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.

Comparing measurements of shared situational awareness in a microworld with a developmental environment

Abstract: Two independent experiments were performed where we compared measurements of shared situational awareness in a microworld with similar measures in a developmental environment. After presenting how the two experimental settings are similar/ different the results regarding shared situational awareness are presented and compared. The results indicate that the measurement techniques are comparable over settings.

Wideband Waveform and Receiver Filter Bank Design for Clutter Suppression

Abstract: Modern wideband radar systems with long integration time, equipped with arbitrarily waveform generators, raise a demand for advanced signaling transmission schemes. In this paper, we propose two algorithms to select transmit waveforms and receiver filters. The techniques are based on a clutter suppression criterion. For the first algorithm, we employ an optimized filter bank, and for the second algorithm, we use a matched filter bank. Clutter suppression is achieved by minimizing the correlation between receiver filters and interfering clutter echoes. The algorithm, for the optimized filter bank, is extended to adapt the transmission scheme and receiver filters to a time-evolving scenario. Adaptation parameters are based on estimates of a clutter map and detected target characteristics. To estimate the clutter map we propose a Kalman filter, whereas target parameters are calculated using a least-squares fit to data. The efficiency of the algorithms and the adaptation scheme are visualized through a numerical simulation.

Parallel solution of industrial compressible flow problems with static load balancing

Abstract: Publisher Summary Many floating-point operations and many grid points are required for an accurate approximation of the steady state solution of compressible flow problems in aerospace applications. The compressible Navier–Stokes equations model the flow of air around airplanes very well. In the parallel implementation, a processor is dedicated to one or several blocks of the grid. The difference stencil at a block boundary needs solution data from the neighboring block on the other side of the boundary. For calculations around realistic aircraft configurations, the number of blocks generated by a grid generator is often greater than the number of available processors. If the processor speed differs in the network, then their relative performance is estimated by submitting a small test program to all the slave processors. The computation automatically recovers after the failure of a slave processor, but when the master processor fails, the computation must be restarted manually or by the queuing system if this is used. An algorithm has been described for preprocessing the grid to achieve a good static-load balance on the processors in parallel computation.

Formulation and Solution of the Multi-agent Concurrent Search and Rescue Problem

Abstract: In this paper we formulate and solve the concurrent multi-agent search and rescue problem (C-SARP), where a multi-agent system is to concurrently search an area and assist the victims found during the search. It is widely believed that a UAV-system can help saving lives by locating and assisting victims over large inaccessible areas in the initial stages after a disaster, such as an earthquake, flood, or plane crash. In such a scenario, a natural objective is to minimize the loss of lives. Therefore, two types of uncertainties needs to be taken into account, the uncertainty in position of the victims, and the uncertainty in health over time. It is rational to start looking where victims are most likely to be found, such as the reported position of a victim in a life boat with access to a radio, but it is also rational to start looking where loss of lives is most likely to occur, such as the uncertain position of victims swimming in cold water. We show that the proposed C-SARP is NP-hard, and that the two elements of search and rescue should not be decoupled, making C-SARP substantially different from previously studied multi agent problems, including coverage, multi agent travelling salesmen problems and earlier studies of decoupled search and rescue. Finally, we provide an experimental comparison between the most promising algorithms used in the literature to address similar problems, and find that the solutions to the C-SARP reproduce the trajectories recommended in search and rescue manuals for simple problems, but outperform those trajectories in terms of expected survivability for more complex scenarios.