Search results for " CAM"
showing 10 items of 1215 documents
Preliminary design process for an adaptive winglet
2017
In the framework of Clean Sky 2 Airgreen 2 GRA ITD project, this paper deals with the design process of a morphing winglet for a regional aircraft. By improving A/C aerodynamic efficiency in off-design flight conditions, the morphing winglet is expected to operate during long (cruise) and short (climb and descent) mission phases to reduce aircraft drag and optimize lift distribution, while providing augmented roll and yaw control capability. The mechanical system is designed to face different flight situations by a proper action on the movable parts represented by two independent and asynchronous control surfaces with variable camber and differential settings. A set of suitable electromecha…
Omnidirectional vision for UAV: applications to attitude, motion and altitude estimation for day and night conditions
2012
International audience; This paper presents the combined applications of omnidirectional vision featuring on its application to aerial robotics. Omnidirectional vision is first used to compute the attitude, altitude and motion not only in rural environment but also in the urban space. Secondly, a combination of omnidirectional and perspective cameras permits to estimate the altitude. Finally we present a stereo system consisting of an omnidirectional camera with a laser pattern projector enables to calculate the altitude and attitude during the improperly illuminated conditions to dark environments. We demonstrate that omnidirectional camera in conjunction with other sensors is suitable cho…
Visual contact with catadioptric cameras
2015
Abstract Time to contact or time to collision (TTC) is utmost important information for animals as well as for mobile robots because it enables them to avoid obstacles; it is a convenient way to analyze the surrounding environment. The problem of TTC estimation is largely discussed in perspective images. Although a lot of works have shown the interest of omnidirectional camera for robotic applications such as localization, motion, monitoring, few works use omnidirectional images to compute the TTC. In this paper, we show that TTC can be also estimated on catadioptric images. We present two approaches for TTC estimation using directly or indirectly the optical flow based on de-rotation strat…
Selective visual odometry for accurate AUV localization
2015
In this paper we present a stereo visual odometry system developed for autonomous underwater vehicle localization tasks. The main idea is to make use of only highly reliable data in the estimation process, employing a robust keypoint tracking approach and an effective keyframe selection strategy, so that camera movements are estimated with high accuracy even for long paths. Furthermore, in order to limit the drift error, camera pose estimation is referred to the last keyframe, selected by analyzing the feature temporal flow. The proposed system was tested on the KITTI evaluation framework and on the New Tsukuba stereo dataset to assess its effectiveness on long tracks and different illumina…
Visual tracking with omnidirectional cameras: an efficient approach
2011
International audience; An effective technique for applying visual tracking algorithms to omni- directional image sequences is presented. The method is based on a spherical image representation which allows taking into account the distortions and nonlinear resolution of omnidirectional images. Experimental results show that both deterministic and probabilistic tracking methods can effectively be adapted in order to robustly track an object with an omnidirectional camera.
Tracking Moving Objects With a Catadioptric Sensor Using Particle Filter
2011
International audience; Visual tracking in video sequences is a widely developed topic in computer vision applications. However, the emergence of panoramic vision using catadioptric sensors has created the need for new approaches in order to track an object in this type of images. Indeed the non-linear resolution and the geometric distortions due to the insertion of the mirror, make tracking in catadioptric images a very challenging task. This paper describes particle filter for tracking moving object over time using a catadioptric sensor. In this work different problems due to the specificities of the catadioptric systems such as geometry are considered. The obtained results demonstrate an…
Design and Calibration of a Specialized Polydioptric Camera Rig
2017
International audience; It has been observed in the nature that all creatures have evolved highly exclusive sensory organs depending on their habitat and the form of resources availability for their survival. In this project, a novel omnidirectional camera rig, inspired from natural vision sensors, is proposed. It is exclusively designed to operate for highly specified tasks in the field of mobile robotics. Navigation problems on uneven terrains and detection of the moving objects while the robot is itself in motion are the core problems that omnidirectional systems tackle. The proposed omnidirectional system is a compact and a rigid vision system with dioptric cameras that provide a 360° f…
Las huellas de la interdisciplinariedad en la trayectoria de Enric Mestre. ?Intercambios e investigaciones cruzadas entre las esculturas cerámicas y …
2020
La destacada actividad artística de Enric Mestre (Alboraya / Valencia, 1936) solo pude abordarse, en su compleja diversidad y riqueza, si se mantiene, como eje metodológico básico de su estudio crítico, el abierto enfoque de su sistemática interdisciplinariedad. Los diálogos e intercambios entre la escultura cerámica, la arquitectura, la pintura, el dibujo y los murales conforman precisamente el ámbito plural de su constante quehacer artístico. Especialmente la investigación se centra en las esculturas cerámicas y en las pinturas geométricas, que constituyen los dos dilatados campos de su creación plástica, cultivados asiduamente, a lo largo del último medio siglo
The Camorra and protection rackets: the cost to business
2016
Based on the observations from the judicial and investigative evidence provided by prosecutors in Camorra areas in Italy, this investigation provides an estimate of the economic impact of extortion racket to businesses. In particular, the estimates refer to the total and average withdrawal of monetary amounts from the businesses victimised by Camorra clans. Further insights are provided in terms of economic activities mostly victimised, and specifically the construction sector, which is subject to a different type of extortion racket.
Health gains through loss frames: Testing the effectiveness of message framing on citizens' use of nutritional warnings.
2021
Abstract The aim of the present work was twofold: (i) to evaluate the effect of nutritional warnings and health-related packaging cues (nutrient claim and images of natural foods) on consumers' food choices, and (ii) to evaluate the influence of two types of messages (gain-framed and loss-framed) aimed at encouraging the use of such warnings and packaging cues on food choices. A total of 510 participants were recruited using an advertisement on Facebook and Instagram targeted at Uruguayan adult users. Participants were randomly allocated to one of three experimental groups: control (n = 167), loss-framed messages (n = 177) and gain-framed messages (n = 166). Then, they completed a choice-co…