Saab Automobile AB

About: Saab Automobile AB is a based out in . It is known for research contribution in the topics: Radar & Signal. The organization has 760 authors who have published 890 publications receiving 11811 citations.

Catalytic converter system for i.c. - engine with divided flow and two converters

Abstract: An exhaust system for a multi-cylinder internal combustion engine comprises at least two exhaust valves (2, 3) per cylinder. A first exhaust valve (2) in each cylinder is connected to a first catalyst (10), and a second exhaust valve (3) in each cylinder is connected to a second catalyst (13) which opens out upstream of the first catalyst (10). The first exhaust valves (2) or their outlet are or is kept closed during a starting phase of the engine, so that, during the starting phase, all the exhaust gases first pass through the second catalyst (13) which is smaller than the first catalyst (10) and is postioned closer than the latter to the engine.

Rate limiters with phase compensation in JAS 39 Gripen

Abstract: For a modern aerodynamically unstable fighter, like the JAS 39 Gripen, the flight control system typically provides 45° phase margin. Therefore rate limiting control surfaces, which may cause large phase shifts, is an important issue. Software rate limiters are placed on the control servo commands in order to prevent the hydraulic servos from rate limiting. When a rate limiter is saturated, the phase shift drastically reduces the stability margins of the closed loop and increases the risk for pilot-induced oscillation (PIO). This paper describes a novel method for compensating the phase shift of a rate limiter. In contrast to earlier phase compensation methods, this method uses feedback instead of logic or feedforward. Open loop and closed loop properties of the method are discussed. The method gives a drastic improvement on stability margins and reduces PIO tendencies.

Polarimetric Wireless Indoor Channel Modeling Based on Propagation Graph

Abstract: This paper generalizes a propagation graph model to polarized indoor wireless channels. In the original contribution, the channel is modeled as a propagation graph in which vertices represent transmitters, receivers, and scatterers, while edges represent the propagation conditions between vertices. Each edge is characterized by an edge transfer function accounting for the attenuation, delay spread, and the phase shift on the edge. In this contribution, we extend this modeling formalism to polarized channels by incorporating depolarization effects into the edge transfer functions and hence, the channel transfer matrix. We derive closed form expressions for the polarimetric power delay spectrum and cross-polarization ratio of the indoor channel. The expressions are derived considering average signal propagation in a graph and relate these statistics to model parameters, thereby providing a useful approach to investigate the averaged effect of these parameters on the channel statistics. Furthermore, we present a procedure for calibrating the model based on method of moments. Simulations were performed to validate the proposed model and the derived approximate expressions using both synthetic data and channel measurements at 15 GHz and 60 GHz. We observe that the model and approximate expressions provide good fit to the measurement data.

Arrangement for preventing mist and ice formation on the side window of a motor vehicle.

Abstract: Le dispositif decrit sert a empecher la formation de buee et de givre sur les fenetres d'un vehicule a moteur, plus particulierement sur les fenetres laterales arriere des portes dudit vehicule. The device described is used to prevent fogging and frost on the windows of a motor vehicle, especially on the rear side windows of the doors of the vehicle. Les dispositifs connus destines a empecher la formation de buee et de givre sur les fenetres laterales arriere d'un vehicule proposent l'utilisation d'air dirigee contre lesdites fenetres par des conduits provenant du systeme de ventilation normale du vehicule. Known devices intended to prevent fogging and icing on the rear side windows of a vehicle propose the use of air directed against said windows by pipes from the vehicle normal ventilation. Dans le but de trouver une solution fonctionnant efficacement et avantageuse du point de vue de l'assemblage et de la production, la presente invention se caracterise essentiellement par le fait qu'un ventilateur (12) et un conduit d'entree et de sortie (11 et 13) sont disposes entre un panneau externe et interne (7 et 6) dans la porte du vehicule au-dessous de la fenetre (4) en question. In order to find a solution that works effectively and advantageous from the point of view of assembly and production, the present invention is essentially characterized in that a fan (12) and an inlet and outlet conduit ( 11 and 13) are arranged between an inner and outer panel (7 and 6) in the vehicle door below the window (4) in question. Le ventilateur (12) aspire l'air de l'interieur du vehicule et le dirige contre la fenetre (4), faisant ainsi disparaitre la buee et le givre qui s'y etaient formes. The fan (12) draws air from inside the vehicle and directs against the window (4), and by removing the fog and frost that had formed it.

Signature-based activity detection based on Bayesian networks acquired from expert knowledge

Abstract: The maritime industry is experiencing one of its longest and fastest periods of growth. Hence, the global maritime surveillance capacity is in a great need of growth as well. The detection of vessel activity is an important objective of the civil security domain. Detecting vessel activity may become problematic if audit data is uncertain. This paper aims to investigate if Bayesian networks acquired from expert knowledge can detect activities with a signature-based detection approach. For this, a maritime pilot-boat scenario has been identified with a domain expert. Each of the scenario's activities has been divided up into signatures where each signature relates to a specific Bayesian network information node. The signatures were implemented to find evidences for the Bayesian network information nodes. AIS-data with real world observations have been used for testing, which have shown that it is possible to detect the maritime pilot-boat scenario based on the taken approach.