Saab Automobile AB

About: Saab Automobile AB is a based out in . It is known for research contribution in the topics: Radar & Antenna (radio). The organization has 760 authors who have published 890 publications receiving 11811 citations.

Advanced remote tower project validation results

Abstract: The Advanced Remote Tower project (ART) studies enhancements to an existing LFV prototype facility for a remotely operated tower: projection on a 360 degrees panorama screen, adding synthesized 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 remote tower operations in Malmo airport Sturup observing Angelholm traffic about 100 km to the North. They were tuned and validated by 15 tower controllers. Emphasis was on the traffic and situation awareness of tower controllers using remote cameras and 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.

Competitive Sorption of Metal Ions on Titanium Phosphate Sorbent (TiP1) in Fixed-Bed Columns: A Closed-Mine Waters Study

Abstract: Sorption fixed-bed column experiments were performed using a titanium phosphate ion-exchanger composed of −H2PO4 units [TiO(OH)(H2PO4)·H2O]. Model mine water containing five divalent metal ions (Cu...

Design of an AUV Research Platform for Demonstration of Novel Technologies

Abstract: Maribot LoLo is an autonomous underwater vehicle (AUV) developed at the KTH Centre for Naval Architecture as part of the Swedish Maritime Robotics Centre (SMaRC). The center’s cross-disciplinary activities require an AUV research platform that can be used for data collection and to test and demonstrate novel technologies. The challenge herein is to create a well-performing and yet versatile vehicle. This paper introduces Maribot LoLo and presents the underlying design philosophy which focuses on versatility and endurance. A free-flooded hull offers modularity and modifiability while reliability and robustness are achieved through hardware redundancy and a hierarchical captain-scientist relationship in the embedded system. The vehicle is designed to be operated at moderate water depths and on long-range missions. This leads to challenges in the design of the variable buoyancy system (VBS) which also is presented. The achievable range of the AUV is evaluated with a simple hydrodynamics model based on frictional drag.

Cost and weight of composite ship structures: A parametric study based on Det Norske Veritas rules:

Abstract: A wider use of composites in larger, commercial vessels has been limited by initial costs and fire regulations, but both of these obstacles are diminishing. Increasing fuel costs and more stringent emission requirements have heightened the value of lightweight structures. Due to the higher acquisition costs and other entry barriers, composite designs must be as cost-efficient as possible in order to compete with traditional steel or aluminium designs. The purpose of this paper is to investigate which FRP-materials and types of structures are most suitable for different parts of a ship design in order to minimize weight or cost. This is done by designing and comparing individual composite panels while varying a wide range of input parameters and strictly following the “Det Norske Veritas (DNV) rules for classification of High Speed, Light Craft and Naval Surface Craft”. The results are presented as weight and cost comparisons between materials and structures and also degree of utilization for the different design criteria; carbon fibre structures are on the average 20-30% lighter than glass fibre structures but are consistently more expensive. The results also indicate that sandwich panels in most cases are lighter than single skin panels and that for sandwich structures the mechanical properties of the core material is commonly the critical design criterion. The minimum amount of reinforcement stipulated by the rules is also found to be a critical factor.

Command Governor Approach to Maneuver Limiting in Fighter Aircraft

Abstract: Modern fighter aircraft require maximum control performance in order to have the upper hand in a dogfight or when they have to outmaneuver an enemy missile. Therefore pilots must be able to maneuver the aircraft very close to the limit of what it is capable of while at the same time focus on the tactical tasks of the mission. To enable this, modern flight control systems have automatic systems for angle of attack and load factor limiting. These types of systems can utilize predictions of the aircraft response to pilot inputs and alter the properties of the closed loop system to minimize the predicted overshoot. Two such design techniques are model predictive control and reference and command governors. Model predictive controllers are most often used as inner loop feedback controllers which alter the control signal as function of the predicted output while reference and command governors are applied in an outer feedback loop around a nominal controller. There can be several benefits from using reference and command governors compared to model predictive controllers. First, the governors can be used as add-ons to existing legacy controllers so there is no need to redo the complete design. Furthermore the nominal inner loop controller can be tuned to achieve good performance in the nominal case, e.g., use nonlinear feedbacks to linearize the closed loop system, and the governor focus on the maneuver limiting task. It also gives a good modularity such that one can replace parts of the control system without the need to redo all of the design. Last but not least from a flight safety perspective it might be easier to certify optimization algorithms running in an outer loop which can be turned off in case of failures without affecting stability. While model predictive controllers have been extensively investigated for flight control applications [1–28] most of them consider reconfigurable flight control systems and only few focus on envelope protection and maneuver limiting [7, 13, 17, 21]. Even though reference governors have been subject to research for quite some time very little research has been performed on applying reference and command governors to flight control design and maneuver limiting [23, 29–33]. Most of these papers consider simplified conditions with only a single linear or nonlinear system and no complex simulation environments. In the papers by Petersen et al. [23] and Zinnecker et al. [29] the authors apply reference governors to the control of hypersonic vehicle. In the paper by Zinnecker the focus is mainly on input constraints. Kolmanovsky and Kahveci [30] uses a reference governor to handle control actuator limitations of a UAV glider and compare this to an adaptive anti-windup scheme and in the paper by Martino [31] the author investigates command governors for handling amplitude and rate constraints on a small commercial aircraft. The authors, Ye et al. [32], investigate reference governors for maneuver limiting in high angle of attack maneuvers. They investigate and compare static and dynamic reference governors with a reference governor structure based on a step response