Saab AB

About: Saab AB is a company organization based out in Thun, Switzerland. It is known for research contribution in the topics: Antenna (radio) & Signal. The organization has 862 authors who have published 928 publications receiving 8807 citations. The organization is also known as: Saab AB & Svenska Aeroplan AB.

Lempel-Ziv-Markov Chain Algorithm Modeling using Models of Computation and ForSyDe

Abstract: The data link is considered a critical function of modern aircraft, responsible for exchanging information to the ground and communicating to other aircraft. Nowadays, the increasing amount of exchanged data and information brings the need for network usage optimization. In this sense, data compression is considered a key approach to make data packages size smaller. Regarding the fact that avionics systems are safety-critical, it is fundamental not losing data nor performance during the compression procedures. In this context, manufacturers and regulatory agencies usually follow DO-178C guidance. Targeting model-based embedded design guidelines, DO-178C includes a supplement document, named DO-331. In this paper, we describe a widely used data compression algorithm, the Lempel-Ziv-Markov Chain algorithm (LZMA). Regarding formal model-based design, we argue that the synchronous dataflow model of computation captures the algorithm behavior more directly. The Formal System Design (ForSyDe) methodology is used to model the LZMA.

A Marginalized Particle Filter approach to an integrated INS/TAP system

Abstract: Accurate and reliable navigation systems will become increasingly important in future aircraft applications, in particular within unmanned aerial vehicle systems. This paper describes a particle filter approach of integrating an Inertial navigation system (INS) with a terrain-aided positioning system (TAP) to achieve such a system. The integrated system is realized applying a marginalized particle filter (MPF) where the highly nonlinear TAP is designed tightly with the INS using one and the same filter. In order to better estimate the multi-modal errors in the altitude measurements, a first order Generalized Pseudo-Bayesian (GPB1) filter is used for this purpose. This will also reduce the number of particles in the MPF and therefore also reduce the computational workload. The performance of the algorithm has been evaluated using recorded flight data from the Saab Gripen fighter aircraft. Compared to an existing INS/TAP system based on a suboptimal integration of a point mass filter representing TAP and a single extended Kalman filter estimating the INS errors, the MPF approach is similar in performance but shows better results on convergence times when recovering after loss of data.

Method for speed compensation of a shaped charge jet, and missile

Abstract: The present invention relates to a method for attacking a target by means of a missile (1) with at least one shaped charge, the direction of action of which differs from the direction of flight of the missile, and to a missile (1) comprising at least one shape charge (2) arranged to act in a direction (4) that differs from the direction of flight (5) of the missile. The shaped charge jet is corrected for the speed of the missile (1). According to the invention, the correction of the shaped charge jet is adjustable, whereby the lethality of the missile can be achieved within a wide range of speeds of the missile.