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Jing-Jing Xiong, Guo-Bao Zhang
A control method based on global fast dynamic terminal sliding mode control (TSMC) technique is proposed to design the flight controller for performing the finite-time position and attitude tracking control of a small quadrotor UAV. Firstly, the dynamic model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. Secondly, the dynamic flight controllers of the quadrotor are formulated based on global fast dynamic TSMC, which is able to guarantee that the position and velocity tracking errors of all system state variables converge to zero in finite-time...
October 20, 2016: ISA Transactions
Boyang Li, Yifan Jiang, Jingxuan Sun, Lingfeng Cai, Chih-Yung Wen
In the development of beyond-line-of-sight (BLOS) Unmanned Aerial Vehicle (UAV) systems, communication between the UAVs and the ground control station (GCS) is of critical importance. The commonly used economical wireless modules are restricted by the short communication range and are easily blocked by obstacles. The use of a communication relay system provides a practical way to solve these problems, improving the performance of UAV communication in BLOS and cross-obstacle operations. In this study, a communication relay system, in which a quadrotor was used to relay radio communication for another quadrotor was developed and tested...
October 13, 2016: Sensors
Yukihisa Sanada, Tadashi Orita, Tatsuo Torii
Aerial radiological survey using an unmanned aerial vehicle (UAV) was applied to measurement surface contamination around the Fukushima Daiichi nuclear power station (FDNPS). An unmanned helicopter monitoring system (UHMS) was developed to survey the environmental effect of radioactive cesium scattered as a result of the FDNPS accident. The UHMS was used to monitor the area surrounding the FDNPS six times from 2012 to 2015. Quantitative changes in the radioactivity distribution trend were revealed from the results of these monitoring runs...
October 3, 2016: Applied Radiation and Isotopes
A Claesson, D Fredman, L Svensson, M Ringh, J Hollenberg, P Nordberg, M Rosenqvist, T Djarv, S Österberg, J Lennartsson, Y Ban
BACKGROUND: The use of an automated external defibrillator (AED) prior to EMS arrival can increase 30-day survival in out-of-hospital cardiac arrest (OHCA) significantly. Drones or unmanned aerial vehicles (UAV) can fly with high velocity and potentially transport devices such as AEDs to the site of OHCAs. The aim of this explorative study was to investigate the feasibility of a drone system in decreasing response time and delivering an AED. METHODS: Data of Global Positioning System (GPS) coordinates from historical OHCA in Stockholm County was used in a model using a Geographic Information System (GIS) to find suitable placements and visualize response times for the use of an AED equipped drone...
October 12, 2016: Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine
Hee-Jin Kwon, Jae-Hyeong Park, Song Soo Kim, Byung Joo Sun, Sun Ah Jin, Jun-Hyung Kim, Jae-Hwan Lee, Siwan Choi, Jin-Ok Jeong, In-Whan Seong
Unicuspid aortic valve (UAV) is an extremely rare form of congenital aortic valvular abnormality. Although UAV shows similar clinical characteristics to bicuspid aortic valve, the clinical symptoms develop at earlier age and progress at a faster pace in UAV. In this report, we are presenting a 42-year-old male with severe aortic stenosis associated with unicommissural UAV. The patients underwent a successful Bentall operation.
September 2016: Journal of Cardiovascular Ultrasound
Eric M Wilcox, Rick M Thomas, Puppala S Praveen, Kristina Pistone, Frida A-M Bender, Veerabhadran Ramanathan
The introduction of cloud condensation nuclei and radiative heating by sunlight-absorbing aerosols can modify the thickness and coverage of low clouds, yielding significant radiative forcing of climate. The magnitude and sign of changes in cloud coverage and depth in response to changing aerosols are impacted by turbulent dynamics of the cloudy atmosphere, but integrated measurements of aerosol solar absorption and turbulent fluxes have not been reported thus far. Here we report such integrated measurements made from unmanned aerial vehicles (UAVs) during the CARDEX (Cloud Aerosol Radiative Forcing and Dynamics Experiment) investigation conducted over the northern Indian Ocean...
October 4, 2016: Proceedings of the National Academy of Sciences of the United States of America
Mitchell B Cruzan, Ben G Weinstein, Monica R Grasty, Brendan F Kohrn, Elizabeth C Hendrickson, Tina M Arredondo, Pamela G Thompson
PREMISE OF THE STUDY: Low-elevation surveys with small aerial drones (micro-unmanned aerial vehicles [UAVs]) may be used for a wide variety of applications in plant ecology, including mapping vegetation over small- to medium-sized regions. We provide an overview of methods and procedures for conducting surveys and illustrate some of these applications. METHODS: Aerial images were obtained by flying a small drone along transects over the area of interest. Images were used to create a composite image (orthomosaic) and a digital surface model (DSM)...
September 2016: Applications in Plant Sciences
Herman Castañeda, Oscar S Salas-Peña, Jesús de León-Morales
This paper addresses the design of attitude and airspeed controllers for a fixed wing unmanned aerial vehicle. An adaptive second order sliding mode control is proposed for improving performance under different operating conditions and is robust in presence of external disturbances. Moreover, this control does not require the knowledge of disturbance bounds and avoids overestimation of the control gains. Furthermore, in order to implement this controller, an extended observer is designed to estimate unmeasurable states as well as external disturbances...
September 22, 2016: ISA Transactions
Subasit Acharji, Arvind Agnihotri, Joseph Carrozza
Unicuspid aortic valve (UAV) offers unique challenges to transcatheter aortic valve replacement (TAVR), due to asymmetric expansion and apposition of the prosthesis during implantation. Although TAVR in bicuspid is now a well described experience, TAVR in unicuspid valve has not yet been described. A challenging case is described with TAVR in UAV using a Edwards Sapiens prosthesis via transapical approach. © 2016 Wiley Periodicals, Inc.
September 23, 2016: Catheterization and Cardiovascular Interventions
Amy Hocraffer, Chang S Nam
A meta-analysis was conducted to systematically evaluate the current state of research on human-system interfaces for users controlling semi-autonomous swarms composed of groups of drones or unmanned aerial vehicles (UAVs). UAV swarms pose several human factors challenges, such as high cognitive demands, non-intuitive behavior, and serious consequences for errors. This article presents findings from a meta-analysis of 27 UAV swarm management papers focused on the human-system interface and human factors concerns, providing an overview of the advantages, challenges, and limitations of current UAV management interfaces, as well as information on how these interfaces are currently evaluated...
January 2017: Applied Ergonomics
Tetsuo Yamanaka, Toru Fukatsu, Yoshimaro Ichinohe, Hirotaka Komatsu, Masahiro Seki, Kenichi Sasaki, Hideaki Takai, Takashi Kunihara, Yasunobu Hirata
We herein report an adult case of unicommissural unicuspid aortic valve (UAV). A 59-year-old man, who was noted to have a cardiac murmur at 31 years of age, was admitted to our hospital due to acute heart failure. Severe calcification in the aortic valve with severe low-flow/low-gradient aortic stenosis and moderate aortic regurgitation was observed and thought to be the cause of heart failure, however, the etiology of aortic valve dysfunction was not clear. Aortic valve replacement was subsequently performed, and unicommissural UAV was diagnosed according to the intraoperative findings...
2016: Internal Medicine
C Quintana, G Erry, A Gomez, Y Thueux, G E Faulkner, D C O'Brien
Weight reduction and low power consumption are key requirements in the next generation of unmanned aerial vehicles (UAVs). To communicate with an operator, a secured link between the UAV and a ground-based station is desirable. To realize these links, retroreflecting free-space optics is potentially attractive as it offers light weight and low complexity at the UAV. However, the base station requires a high-performance tracking module to enable a steady illumination of the UAV retroreflector. In this paper, we present the design and implementation of a tracking system, which consists of coarse tracking and holographic fine tracking modules working cooperatively...
September 1, 2016: Applied Optics
Changhong Fu, Ran Duan, Dogan Kircali, Erdal Kayacan
In this paper, we present a novel onboard robust visual algorithm for long-term arbitrary 2D and 3D object tracking using a reliable global-local object model for unmanned aerial vehicle (UAV) applications, e.g., autonomous tracking and chasing a moving target. The first main approach in this novel algorithm is the use of a global matching and local tracking approach. In other words, the algorithm initially finds feature correspondences in a way that an improved binary descriptor is developed for global feature matching and an iterative Lucas-Kanade optical flow algorithm is employed for local feature tracking...
2016: Sensors
Tao Yang, Guangpo Li, Jing Li, Yanning Zhang, Xiaoqiang Zhang, Zhuoyue Zhang, Zhi Li
This paper proposes a novel infrared camera array guidance system with capability to track and provide real time position and speed of a fixed-wing Unmanned air vehicle (UAV) during a landing process. The system mainly include three novel parts: (1) Infrared camera array and near infrared laser lamp based cooperative long range optical imaging module; (2) Large scale outdoor camera array calibration module; and (3) Laser marker detection and 3D tracking module. Extensive automatic landing experiments with fixed-wing flight demonstrate that our infrared camera array system has the unique ability to guide the UAV landing safely and accurately in real time...
2016: Sensors
Pedro Pina, Gonçalo Vieira, Lourenço Bandeira, Carla Mora
The ice-free areas of Maritime Antarctica show complex mosaics of surface covers, with wide patches of diverse bare soils and rock, together with various vegetation communities dominated by lichens and mosses. The microscale variability is difficult to characterize and quantify, but is essential for ground-truthing and for defining classifiers for large areas using, for example high resolution satellite imagery, or even ultra-high resolution unmanned aerial vehicle (UAV) imagery. The main objective of this paper is to verify the ability and robustness of an automated approach to discriminate the variety of surface types in digital photographs acquired at ground level in ice-free regions of Maritime Antarctica...
August 25, 2016: Science of the Total Environment
Yongzheng Xu, Guizhen Yu, Yunpeng Wang, Xinkai Wu, Yalong Ma
A new hybrid vehicle detection scheme which integrates the Viola-Jones (V-J) and linear SVM classifier with HOG feature (HOG + SVM) methods is proposed for vehicle detection from low-altitude unmanned aerial vehicle (UAV) images. As both V-J and HOG + SVM are sensitive to on-road vehicles' in-plane rotation, the proposed scheme first adopts a roadway orientation adjustment method, which rotates each UAV image to align the roads with the horizontal direction so the original V-J or HOG + SVM method can be directly applied to achieve fast detection and high accuracy...
2016: Sensors
Maria Tattaris, Matthew P Reynolds, Scott C Chapman
Remote sensing (RS) of plant canopies permits non-intrusive, high-throughput monitoring of plant physiological characteristics. This study compared three RS approaches using a low flying UAV (unmanned aerial vehicle), with that of proximal sensing, and satellite-based imagery. Two physiological traits were considered, canopy temperature (CT) and a vegetation index (NDVI), to determine the most viable approaches for large scale crop genetic improvement. The UAV-based platform achieves plot-level resolution while measuring several hundred plots in one mission via high-resolution thermal and multispectral imagery measured at altitudes of 30-100 m...
2016: Frontiers in Plant Science
Timothy K Amukele, Jeff Street, Karen Carroll, Heather Miller, Sean X Zhang
Unmanned aerial vehicles (UAVs) could potentially be used to transport microbiological specimens. To examine the impact of UAVs on microbiological specimens, blood and sputum culture specimens were seeded with usual pathogens and flown in a UAV for 30 ± 2 min. Times to recovery, colony counts, morphologies, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based identifications of the flown and stationary specimens were similar for all microbes studied.
October 2016: Journal of Clinical Microbiology
Max Messinger, Miles Silman
Unmanned aerial vehicles (UAVs) offer new opportunities to monitor pollution and provide valuable information to support remediation. Their low-cost, ease of use, and rapid deployment capability make them ideal for environmental emergency response. Here we present a UAV-based study of the third largest coal ash spill in the United States. Coal ash from coal combustion is a toxic industrial waste material present worldwide. Typically stored in settling ponds in close proximity to waterways, coal ash poses significant risk to the environment and drinking water supplies from both chronic contamination of surface and ground water and catastrophic pond failure...
November 2016: Environmental Pollution
Kai Chang, Yuanqing Xia, Kaoli Huang
This paper considers the artificial potential field method combined with rotational vectors for a general problem of multi-unmanned aerial vehicle (UAV) systems tracking a moving target in dynamic three-dimensional environment. An attractive potential field is generated between the leader and the target. It drives the leader to track the target based on the relative position of them. The other UAVs in the formation are controlled to follow the leader by the attractive control force. The repulsive force affects among the UAVs to avoid collisions and distribute the UAVs evenly on the spherical surface whose center is the leader-UAV...
2016: SpringerPlus
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