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http://hdl.handle.net/10985/17395
Instability Mechanism of Roll/Lateral Biodynamic Rotorcraft–Pilot Couplings
MUSCARELLO, Vincenzo; MASARATI, Pierangelo; QUARANTA, Giuseppe; TOD, Georges; PAVEL, Marilena; GOMAND, Julien; MALBURET, François
The paper investigates the basic mechanism of aeroservoelastic pilot-assisted oscillation about the roll axis due to the interaction with pilot's arm biomechanics. The motivation stems from the observation that a rotor imbalance may occur as a consequence of rotor cyclic lead–lag modes excitation. The work shows that the instability mechanism is analogous to air resonance, in which the pilot's involuntary action plays the role of the automatic flight control system. Using robust stability analysis, the paper shows how the pilot's biodynamics may involuntarily lead to a roll/lateral instability. The mechanism of instability proves that the pilot biodynamics is participating in the destabilization of the system by transferring energy, i.e., by producing forces that do work for the energetically conjugated displacement, directly into the flapping mode. This destabilizes the airframe roll motion, which, in turn, causes lead–lag motion imbalance. It is found that, depending on the value of the time delay involved in the lateral cyclic control, the body couples with rotor motion in a different way. In the presence of small or no time delays, body roll couples with the rotor through the lead–lag degrees of freedom. The increase of the time delay above a certain threshold modifies this coupling: The body no longer couples with the rotor through lead–lag but directly through flap motion.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/173952018-01-01T00:00:00ZMUSCARELLO, VincenzoMASARATI, PierangeloQUARANTA, GiuseppeTOD, GeorgesPAVEL, MarilenaGOMAND, JulienMALBURET, FrançoisThe paper investigates the basic mechanism of aeroservoelastic pilot-assisted oscillation about the roll axis due to the interaction with pilot's arm biomechanics. The motivation stems from the observation that a rotor imbalance may occur as a consequence of rotor cyclic lead–lag modes excitation. The work shows that the instability mechanism is analogous to air resonance, in which the pilot's involuntary action plays the role of the automatic flight control system. Using robust stability analysis, the paper shows how the pilot's biodynamics may involuntarily lead to a roll/lateral instability. The mechanism of instability proves that the pilot biodynamics is participating in the destabilization of the system by transferring energy, i.e., by producing forces that do work for the energetically conjugated displacement, directly into the flapping mode. This destabilizes the airframe roll motion, which, in turn, causes lead–lag motion imbalance. It is found that, depending on the value of the time delay involved in the lateral cyclic control, the body couples with rotor motion in a different way. In the presence of small or no time delays, body roll couples with the rotor through the lead–lag degrees of freedom. The increase of the time delay above a certain threshold modifies this coupling: The body no longer couples with the rotor through lead–lag but directly through flap motion.Procédé de commande et de régulation de l’angle braquage d’un empennage d’hélicoptére hybride
http://hdl.handle.net/10985/9229
Procédé de commande et de régulation de l’angle braquage d’un empennage d’hélicoptére hybride
EGLIN, Paul; QUEIRAS, Nicolas; BARRACO, André; MALBURET, François
La présente invention concerne un procédé de commande et de régulation d'un giravion à vitesse d'avancement élevée et stabilisée, comportant au moins un rotor principal (10) de sustentation, au moins une hélice (6) propulsive à pas variable et au moins une source motrice pour entraîner le(s) rotor(s) principal(aux) (10) et au moins une hélice (6), ledit procédé consistant à utiliser une première boucle de régulation en tangage ou assiette et une seconde boucle de régulation en vitesse par l'intermédiaire d'une commande du pas moyen de la ou des hélices (6) propulsives, caractérisé en ce qu'il consiste à commander l'angle de braquage d'un empennage (30,25,35) horizontal en utilisant une troisième boucle de commande et de régulation dudit angle de braquage de l'empennage (30,25,35) horizontal, pour minimiser la puissance totale consommée par le rotor principal (10) et la ou les hélices (6) propulsives, pour une assiette et une vitesse donnée.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/92292012-01-01T00:00:00ZEGLIN, PaulQUEIRAS, NicolasBARRACO, AndréMALBURET, FrançoisLa présente invention concerne un procédé de commande et de régulation d'un giravion à vitesse d'avancement élevée et stabilisée, comportant au moins un rotor principal (10) de sustentation, au moins une hélice (6) propulsive à pas variable et au moins une source motrice pour entraîner le(s) rotor(s) principal(aux) (10) et au moins une hélice (6), ledit procédé consistant à utiliser une première boucle de régulation en tangage ou assiette et une seconde boucle de régulation en vitesse par l'intermédiaire d'une commande du pas moyen de la ou des hélices (6) propulsives, caractérisé en ce qu'il consiste à commander l'angle de braquage d'un empennage (30,25,35) horizontal en utilisant une troisième boucle de commande et de régulation dudit angle de braquage de l'empennage (30,25,35) horizontal, pour minimiser la puissance totale consommée par le rotor principal (10) et la ou les hélices (6) propulsives, pour une assiette et une vitesse donnée.On a robust modeling of piezo-systems
http://hdl.handle.net/10985/8958
On a robust modeling of piezo-systems
CORBIER, Christophe; BOUKARI, Abdou Fadel; CARMONA, Jean-Claude; MARTINEZ, Victor Alvarado; MORARU, George; MALBURET, François
This paper proposes a new modeling approach which is experimentally validated on piezo-electric systems in order to provide a robust Black-box model for complex systems control. Industrial applications such as vibration control in machining and active suspension in transportation should be concerned by the results presented here. Generally one uses physical based approaches. These are interesting as long as the user cares about the nature of the system. However, sometimes complex phenomena occur in the system while there is not sufficient expertise to explain them. Therefore, we adopt identification methods to achieve the modeling task. Since the microdisplacements of the piezo-system sometimes generate corrupted data named observation outliers leading to large estimation errors, we propose a parameterized robust estimation criterion based on a mixed L2 – L1 norm with an extended range of a scaling factor to tackle efficiently these outliers. This choice is motivated by the high sensitivity of least-squares methods to the large estimation errors. Therefore, the role of the L1 -norm is to make the L2 -estimator more robust. Experimental results are presented and discussed.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/89582012-01-01T00:00:00ZCORBIER, ChristopheBOUKARI, Abdou FadelCARMONA, Jean-ClaudeMARTINEZ, Victor AlvaradoMORARU, GeorgeMALBURET, FrançoisThis paper proposes a new modeling approach which is experimentally validated on piezo-electric systems in order to provide a robust Black-box model for complex systems control. Industrial applications such as vibration control in machining and active suspension in transportation should be concerned by the results presented here. Generally one uses physical based approaches. These are interesting as long as the user cares about the nature of the system. However, sometimes complex phenomena occur in the system while there is not sufficient expertise to explain them. Therefore, we adopt identification methods to achieve the modeling task. Since the microdisplacements of the piezo-system sometimes generate corrupted data named observation outliers leading to large estimation errors, we propose a parameterized robust estimation criterion based on a mixed L2 – L1 norm with an extended range of a scaling factor to tackle efficiently these outliers. This choice is motivated by the high sensitivity of least-squares methods to the large estimation errors. Therefore, the role of the L1 -norm is to make the L2 -estimator more robust. Experimental results are presented and discussed.Study and Analysis of Anti Vibratory Passive and Active Methods Applied to Complex Mechanical System
http://hdl.handle.net/10985/9196
Study and Analysis of Anti Vibratory Passive and Active Methods Applied to Complex Mechanical System
LOPEZ, Cédric; BARRACO, André; MALBURET, François
This paper studies problematic of a mechanical system composed of different coupled parts submitted to a high speed shock and proposes analysis of anti vibratory passive and active methods based on an experimental and theoretical coupled approach. After a shock, different parts of the system oscillate. If one of them is excited at a particular frequency, such as its proper frequency, important oscillations appear and can lead to the deterioration of the system by introducing important stresses. In this paper, we propose an analysis in order to understand this kind of problem and what we can do to avoid it. Firstly, we discuss problematic and we expose the studied system. In a second time, we develop two approaches of modeling that allow us to understand the phenomenon by carrying out numerical simulations. Then cross checking of model is completed via experimental study on drop test bench. Passive minimization method of vibrations based on experimental and theoretical coupled approach is exposed. Finally, a comparative analysis of different methods of control and experimental results of controlled system are presented.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/91962012-01-01T00:00:00ZLOPEZ, CédricBARRACO, AndréMALBURET, FrançoisThis paper studies problematic of a mechanical system composed of different coupled parts submitted to a high speed shock and proposes analysis of anti vibratory passive and active methods based on an experimental and theoretical coupled approach. After a shock, different parts of the system oscillate. If one of them is excited at a particular frequency, such as its proper frequency, important oscillations appear and can lead to the deterioration of the system by introducing important stresses. In this paper, we propose an analysis in order to understand this kind of problem and what we can do to avoid it. Firstly, we discuss problematic and we expose the studied system. In a second time, we develop two approaches of modeling that allow us to understand the phenomenon by carrying out numerical simulations. Then cross checking of model is completed via experimental study on drop test bench. Passive minimization method of vibrations based on experimental and theoretical coupled approach is exposed. Finally, a comparative analysis of different methods of control and experimental results of controlled system are presented.An Energetic Approach to Aeroelastic Rotorcraft-Pilot Couplings Analysis
http://hdl.handle.net/10985/9458
An Energetic Approach to Aeroelastic Rotorcraft-Pilot Couplings Analysis
TOD, Georges; BARRE, Pierre-Jean; BOUDON, Benjamin; GOMAND, Julien; MALBURET, François
This paper describes an energetic method using multibond graphs to model multi-physical systems. Its potential in building physical meaningful graphs that represent equivalent mathematical models of classic analytical approaches is shown. An application to the study of an aeroelastic rotorcraft-pilot coupling is studied by analyzing the passive pilot behavior in the cyclic control loop. A rotorcraft in hover flight is simulated and perturbed on its rolling motion axis. Depending on the rotorcraft characteristics air resonance may occur, and the pilot may involuntarily excite the cyclic lever, increasing the rolling motion of the fuselage to an unstable point. Future work will explore eventual alternative solutions to notch filters to avoid passive pilot reinjection at low fuselage frequency modes by controlling for example the actuators of the swashplate through model inversion using the bond graph method
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10985/94582013-01-01T00:00:00ZTOD, GeorgesBARRE, Pierre-JeanBOUDON, BenjaminGOMAND, JulienMALBURET, FrançoisThis paper describes an energetic method using multibond graphs to model multi-physical systems. Its potential in building physical meaningful graphs that represent equivalent mathematical models of classic analytical approaches is shown. An application to the study of an aeroelastic rotorcraft-pilot coupling is studied by analyzing the passive pilot behavior in the cyclic control loop. A rotorcraft in hover flight is simulated and perturbed on its rolling motion axis. Depending on the rotorcraft characteristics air resonance may occur, and the pilot may involuntarily excite the cyclic lever, increasing the rolling motion of the fuselage to an unstable point. Future work will explore eventual alternative solutions to notch filters to avoid passive pilot reinjection at low fuselage frequency modes by controlling for example the actuators of the swashplate through model inversion using the bond graph methodCAD modelling based on knowledge synthesis for design rational
http://hdl.handle.net/10985/16760
CAD modelling based on knowledge synthesis for design rational
GEROMIN, Anthony; LOPEZ, Cédric; ROUCOULES, Lionel; MALBURET, François
Although many new methodological and modelling concepts have been proposed by the scientific community, current industries are still focusing their engineering design process on CAD model since they assume it is the starting point of many analyses with respect to product life cycle (CAM, FEA, LCA…). The paper presents the application of modelling concepts that lead the progressive justification of CAD model with respect to knowledge synthesis by least commitment. Design experts are first formalizing their knowledge that is therefore translated to form features and parameters (topology, position, orientation, dimensions…). The results show that this new design approach and models support design intents and rational, but the generated CAD model is not fully justified. That drives to many conclusions: CAD model is many often non-100% rational by designers’ knowledge, design solution space is therefore larger than the one modelled in CAD software and could be used to foster innovation.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/167602018-01-01T00:00:00ZGEROMIN, AnthonyLOPEZ, CédricROUCOULES, LionelMALBURET, FrançoisAlthough many new methodological and modelling concepts have been proposed by the scientific community, current industries are still focusing their engineering design process on CAD model since they assume it is the starting point of many analyses with respect to product life cycle (CAM, FEA, LCA…). The paper presents the application of modelling concepts that lead the progressive justification of CAD model with respect to knowledge synthesis by least commitment. Design experts are first formalizing their knowledge that is therefore translated to form features and parameters (topology, position, orientation, dimensions…). The results show that this new design approach and models support design intents and rational, but the generated CAD model is not fully justified. That drives to many conclusions: CAD model is many often non-100% rational by designers’ knowledge, design solution space is therefore larger than the one modelled in CAD software and could be used to foster innovation.Modeling Stiffness and Damping in Rotational Degrees of Freedom Using Multibond Graphs
http://hdl.handle.net/10985/9227
Modeling Stiffness and Damping in Rotational Degrees of Freedom Using Multibond Graphs
TOD, Georges; BARRE, Pierre-Jean; GOMAND, Julien; MALBURET, François
A contribution is proposed for the modeling of mechanical systems using multibond graphs. When modeling a physical system, it may be needed to catch the dynamic behavior contribution of the joints between bodies of the system and therefore to characterize the stiffness and damping of the links between them. The visibility of where dissipative or capacitive elements need to be implemented to represent stiffness and damping in multibond graphs is not obvious and will be explained. A multibond graph architecture is then proposed to add stiffness and damping in hree rotational degrees of freedom. The resulting joint combines the spherical joint multibond graph relaxed causal constraints while physically representing three concatenated revolute joints. The mathematical foundations are presented, and then illustrated through the modeling and simulation of an inertial navigation system; in which stiffness and damping between the gimbals are taken into account. This method is particularly useful when modeling and simulating multibody systems using Newton-Euler formalism in multibond graphs. Future work will show how this method can be extended to more complex systems such as rotorcraft blades' connections with its rotor hub.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/10985/92272013-01-01T00:00:00ZTOD, GeorgesBARRE, Pierre-JeanGOMAND, JulienMALBURET, FrançoisA contribution is proposed for the modeling of mechanical systems using multibond graphs. When modeling a physical system, it may be needed to catch the dynamic behavior contribution of the joints between bodies of the system and therefore to characterize the stiffness and damping of the links between them. The visibility of where dissipative or capacitive elements need to be implemented to represent stiffness and damping in multibond graphs is not obvious and will be explained. A multibond graph architecture is then proposed to add stiffness and damping in hree rotational degrees of freedom. The resulting joint combines the spherical joint multibond graph relaxed causal constraints while physically representing three concatenated revolute joints. The mathematical foundations are presented, and then illustrated through the modeling and simulation of an inertial navigation system; in which stiffness and damping between the gimbals are taken into account. This method is particularly useful when modeling and simulating multibody systems using Newton-Euler formalism in multibond graphs. Future work will show how this method can be extended to more complex systems such as rotorcraft blades' connections with its rotor hub.Lightweight design: mass in transit
http://hdl.handle.net/10985/8964
Lightweight design: mass in transit
KRYSINSKI, Tomasz; NAUZIN, Jean-Paul; MALBURET, François
This paper is part of an effort to reduce a vehicle’s CO2 emissions through lightweight design. The originality of the approach consists in harnessing the optimal vehicle architecture with regard to CO2 emissions. Reducing a vehicle’s weight provides an opportunity to reassess performance features like shock, noise, vibrations and road holding, thereby generating additional savings through a virtuous cycle of weight reduction. The paper sheds light on some methodological aspects used by PSA Peugeot-Citroen for designing lightweight vehicles.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/89642012-01-01T00:00:00ZKRYSINSKI, TomaszNAUZIN, Jean-PaulMALBURET, FrançoisThis paper is part of an effort to reduce a vehicle’s CO2 emissions through lightweight design. The originality of the approach consists in harnessing the optimal vehicle architecture with regard to CO2 emissions. Reducing a vehicle’s weight provides an opportunity to reassess performance features like shock, noise, vibrations and road holding, thereby generating additional savings through a virtuous cycle of weight reduction. The paper sheds light on some methodological aspects used by PSA Peugeot-Citroen for designing lightweight vehicles.Multi-physic system simplification method applied to a helicopter flight axis active control
http://hdl.handle.net/10985/8963
Multi-physic system simplification method applied to a helicopter flight axis active control
MARTIN, Mikael; BARRE, Pierre-Jean; GOMAND, Julien; MALBURET, François
A helicopter flight axis control, which is a complex multi-physic system, is modelled using an energetic based graphical tool: the Energetic Macroscopic Representation. Elements of the system are mainly composed of passive technologies and their number tends to increase year after year to improve the pilots comfort by adding new functions. A new methodology is proposed to transform the system into a new active one by replacing some hydro-mechanical elements by a new controllable active mechanical source. The challenge is to simplify the flight control architecture while preserving the global behaviour of the system.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/89632012-01-01T00:00:00ZMARTIN, MikaelBARRE, Pierre-JeanGOMAND, JulienMALBURET, FrançoisA helicopter flight axis control, which is a complex multi-physic system, is modelled using an energetic based graphical tool: the Energetic Macroscopic Representation. Elements of the system are mainly composed of passive technologies and their number tends to increase year after year to improve the pilots comfort by adding new functions. A new methodology is proposed to transform the system into a new active one by replacing some hydro-mechanical elements by a new controllable active mechanical source. The challenge is to simplify the flight control architecture while preserving the global behaviour of the system.Complementary use of BG and EMR formalisms for multiphysics systems analysis and control
http://hdl.handle.net/10985/9041
Complementary use of BG and EMR formalisms for multiphysics systems analysis and control
CHIKHAOUI, Zeineb; BARRE, Pierre-Jean; GOMAND, Julien; MALBURET, François
In this paper, a complex multiphysics system is modeled using two different energy-based graphical techniques: Bond Graph and Energetic Macroscopic Representation. These formalisms can be used together to analyze, model and control a system. The BG is used to support physical, lumped-parameter modeling and analysis processes, and then EMR is used to facilitate definition of a control structure through inversion-based methodology. This complementarity between both of these tools is set out through a helicopter flight control subsystem.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/90412012-01-01T00:00:00ZCHIKHAOUI, ZeinebBARRE, Pierre-JeanGOMAND, JulienMALBURET, FrançoisIn this paper, a complex multiphysics system is modeled using two different energy-based graphical techniques: Bond Graph and Energetic Macroscopic Representation. These formalisms can be used together to analyze, model and control a system. The BG is used to support physical, lumped-parameter modeling and analysis processes, and then EMR is used to facilitate definition of a control structure through inversion-based methodology. This complementarity between both of these tools is set out through a helicopter flight control subsystem.