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Hoek van Holland, Netherlands

Rudinger I.,Institute of Flight Systems
DLR Deutsches Zentrum fur Luft- und Raumfahrt e.V. - Forschungsberichte | Year: 2014

This thesis covers the topic of pilot gain in flight test based on simulator tests in Germany and flight tests with the NF-16D "VISTA" at the USAF test pilot school. Potential pilot gain measures are introduced and validated based on a dedicated approach which can be easily adapted to different types of tasks. In a second section, a potential root cause for differences in natural pilot gain is evaluated and discussed. Based on the cortical arousal theory, a correlation between the pilot's personality trait of "extraversion" and pilot gain was assumed and supported by simulator and personality tests. Finally, the workload buildup flight test technique is investigated as a potential means to increase pilot gain in flight test. The results of this thesis confirm that this technique is able to gradually increase pilot gain; however, the resulting pilot gain is often not higher than for an intentional pilot gain increase on command.

Bertram O.,Institute of Flight Systems
10th Annual International Systems Conference, SysCon 2016 - Proceedings | Year: 2016

There is a strong need to investigate future aircraft high-lift systems in virtual as well as real test rigs. An investigation of innovative high-lift systems is only possible with integrated approaches of different disciplines involved in the aircraft design process. For this reason, an interdisciplinary design method for determination of actuator loads will be presented. Involved disciplines are aerodynamics and systems. The method will be applied to a future test rig for high-lift systems. Two different kinematic mechanisms will be modeled with the so-called "module method" for analyzing flap deployment and determination of actuation loads. Aerodynamic calculations of the pressure distributions, which are used for the air load calculations, are carried out with the panel method in the VSAERO software tool. The air loads will be the input for the calculation of the actuation loads, which constitute the basis for the dimensioning of the test rig components. A comparative study for flap movement and actuation loads is finally carried out for different mechanisms. © 2016 IEEE.

Adolf F.-M.,Institute of Flight Systems
AIAA Infotech at Aerospace Conference and Exhibit 2012 | Year: 2012

This paper presents an online multi-query path planner for exploration tasks planned onboard an unmanned helicopter. While the desirable properties of roadmaps can be exploited in offine path planning, the dynamic nature of exploration scenarios hinders to utilize conventional roadmap planners. Hence, the presented path planning approach utilizes a deterministically sampled roadmap which is dynamically indexed in real time. To address situations of partial terrain knowledge, the roadmap can be extended from its a priori dimensions towards locations of unknown terrain that are outside its original, a priori boundaries. The multi-query property of the planning system allows for combinatorial optimization such that a rapidly acting decisional autonomy is achievable during exploration flights. D*-Lite is used as dynamic heuristic path searcher in order to re-plan effIciently. Inspired by the original work on this path search algorithm, the roadmap graph is augmented with an exploration vertex which steers the exploration behavior of the vehicle. As a result, the presented roadmap guides an unmanned rotorcraft through a priori unknown urban terrain in real time. © 2012 by Florian-M. Adolf, German Aerospace Center (DLR).

Vicroy D.D.,NASA | Huber K.C.,German Aerospace Center | Rohlf D.,German Aerospace Center | Rohlf D.,Institute of Flight Systems | Loser T.,DNW
32nd AIAA Applied Aerodynamics Conference | Year: 2014

Several static and dynamic forced-motion wind tunnel tests have been conducted on a generic unmanned combat air vehicle (UCAV) configuration with a 53° swept leading edge. These tests are part of an international research effort to assess and advance the state-of-art of computational fluid dynamics (CFD) methods to predict the static and dynamic stability and control characteristics for this type of configuration. This paper describes the dynamic forced motion data collected from two different models of this UCAV configuration as well as analysis of the control surface deflections on the dynamic forces and moments.

Rohlf D.,German Aerospace Center | Rohlf D.,Institute of Flight Systems | Schmidt S.,Defence Science and Technology Organisation, Australia | Irving J.,BAE Systems
Journal of Aircraft | Year: 2012

Different methods are described to determine dynamic derivatives of an unmanned combat air vehicle configuration called SACCON (for "stability and control configuration"). These methods can be applied to both experimental and computationally obtained data sets. The first method assumes a linear derivative model and is based on a least-square curve-fitting technique and a subsequent evaluation step to actually compute the derivatives themselves. Based on the unsteady simulation obtained by computational fluid dynamics, the routine is able to recover the major trends of vehicle performance with reasonable agreement for pitching stiffness and damping. Lift-related quantities do show a discrepancy, particularly at high angle of attack. The second approach also assumes a linear derivative model. In this case, however, the static pitching stiffness terms are defined explicitly from the static test results and then subtracted from the dynamic results to give the residual effect of the damping terms. A leastsquares fit of these is used to determine the damping derivatives. Using this approach, it is demonstrated that the linear-derivative assumption falls down at higher angle of attack, and a more-generalized modeling paradigm is required. The final approach enables the use of nonlinear model equations and is therefore applicable to the entire tested angle-of-attack and angle-of-sideslip regime, generating a single set of nonlinear derivatives. Thus, the hysteresis loops of the coefficients derived from dynamic wind-tunnel tests can be reproduced satisfactorily with most of their inherent significant changes depending on angle of attack and forced oscillation frequency.

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