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Showing papers by "Saab AB published in 2018"


Journal ArticleDOI
14 Dec 2018-Sensors
TL;DR: An alternative NLOS path loss model based on analysis from measured V2V communication channels at 5.9 GHz between six vehicles in two urban intersections is presented and it is stressed that vehicular ad-hoc network (VANET) simulations should be based on the current geometry, i.e., a proper path Loss model should be applied depending on whether the V1V communication is blocked or not by other vehicles or buildings.
Abstract: The non line-of-sight (NLOS) scenario in urban intersections is critical in terms of traffic safety—a scenario where Vehicle-to-Vehicle (V2V) communication really can make a difference by enabling communication and detection of vehicles around building corners. A few NLOS V2V channel models exist in the literature but they all have some form of limitation, and therefore further research is need. In this paper, we present an alternative NLOS path loss model based on analysis from measured V2V communication channels at 5.9 GHz between six vehicles in two urban intersections. We analyze the auto-correlation of the large scale fading process and the influence of the path loss model on this. In cases where a proper model for the path loss and the antenna pattern is included, the de-correlation distance for the auto-correlation is as low as 2–4 m, and the cross-correlation for the large scale fading between different links can be neglected. Otherwise, the de-correlation distance has to be much longer and the cross-correlation between the different communication links needs to be considered separately, causing the computational complexity to be unnecessarily large. With these findings, we stress that vehicular ad-hoc network (VANET) simulations should be based on the current geometry, i.e., a proper path loss model should be applied depending on whether the V2V communication is blocked or not by other vehicles or buildings.

32 citations


Journal ArticleDOI
TL;DR: A mathematical model is presented for an industrially relevant avionic system and a constraint generation procedure for the scheduling of such systems is presented and the optimisation approach can be used to create schedules for such instances within a reasonable time.
Abstract: In modern integrated modular avionic systems, applications share hardware resources on a common avionic platform. Such an architecture necessitates strict requirements on the spatial and temporal p ...

21 citations


Proceedings ArticleDOI
Henrik Ljunggren1
10 Jul 2018
TL;DR: How deep learning can be applied to the field of sea surveillance by classifying ship types from their trajectories by teaching 16 different neural networks to classify ships using only motion trajectories and without relying on the reported ship type.
Abstract: In this paper we demonstrate how deep learning can be applied to the field of sea surveillance by classifying ship types from their trajectories. Commercial ships using AIS continually report information such as their ship type, e.g. fishing or cargo ship. A problem with AIS information however is that it can easily be modified and therefore deliberately or accidentally incorrect. In an attempt to address this we use a 1100 hours long AIS data set to teach 16 different neural networks to classify ships using only motion trajectories and without relying on the reported ship type. We also test three baseline methods using a more conventional1-nearest neighbor approach. The evaluation showed that the best performing classifier was the one based on deep learning.

18 citations


Journal ArticleDOI
TL;DR: The EMFIS model is presented, which allows companies to explicate a representation of the organization's current situation regarding continuous integration impediments, and visualizes what the organization must focus on in order to enable more frequent integration of software.

15 citations


Journal ArticleDOI
TL;DR: This paper presents a multidisciplinary design optimization framework applied to the development of unmanned aerial vehicles with a focus on radar signature and sensor performance requirements with a aim to provide real-time information about the vehicle’s aerodynamic performance.
Abstract: This paper presents a multidisciplinary design optimization framework applied to the development of unmanned aerial vehicles with a focus on radar signature and sensor performance requirements whil ...

14 citations


Journal ArticleDOI
TL;DR: Carbon nanotubes offer the potential for improved or changed matrix properties, thereby enabling the creation of novel, multifunctional composite materials as mentioned in this paper, by using highly-aligned, multi-wall, carb...
Abstract: Carbon nanotubes offer the potential for improved or changed matrix properties, thereby enabling the creation of novel, multifunctional composite materials. By using highly-aligned, multiwall, carb ...

9 citations


Journal ArticleDOI
TL;DR: Multigrid schemes for high order finite difference methods on summation-by-parts form are studied by comparing the effect of different interpolation operators by using the standard linear prolonga operators.

8 citations


Proceedings ArticleDOI
01 Oct 2018
TL;DR: This work proposes a domain-specific language and a repository to represent power grids and related IT components that control the power grid and applies its tool to a standard example used in the literature to assess its expressiveness.
Abstract: Power grids form the central critical infrastructure in all developed economies. Disruptions of power supply can cause major effects on the economy and the livelihood of citizens. At the same time, power grids are being targeted by sophisticated cyber attacks. To counter these threats, we propose a domain-specific language and a repository to represent power grids and related IT components that control the power grid. We apply our tool to a standard example used in the literature to assess its expressiveness.

7 citations


Proceedings ArticleDOI
01 May 2018
TL;DR: In this paper, a double-sided carbon nanotubes (CNT) hybrid film is used as a thermal pad for large scale roll-to-roll CNT synthesis.
Abstract: Hybrid films based on vertically aligned carbon nanotubes (CNTs) on graphene or graphite sheets have been proposed for application as thermal interface materials and micro heat sinks. However, the fabrication of these materials are limited to small scale, expensive and complicated chemical vapor deposition (CVD) for CNT synthesis. We present a new method for direct growth of CNTs on one or both sides of a thin graphene film (GF) using joule self-heating of the graphene film to provide the necessary heat for the thermal breakdown of carbon feedstock in a CVD process. The resulting CNT forests show good density and alignment consistent with regular CVD synthesis processes on silicon surfaces. The resulting double sided GF/CNT hybrid film is directly applicable as a thermal pad. The CNT forest has a thermal conductivity of 30 W/mK, measured by pulsed photothermal reflectance, and the total thermal interface resistance between aluminum blocks was measured to be 60 Kmm^2/W using an ASTM D5470 compliant 1-D measurement setup. This method of directly synthesizing CNTs on graphene films is more energy efficient and capable of larger volume production compared to traditional CVD methods. It is also compatible with scaling up towards continuous roll-to-roll production for large scale commercial production, one of the major limitations preventing CVD-grown CNTs from commercial applications.

6 citations


Proceedings ArticleDOI
01 Jan 2018
TL;DR: In this paper, an efficient transition from a grid of amplifiers to a single substrate integrated waveguide (SIW) is presented based on the excitation of the spatially distributed SIW mode with an array of parallel and strongly coupled microstrip lines (MLs), each of which is connected to an amplifier.
Abstract: An efficient transition from a grid of amplifiers to a single substrate integrated waveguide (SIW) is presented.It is based on the excitation of the spatially distributed SIW mode with an array of parallel and strongly coupled microstrip lines (MLs), each of which is connected to an amplifier. The proposed configuration is optimized by minimizing the ‘active’ reflection coefficients at the TL ports. This equalizes the amplifier optimal load impedances and excites the TE10 SIW mode most efficiently. Also, signals are transferred with nearly uniform power distribution at the amplifier outputs. Numerical results show that this configuration can generate 16x more power per unit volume relative to a single microstripto- SIW transition, while offering a larger bandwidth. A prototype has been developed to validate the proof-of-concept.

4 citations


Patent
28 Jun 2018
TL;DR: In this paper, a rebalancing device (100) is presented to rebalance an underwater vehicle comprising at least one thruster and at least storage space, which is used to determine a difference between a center of gravity, CoG, of the underwater vehicle and a centre of buoyancy, CoB, based on sensor data and thruster data.
Abstract: The present disclosure relates to a rebalancing device (100) for rebalancing of an underwater vehicle comprising at least one thruster and at least one storage space. The rebalancing device (100) comprises control circuitry (140). The control circuitry (140) is configured to receive sensor data comprising information relating to a depth and an attitude of the underwater vehicle, and thruster data comprising information relating to thrust and orientation of thrust of the at least one thruster. The control circuitry (140) is further configured to determine a difference between a centre of gravity, CoG, of the underwater vehicle and a centre of buoyancy, CoB, of the underwater vehicle based on the sensor data and the thruster data, and to determine a difference between a gravitational force acting on the underwater vehicle and a buoyancy of the underwater vehicle based on the sensor data and the thruster data. The control circuitry (140) is also configured to generate rebalancing information relating to a deviation of a current load distribution from an ideal load distribution based on the determined differences. The present disclosure also relates to corresponding underwater vehicles, methods and computer programs.

Book ChapterDOI
21 Jul 2018
TL;DR: A research process where fighter pilots’ behaviors were investigated from a teamwork perspective and the findings conveyed to the designers of cockpit interfaces in order to improve the fighter aircraft system.
Abstract: We describe a research process where fighter pilots’ behaviors were investigated from a teamwork perspective and the findings conveyed to the designers of cockpit interfaces in order to improve the fighter aircraft system. The teamwork perspective was selected because fighter aircraft are complex systems that require an advanced and trained pilot, who also, in addition to managing the aircraft systems needs to be a team player, collaborating with team members during dynamic and fast-paced circumstances to achieve the mission goals. A generic theoretical model for effective teamwork was selected as a starting point and a survey was conducted in order to investigate how fighter pilots collaborate during missions. The teamwork model and the survey results were then presented at workshops with designers of cockpit interfaces participating. The focus on the workshops was pilot teamwork and several design ideas aiming at improving the system for collaboration were generated.

Proceedings ArticleDOI
15 Jun 2018
TL;DR: In this paper, the authors derived the signal-to-noise and distortion ratio (SNDR) for low noise amplifiers (LNA) from the commonly specified parameters noise figure, gain, third order output intercept point and 1 dB compression point.
Abstract: This paper shows how the signal-to-noise and distortion ratio (SNDR) for low noise amplifiers (LNA) can be derived from the commonly specified parameters noise figure, gain, third order output intercept point and 1 dB compression point. The parameters dependency of the biasing of the amplifier are also incorporated which enables the possibility to study how SNDR can be optimized for different operating conditions by dynamically change the gate- and drain voltage. An experimental verification shows that improvements in SNDR can be achieved by selecting gate- and drain voltage of the LNA according to the level of the input signal power.

Proceedings ArticleDOI
01 Oct 2018
TL;DR: A number of mitigation techniques against upsets are discussed together with the use of a COTS IP and practical tests are performed to validate the upset rates and mitigation techniques.
Abstract: The increase in performance and the relatively low cost have made the FPGA an attractive technology for use in various product areas. When used in safety-critical applications, the susceptibility against upsets due to cosmic radiation requires special considerations. In this paper, a number of mitigation techniques against upsets are discussed together with the use of a COTS IP. Furthermore, practical tests are performed to validate the upset rates and mitigation techniques. The tests are performed on a Xilinx UltraScale+MPSOC FPGA.

Book ChapterDOI
TL;DR: The explicit modelling of multiple intervals strengthens the formulation used in the constraint generation procedure and the computational effects on an industrial relevant avionics scheduling problem are illustrated.
Abstract: Multiprocessor scheduling is a well studied NP-hard optimisation problem that occurs in variety of forms. The focus of this paper is explicit modelling of multiple task intervals. This work extends a constraint generation procedure previously developed for an avionics scheduling context. We here address a relaxation of the original problem and this relaxation can be considered as multiprocessor scheduling with precedence relations and multiple intervals. The explicit modelling of multiple intervals strengthens the formulation used in the constraint generation procedure and we illustrate the computational effects on an industrial relevant avionics scheduling problem.

Book ChapterDOI
TL;DR: Pre-runtime scheduling of the kind of Integrated Modular Avionic (IMA) system addressed in this paper can be considered as multiprocessor scheduling with additional constraints on precedence relations between tasks and the concurrent scheduling of a communication network with discrete time slots for sending messages.
Abstract: Pre-runtime scheduling of the kind of Integrated Modular Avionic (IMA) system addressed in this paper can be considered as multiprocessor scheduling with additional constraints on precedence relations between tasks and the concurrent scheduling of a communication network with discrete time slots for sending messages. This paper extends an existing constraint generation procedure for such IMA-systems to facilitate co-allocation of messages in the time slots. To send a communication message involves the execution of a set of tasks. Co-allocation of messages means that tasks of the same type that originate from these messages are merged and their total execution requirements are shortened. The reduction of the execution requirements induces capacity savings that can have a positive impact on the feasibility of the problem.

Journal ArticleDOI
TL;DR: In this paper, the lateral heat propagation in an AlGaN/GaN heterostructure grown on a silicon carbide substrate was investigated using a temperature sensor that utilizes the temperature-dependent $I$ − $V$ characteristic of a semiconductor resistor, making it suitable for integration in GaN monolithic microwave integrated circuit technologies.
Abstract: This paper presents a study of the lateral heat propagation in an aluminum gallium nitride/gallium nitride (AlGaN/GaN) heterostructure grown on a silicon carbide substrate The study is enabled by the design of a temperature sensor that utilizes the temperature-dependent $I$ – $V$ characteristic of a semiconductor resistor, making it suitable for integration in GaN monolithic microwave integrated circuit technologies Using the sensor, we are able to characterize the thermal transient response and extract lateral thermal time constants from the measurements Time constants in the range from 25 $\mu \text{s}$ to 12 ms are identified Furthermore, the heat propagation properties are characterized for heat source-to-sensor distances of 86– $484~\mu \text{m}$ , resulting in delay times from 35 to $111~\mu \text{s}$ It is shown that both the time constants and propagation delay increase with temperature An empirical model of the sensor current versus temperature and voltage is proposed and used to predict the junction temperature of the sensor The study provides knowledge for heat management design and proposes an integrated temperature measurement solution for future highly integrated GaN applications

Proceedings ArticleDOI
15 Apr 2018
TL;DR: In this paper, experimental evaluation of several active anti-condensation methods for application in non-hermetic electronics enclosures was performed in harsh climatic conditions, including RH = 70% and T = 43 °C.
Abstract: Experimental evaluation of several active anti-condensation methods for application in non-hermetic electronics enclosures was performed in harsh climatic conditions, including RH = 70% and T = 43 °C. The studied methods included blowing the air along the exposed surface, combination of blowing and air heating as well as local heating of the exposed surface in natural convection conditions. The purpose was to prevent/remove the dew on/from the exposed surface of a micro-condensation sensor. The difference between the methods was quantified in terms of time for dew removal. The power consumption aspects were discussed. A CFD based optimization methodology was developed to determine the heating profiles for the local anti-condensation PCB heater in a non-hermetic cabinet exposed to the quickly changing climatic conditions. The potential for 60% energy savings was revealed by simulation.

Patent
Hellsten Hans1
01 Aug 2018
TL;DR: In this article, a method and a device for detecting at least one target in an image, wherein the image comprises a set of pixels with a magnitude assigned to each pixel is provided, and the method comprises an iterative process until the K+1th target does not show a probability increase above a predetermined threshold value.
Abstract: A method and a device for detecting at least one target in an image, wherein the image comprises a set of pixels with a magnitude assigned to each pixel is provided. The method comprises an iterative process until the K+1th target does not show a probability increase above a predetermined threshold value. The method is performed by creating a candidate free image, calculating, for the candidate free image, the probability of there being a target at each pixel, by using Bayes theorem, determining a location of the candidate target K+1 in the image, determining the probability that there is a target at the determined location, by determining the calculated probability of there being a target at the determined location. By performing the above, the most probable locations for targets in the image are located together with the probability that the location holds a true target.

Patent
Soderstrom Fredrik1
27 Dec 2018
TL;DR: In this paper, the authors proposed a pivot frame arrangement and a control system for automatic alignment of a subsystem relative to a platform, wherein the pivot mount arrangement is arranged to pivotably support the subsystem.
Abstract: The present invention relates to a director mount arrangement for automatic alignment of a subsystem relative to a platform, wherein said director mount arrangement is arranged to pivotably support the subsystem. The director mount arrangement comprises a pivot frame arrangement and a control system. The control system comprises a control unit arranged to generate control signals so as to control the orientation of and stabilize the subsystem. The control signals are generated based on angular rate of subsystem and orientation operating commands provided from an operator. The control unit further generates estimated control signals based on platform orientation information and determine a difference between the control signals and the estimated control signals, wherein the difference is indicative of mechanical misalignments between the subsystem and the platform. The control unit further generates alignment corrections based on the determined difference so as to automatically align the subsystem relative to the platform.

Patent
20 Nov 2018
TL;DR: In this paper, an airframe leading edge part is designed to be replaceable fixed to a structural portion which during use moves through the air, and a repair method for exchanging a damaged leading edge is presented.
Abstract: An airframe leading edge part designed to be replaceable fixed to a structural portion which during use moves through the air. The airframe leading edge part includes first and second longitudinal joint edges adapted to fit the structural portion. At least one joint is provided between the structural portion and at least one of the longitudinal joint edges. The joint is adapted to break in the event of a object strikes and deforms the airframe leading edge part during use. The joint is designed to break at beforehand determined maximum joint strength of the joint. Also a repair method for exchanging a damaged leading edge.

Patent
Mathias Lindström1
28 Jun 2018
TL;DR: In this paper, a method for launching a projectile and a launcher comprising a barrel (1) accommodating a projectile (2), a rocket motor (13), and a countermass (3) at the rear end of the barrel was described.
Abstract: The invention relates to a method for launching a projectile and a launcher comprising a barrel (1) accommodating a. a projectile (2); b. a rocket motor (13) at the rear end of the projectile (2) comprising a first compartment containing a first propellant; c. a countermass (3) at the rear end of the barrel (1); and d. a second compartment between the rocket motor (13) and the countermass (3) containing a second propellant, wherein said first and second compartments form a high pressure chamber (6) subsequent to firing of the projectile (2).

Patent
Wallen Max1, Lumetzberger Bruno1
20 Sep 2018
TL;DR: In this article, the authors present exemplary embodiments of radar systems for providing increased robustness against radar interference transmissions and methods for controlling such radar systems, wherein the methods refer to measuring interference levels within the second frequency range, analysing measured interference levels, determining favorable frequency channels in respect to interference level and possibly changing operating frequency channel in relation to measured interference level.
Abstract: The present disclosure relates to exemplary embodiments of radar systems for providing increased robustness against radar interference transmissions and methods for controlling such radar systems. The radar system comprises at least one radar antenna configured at least for receiving a radar signal, a radar signal dividing means, a first receiver device and a second receiver device. The first receiver device is configured for monitoring a first frequency range and the second receiver device is configured for monitoring a second frequency range, wherein the second frequency range is wider than the first frequency range and the first frequency range is a subset of the second frequency range. The second receiver device is configured for measuring interference levels within the second frequency range. The present disclosure further relates to exemplary embodiments of methods for controlling the radar system, wherein the methods refer to measuring interference levels within the second frequency range, analysing measured interference levels, determining favourable frequency channels within the second frequency range in respect to interference level and possibly changing operating frequency channel in respect to measured interference levels.

30 Jul 2018
TL;DR: In this article, the RF power amplifier demonstrators containing each one GaN-on-SiC, HEMT, CHZ015A-QEG, from UMS in SMD quad-flat no-leads package (QFN) were subjected to thermal cycles (TC) and power cycles (PC) and evaluated electrically, thermally and structurally.
Abstract: The RF power amplifier demonstrators containing each one GaN-on-SiC, HEMT, CHZ015A-QEG, from UMS in SMD quad-flat no-leads package (QFN) were subjected to thermal cycles (TC) and power cycles (PC) and evaluated electrically, thermally and structurally. Two types of solders, Sn63Pb36Ag2 and lead-free SnAgCu (SAC305), and two types of TIM materials, NanoTIM and TgonTM 805, for PCB attachment to the liquid cold plate were tested for thermo-mechanical reliability. Changes in the electrical performance of the devices, namely the reduction of the current saturation value, threshold voltage shift, increase of the leakage current and degradation of the HF performance were observed as a result of an accumulated current stress during PC. No significant changes in the investigated solder or TIM materials were observed.

Patent
Landberg Magnus1
24 May 2018
TL;DR: In this paper, a fluid actuator arrangement comprising a first cylinder housing (3, 3'), a first piston body (5, 5'), a second through-bore (11'') and a second clamping element (13'') provided for releasable clamping onto a second piston rod (15''.
Abstract: The present invention regards a fluid actuator arrangement (1) comprising a first cylinder housing (3,3') comprising a first piston body (5, 5') comprising a first through-bore (11') and a first clamping element (13') provided for releasable clamping onto a first piston rod (15'). The first piston body (5, 5') comprises a second through-bore (11'') and a second clamping element (13'') provided for releasable clamping onto a second piston rod (15''); a first static holding unit (17) comprising a first clamping unit (19') provided for releasable clamping onto the first piston rod (15'); a second clamping unit (19'') provided for releasable clamping onto the second piston rod (15''); a first base member (23, 23') coupled to the first piston rod (15') via a first universal joint (31, 32', 34) for providing a rotational motion (R1, T1) of the first base member (23, 23') during longitudinal motion of the first piston rod (15'). The present invention also regards a method for providing a rotational motion of a first base member (23').

Patent
23 Nov 2018
TL;DR: In this article, the authors proposed a shape charge liner for hard targets, which consisted of a carrier having a density below 9500 kg/m3, and a coating on the carrier comprising at least one metal and/or metal oxide, and the thickness ratio of the carrier to the coating ranges from 100:1 to 1:1.
Abstract: The present invention relates to a liner for shaped charge for penetrating hard targets, wherein the liner comprises i) a carrier having a density below 9500 kg/m3; and ii) a coating deposited on said carrier comprising at least one metal and/or metal oxide, wherein the coating has a density greater than 10000 kg/m3; wherein the thickness ratio of the carrier to the coating ranges from 100:1 to 1:1, and wherein the oxygen content in the coating is less than 100 ppm atomic. The invention also relates to a method of producing such shaped charge liner and the use 0 thereof in a projectile for penetrating a hard military target.

Patent
Tjus Emil1, Jansson Per
08 Nov 2018
TL;DR: In this paper, an arrangement for aligning a sub-calibre barrel (1) for use in a principal weapon barrel comprising an insert (4) arranged in said principal firearm barrel ii) front securing means (8) for alignment the sub-carbore barrel and iii) rear securing means for securing the rear end of the subcabre barrel, wherein iii.b) clamping means (3a, 3b) securing said barrel nut (2) to said insert(4).
Abstract: The present invention relates to an arrangement for aligning a sub-calibre barrel (1) for use in a principal weapon barrel comprising i) an insert (4) arranged in said principal weapon barrel ii) front securing means (8) for aligning the sub-calibre barrel (1) iii) rear securing means for securing the rear end of the sub-calibre barrel (1), wherein iii.a) said rear securing means comprise a barrel nut (2) in which said sub-calibre barrel (1) is inserted; iii.b) clamping means (3a, 3b) securing said barrel nut (2) to said insert (4) and said clamping means (3a, 3b) in said principal weapon barrel. The invention also relates to a training weapon comprising the arrangement and a method of aligning the training weapon.

Patent
Bengtsson Ulf1
21 Jun 2018
TL;DR: In this article, a counter mass container enclosing a plurality of parallel axially extending channels is described. And the present invention relates to a weapon comprising a barrel (5) accommodating such an assembly.
Abstract: The present invention relates to a counter mass container (2) enclosing a plurality of parallel axially extending channels (1). The invention also relates to an assembly of a plurality of such counter mass containers (2). The invention also relates to a weapon comprising a barrel (5) accommodating such an assembly.