In a conventional Unmanned aerial vehicles (UAV) navigational system Global Navigation Satellite System (GNSS) sensor is often a main source of data for trajectory generation. Even video tracking based systems need some GNSS data for proper work. The goal of this study is to develop an optics-based system to estimate the ground speed of the UAV in the case of the GNSS failure, jamming, or unavailability. The proposed approach uses a camera mounted on the fuselage belly of the UAV. We can obtain the ground speed of the airplane by using the digital cropping, the stabilization of the real time image, and template matching algorithms. By combining the ground speed vector components with measurements of airspeed and altitude, the wind velocity and drift are computed. The obtained data were used to improve efficiency of the video-tracking based on a navigational system. An algorithm allows this computation to be performed in real time on board of a UAV. The algorithm was tested in Software-in-the-loop and implemented on the UAV hardware. Its effectiveness has been demonstrated through the experimental test results. The presented work could be useful for upgrading the existing MUAV products (with embedded cameras) already delivered to the customers only by updating their software. It is especially significant in the case when any necessary hardware upgrades would be economically unjustified or even impossible to be carried out.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8070126 | PMC |
| http://dx.doi.org/10.3390/s21082754 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Biomechanics of the bobsleigh push phase.
J Sports Sci
January 2025
Institute of Biomechanics and Orthopaedics, German Sport University Cologne, Cologne, Germany.
The purpose of this work was to provide a fundamental, in-depth analysis of kinematics and kinetics of the bobsleigh push phase to establish a basis for performance analysis and enhancement. Fifteen elite male athletes performed maximal effort push starts, while ground reaction forces (GRF) and 3D marker trajectories were simultaneously recorded for ground contacts of different sub-sections of the push phase (start acceleration phase: first and second ground contact after the initial push-off from the start block, acceleration phase: 10 m and high-velocity phase: 30 m). To obtain a comprehensive view of the push phase, whole-body kinematics as well as joint kinetics were analysed and compared across the push phase.
View Article and Find Full Text PDFImpact of muscle fatigue on anticipatory postural adjustments during gait initiation.
Front Physiol
January 2025
Human Physiology Section of the Department of Pathophysiology and Transplantation, Università Degli Studi, Milano, Italy.
Introduction: Prolonged or strenuous exercise leads to a temporary decrease in muscle function and performance, which interferes with activity of both prime movers and postural muscles. This effect of fatigue has been reported both for single segment movements and for locomotion. However, little is known regarding the effects of fatigue on anticipatory postural adjustments (APAs) during gait initiation, a task in which the control of focal movement should be strictly coupled to a feedforward control of posture.
View Article and Find Full Text PDFOptimizing key parameters for grinding energy efficiency and modeling of particle size distribution in a stirred ball mill.
Sci Rep
January 2025
Minerals Beneficiation and Agglomeration Department, Minerals Technology Institute, Central Metallurgical Research & Development Institute (CMRDI), P.O. Box 87, Helwan, Cairo, 11722, Egypt.
Fine grinding using a stirred ball mill can enhance ore liberation but incurs high energy consumption, which can be minimized by optimizing operating conditions. This study explores the impact of key operational parameters-grinding time, stirrer tip speed, solid concentration, and feed size-on grinding efficiency, evaluated using specific energy inputs, in stirred milling of Egyptian copper ore. The particle size distribution (PSD) of ground products was simulated using the Gates-Gaudin-Schuhmann model (GGS) and the Rosin-Rammler-Benne (RRB) function.
View Article and Find Full Text PDFStrong turbulent flow in the subauroral region in the Antarctic can deteriorate satellite-based navigation signals.
Sci Rep
January 2025
Department of Physics, University of Oslo, P.O. Box 1048 Blindern, 0316, Oslo, Norway.
In the subauroral zone at the boundary of the auroral oval in the evening and night hours during geomagnetic disturbances, a narrow (about 1°-2°) and extended structure (several hours in longitude) is formed. It is known as a polarization jet (PJ) or the subauroral ion drift (SAID). The PJ/SAID is a fast westward ion drift and is one of the main signatures of a geomagnetic disturbance in the subauroral ionosphere at the altitudes of the F-layer, when the geomagnetic AE index reaches more than 500 nT.
View Article and Find Full Text PDFUAV selection for high-speed train communication using OTFS modulation.
Sci Rep
January 2025
Computational Learning Theory Team, RIKEN-Advanced Intelligence Project, Fukuoka, 819-0395, Japan.
Providing continuous wireless connectivity for high-speed trains (HSTs) is challenging due to their high speeds, making installing numerous ground base stations (BSs) along the HST route an expensive solution, particularly in rural and wilderness areas. This paper proposes using multiple unmanned aerial vehicles (UAVs) to deliver high data rate wireless connectivity for HSTs, taking advantage of their ability to fly, hover, and maneuver at low altitudes. However, autonomously selecting the optimal UAV by the HST is challenging.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!