| 1. |
- Berger, Cyrille, 1982-, et al.
(författare)
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Area Coverage with Heterogeneous UAVs using Scan Patterns
- 2016
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Ingår i: 2016 IEEE International Symposium on Safety, Security, and Rescue Robotics (SSRR). - : IEEE Robotics and Automation Society. - 9781509043491
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Konferensbidrag (refereegranskat)abstract
- In this paper we consider a problem of scanningan outdoor area with a team of heterogeneous Unmanned AirVehicles (UAVs) equipped with different sensors (e.g. LIDARs).Depending on the availability of the UAV platforms and themission requirements there is a need to either minimise thetotal mission time or to maximise certain properties of thescan output, such as the point cloud density. The key challengeis to divide the scanning task among UAVs while taking intoaccount the differences in capabilities between platforms andsensors. Additionally, the system should be able to ensure thatconstraints such as limit on the flight time are not violated.We present an approach that uses an optimisation techniqueto find a solution by dividing the area between platforms,generating efficient scan trajectories and selecting flight andscanning parameters, such as velocity and flight altitude. Thismethod has been extensively tested on a large set of randomlygenerated scanning missions covering a wide range of realisticscenarios as well as in real flights.
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| 2. |
- Berger, Cyrille, 1982-
(författare)
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Colour perception graph for characters segmentation
- 2014
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Ingår i: Advances in Visual Computing. - Cham : Springer. - 9783319143644 - 9783319143637 ; , s. 598-608
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Konferensbidrag (refereegranskat)abstract
- Characters recognition in natural images is a challenging problem, asit involves segmenting characters of various colours on various background. Inthis article, we present a method for segmenting images that use a colour percep-tion graph. Our algorithm is inspired by graph cut segmentation techniques andit use an edge detection technique for filtering the graph before the graph-cut aswell as merging segments as a final step. We also present both qualitative andquantitative results, which show that our algorithm perform at slightly better andfaster to a state of the art algorithm.
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| 3. |
- Berger, Cyrille, 1982-, et al.
(författare)
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DSeg : Détection directe de segments dans une image
- 2010
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Ingår i: 17ème congrès francophone AFRIF-AFIA Reconnaissance des Formes et Intelligence Artificielle (RFIA).
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Konferensbidrag (refereegranskat)abstract
- Cet article présente une approche ``model-driven'' pour détecter des segmentsde droite dans une image. L'approche détecte les segments de manièreincrémentale sur la base du gradient de l'image, en exploitant un filtre deKalman linéaire qui estime les paramètres de la droite support des segments etles variances associées. Les algorithmes sont rapides et robustes au bruit etaux variations d'illumination de la scène perçue, ils permettent de détecterdes segments plus longs que les approches existantes guidées par les données(``data-driven''), et ils ne nécessitent pas de délicate détermination deparamètres. Des résultats avec différentes conditions d'éclairage et descomparaisons avec les approches existantes sont présentés.
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| 4. |
- Berger, Cyrille, 1982-, et al.
(författare)
-
DSeg: Direct Line Segments Detection
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a model-driven approach to detect image line segments. The approach incrementally detects segments on the gradient image using a linear Kalman filter that estimates the supporting line parameters and their associated variances. The algorithm is fast and robust with respect to image noise and illumination variations, it allows the detection of longer line segments than data-driven approaches, and does not require any tedious parameters tuning. An extension of the algorithm that exploits a pyramidal approach to enhance the quality of results is proposed. Results with varying scene illumination and comparisons to classic existing approaches are presented.
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| 5. |
- Berger, Cyrille, 1982-, et al.
(författare)
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Evaluation of Reactive Obstacle Avoidance Algorithms for a Quadcopter
- 2016
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Ingår i: Proceedings of the 14th International Conference on Control, Automation, Robotics and Vision 2016 (ICARCV). - : IEEE conference proceedings. - 9781509035496 - 9781509047574 - 9781509035502
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Konferensbidrag (refereegranskat)abstract
- In this work we are investigating reactive avoidance techniques which can be used on board of a small quadcopter and which do not require absolute localisation. We propose a local map representation which can be updated with proprioceptive sensors. The local map is centred around the robot and uses spherical coordinates to represent a point cloud. The local map is updated using a depth sensor, the Inertial Measurement Unit and a registration algorithm. We propose an extension of the Dynamic Window Approach to compute a velocity vector based on the current local map. We propose to use an OctoMap structure to compute a 2-pass A* which provide a path which is converted to a velocity vector. Both approaches are reactive as they only make use of local information. The algorithms were evaluated in a simulator which offers a realistic environment, both in terms of control and sensors. The results obtained were also validated by running the algorithms on a real platform.
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| 6. |
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| 7. |
- Berger, Cyrille, 1982-
(författare)
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Perception de la géométrie de l'environment pour la navigation autonome
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Le but de la recherche en robotique mobile est de donner aux robots la capacité d'accomplir des missions dans un environnement qui n'est pas parfaitement connu. Mission, qui consiste en l'exécution d'un certain nombre d'actions élémentaires (déplacement, manipulation d'objets...) et qui nécessite une localisation précise, ainsi que la construction d'un bon modèle géométrique de l'environnement, a partir de l'exploitation de ses propres capteurs, des capteurs externes, de l'information provenant d'autres robots et de modèle existant, par exemple d'un système d'information géographique. L'information commune est la géométrie de l'environnement. La première partie du manuscrit couvre les différentes méthodes d'extraction de l'information géométrique. La seconde partie présente la création d'un modèle géométrique en utilisant un graphe, ainsi qu'une méthode pour extraire de l'information du graphe et permettre au robot de se localiser dans l'environnement.
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| 8. |
- Berger, Cyrille, 1982-
(författare)
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Strokes detection for skeletonisation of characters shapes
- 2014
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Ingår i: Advances in Visual Computing. - Cham : Springer. - 9783319143644 - 9783319143637 ; , s. 510-520
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Konferensbidrag (refereegranskat)abstract
- Skeletonisation is a key process in character recognition in natural images. Under the assumption that a character is made of a stroke of uniform colour, with small variation in thickness, the process of recognising characters can be decomposed in the three steps. First the image is segmented, then each segment is transformed into a set of connected strokes (skeletonisation), which are then abstracted in a descriptor that can be used to recognise the character. The main issue with skeletonisation is the sensitivity with noise, and especially, the presence of holes in the masks. In this article, a new method for the extraction of strokes is presented, which address the problem of holes in the mask and does not use any parameters.
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| 9. |
- Berger, Cyrille, 1982-
(författare)
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Toward rich geometric map for SLAM: Online Detection of Planes in 2D LIDAR
- 2012
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Ingår i: Proceedings of the International Workshop on Perception for Mobile Robots Autonomy (PEMRA).
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Konferensbidrag (refereegranskat)abstract
- Rich geometric models of the environment are needed for robots to accomplish their missions. However a robot operatingin a large environment would require a compact representation.In this article, we present a method that relies on the idea that a plane appears as a line segment in a 2D scan, andthat by tracking those lines frame after frame, it is possible to estimate the parameters of that plane. The method istherefore divided in three steps: fitting line segments on the points of the 2D scan, tracking those line segments inconsecutive scan and estimating the parameters with a graph based SLAM (Simultaneous Localisation And Mapping)algorithm.
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| 10. |
- Berger, Cyrille, 1982-
(författare)
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Toward rich geometric map for SLAM: online detection of planets in 2D LIDAR
- 2013
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Ingår i: Journal of Automation, Mobile Robotics & Intelligent Systems. - 1897-8649 .- 2080-2145. ; 7:1, s. 35-41
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Tidskriftsartikel (refereegranskat)abstract
- Rich geometric models of the environment are needed for robots to carry out their missions. However a robot operating in a large environment would require a compact representation. In this article, we present a method that relies on the idea that a plane appears as a line segment in a 2D scan, and that by tracking those lines frame after frame, it is possible to estimate the parameters of that plane. The method is divided in three steps: fitting line segments on the points of the 2D scan, tracking those line segments in consecutive scan and estimating the parameters with a graph based SLAM (Simultaneous Localisation And Mapping) algorithm.
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