to evaluate UAV utilization in emergency rescue and explore the impediments to its further development in China. To date, UAVs have been mainly used for on-site monitoring and commanding, relay of communications, delivery of materials, disaster assessment, and life detection. Aerial emergency rescue is a vital component of the whole emergency rescue system in China. In the future, it is recommended that China take measures to boost UAV technical innovation and professional team development and promote the integrated application of manned aircraft and UAVs. Keywords: disasters, rescue scene, drone, technical innovation
Oedaleus decorus asiaticus is one of the dominant harmful pests in central Inner Mongolia, China. Large-scale outbreaks of this pest create many serious problems in animal husbandry and agriculture. ...Therefore, understanding the underlying mechanisms between plant losses and Odecorus at different density levels and growth stages can guide the development of monitoring and prediction measures to reduce damage. In this study, an unmanned aerial vehicle (UAV) carrying a camera was employed to collect multi-spectral data. Further, nine vegetation indices (VIs) were analyzed to explore the most suitable indices for estimating plant loss caused by O. decorus in different growth stages. The following results were obtained: (1) The second instar nymphs of O. decorus could promote vegetation growth. As the density level in each cage increased, the biomass of each cage increased (nymph density < 30 nymphs/msup.2) and then decreased (nymph density ≥ 30 nymphs/msup.2). When nymph density was greater than 60 nymphs/msup.2, the biomass in those cages decreased significantly. (2) With respect to the control group, large damage began to emerge during the third instar nymphal stage. In particular, the largest vegetation loss was caused by fourth nymphal larvae. (3) The ratio vegetation index (RVI) appeared as the most excellent index for reflecting Leymus chinensis loss caused by O. decorus at different growth stages. Nevertheless, the difference vegetation index (DVI) was better than the RVI in the fifth instar nymphal stage.
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