Papers published on a yearly basis
Papers
More filters
••
TL;DR: In this article, a model for computation of the time-averaged inviscid flow around airplane configurations with propellers is described, where the propeller is replaced by an actuator disk in the Euler equations.
Abstract: A model for computation of the time-averaged inviscid flow around airplane configurations with propellers is described. The propeller is replaced by an actuator disk in the Euler equations. The propeller forces are determined by a combined momentum-blade element theory. The computed results are compared to onedimensional theory, calculations with a panel method, and wind-tunnel experiments. The tested configurations include a full aircraft at subsonic speed. The influence of the grid resolution and numerical parameters is also investigated.
17 citations
•
27 Aug 2002TL;DR: In this article, a method and a device for measuring, by means of radar, in an enclosed space (1) in which a liquid (2) is stored, the level of a liquid surface (6), where the method involves the steps: a radar unit (3) mounted on the roof (4) of the enclosed space transmits a microwave signal downwards into the room, through a waveguide that communicates with the liquid in the room; the transmitted microwave signal's polarization alters according to a predetermined time sequence in such a way that the signal is propagated alternately at
Abstract: A method and a device for measuring, by means of radar, in an enclosed space (1) in which a liquid (2) is stored, the level of a liquid surface (6), where the method involves the steps: a radar unit (3) mounted on the roof (4) of the enclosed space transmits a microwave signal downwards into the enclosed space (1) through a waveguide (7) that communicates with the liquid in the enclosed space; the transmitted microwave signal's polarization alters according to a predetermined time sequence in such a way that the signal is propagated alternately at least in a first and a second plane of polarization; the signal transmitted in the first plane of polarization is reflected by the liquid surface (6) back to the radar unit (3); the signal in the second plane of polarization is reflected by at least one reference transmitter placed at a known distance from the radar unit; a calculating unit calculates the level of the liquid surface based partly on the propagation time for the microwave signal, i.e. for the time between the signals emitted and received by the radar unit, partly on the microwave signal's velocity of propagation, which is obtained from measurements in relation to the references.
17 citations
••
TL;DR: In this paper, computational fluid dynamics simulations are performed to predict the temperature distribution on a part during an autoclave run, and data from an experimental study are used as input to the simulation.
Abstract: In this work, computational fluid dynamics simulations are performed to predict the temperature distribution on a part during an autoclave run. Data from an experimental study are used as input to ...
17 citations
••
TL;DR: Findings indicate that a GUI in 3D, presented either on a screen or in a Virtual Reality (VR) setting provides several benefits compared to a Baseline GUI representing traditional tools.
17 citations
••
TL;DR: A highly accurate method to estimate the attitude by horizon detection in fisheye images using a Canny edge detector and a probabilistic Hough voting scheme, and the ray refraction in the earth's atmosphere has been taken into account.
Abstract: Attitude pitch and roll angle estimation from visual information is necessary for GPS-free navigation of airborne vehicles. We propose a highly accurate method to estimate the attitude by horizon detection in fisheye images. A Canny edge detector and a probabilistic Hough voting scheme are used to compute an approximate attitude and the corresponding horizon line in the image. Horizon edge pixels are extracted in a band close to the approximate horizon line. The attitude estimates are refined through registration of the extracted edge pixels with the geometrical horizon from a digital elevation map DEM, in our case the SRTM3 database, extracted at a given approximate position. The proposed method has been evaluated using 1629 images from a flight trial with flight altitudes up to 600i¾?m in an area with ground elevations ranging from sea level up to 500i¾?m. Compared with the ground truth from a filtered inertial measurement unit IMU/GPS solution, the standard deviation for the pitch and roll angle errors obtained with 30 Mpixel images are 0.04i¾? and 0.05i¾?, respectively, with mean errors smaller than 0.02i¾?. To achieve the high-accuracy attitude estimates, the ray refraction in the earth's atmosphere has been taken into account. The attitude errors obtained on real images are less or equal to those achieved on synthetic images for previous methods with DEM refinement, and the errors are about one order of magnitude smaller than for any previous vision-based method without DEM refinement.
17 citations
Authors
Showing all 760 results
Name | H-index | Papers | Citations |
---|---|---|---|
Christer Larsson | 64 | 272 | 12916 |
Björn Johansson | 62 | 637 | 16030 |
David C. Viano | 48 | 232 | 8283 |
Thomas Schiex | 47 | 138 | 11031 |
Robin Hanson | 28 | 114 | 3519 |
Per Lötstedt | 28 | 109 | 2960 |
Brigitte Mangin | 26 | 48 | 2652 |
Lars Hanson | 19 | 117 | 1138 |
Carl Gustafson | 17 | 34 | 1035 |
Magnus Carlsson | 16 | 37 | 808 |
Per-Johan Nordlund | 14 | 26 | 2738 |
David Allouche | 14 | 26 | 680 |
Mark A. Saab | 13 | 16 | 1153 |
Andreas Gällström | 13 | 34 | 402 |
Hans Hellsten | 12 | 37 | 549 |