Showing papers by "Saab AB published in 1997"
TL;DR: The Euler and Navier-Stokes equations with a k -ϵ turbulence model are solved numerically in parallel on a distributed memory machine IBM SP2, a shared memory machine SGI Power Challenge, and a cluster of SGI workstations to develop a heuristic algorithm for distributing and splitting blocks for a good static load balance.
9 citations
28 Jul 1997
TL;DR: A new approach to decentralized sensor fusion and tracking, where `decentralized' means that there are a considerable amount of pre-computation performed in the sensors.
Abstract: In an aircraft application there are a number of limitations (limited computational capability, limited data bus bandwidth) on a sensor system as well as there are a number of requirements to fulfill to make the sensor system robust against jamming and other kinds of disturbances We are presenting a new approach to decentralized sensor fusion and tracking, where `decentralized' means that there are a considerable amount of pre-computation performed in the sensors The novelty of the approach lies in the way the information is fed back from the central fusion unit that is handling the information delivered by the sensors The information is fed back to the sensors to enable an improved tracking performance and at the same time not contaminating the sensor in the case the central fusion information is distorted due to jamming The algorithm is realized by using an extend version of the multiple models algorithm AFMM (same class of algorithms as the IMM), in combination with a decentralized Kalman filtering scheme The extension of AFMM consists of a possibility to include externally hypotheses in the regular split and prune mechanism This way the external information is treated the same way as a prior in a Kalman filtering scheme and thus the global track estimate is confronted with the sensor's view before accepted by the sensor In the paper the performance of the tracking algorithm is evaluated in a system consisting of a Radar and an Infrared search and track sensor
6 citations
TL;DR: In this paper, the analytical and numerical solutions of the equations of the k-e turbulence model are analyzed under certain conditions on the boundary values and the interior values of k and e. The simplifications and conclusions are supported by data from a numerical solution of flow over a flat plate.
2 citations
TL;DR: Updating nite element models of complex mechanical structures requires some extra considerations and it is stressed that the two most important aspects on updating finite element models are parameter ...
2 citations
Patent•
04 Jul 1997TL;DR: In this article, the authors proposed a method of transmission of information in packet form in a channel between a number of transmitter/receiver stations using two access methods. But the method was not considered in this paper.
Abstract: The invention relates to a method of transmission of information in packet form in a channel between a number of transmitter/receiver stations. According to the method, information is transmitted between the stations using two access methods. The first access method listens to the channel and transmits on the channel after a certain time after the channel has been confirmed to be free. The second access method uses time division. According to the invention, these two access methods are combined in such a manner that a transmission (TC1) using the first access method with acknowledgement request (PF) is followed by acknowledgement transmissions (KV1-KVn) using the second, time division access method, and that acknowledgement information is always received in the transmitter station irrespective of the level of interference on the channel.
Patent•
20 Mar 1997TL;DR: In this article, a structure-dividing charge is arranged in the supporting structure in order to divide the structure into two separate parts, which are used to prevent the impact from the first activated warhead reaching the warheads.
Abstract: The present invention relates to an ammunition unit (1) in the form of a shell or the like, with at least two warheads (18, 19) connected via a supporting structure (5). In order to prevent the impact from the first activated warhead (18) reaching the warheads (19) situated to the rear, and to prevent an interference effect on these warheads, according to the invention a structure-dividing charge (8) is arranged in the supporting structure (5) in order to divide the structure into two separate parts (14, 15).