scholarly journals Flying UltraSonic – A new way to measure the wind

2019 ◽  
Author(s):  
Martin Hofsäß ◽  
Dominique Bergmann ◽  
Jan Denzel ◽  
Po Wen Cheng

Abstract. Measurements of flow conditions at complex sites that are difficult to install a met mast are expensive and can only be carried out with great effort. Concepts and new measuring methods are needed to evaluate these sites. This article presents an experiment in which an unmanned aerial vehicle (UAV), more precisely a helicopter, was equipped with a standard 3-D ultrasonic anemometer. This UAV was positioned closed to a meteorological measuring mast and remained stationary at a constant altitude to measure the wind speed components. The data of the UAV were compared with the measurements of an ultrasonic sensor installed on the met mast. The measurements shows a deviation of 0.1 m/s for the horizontal speed. A comparison of the PSDs shows a very good agreement.

2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.


2019 ◽  
Vol 62 (6) ◽  
pp. 1447-1453 ◽  
Author(s):  
Brian Richardson ◽  
Carol A. Rolando ◽  
Mark O. Kimberley ◽  
Tara M. Strand

HighlightsThe swath pattern was measured from an Agras MG-1 UAV spraying fine and extra-coarse droplet spectra.The recommended lane separation of 3.6 m did not differ for the two droplet size classes tested in this study.The applied spray deposited within the swath was higher with extra-coarse (>90%) than with fine (73%) droplets.There was potential for substantial downwind drift with fine droplets, even when flying close to the ground at low speed.Abstract. While there is increasing interest in the use of small, multi-rotor UAVs for application of agrichemicals, there is also uncertainty about their performance. Consequently, the purpose of this study was to quantify the performance of an Agras MG-1 with modified nozzle positions that, at the time of writing, was being used for commercial spraying in New Zealand. The approach was to release spray from the UAV along a single 50 m line. Spray deposits were measured using horizontal collectors placed on the ground in three 15 m transects centered on, and perpendicular to, the flight line. Airborne deposits were measured with a 10 m mast that supported spherical samplers at 1 m vertical intervals. Analysis of deposition data was undertaken to quantify factors influencing overall swath pattern variability, lane separation associated with a coefficient of variation (CV) of deposition of 30%, and spray application efficiency, which is the proportion of applied spray deposited within the swath. For two droplet size classes (extra-coarse and fine), the lane separation associated with a CV of 30% was about 3.6 m, with no significant effect of droplet size. This is a surprising result and may reflect the relatively small range of environmental conditions experienced during the field tests, including wind speed, which was relatively low for all tests. We speculate that this result may also be a consequence of the strong downwash. The swath width was positively correlated with wind speed. Spray efficiency was shown to be high (>90%) for the extra-coarse droplets but dropped significantly (73%) with the fine droplet spectrum. Combining in-swath deposition with the amount of airborne spray sampled in a 10 m vertical profile close to the edge of the swath accounted for 98.0% of the spray released with the extra-coarse spectrum but only 88.6% of the spray with the fine droplet spectrum. These results highlight that even with UAVs flying relatively close to the ground at a low forward speed, there is potential for substantial drift downwind of the swath when using smaller droplet size classes. Overall, the swath pattern was reasonably consistent across the two droplet size classes and for the narrow range of operational and meteorological conditions tested. Keywords: Aerial spraying, Pesticides, Spray application efficiency, Spray deposition, Swath pattern, UAV, Unmanned aerial vehicle.


2018 ◽  
Vol 35 (8) ◽  
pp. 1621-1631 ◽  
Author(s):  
Tomoya Shimura ◽  
Minoru Inoue ◽  
Hirofumi Tsujimoto ◽  
Kansuke Sasaki ◽  
Masato Iguchi

AbstractSmall unmanned aerial vehicles (UAVs), also known as drones, have recently become promising tools in various fields. We investigated the feasibility of wind vector profile measurement using an ultrasonic anemometer installed on a 1-m-wide hexarotor UAV. Wind vectors measured by the UAV were compared to observations by a 55-m-high meteorological tower, over a wide range of wind speed conditions up to 11 m s−1, which is a higher wind speed range than those used in previous studies. The wind speeds and directions measured by the UAV and the tower were in good agreement, with a root-mean-square error of 0.6 m s−1 and 12° for wind speed and direction, respectively. The developed method was applied to field meteorological observations near a volcano, and the wind vector profiles, along with temperature and humidity, were measured by the UAV for up to an altitude of 1000 m, which is a higher altitude range than those used in previous studies. The wind vector profile measured by the UAV was compared with Doppler lidar measurements (collected several kilometers away from the UAV measurements) and was found to be qualitatively similar to that captured by the Doppler lidar, and it adequately represented the features of the atmospheric boundary layer. The feasibility of wind profile measurement up to 1000 m by a small rotor-based UAV was clarified over a wide range of wind speed conditions.


Atmosphere ◽  
2017 ◽  
Vol 8 (10) ◽  
pp. 195 ◽  
Author(s):  
Brandon Witte ◽  
Robert Singler ◽  
Sean Bailey

This paper describes the components and usage of an unmanned aerial vehicle developed for measuring turbulence in the atmospheric boundary layer. A method of computing the time-dependent wind speed from a moving velocity sensor data is provided. The physical system built to implement this method using a five-hole probe velocity sensor is described along with the approach used to combine data from the different on-board sensors to allow for extraction of the wind speed as a function of time and position. The approach is demonstrated using data from three flights of two unmanned aerial vehicles (UAVs) measuring the lower atmospheric boundary layer during transition from a stable to convective state. Several quantities are presented and show the potential for extracting a range of atmospheric boundary layer statistics.


Author(s):  
J. B. Babaan ◽  
J. P. Ballori ◽  
A. M. Tamondong ◽  
R. V. Ramos ◽  
P. M. Ostrea

<p><strong>Abstract.</strong> As the unmanned aerial vehicle (UAV) technology has gained popularity over the years, it has been introduced for air quality monitoring. This study demonstrates the feasibility of customized UAV with mobile monitoring devices as an effective, flexible, and alternative means to collect three-dimensional air pollutant concentration data. This also shows the vertical distribution of PM concentration and the relationship between the PM<sub>2.5</sub> vertical distribution and the meteorological parameters within 500<span class="thinspace"></span>m altitude on a single flight in UP Diliman, Quezon City. Measurement and mapping of the vertical distribution of particulate matter (PM)<sub>2.5</sub> concentration is demonstrated in this research using integrated air quality sensors and customized Unmanned Aerial Vehicle. The flight covers an area with a radius of 80 meters, following a cylindrical path with 40-meter interval vertically. The PM<sub>2.5</sub> concentration values are analyzed relative to the meteorological parameters including air speed, pressure, temperature, and relative humidity up to a 500<span class="thinspace"></span>meter-flying height in a single flight in Barangay UP Campus, UP Diliman, Quezon City. The study shows that generally, the PM<sub>2.5</sub> concentration decreases as the height increases with an exception in the 200&amp;ndash;280<span class="thinspace"></span>m above ground height interval due to a sudden change of atmospheric conditions at the time of the flight. Using correlation and regression analysis, the statistics shows that PM<sub>2.5</sub> concentration has a positive relationship with temperature and a negative relationship with relative humidity and wind speed. As relative humidity and wind speed increases, PM<sub>2.5</sub> decreases, while as temperature increases, PM<sub>2.5</sub> also increases.</p>


2020 ◽  
pp. paper82-1-paper82-10
Author(s):  
Mainak Mondal ◽  
Stanislav Shidlovskiy ◽  
Dmitriy Shashev

This article describes the use of a monocular camera attached to a multirotor perpendicular to the horizon, to recognize visual cues or artefacts (AprilTag) and use it as an anchor for aerial alignment to finally land on it, thus attempting to make autonomous flights safer and usable in slightly hard-to-reach locations. A Hexacopter frame with the DJI N3 flight controller was used for prototyping and realizing the desired algorithm. Factors like wind speed and gusts were taken into account as well as the center of gravity of the multirotor and the position of the molecular camera attached to the copter facing downwards or at a 90-degree angle. The results of the experiments conducted were verified against existing methods like the GPS (Global Positioning System) waypoint mission provided by major commercial Unmanned Aerial Vehicle(UAV) or Flight Controller manufacturers and were also compared to experimental methods presented in related research articles, fairing excellent results


2017 ◽  
Vol 64 (1) ◽  
pp. 37-55 ◽  
Author(s):  
Mirosław Rodzewicz ◽  
Dominik Głowacki ◽  
Jarosław Hajduk

Abstract The article presents the analyses of the flights carried out the by the Unmanned Aerial Vehicle (UAV) named PW-ZOOM used to perform a photogrammetric mission and monitoring of fauna in Antarctic areas. The analyses focus on the deviations of the optical axis of the photo-camera which occurred during photogrammetric flights carried out on the same route but during several Antarctic expeditions performed in subsequent years (2014 and 2015). The results were subjected to correlation tests with weather conditions (wind speed and variability). The basis for these analyses are the data from the onboard signal recorder integrated with an autopilot.


Atmosphere ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 363 ◽  
Author(s):  
Min-Seong Kim ◽  
Byung Hyuk Kwon

In this work, sensible heat flux estimated using a bulk transfer method was validated with a three-dimensional ultrasonic anemometer or surface layer scintillometer at various sites. Results indicate that it remains challenging to obtain temperature and wind speed at an appropriate reference height. To overcome this, alternative observations using an unmanned aerial vehicle (UAV) were considered. UAV-based wind speed and sensible heat flux were indirectly estimated and atmospheric boundary layer (ABL) height was then derived using the sensible heat flux data. UAV-observed air temperature was measured by attaching a temperature sensor 40 cm above the rotary-wing of the UAV, and UAV-based wind speed was estimated using attitude data (pitch, roll, and yaw angles) recorded using the UAV’s inertial measurement unit. UAV-based wind speed was close to the automatic weather system-observed wind speed, within an error range of approximately 10%. UAV-based sensible heat flux estimated from the bulk transfer method corresponded with sensible heat flux determined using the eddy correlation method, within an error of approximately 20%. A linear relationship was observed between the normalized UAV-based sensible heat flux and radiosonde-based normalized ABL height.


2020 ◽  
Author(s):  
Christian Ingenhorst ◽  
Georg Jacobs ◽  
Laura Stößel ◽  
Ralf Schelenz ◽  
Björn Juretzki

Abstract. Wind farm sites within complex terrain are subject to local wind phenomena, which have a huge impact on a wind turbine's annual energy production. To reduce investment risk, an extensive site evaluation is therefore mandatory. Stationary long-term measurements are supplemented by CFD simulations, which are a commonly used tool to analyse and understand the three-dimensional wind flows above complex terrain. Though being under heavy research, such simulations still show a huge sensitivity for various input parameters like terrain, atmosphere and numerical setup. Within this paper, a different approach aims to measure instead of simulate wind speed deviations above complex terrain by using a flexible, airborne measurement system. An unmanned aerial vehicle is equipped with a standard ultrasonic anemometer. The uncertainty of the system is evaluated against stationary anemometer at different heights and shows very good agreement, especially in mean wind speed (


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