scholarly journals Computer Vision for Autonomous UAV Flight Safety: An Overview and a Vision-based Safe Landing Pipeline Example

2022 ◽  
Vol 54 (9) ◽  
pp. 1-37
Author(s):  
Efstratios Kakaletsis ◽  
Charalampos Symeonidis ◽  
Maria Tzelepi ◽  
Ioannis Mademlis ◽  
Anastasios Tefas ◽  
...  
Keyword(s):  
Computer Vision ◽  
Point Of View ◽  
Wildlife Monitoring ◽  
Flight Safety ◽  
Crucial Issue ◽  
Military Applications ◽  
Crowd Monitoring ◽  
Uav Navigation ◽  
Landing Control ◽  
Broad Interest

Recent years have seen an unprecedented spread of Unmanned Aerial Vehicles (UAVs, or “drones”), which are highly useful for both civilian and military applications. Flight safety is a crucial issue in UAV navigation, having to ensure accurate compliance with recently legislated rules and regulations. The emerging use of autonomous drones and UAV swarms raises additional issues, making it necessary to transfuse safety- and regulations-awareness to relevant algorithms and architectures. Computer vision plays a pivotal role in such autonomous functionalities. Although the main aspects of autonomous UAV technologies (e.g., path planning, navigation control, landing control, mapping and localization, target detection/tracking) are already mature and well-covered, ensuring safe flying in the vicinity of crowds, avoidance of passing over persons, or guaranteed emergency landing capabilities in case of malfunctions, are generally treated as an afterthought when designing autonomous UAV platforms for unstructured environments. This fact is reflected in the fragmentary coverage of the above issues in current literature. This overview attempts to remedy this situation, from the point of view of computer vision. It examines the field from multiple aspects, including regulations across the world and relevant current technologies. Finally, since very few attempts have been made so far towards a complete UAV safety flight and landing pipeline, an example computer vision-based UAV flight safety pipeline is introduced, taking into account all issues present in current autonomous drones. The content is relevant to any kind of autonomous drone flight (e.g., for movie/TV production, news-gathering, search and rescue, surveillance, inspection, mapping, wildlife monitoring, crowd monitoring/management), making this a topic of broad interest.

scholarly journals Reuse of Urban Soils as Earthworks Material: Geotechnical and Environmental Specifications

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 3
Author(s):  
Lenoir
Keyword(s):  
Urban Soils ◽  
Soil Stabilization ◽  
Construction Materials ◽  
Point Of View ◽  
Crucial Issue ◽  
Common Features ◽  
Crucial Problem ◽  
Promising Solution ◽  
Mechanical Performances ◽  
Resource Shortage

In the context of urban extension, the depletion of natural resources for construction constitutes a crucial issue. Specifically, in the field of earthworks, the amounts of materials can be massive and pose the crucial problem of resource shortage. Therefore, the reuse of excavated urban soils from foundation layers as new earthwork construction materials appears to be a sustainable and promising solution. Two questions are thus asked: (1) Are urban soils relevant from a geotechnical point of view? (2) Are they relevant from an environmental point of view? To answer those issues, two urban soils from the suburb of Paris (France) have been studied. Geotechnical approach and environmental approach exhibit that both soils have common features. Specifically, they are bearer of several pollutant phases like metals, organic carbon and sulphates. Interestingly, those materials, when treated with few percent of hydraulic binders reach required mechanical performances for a use in road structure despite the occurrence of pollutants that are known to have deleterious effects on soil stabilization with lime and cements. However, even if permeability of materials is reduced when they are treated with cement, leaching tests under neutral pH (7) and alkaline pH (12) show, that treatment could have inhibitor effects or activating effects on pollutants release.

An UAV navigation aided with computer vision

2014 ◽  
Author(s):  
ChengHao Zhang ◽  
JiaBin Chen ◽  
ChunLei Song ◽  
JianHua Xu
Keyword(s):  
Computer Vision ◽  
Uav Navigation

scholarly journals Aeroelastic Assessments and Functional Hazard Analysis of a Regional Aircraft Equipped with Morphing Winglets

Aerospace ◽  
2019 ◽  
Vol 6 (10) ◽  
pp. 104 ◽  
Author(s):  
Noviello ◽  
Dimino ◽  
Concilio ◽  
Amoroso ◽  
Pecora
Keyword(s):  
Hazard Analysis ◽  
External Environment ◽  
Point Of View ◽  
Design Solution ◽  
Flight Safety ◽  
Single Event ◽  
Safety Requirements ◽  
Safety Regulations ◽  
Safety Design ◽  
Aircraft Performance

The application of morphing wing devices can bring several benefits in terms of aircraft performance, as the current literature shows. Within the scope of Clean Sky 2 AirGreen 2 European project, the authors provided a safety-driven design of an adaptive winglet, through the examination of potential hazards resulting from operational faults, such as actuation chain jamming or links structural fails. The main goal of this study was to verify whether the morphing winglet systems could comply with the standard civil flight safety regulations and airworthiness requirements (EASA CS25). Systems functions were firstly performed from a quality point of view at both aircraft and subsystem levels to detect potential design, crew and maintenance faults, as well as risks due to the external environment. The severity of the hazard effects was thus identified and then sorted in specific classes, representative of the maximum acceptable probability of occurrence for a single event, in association with safety design objectives. Fault trees were finally developed to assess the compliance of the system structures to the quantitative safety requirements deriving from the Fault and Hazard Analyses (FHAs). The same failure scenarios studied through FHAs have been simulated in flutter analyses performed to verify the aeroelastic effects due to the loss of the actuators or structural links at aircraft level. Obtained results were used to suggest a design solution to be implemented in the next loop of design of the morphing winglet.

scholarly journals Composites Bond Inspection Using Heterodyne Effect and SuRE Methods

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Shervin Tashakori ◽  
Amin Baghalian ◽  
Volkan Y. Senyurek ◽  
Saman Farhangdoust ◽  
Dwayne McDaniel ◽  
...  
Keyword(s):  
Composite Materials ◽  
Aerospace Industry ◽  
Experimental Studies ◽  
Flight Safety ◽  
Composite Joint ◽  
Bonding Condition ◽  
Military Applications ◽  
Contamination Levels ◽  
Effect Method

With increasing utilization of the composite materials in commercial and military applications, the longevity of composite bonds has become a crucial concern of the aerospace industry. In spite of the previous studies in the literature for characterization of bonding condition in composite materials, implementation of more advanced structural health monitoring (SHM) techniques are still required to ensure flight safety and quick inspections of structures. In this study, two different SHM methods were used to evaluate the strength of composite bonds by using two separate experimental setups. First, the heterodyne effect method was used for assessing the separation in the composite joint. Then, the surface response to excitation (SuRE) method was used for studying various simulated contamination levels. Results of the experimental studies showed that the proposed methods could be efficiently utilized for evaluating bonding strength of composite materials.

scholarly journals Large Area Robust Hybrid Tracking with Life-size Avatar in Mixed Reality Environment for Cultural and Historical Installation

2009 ◽  
Vol 8 (2) ◽  
pp. 13-18
Author(s):  
William Russell Pensyl ◽  
Tran C. T. Qui ◽  
Pei Fang Hsin ◽  
Shang Ping Lee ◽  
Daniel K. Jernigan
Keyword(s):  
Computer Vision ◽  
Mixed Reality ◽  
Inertial Sensors ◽  
Point Of View ◽  
Historical Narratives ◽  
Large Area ◽  
The Real ◽  
Lighting Conditions ◽  
Low Jitter ◽  
Present World

We have developed a system which enables us to track participant-observers accurately in a large area for the purpose of immersing them in a mixed reality environment. This system is robust even under uncompromising lighting conditions. Accurate tracking of the observer�s spatial and orientation point of view is achieved by using hybrid inertial sensors and computer vision techniques. We demonstrate our results by presenting a life-size, animated human avatar sitting in a real chair, in a stable and low-jitter manner. The system installation allows the observers to freely walk around and navigate themselves in the environment even while still being able to see the avatar from various angles. The project installation provides an exciting way for cultural and historical narratives to be presented vividly in the real present world.

scholarly journals UAV VISUAL AUTOLOCALIZATON BASED ON AUTOMATIC LANDMARK RECOGNITION

2017 ◽  
Vol IV-2/W3 ◽  
pp. 89-94 ◽  
Author(s):  
P. Silva Filho ◽  
E. H. Shiguemori ◽  
O. Saotome
Keyword(s):  
Computer Vision ◽  
Scientific Community ◽  
Aerial Images ◽  
Gps Data ◽  
Navigation Systems ◽  
Landmark Recognition ◽  
Simulated Environment ◽  
Vision Based Navigation ◽  
Aerial Vehicle ◽  
Uav Navigation

Deploying an autonomous unmanned aerial vehicle in GPS-denied areas is a highly discussed problem in the scientific community. There are several approaches being developed, but the main strategies yet considered are computer vision based navigation systems. This work presents a new real-time computer-vision position estimator for UAV navigation. The estimator uses images captured during flight to recognize specific, well-known, landmarks in order to estimate the latitude and longitude of the aircraft. The method was tested in a simulated environment, using a dataset of real aerial images obtained in previous flights, with synchronized images, GPS and IMU data. The estimated position in each landmark recognition was compatible with the GPS data, stating that the developed method can be used as an alternative navigation system.

scholarly journals COMPARATIVE ANALYSIS OF SUPERPIXEL SEGMENTATION METHODS

2020 ◽  
Vol 5 (3) ◽  
pp. 1-9
Author(s):  
Sumit Kaur ◽  
R.K Bansal
Keyword(s):  
Computer Vision ◽  
Comparative Analysis ◽  
Computational Complexity ◽  
Point Of View ◽  
Computational Time ◽  
Time Consumption ◽  
Superpixel Segmentation ◽  
Segmentation Methods ◽  
Computer Vision Applications ◽  
High Computational Complexity

Superpixel segmentation showed to be a useful preprocessing step in many computer vision applications. Superpixel’s purpose is to reduce the redundancy in the image and increase efficiency from the point of view of the next processing task. This led to a variety of algorithms to compute superpixel segmentations, each with individual strengths and weaknesses. Many methods for the computation of superpixels were already presented. A drawback of most of these methods is their high computational complexity and hence high computational time consumption. K mean based SLIC method shows better performance as compare to other while evaluating on the bases of under segmentation error and boundary recall, etc parameters.

A Computational Geometric Approach to Visual Hulls

1998 ◽  
Vol 08 (04) ◽  
pp. 407-436 ◽  
Author(s):  
Sylvain Petitjean
Keyword(s):  
Computer Vision ◽  
Geometric Approach ◽  
Point Of View ◽  
Visual Hull ◽  
3 Dimensional ◽  
3D Objects ◽  
The Best Approximation ◽  
Recognition Of Objects ◽  
Visual Hulls ◽  
Volume Intersection

Recognizing 3D objects from their 2D silhouettes is a popular topic in computer vision. Object reconstruction can be performed using the volume intersection approach. The visual hull of an object is the best approximation of an object that can be obtained by volume intersection. From the point of view of recognition from silhouettes, the visual hull can not be distinguished from the original object. In this paper, we present efficient algorithms for computing visual hulls. We start with the case of planar figures (polygons and curved objects) and base our approach on an efficient algorithm for computing the visibility graph of planar figures. We present and tackle many topics related to the query of visual hulls and to the recognition of objects equal to their visual hulls. We then move on to the 3-dimensional case and give a flavor of how it may be approached.

High-Tech Video Capture and Analysis for Counting Park Users

2020 ◽  
Vol 3 (2) ◽  
pp. 147-156
Author(s):  
Richard R. Suminski ◽  
Gregory M. Dominick ◽  
Philip Saponaro ◽  
Elizabeth M. Orsega-Smith ◽  
Eric Plautz ◽  
...  
Keyword(s):  
Computer Vision ◽  
Traditional Approach ◽  
Age Groups ◽  
Point Of View ◽  
High Tech ◽  
The Novel ◽  
Good Reliability ◽  
Novel Approach ◽  
Study Support ◽  
Number Of Individuals

Today’s technology could contribute substantially to measuring physical activity. The current study evaluated traditional and novel approaches for assessing park use. The traditional approach involved a trained observer performing the System for Observing Play and Recreation in Communities (SOPARC) at 14 parks while wearing a point-of-view, wearable video device (WVD). The novel approach utilized computer vision to count park users in the WVD videos taken during in-person SOPARCs. Both approaches were compared to criterion counts from expert reviews of the WVD videos. In the 676 scans made during in-person SOPARCs, 293 individuals were observed while 341 were counted by experts in the corresponding WVD videos. When using scans/videos having individuals in them (84 scans/videos), intra-class correlations (ICC) indicated good-to-excellent reliability between in-person SOPARC and experts for counts of total women and men, within age groups (except seniors), of Blacks and Whites, and within intensity categories (ICCs > .87; p < 0.001). In a subsample of 42 scans/videos, 174 individuals were counted using computer vision and 213 by experts. When using 27 of the 42 WVD videos with individuals in them, ICCs indicated good reliability between computer vision and expert reviews (ICC = .83; p < 0.001). Bland-Altman analysis showed the concurrence of expert counts with both in-person SOPARC and computer vision counts decreased as the number of individuals in a scan/video increased. The results of this study support the use of a highly discrete method for obtaining point-of-view videos and the application of computer vision for automating the counting of park users in the videos.

A Comparative of 3D Surface Extraction Methods for Potential Metrology Applications

2014 ◽  
Vol 615 ◽  
pp. 15-21
Author(s):  
Sinué Ontiveros-Zepeda ◽  
José Antonio Yagüe-Fabra ◽  
Roberto Jiménez Pacheco ◽  
Francisco Javier Brosed-Dueso
Keyword(s):  
Computer Vision ◽  
Edge Detection ◽  
Extraction Methods ◽  
Point Of View ◽  
Detection Methods ◽  
Volume Data ◽  
Surface Extraction ◽  
Advantages And Disadvantages ◽  
Factors Influencing ◽  
Number Of Factors

The number of factors influencing the CT process for metrology applications increases its complexity and cause the loss of accuracy during CT measurements. One of the most critical is the edge detection also called surface extraction or image segmentation, which is the process of surface formation from the CT`s volume data. This paper presents different edge detection methods commonly used in areas like machine and computer vision and they are analyzed as an alternative to the commonly and commercially used for CT metrology applications. Each method is described and analyzed separately in order to highlight its advantages and disadvantages from a metrological point of view. An experimental comparative between two of them is also shown.

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