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European control Conference (ECC)

作者： Fabrice Demourant Beatrice Jacquier Alexandre Janot System Control and Flight Dynamics Department 2 avenue Edouard Belin BP74025 Research scientists Toulouse France

The article deals with the non-linear identification using a block structure to reproduce the behavior of a unknown non-linear system which presents two equilibria: a static equilibrium point, which is in our case unstable, and a dynamic equilibrium, which can correspond, for example, to a Limit Cycle Oscillation (LCO). This non-linear system is representative of a supercritical model which appears in the Hopf bifurcation. The generic proposed methodology is based on three identification steps: firstly the linear identification of the static equilibrium, called the fixed point, secondly, the identification of a Wiener feedback structure to reproduce the LCO, and lastly the tuning of a Wiener-Hammerstein feedback structure to improve the accuracy level of the identified nonlinear model. Finally, time-domain simulations are performed to evaluate and compare results with the original non-linear system.

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Robust Path-following control with Anti-Windup for HALE Aircraft

Robust Path-following Control with Anti-Windup for HALE Airc...

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Mediterranean Conference on control and Automation (MED)

作者： Christian Weiser Daniel Ossmann Harald Pfifer German Aerospace Center (DLR) Institute of System Dynamics &amp Control We&#x00DF ling Germany Department of Mechanical Automotive &amp Aerospace Engineering Munich University of Applied Sciences HM Munich Germany Chair of Flight Mechanics &amp Control TU Dresden Dresden Germany

ISBN: (数字)9781665406734

ISBN: (纸本)9781665406741

In this paper, a robust path-tracking controller for a High Altitude Long Endurance (HALE) aircraft is presented. The main control paradigm for operating a HALE aircraft consists of a basic path following control, i.e. tracking a reference flight path and airspeed while dealing with very limited thrust. The priority lies in keeping airspeed inside the small flight envelope of HALE aircraft even during saturated thrust. For the basic path following objective, a mixed sensitivity approach is proposed which can easily deal with decoupled tracking and robustness requirements. To deal with saturated control inputs, an anti-windup scheme is incorporated in the control design. A novel observer-based mixed sensitivity design is used which allows directly using classical anti-windup methods based on back-calculation. The control design is verified in nonlinear simulation and compared to a classical total energy control based controller.

关键词： State feedback Sensitivity systematics control design Windup Atmospheric modeling Aircraft

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Providing optimum lateral static stability margin of highly augmented aircraft 58

Providing optimum lateral static stability margin of highly ...

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58th Israel Annual Conference on Aerospace Sciences, IACAS 2018

作者： Desyatnik, P.A. Zaichik, L.E. Yashin, Y.P. TsAGI Zhukovsky140180 Russia Flight Dynamics and Control System Department Russia

The equation of aircraft lateral/directional motion is analyzed and modified to determine generalized parameters critical to develop handling quality criterion in directional control axis. An extensive experimental database is collected on TsAGI PSPK-102 flight simulator to assess the effect of the generalized parameters on the optimum (in pilot opinion) values of Lβ which determines the best interaction between directional and lateral motion while pedal control. The derivation of the directional handling quality criterion is presented based on the collected experimental database. Effectiveness of the criterion is demonstrated by its coincidence with experimental results. © 2018 Israel Annual Conference on Aerospace Sciences. All rights reserved.

关键词： flight simulators

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Adequacy of on-ground simulation of aircraft upset and recovery 58

Adequacy of on-ground simulation of aircraft upset and recov...

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58th Israel Annual Conference on Aerospace Sciences, IACAS 2018

作者： Bushgens, A.G. Zaichik, L.E. Yashin, Y.P. Arkhangelskiy, Y.A. TsAGI Zhukovsky140180 Russia Flight Dynamics and Control System Department Russia

The paper concerns a problem of on-ground reproduction of motion cues typical of the most critical modes of civil airliner flight, namely aircraft upset and recovery. Analysis conducted in the paper shows that there is not yet any on-ground device to provide sustained G-loads without false cues, which can distort pilot idea about maneuver even greater than entire absence of simulator motion. Nevertheless, the comparison of the false cues arising in a Stewart platform - based simulator and a centrifuge-based simulator results in favour of Stewart platform. The paper shows that the most important thing in motion cueing, for upset/recovery modes in particular, is minimization of false cues. The minimization is achieved by the adequate motion drive algorithms tuning, which can be successfully performed with the described criteria. © 2018 Israel Annual Conference on Aerospace Sciences. All rights reserved.

关键词： Simulators

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Sausage, kink, and fluting MHD wave modes identified in solar magnetic pores by Solar Orbiter/PHI

arXiv

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arXiv 2024年

作者： Jafarzadeh, S. Schiavo, L.A.C.A. Fedun, V. Solanki, S.K. Stangalini, M. Calchetti, D. Verth, G. Jess, D.B. Grant, S.D.T. Ballai, I. Gafeira, R. Keys, P.H. Fleck, B. Morton, R.J. Browning, P.K. Silva, S.S.A. Appourchaux, T. Gandorfer, A. Gizon, L. Hirzberger, J. Kahil, F. Suárez, D. Orozco Schou, J. Strecker, H. del Toro Iniesta, J.C. Valori, G. Volkmer, R. Woch, J. Max Planck Institute for Solar System Research Justus-von-Liebig-Weg 3 Göttingen37077 Germany School of Physics & Astronomy The University of Manchester Oxford Road ManchesterM13 9PL United Kingdom Department of Mathematics Physics and Electrical Engineering Northumbria University Newcastle upon TyneNE1 8ST United Kingdom Plasma Dynamics Group Department of Automatic Control and Systems Engineering The University of Sheffield Mappin Street SheffieldS1 3JD United Kingdom ASI Italian Space Agency Via del Politecnico snc RomeI-00133 Italy Plasma Dynamics Group School of Mathematics and Statistics The University of Sheffield Hicks Building Hounsfield Road SheffieldS3 7RH United Kingdom Astrophysics Research Centre School of Mathematics and Physics Queen’s University Belfast BelfastBT7 1NN United Kingdom Department of Physics and Astronomy California State University Northridge NorthridgeCA91330 United States Instituto de Astrofísica e Ciências do Espaço Department of Physics University of Coimbra Coimbra3040-004 Portugal ESA Science and Operations Department c/o NASA Goddard Space Flight Center GreenbeltMD20771 United States Univ. Paris-Sud Institut d’Astrophysique Spatiale UMR 8617 CNRS Bâtiment 121 Orsay91405 Cedex France Apartado de Correos 3004 GranadaE-18080 Spain Leibniz-Institut für Sonnenphysik Schöneckstr. 6 FreiburgD-79104 Germany Institut für Astrophysik und Geophysik Georg-August-Universität Göttingen Friedrich-Hund-Platz 1 Göttingen37077 Germany

Solar pores are intense concentrations of magnetic flux that emerge through the Sun’s photosphere. When compared to sunspots, they are much smaller in diameter and hence can be impacted and buffeted by neighbouring granular activity to generate significant magnetohydrodynamic (MHD) wave energy flux within their confines. However, observations of solar pores from ground-based telescope facilities may struggle to capture subtle motions synonymous with higher-order MHD wave signatures due to seeing effects produced in the Earth’s atmosphere. Hence, we have exploited timely seeing-free and high-quality observations of four small magnetic pores from the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (PHI) on board the Solar Orbiter spacecraft, during its first close perihelion passage in March 2022 (at a distance of 0.5 au from the Sun). Through acquisition of data under stable observing conditions, we have been able to measure the area fluctuations and horizontal displacements of the solar pores. Cross correlations between perturbations in intensity, area, line-of-sight velocity, and magnetic fields, coupled with the first-time application of novel Proper Orthogonal Decomposition (POD) techniques on the boundary oscillations, provide a comprehensive diagnosis of the embedded MHD waves as sausage and kink modes. Additionally, the previously elusive m = 2 fluting mode is identified in the most magnetically isolated of the four pores. An important consideration lies in how the identified wave modes contribute towards the transfer of energy into the upper solar atmosphere. We find that the four pores examined have approximately 56%, 72%, 52%, and 34% of their total wave energy associated with the identified sausage modes, and around 23%, 17%, 39%, and 49% to their kink modes, respectively, while the first pore also has around an 11% contribution linked to the fluting mode. This study marks the first-time identification of concurrent sausage, kin

关键词： Magnetohydrodynamics

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control of longitudinal aircraft motion with loadcase robustness using LPV-control with partly-measurable parameters

Control of longitudinal aircraft motion with loadcase robust...

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AIAA Guidance, Navigation, and control Conference, 2018

作者： Goßmann, Felix Svariceky, Ferdinand Gabrys, Agnes Department of Aviation and Space Engineering Institute of Control Engineering University of the German Federal Armed Forces Munich Neubiberg Munich85577 Germany Department of Mechanical Engineering Institute of Flight System Dynamics Technische Universität München Garching Munich85748 Germany

ISBN: (数字)9781624105265

ISBN: (纸本)9781624105265

This paper addresses the design of a longitudinal baseline controller of an aircraft. flight dynamics are usually described through linearized models of the nonlinear rigid body equations, which are only valid in the area of a trimpoint. Hence the dynamics are dependent on parameters such as altitude, airspeed or loadcase, which describes a certain combination of mass, center of gravity and inertia tensor. The current loadcase is often not available during operation. However the ight control system has to fulfill specifications for all possible loadcases. Therefore the loadcase is introduced as an additional parametric dependency besides static and dynamic pressure, which represent current altitude and airspeed. An linear parameter-variant (LPV) controller is designed which depends on static and dynamic pressure only. The design is realized with the use of an LPV technique with partly-measurable parameters. A showcase design for a small regional aircraft is accomplished to present the synthesis and show its capabilities for ight control problems. © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： controllers

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The insight HP3 penetrator (Mole) on mars: Soil properties derived from the penetration attempts and related activities

arXiv

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arXiv 2021年

作者： Spohn, Tilman Hudson, T.L. Marteau, E. Golombek, M. Grott, M. Wippermann, T. Ali, K.S. Schmelzbach, C. Kedar, S. Hurst, K. Trebi-Ollennu, A. Ansan, V. Garvin, J. Knollenberg, J. Müller, N. Piqueux, S. Lichtenheldt, R. Krause, C. Fantinati, C. Brinkman, N. Sollberger, D. Delage, P. Vrettos, C. Reershemius, S. Wisniewski, L. Grygorczuk, J. Robertsson, J. Edme, P. Andersson, F. Krömer, O. Lognonné, P. Giardini, D. Smrekar, S.E. Banerdt, W.B. International Space Science Institute Hallerstrasse 6 Bern3012 Switzerland DLR Institute of Planetary Research Rutherfordstr. 2 Berlin12489 Germany DLR Institute of Space Systems Robert-Hooke-Str. 7 Bremen28359 Germany DLR MUSC Space Operations and Astronaut Training Linder Höhe Köln51147 Germany DLR Institute of System Dynamics and Control Münchener Strasse 20 Wessling82234 Germany Jet Propulsion Laboratory California Institute of Technology Oak Grove Drive PasadenaCa91109 United States NASA Goddard Space Flight Center 8800 Greenbelt Road GreenbeltMD20771 United States Astronika Sp. z o.o ul. Bartycka 18 Warszawa00-716 Poland Institute of Geophysics Department of Earth Sciences ETH Zürich ZürichCH-8092 Switzerland Laboratoire de Planétologie et Géodynamique de Nantes Université de Nantes Nantes44322 France École nationale des ponts et chaussées Laboratoire Navier Paris France Department of Civil Engineering University of Kaiserslautern Kaiserslautern Germany Institut du Physique du Globe Paris Paris France Astrium Bremen Germany

The NASA InSight Lander on Mars includes the Heat Flow and Physical Properties Package HP3 to measure the surface heat flow of the planet. The package uses temperature sensors that would have been brought to the target depth of 3–5 m by a small penetrator, nicknamed the mole. The mole requiring friction on its hull to balance remaining recoil from its hammer mechanism did not penetrate to the targeted depth. Instead, by precessing about a point midway along its hull, it carved a 7 cm deep and 5-6 cm wide pit and reached a depth of initially 31 cm. The root cause of the failure - as was determined through an extensive, almost two years long campaign - was a lack of friction in an unexpectedly thick cohesive duricrust. During the campaign – described in detail in this paper – the mole penetrated further aided by friction applied using the scoop at the end of the robotic Instrument Deployment Arm and by direct support by the latter. The mole finally reached a depth of 40 cm, bringing the mole body 1–2 cm below the surface. It reversed its downward motion twice during attempts to provide friction through pressure on the regolith instead of directly with the scoop to the hull. The penetration record of the mole and its thermal sensors were used to measure thermal and mechanical soil parameters such as the penetration resistance of the duricrust of 0.5 - 1.2 MPa and a penetration resistance of a deeper layer (> 30 cm depth) of 5.3 MPa. Applying cone penetration theory, the resistance of the duricrust was used to estimate a cohesion of the latter of 4 - 25 kPa depending on the internal friction angle of the duricrust. Pushing the scoop with its blade into the surface and chopping off a piece of duricrust provided another estimate of the cohesion of 5.8 kPa. The hammerings of the mole were recorded by the seismometer SEIS and the signals could be used to derive a P-wave velocity of 114+40−19 m/s and a S-wave velocity of 60+10−7 m/s (Brinkman et al., 2021) representative of

关键词： Soils

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Discrete time open-loop and closed-loop flow control based on van der pol modeling 8

Discrete time open-loop and closed-loop flow control based o...

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8th AIAA Flow control Conference, 2016

作者： Motta, Valentina Döll, Carsten Mouyon, Philippe ONERA-DCSD System Control and Flight Dynamics Department 2 av. Edouard Belin Toulouse Cedex31055 France

ISBN: (数字)9781624104329

ISBN: (纸本)9781624104329

A real-time modeling and control architecture for coupled shear layer Von Ḱarḿan instabilities on a low Reynolds wing wake is developed. Previous wind tunnel experiments highlight that these wake instabilities give rise to limit cycles on both local and resulting airloads. The two states Van der Pol system is employed to model the self-sustained oscillations exhibited by the actual flow. Schemes featuring either one or two coupled Van der pol oscillators in parallel are taken under consideration. Open-loop and closed-loop control laws to manipulate and reduce the self-sustained oscillations are extensively studied. An adaptive control scheme is developed to optimize the performance of the controller, according to the flow conditions. The feedback control is meant to provide real time motion laws for trailing edge piezo-actuators on a wing section wind tunnel model. © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Wakes

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Rethinking ground systems: Supporting new mission types through modularity and standardization 15th

Rethinking ground systems: Supporting new mission types thro...

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15th International Conference on Space Operations, SpaceOps 2018

作者： Gärtner, Stefan A. Geyer, Michael P. Hackel, Stefan Hauke, Armin O’meara, Corey Wasser, Yi Mission Control and Data Systems Engineer Mission Operations DLR German Aerospace Center Münchner Straße 20 Weßling82234 Germany Deputy Group Leader Mission Control and Data Systems Mission Operations DLR German Aerospace Center Münchner Straße 20 Weßling82234 Germany Mission Operations DLR German Aerospace Center Münchner Straße 20 Weßling82234 Germany Department Communication and Ground Stations Mission Operations DLR German Aerospace Center Münchner Straße 20 Weßling82234 Germany Mission Planning System Engineer Mission Operations DLR German Aerospace Center Münchner Straße 20 Weßling82234 Germany Flight Dynamics Engineer Mission Operations DLR German Aerospace Center Münchner Straße 20 Weßling82234 Germany

ISBN: (数字)9781624105623

ISBN: (纸本)9781624105623

We begin to see an increase in the diversity of today’s space missions: Small student-designed satellites, unique scientific missions and fleets of commercial spacecraft are just a few of those mission types. In order to cater for new demands on the ground system and to offer customer-tailored solutions we started to rethink the foundations of the German Space Operations Center (GSOC) ground system in terms of a service-oriented architecture approach using standardized technology, mainly CCSDS Mission Operations services. We show how we modularize our ground system, identify and clearly name the mission functions present in the current system complete with timing information and data size requirements. We illustrate this process by employing a concrete prototypical mission with involvement across all departments from antenna control, data processing to mission planning and flight dynamics, and hint at the challenges encountered along the way. The chosen technical solution is motivated and explained, and aspects of deployment, performance, and security are discussed. © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Antennas

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Generalised Error Functions from the Kerr Metric

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Chinese Physics Letters 2016年第3期33卷 12-16页

作者：唐文林罗子人刘润球 Science and Technology on Aerospace Flight Dynamics Laboratory Beijing Aerospace Control Center Department of Aerospace Guidance Navigation and Control School of AstronauticsBeihang University QUEST Center of Quantum Engineering and Space-Time Research Leibniz Universitt Hannover Max Planck Institute for Gravitational Physics(Albert Einstein Institute) Institute of Applied Mathematics Morningside Center of Mathematics and LESCInstitute of Computational MathematicsAcademy of Mathematics and System ScienceChinese Academy of Sciences

Motivated by the effort to understand the mathematical structure underlying the Teukolsky equations in a Kerr metric background, a homogeneous integral equation related to the prolate spheroidal function is studied. From the consideration of the Fredholm determinant of the integral equation, a family of generalized error function is defined, with which the Fredholm determinant of the sinc kernel is also evaluated. An analytic solution of a special ease of the fifth Painlev~ transcendent is then worked out explicitly.

关键词： of is exp in Generalised Error Functions from the Kerr Metric from

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