scholarly journals Localization System for Lightweight Unmanned Aerial Vehicles in Inspection Tasks

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5937
Author(s):  
Diego Benjumea ◽  
Alfonso Alcántara ◽  
Agustin Ramos ◽  
Arturo Torres-Gonzalez ◽  
Pedro Sánchez-Cuevas ◽  
...  
Keyword(s):  
High Altitude ◽  
Unmanned Aerial Vehicles ◽  
Satellite System ◽  
Localization System ◽  
Aerial Vehicles ◽  
System Defect ◽  
Angular Velocities ◽  
Infrastructure Inspection ◽  
Inspection Tasks ◽  
Global Navigation Satellite

This paper presents a localization system for Unmanned Aerial Vehicles (UAVs) especially designed to be used in infrastructure inspection, where the UAVs have to fly in challenging conditions, such as relatively high altitude (e.g., 15 m), eventually with poor or absent GNSS (Global Navigation Satellite System) signal reception, or the need for a BVLOS (Beyond Visual Line of Sight) operation in some periods. In addition, these infrastructure inspection applications impose the following requirements for the localization system: defect traceability, accuracy, reliability, and fault tolerance. Our system proposes a lightweight solution combining multiple stereo cameras with a robotic total station to comply with these requirements, providing full-state estimation (i.e., position, orientation, and linear and angular velocities) in a fixed and time-persistent reference frame. Moreover, the system can align and fuse all sensor measurements in real-time at high frequency. We have integrated this localization system in our aerial platform, and we have tested its performance for inspection in a real-world viaduct scenario, where the UAV has to operate with poor or absent GNSS signal at high altitude.

scholarly journals Relative Navigation in UAV Applications

2020 ◽  
Vol vm01 (is02) ◽  
pp. 52-65
Author(s):  
Tuncay Yunus Erkec ◽  
Chingiz Hajiyev
Keyword(s):  
State Estimation ◽  
Unmanned Aerial Vehicles ◽  
Satellite System ◽  
Formation Flight ◽  
Navigation Systems ◽  
Relative Navigation ◽  
Inertial Navigation Systems ◽  
Estimation Algorithms ◽  
Aerial Vehicles ◽  
Global Navigation Satellite

This paper is committed to the relative navigation of Unmanned Aerial Vehicles (UAVs) flying in formation flight. The concept and methods of swarm UAVs technology and architecture have been explained. The relative state estimation models of unmanned aerial vehicles which are based on separate systems as Inertial Navigation Systems (INS)&Global Navigation Satellite System (GNSS), Laser&INS and Vision based techniques have been compared via various approaches. The sensors are used individually or integrated each other via sensor integration for solving relative navigation problems. The UAV relative navigation models are varied as stated in operation area, type of platform and environment. The aim of this article is to understand the correlation between relative navigation systems and potency of state estimation algorithms as well during formation flight of UAV.

scholarly journals Control System Architecture for Automatic Recovery of Fixed-Wing Unmanned Aerial Vehicles in a Moving Arrest System

2021 ◽  
Vol 103 (4) ◽  
Author(s):  
Kristoffer Gryte ◽  
Martin L. Sollie ◽  
Tor Arne Johansen
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Low Cost ◽  
Field Testing ◽  
Satellite System ◽  
Base Station ◽  
Research Literature ◽  
Aerial Vehicles ◽  
Global Navigation Satellite ◽  
The Right ◽  
Automatic Recovery

AbstractAutomatic recovery is an important step in enabling fully autonomous missions using fixed-wing unmanned aerial vehicles (UAVs) operating from ships or other moving platforms. However, automatic recovery in moving arrest systems is only briefly studied in the research literature, and is not yet an option when using low-cost, commercial off-the-shelf (COTS) autopilots. Acknowledging the reliability and low cost of COTS avionics, this paper adds recovery functionality as a modular extension based on non-intrusive additions to an autopilot with very general assumptions on its interface. This is achieved by line-of-sight guidance, which sends an augmented desired position to the autopilot, to ensure line-following along a virtual runway that guides the UAV into the arrest system. The translation and rotation of this line is determined by the pose of the arrest system, determined using two Global Navigation Satellite System (GNSS) receivers, where one is configured as a Real-Time Kinematic (RTK) base station. The relative position of the UAV and arrest system is also precisely estimated using RTK GNSS. Through extensive field testing, on two different fixed-wing UAVs, the system has shown its performance and reliability; 43 recovery attempts in a stationary net hit 0.01 ± 0.25m to the right and 0.07 ± 0.20m below the target in calm conditions. Further, 15 recoveries in a barge-mounted, ship-towed net hit 0.06 ± 0.53m to the right and 0.98 ± 0.27m below the target in winds up to 4 m/s. The remaining error is largely systematic, caused by communication delays, and could be reduced with more integral effect or through direct compensation.

scholarly journals Investigation of Unmanned Aerial Vehicles-Based Photogrammetry for Large Mine Subsidence Monitoring

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 196 ◽  
Author(s):  
Danijela Ignjatović Stupar ◽  
Janez Rošer ◽  
Milivoj Vulić
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Coal Mine ◽  
Negative Impact ◽  
Local Environment ◽  
Satellite System ◽  
Reference Points ◽  
Coal Extraction ◽  
Observation Data ◽  
Aerial Vehicles ◽  
Global Navigation Satellite

With the exploitation of underground sources, nature receives a huge negative impact on the local environment introducing surface subsidence. A mining region needs to be observed in sequences before, during, and after coal extraction from the coal mine. Different measuring methods exist to monitor subsidence, and all of them apply various instrumentation. A choice of methodology depends on access to a field of observation and requested accuracy. Obviously, the most accurate results provide geometric leveling, but, many times, the terrain does not allow surveyors to walk over the dangerous outfields. Looking for the most adequate and feasible method, this research did a comparison between observation of the same points, applying statistical analysis of differences between the reference points heights, and tested methods. Monitoring procedure comprised utilization of total stations (TS), global navigation satellite system (GNSS), and unmanned aerial vehicles (UAV). In this paper, the Velenje coal mine was taken as a case study, and observation data were collected during 2017.

scholarly journals Algorithm for Control of Unmanned Aerial Vehicles in the Process of Visual Tracking of Objects with a Variable Movement’s Trajectory

2021 ◽  
Vol 12 (1) ◽  
pp. 46-57
Author(s):  
A. A. Adnastarontsau ◽  
D. A. Adnastarontsava ◽  
R. V. Fiodortsev ◽  
D. V. Katser ◽  
A. Y. Liavonau ◽  
...  
Keyword(s):  
Coordinate System ◽  
Unmanned Aerial Vehicles ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Optoelectronic System ◽  
Aerial Vehicles ◽  
Aerial Vehicle ◽  
Stabilized Platform ◽  
Global Navigation Satellite

The purpose of the research was to create an algorithm for determining and correcting the output parameters of the navigation module and the flight-navigation complex of unmanned aerial vehicles which provides control of an aviation gyro-stabilized platform with a multispectral optoelectronic system during flight and tracking various objects of observation.Principles of control of an aviation technical vision system located on an unmanned aerial vehicle on a two-degree gyro-stabilized platform with the possibility of full turn around two perpendicular axes along the course and pitch are considered. Stability of tracking of observation objects at a distance of up to 10000 m is ensured by the use of a multispectral optoelectronic system including a rangefinder, thermal imaging and two visual channels.Analysis of the object of observation and the method of its support are carried out. An algorithm is proposed for integrating a Global Navigation Satellite System and a strapdown inertial navigation system based on the extended Kalman filter which includes two stages of calculations, extrapolation (prediction) and correction. Specialized software in the FreeRTOS v9.0 environment has been developed to obtain a navigation solution: latitude, longitude and altitude of the unmanned aerial vehicle in the WGS-84 coordinate system, as well as the pitch, heading and roll angles; north, east and vertical components of velocities in the navigation coordinate system; longitudinal, vertical and transverse components of free accelerations and angular velocities in the associated coordinate system based on data from the receiving and measuring module of the Global Navigation Satellite System and data from the 6-axis MEMS sensor STIM300.

scholarly journals APPLICATION OF UNMANNED AERIAL VEHICLES FOR GLACIER RESEARCH IN THE ARCTIC AND ANTARCTIC

2019 ◽  
Vol 1 ◽  
pp. 131
Author(s):  
Kristaps Lamsters ◽  
Jānis Karušs ◽  
Māris Krievāns ◽  
Jurijs Ješkins
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Satellite System ◽  
Aerial Photographs ◽  
The Arctic ◽  
Polar Regions ◽  
Flight Duration ◽  
Aerial Vehicles ◽  
Surface Models ◽  
Global Navigation Satellite ◽  
Glacier Mapping

Unmanned aerial vehicles or drones are nowadays widely used in a broad field of scientific and commercial applications. Despite this, it is quite a new method for glacier mapping in polar regions and has a lot of advantages, as well as disadvantages over more classical remote sensing instruments. Here we examine the main issues associated with the application of drones for glacier research from our experience in Iceland, Greenland and the Antarctic. We use DJI Phantom series drones for the obtaining of aerial photographs and produce digital surface models (resolution of 8 – 16 cm) and orthomosaics (resolution of 2 – 4 cm) for glacier mapping. Several issues related to the ground control points, geolocation using Global Navigation Satellite System receiers and creation of final products are addressed as well. We recommend the further use of drones in remote polar areas because it allows obtaining very high-resolution orthomosaics and digital surface models that are not achieved by other methods. Short summer season, raw weather with precipitation and winds, limited drone flight duration and problems with connection cables are the main issues everyone can encounter working in polar regions but all issues can be restricted with careful planning and readiness to gather data whenever it is possible during all field campaign.

scholarly journals THE POTENTIAL OF LIGHT LASER SCANNERS DEVELOPED FOR UNMANNED AERIAL VEHICLES – THE REVIEW AND ACCURACY

2016 ◽  
Vol XLII-2/W2 ◽  
pp. 87-95 ◽  
Author(s):  
M. Pilarska ◽  
W. Ostrowski ◽  
K. Bakuła ◽  
K. Górski ◽  
Z. Kurczyński
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Laser Scanning ◽  
Measurement Accuracy ◽  
Laser Scanner ◽  
Satellite System ◽  
Measurement Unit ◽  
Aerial Vehicles ◽  
Laser Scanners ◽  
Final Measurement ◽  
Global Navigation Satellite

Modern photogrammetry and remote sensing have found small Unmanned Aerial Vehicles (UAVs) to be a valuable source of data in various branches of science and industry (e.g., agriculture, cultural heritage). Recently, the growing role of laser scanning in the application of UAVs has also been observed. Laser scanners dedicated to UAVs consist of four basic components: a laser scanner (LiDAR), an Inertial Measurement Unit (IMU), a Global Navigation Satellite System (GNSS) receiver and an on-board computer. The producers of the system provide users with detailed descriptions of the accuracies separately for each component. However, the final measurement accuracy is not given. This paper reviews state-of-the-art of laser scanners developed specifically for use on a UAV, presenting an overview of several constructions that are available nowadays. The second part of the paper is focussed on analysing the influence of the sensor accuracies on the final measurement accuracy. Mathematical models developed for Airborne Laser Scanning (ALS) accuracy analyses are used to estimate the theoretical accuracies of different scanners with conditions typical for UAV missions. Finally, the theoretical results derived from the mathematical simulations are compared with an experimental use case.

scholarly journals Learning-Based Autonomous UAV System for Electrical and Mechanical (E&M) Device Inspection

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1385
Author(s):  
Yurong Feng ◽  
Kwaiwa Tse ◽  
Shengyang Chen ◽  
Chih-Yung Wen ◽  
Boyang Li
Keyword(s):  
System Design ◽  
State Estimation ◽  
Unmanned Aerial Vehicles ◽  
Visual Inspection ◽  
Spatial Information ◽  
Free Flight ◽  
Object State ◽  
Aerial Vehicles ◽  
Inspection Tasks ◽  
Autonomous Inspection

The inspection of electrical and mechanical (E&M) devices using unmanned aerial vehicles (UAVs) has become an increasingly popular choice in the last decade due to their flexibility and mobility. UAVs have the potential to reduce human involvement in visual inspection tasks, which could increase efficiency and reduce risks. This paper presents a UAV system for autonomously performing E&M device inspection. The proposed system relies on learning-based detection for perception, multi-sensor fusion for localization, and path planning for fully autonomous inspection. The perception method utilizes semantic and spatial information generated by a 2-D object detector. The information is then fused with depth measurements for object state estimation. No prior knowledge about the location and category of the target device is needed. The system design is validated by flight experiments using a quadrotor platform. The result shows that the proposed UAV system enables the inspection mission autonomously and ensures a stable and collision-free flight.

scholarly journals Development of Non Expensive Technologies for Precise Maneuvering of Completely Autonomous Unmanned Aerial Vehicles

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 391
Author(s):  
Luca Bigazzi ◽  
Stefano Gherardini ◽  
Giacomo Innocenti ◽  
Michele Basso
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Degrees Of Freedom ◽  
Vision System ◽  
Video Stream ◽  
Measurement Unit ◽  
Absolute Position ◽  
Light Load ◽  
Aerial Vehicles ◽  
Angular Velocities ◽  
Custom Hardware

In this paper, solutions for precise maneuvering of an autonomous small (e.g., 350-class) Unmanned Aerial Vehicles (UAVs) are designed and implemented from smart modifications of non expensive mass market technologies. The considered class of vehicles suffers from light load, and, therefore, only a limited amount of sensors and computing devices can be installed on-board. Then, to make the prototype capable of moving autonomously along a fixed trajectory, a “cyber-pilot”, able on demand to replace the human operator, has been implemented on an embedded control board. This cyber-pilot overrides the commands thanks to a custom hardware signal mixer. The drone is able to localize itself in the environment without ground assistance by using a camera possibly mounted on a 3 Degrees Of Freedom (DOF) gimbal suspension. A computer vision system elaborates the video stream pointing out land markers with known absolute position and orientation. This information is fused with accelerations from a 6-DOF Inertial Measurement Unit (IMU) to generate a “virtual sensor” which provides refined estimates of the pose, the absolute position, the speed and the angular velocities of the drone. Due to the importance of this sensor, several fusion strategies have been investigated. The resulting data are, finally, fed to a control algorithm featuring a number of uncoupled digital PID controllers which work to bring to zero the displacement from the desired trajectory.

scholarly journals Suitability of Unmanned Aerial Vehicles for Cadastral Surveys

2019 ◽  
Vol 19 (1) ◽  
pp. 1-8
Author(s):  
S. Mantey
Keyword(s):  
High Resolution ◽  
Unmanned Aerial Vehicles ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Aerial Vehicles ◽  
High Resolution Images ◽  
The Difference ◽  
Cadastral Surveying ◽  
Difficult Terrain ◽  
Global Navigation Satellite

Cadastral surveys in Ghana often employ well known surveying equipment such as Total Station andGNSSreceivers or a combination of both. These survey techniques are well-established and widely accepted. However, there are limitations in certain areas. In situations where difficult terrain and inaccessible areas and dense vegetation are encountered or when surveyor’s life may be at risk, Unmanned Aerial Vehicles (UAVs) could be used to overcome the limitations of these well-established survey instruments. This research used high resolution images from UAV (DJI Phantom 4) to survey plots within the University of Mines and Technology land area. Coordinates of the boundary points were extracted using Agisoft Photoscan.GNSSreceivers were also used to survey the land and the same boundary point coordinates obtained and compared. This enabled the establishment of accurate ground control points for georeferencing. The coordinates obtained from both UAV andGNSSSurveys were used to prepare cadastral plans and compared. The difference in Northings and Eastings from UAV andGNSSsurveys were +0.380 cmand +0.351 cmrespectively. These differences are well within tolerance of +/-0.9114 m(+/-3 ft) set by the Survey and Mapping Division (SMD) of the Lands Commission for cadastral plans production. This research therefore concludes that high resolution images from UAVs are suitable for cadastral surveying. Keywords: Unmanned Aerial Vehicles, Drones, Global Navigation Satellite Systems, Cadastral Surveys

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