Showing papers by "Saab Automobile AB published in 2016"
TL;DR: In this paper, a case study of a missile launcher beam redesigned for additive manufacturing using three different approaches is presented, and the redesigned parts are compared for mass and cost, and it is shown that redesigning for AM can reduce mass but depending on part size and print speed, the part can become more expensive than the original design, creating a need to know the customer value of what the redesigned part provides.
74 citations
TL;DR: Analysis of the costs and factors associated with the maintenance of automated GUI-based tests in industrial practice concludes that test automation can lower overall software development costs of a project while also having positive effects on software quality.
Abstract: Context: Verification and validation (V&V) activities make up 20-50% of the total development costs of a software system in practice. Test automation is proposed to lower these V&V costs but available research only provides limited empirical data from industrial practice about the maintenance costs of automated tests and what factors affect these costs. In particular, these costs and factors are unknown for automated GUI-based testing.Objective: This paper addresses this lack of knowledge through analysis of the costs and factors associated with the maintenance of automated GUI-based tests in industrial practice.Method: An empirical study at two companies, Siemens and Saab, is reported where interviews about, and empirical work with, Visual GUI Testing is performed to acquire data about the technique's maintenance costs and feasibility.Results: 13 factors are observed that affect maintenance, e.g. tester knowledge/experience and test case complexity. Further, statistical analysis shows that developing new test scripts is costlier than maintenance but also that frequent maintenance is less costly than infrequent, big bang maintenance. In addition a cost model, based on previous work, is presented that estimates the time to positive return on investment (ROI) of test automation compared to manual testing.Conclusions: It is concluded that test automation can lower overall software development costs of a project while also having positive effects on software quality. However, maintenance costs can still be considerable and the less time a company currently spends on manual testing, the more time is required before positive, economic, ROI is reached after automation.
56 citations
TL;DR: In this article, a method for 3D data exchange for additive manufacturing using STEP and geometric requirements is proposed until better accuracy AM formats can be used until better precision can be achieved.
48 citations
TL;DR: In this article, the authors used AM build time simulations to predict series part cost for eight parts that are possible to cut from rod blanks using High Speed Machining (HSM).
43 citations
TL;DR: This paper presents an analysis of DRX, which is novel in two dimensions due to the use of Markov chain instead of the semi-Markov ones, and analyzes the efficiency ofDRX for military training application systems, what has not been done before.
Abstract: Long-term evolution (LTE)/long-term evolution advanced (LTE-A) are emerging communication technologies on the way toward 5G telecommunication systems. Ubiquitous adoption of connectivity in between different kinds of sensors, wearable devices, and other low-power equipment raises an importance of the energy-efficient wireless communications. In LTE/LTE-A, the discontinuous reception mechanism (DRX) aims at power saving of user equipment (UE) devices. In this paper, we present an analysis of DRX, which is novel in two dimensions. First, our analytical approach is different from existing ones due to the use of Markov chain instead of the semi-Markov ones. Secondly, along with the generic traffic models, we also analyze the efficiency of DRX for military training application systems, what has not been done before. We suggest few practical recommendations regarding the DRX parameters tuning also.
27 citations
TL;DR: In this paper, a new search strategy within the scope of factorized geometrical autofocus (FGA) and synthetic-aperture-radar processing is described.
Abstract: This paper describes a new search strategy within the scope of factorized geometrical autofocus (FGA) and synthetic-aperture-radar processing. The FGA algorithm is a fast factorized back-projection formulation with six adjustable geometry parameters. By tuning the flight track step by step and maximizing focus quality by means of an object function, a sharp image is formed. We propose an efficient two-stage approach for the geometrical variation. The first stage is a low-order (few parameters) parallel search procedure involving small image areas. The second stage then combines the local hypotheses into one global autofocus solution, without the use of images. This method has been applied successfully on ultrawideband CARABAS II data. Errors due to a constant acceleration are superposed on the measured track prior to processing, giving a 6-D autofocus problem. Image results, including resolution, peak-to-sidelobe ratio and magnitude values for point-like targets, finally confirm the validity of the strategy. The results also verify the prediction that there are several satisfying autofocus solutions for the same radar data.
26 citations
TL;DR: In this article, the temperature distribution on an industrial mold tool is monitored during autoclave runs with three settings, and the temperature and pressure follow a scheme based on a scheme.
Abstract: In this work, the temperature distribution on an industrial mold tool is monitored during autoclave runs with three settings. In one of the settings, the temperature and pressure follow a scheme us...
23 citations
TL;DR: In this letter, it is found that, for “good” image pairs, the subtracted image has Gaussian distributed clutter backscattering and that the noise mainly consists of the thermal noise and, therefore, speckle noise does not have to be considered.
Abstract: This letter presents an analysis of prefiltered clutter ultrawideband (UWB) very high frequency synthetic aperture radar (SAR) images. The image data are reorganized into subvectors based on the observation of the image-pair magnitude samples. Based on this approach, we present a statistical description of the SAR clutter obtained by the subtraction between two real SAR images. The statistical analysis based on bivariate distribution data organized into different intervals of magnitude can be an important tool to further understand the properties of the backscattered signal for low-frequency SAR images. In this letter, it is found that, for “good” image pairs, the subtracted image has Gaussian distributed clutter backscattering and that the noise mainly consists of the thermal noise and, therefore, speckle noise does not have to be considered. This is a consequence of the stable backscattering for a UWB low-frequency SAR system.
21 citations
TL;DR: This paper describes the knowledge-based design automated methodology of RAPIDs, data processing between RAPID and Tango and its application in the courses “Aircraft conceptual design” and ”Aircraft project course” at Linköping University.
Abstract: "The conceptual design is the early stage of aircraft design process where results are needed fast, both analytically and visually so that the design can be analyzed and eventually improved in the ...
20 citations
TL;DR: In this paper, computational fluid dynamics simulations are performed to predict the temperature distribution on a part during an autoclave run, and data from an experimental study are used as input to the simulation.
Abstract: In this work, computational fluid dynamics simulations are performed to predict the temperature distribution on a part during an autoclave run. Data from an experimental study are used as input to ...
17 citations
TL;DR: A highly accurate method to estimate the attitude by horizon detection in fisheye images using a Canny edge detector and a probabilistic Hough voting scheme, and the ray refraction in the earth's atmosphere has been taken into account.
Abstract: Attitude pitch and roll angle estimation from visual information is necessary for GPS-free navigation of airborne vehicles. We propose a highly accurate method to estimate the attitude by horizon detection in fisheye images. A Canny edge detector and a probabilistic Hough voting scheme are used to compute an approximate attitude and the corresponding horizon line in the image. Horizon edge pixels are extracted in a band close to the approximate horizon line. The attitude estimates are refined through registration of the extracted edge pixels with the geometrical horizon from a digital elevation map DEM, in our case the SRTM3 database, extracted at a given approximate position. The proposed method has been evaluated using 1629 images from a flight trial with flight altitudes up to 600i¾?m in an area with ground elevations ranging from sea level up to 500i¾?m. Compared with the ground truth from a filtered inertial measurement unit IMU/GPS solution, the standard deviation for the pitch and roll angle errors obtained with 30 Mpixel images are 0.04i¾? and 0.05i¾?, respectively, with mean errors smaller than 0.02i¾?. To achieve the high-accuracy attitude estimates, the ray refraction in the earth's atmosphere has been taken into account. The attitude errors obtained on real images are less or equal to those achieved on synthetic images for previous methods with DEM refinement, and the errors are about one order of magnitude smaller than for any previous vision-based method without DEM refinement.
01 Oct 2016
TL;DR: In this article, the authors introduced a new likelihood ratio test for incoherent wavelength-resolution SAR change detection where the assumption of bivariate zero-mean circular Gaussian processes for noise and clutter is replaced by bivariate Rayleigh processes.
Abstract: The paper introduces a new likelihood ratio test for incoherent wavelength-resolution SAR change detection where the assumption of bivariate zero-mean circular Gaussian processes for noise and clutter is replaced by bivariate Rayleigh processes. This replacement brings a higher average probability of detection and/or lower false alarm rate. Hence, the experimental result shows that an average probability of detection is up to 98% with few low false alarms.
01 Oct 2016
TL;DR: It is concluded that applying a CDIO approach for a CPS program together with infusion of a suitable portion of SE practices appears to be a promising way forward to reform CPS programs.
Abstract: Education of future engineers and other stakeholders will be of paramount importance for designing, producing, procuring, operating and managing future Cyber-Physical Systems (CPS) of unprecedented complexity that will underpin most technological systems in society. We investigate the relation between CPS, Systems Engineering (SE) and the Conceive - Design - Implement -Operate (CDIO) engineering education initiative with the aim to find ways of improving current CPS education. With its emphasis on experiences with realistic engineering settings, lifecycle perspective and complementary skills in communication and collaboration, CDIO provides several ingredients that are essential for future engineers. SE with its set of best practices and systems thinking, provides guidelines and practices of strong relevance for most (if not all) engineering programs and especially for those involving the engineering of highly complex systems such as CPS. We conclude that applying a CDIO approach for a CPS program together with infusion of a suitable portion of SE practices appears to be a promising way forward to reform CPS programs. We discuss how such SE practices can be integrated into engineering programs and in particular propose aspects of SE that would be useful to incorporate into capstone courses (larger education projects in the final master level stages).
01 Jan 2016
TL;DR: The composition and validation of the so-called visual cue list for tower control, and the conclusion that state-of-the-art media are just able to provide the required image resolution for visual detection but not for recognition.
Abstract: Remote control of airports implies application of cameras to replace direct visual observation from airport control towers by projection of the airport and its traffic in a remote control centre. Surprisingly, hardly any literature can be found to list the required visual objects and phenomena for tower control, i.e. the visual cues that need to be seen for tower control. The composition and validation of the so-called visual cue list for tower control is the subject of this study. Tower controller task analysis was used to compose a ‘long-list’ of visual features. The long-list has been presented to a group of operational air traffic controllers to test the need and the circumstances to observe these visual cues. Our analysis shows that most of the visual cues are useful for operational tower control but are not strictly mandatory for applying the rules of the International Civil Aviation Organisation. The requirement for visual image resolution of remote tower control is the second subject of the paper. Our analysis leads to definition of a ‘shortlist’ of important safety-related visual objects and phenomena for tower control and the conclusion that state-of-the-art media are just able to provide the required image resolution for visual detection but not for recognition.
01 Oct 2016
TL;DR: The tradeoff between the power saving and the queuing delay in LTE/LTE-A radio devices with Discontinuous Reception (DRX) Mechanism is discussed and an optimal performance determined by exhaustive search over a large parameter set and a reduced parameter set, obtained by disabling short DRX cycles, is compared.
Abstract: The tradeoff between the power saving and the queuing delay in LTE/LTE-A radio devices with Discontinuous Reception (DRX) Mechanism is discussed. Two optimization problems to tune the DRX parameters are formulated. An optimal performance determined by exhaustive search over a large parameter set and a reduced parameter set, obtained by disabling short DRX cycles, is compared.
21 Mar 2016
TL;DR: A model of task performance for military fighter pilots based on the teamwork model “Big Five” proposed by Salas, Sims, and Burke, which consists of eight teamwork elements that are essential for successful team performance is presented.
Abstract: Fighter pilots performing air missions rely heavily on teamwork for successful outcomes. Designing systems that support such teamwork in highly dynamic missions is a challenging task, and to the best of our knowledge, current teamwork models are not specifically adapted for this domain. This paper presents a model of task performance for military fighter pilots based on the teamwork model “Big Five” proposed by Salas, Sims, and Burke [1]. The “Big Five” model consists of eight teamwork elements that are essential for successful team performance. In-depth interviews were performed with fighter pilots to explore and describe the teamwork elements for the fighter aircraft domain. The findings from these interviews are used to suggest where in the task cycle of mission performance each teamwork element comes in to play.
02 May 2016
TL;DR: To optimize the geometry (from a focus perspective) for a small image area, this paper proposes an efficient routine based on correlation, sensitivity analysis and Broyden-Fletcher-Goldfarb-Shanno (BFGS) minimization that is approximately 100 times faster than a brute-force approach.
Abstract: This paper deals with local geometry optimization within the scope of Factorized Geometrical Autofocus (FGA). The FGA algorithm is a Fast Factorized Back-Projection (FFBP) formulation with six free geometry parameters. These are tuned until a sharp image is obtained, i.e. with respect to an object function. To optimize the geometry (from a focus perspective) for a small image area, we propose an efficient routine based on correlation, sensitivity analysis and Broyden-Fletcher-Goldfarb-Shanno (BFGS) minimization. The new routine is evaluated using simulated Ultra-WideBand (UWB) data. By applying the FGA algorithm step-by-step, an erroneous geometry is compensated. This gives a focused image. In regard to run time, the new routine is approximately 100 times faster than a brute-force approach, i.e. for this FGA problem. For a general problem, the run time reduction will be far greater. To be more specific: with x parameters and N values to assess for each parameter; it is anticipated that the computational effort will decrease exponentially by a factor close to Nx.
01 Jan 2016
TL;DR: Deployment of multi-core platforms in safety-critical applications requires reliable estimation of worst-case response time (WCRT) for critical processes, and determination of WCRT needs to accurately be determined.
Abstract: Deployment of multi-core platforms in safety-critical applications requires reliable estimation of worst-case response time (WCRT) for critical processes. Determination of WCRT needs to accurately ...
04 Jan 2016
TL;DR: In this article, a model for the thermal environment of the pilot is presented, where the thermal comfort of a pilot is of crucial importance to maintain a high level of concentration and awareness during the entire mission.
Abstract: The thermal comfort of a pilot is of crucial importance to maintain a high level ofconcentration and awareness during the entire ight mission. In this work a model for thethermal environment of the ...
21 Oct 2016
TL;DR: In this article, an optics detection laser sensor demonstrator has been implemented on a combat vehicle, which consists of a stabilised gimbal and was integrated together with a LEMUR remote electro-optical sight.
Abstract: Magnifying optical assemblies used for weapon guidance or rifle scopes may possess a threat for a combat vehicle and its personnel. Detection and localisation of optical threats is consequently of interest in military applications. Typically a laser system is used in optics detection, or optical augmentation, to interrogate a scene of interest to localise retroreflected laser radiation. One interesting approach for implementing optics detection on a combat vehicle is to use a continuous scanning scheme. In addition, optics detection can be combined with laser countermeasures, or a laser dazzling function, to efficiently counter an optical threat. An optics detection laser sensor demonstrator has been implemented on a combat vehicle. The sensor consists of a stabilised gimbal and was integrated together with a LEMUR remote electro-optical sight. A narrow laser slit is continuously scanned around the horizon to detect and locate optical threats. Detected threats are presented for the operator within the LEMUR presentation system, and by cueing a countermeasure laser installed in the LEMUR sensor housing threats can be defeated. Results obtained during a field demonstration of the optics detection sensor and the countermeasure laser will be presented. In addition, results obtained using a dual-channel optics detection system designed for false alarm reduction are also discussed.
TL;DR: A method for credibility assessment of simulator applications, in which credibility information is presented to end users directly during simulation, that facilitates an intuitive overview of model dependencies, as well as credibility information for individual models and for a simulat...
Abstract: An efficient methodology for verification, validation, and credibility assessment of simulation models and simulator applications is an enabler for the aeronautical industrys increasing reliance on ...
24 Oct 2016
TL;DR: In this article, the authors derived the correct formula for thermal transmission of a camouflage net, based on the setup described in the US standard for lightweight camouflage nets, and compared the results and implications with the use of an incorrect formula that have been seen in several recent tenders.
Abstract: In this article we derive, from first principles, the correct formula for thermal transmission of a camouflage net, based on the setup described in the US standard for lightweight camouflage nets. Furthermore, we compare the results and implications with the use of an incorrect formula that have been seen in several recent tenders. It is shown that the incorrect formulation not only gives rise to large errors, but the result also depends on the surrounding room temperature, which in the correct derivation cancels out. The theoretical results are compared with laboratory measurements. The theoretical results agree with the laboratory results for the correct derivation. To summarize we discuss the consequences for soldiers on the battlefield if incorrect standards and test methods are used in procurement processes.
01 Jan 2016
TL;DR: The Advanced Remote Tower project studied enhancements to an existing LFV prototype facility (ROT) for a single airport remotely operated tower: projection on a 360° panorama screen, adding synthesised geographic information and meteorological information, video tracking, fusion of video and radar tracks, labelling, visibility enhancement and surveillance operations with a remotely controlled Pan Tilt Zoom camera.
Abstract: The Advanced Remote Tower (ART) project studied enhancements to an existing LFV prototype facility (ROT) for a single airport remotely operated tower: projection on a 360° panorama screen, adding synthesised geographic information and meteorological information, video tracking, fusion of video and radar tracks, labelling, visibility enhancement and surveillance operations with a remotely controlled Pan Tilt Zoom camera. The ART functions have been embedded in the existing Swedish test facility for single airport remote tower operations in Malmo airport Sturup observing Angelholm traffic about 100 km to the North. These functions were tuned and validated during tests with 15 operational tower air traffic controllers. Emphasis was on the traffic and situation awareness of the tower controllers using remote cameras and a projection system for safe operational tower control, replacing direct view on the airport and its traffic. The validation results give valuable information for further development and operational application even outside the Remote Tower application area.
TL;DR: In this article, a case-based approach was applied to a multinational firm, engaged in business-to-business sales that simultaneously launched a solution sales strategy in 17 countries, and interviews with 29 managers and sales representatives were performed to inductively identify why some countries succeeded in the launch, while others did not.
Abstract: Purpose: This research investigates how to manage and organize existing employees when launching a solution sales strategy, specifically addressing whether it is possible to migrate existing sales representatives active in product sales to solution sales, and whether it is possible to combine the roles.Methodology/approach: A case-based approach was applied to a multinational firm, engaged in business-to-business sales that simultaneously launched a solution sales strategy in 17 countries. In-depth interviews with 29 managers and sales representatives were performed to inductively identify why some countries succeeded in the launch, while others did not.Findings: Because of fundamental differences in approach between solution and product sales, those countries where the solutions and product businesses were separated performed better. The difference in required capabilities and mindset meant that migrating sales representatives from product to solution sales is problematic.Research implications: T...
26 Sep 2016
TL;DR: In this article, the effect of commutation terms at the RANS-LES interface was investigated and it was concluded that the proposed commutation term is needed for the LES simulated flow to accurately predict the skin friction.
Abstract: With the aim to mitigate the grey area at the RANS-LES interface, the effect of commutation terms is investigated. Simulations of fully developed channel flow and spatially developing boundary layer flow are presented using the commutation terms at the RANS-LES interfaces. The commutation terms are added as source terms in the k, \(\omega \) and momentum equations of a zonal RANS-LES model. It is concluded that as an inlet in embedded LES of the developing boundary layer flow, the use of the proposed commutation terms are needed for the LES simulated flow to accurately predict the skin friction. However, it is demonstrated for flows where the RANS-LES interface aligns with the mean flow direction that the effect of the proposed interface methodology is weak.
TL;DR: System characteristics and contextual constraints are highlighted to guide research as well as system development for intelligent fighter pilot support and distributed unmanned and manned decision making.
Abstract: Research on decision support systems for fighter aircraft has to regard future manned and unmanned cooperating aircraft. This paper highlights system characteristics and contextual constraints to guide research as well as system development. Long term trends have been identified for the domain that has to be coped with, including the transformation of the fighter pilot from pilot to tactical decision maker. Automation strategies have to be developed to support manned and unmanned aircraft in a joint cognitive system. For instance, for intelligent fighter pilot support, for distributed unmanned and manned decision making, function allocation has to be concerned. For function allocation it is important not only to regard which agent is best at performing a task but also to regard the risk/cost of performing a task in this kind of potentially hazardous context.
01 Jul 2016
TL;DR: The challenges encountered when combining the traditional Systems Engineering approach with that of software Domain Driven Design in the development of the Gripen E fighter aircraft are recounted.
04 Jan 2016
01 Sep 2016
TL;DR: Autonomous Underwater Vehicle Intervention for Advanced Undersea Networks (AUBVIN) as mentioned in this paper is a system for underwater vehicle intervention for advanced underwater networks (U2N) that uses underwater sensors.
Abstract: Autonomous Underwater Vehicle Intervention for Advanced Undersea Networks.
13 Jun 2016