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A two-stage approach for managing actuators redundancy and its application to fault tolerant flight control

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Chinese Journal of Aeronautics 2015年第2期28卷 469-477页

作者： Zhong Lunlong félix mora-camino Tianjin Key Laboratory for Advanced Signal and Image Processing Civil Aviation University of China Automation Research Group of MAIAA ENAC Toulouse University

In safety-critical systems such as transportation aircraft, redundancy of actuators is introduced to improve fault tolerance. How to make the best use of remaining actuators to allow the system to continue achieving a desired operation in the presence of some actuators failures is the main subject of this paper. Considering that many dynamical systems, including flight dynamics of a transportation aircraft, can be expressed as an input affine nonlinear system, a new state repre- sentation is adopted here where the output dynamics are related with virtual inputs associated with the intended operation. This representation, as well as the distribution matrix associated with the effectiveness of the remaining operational actuators, allows us to define different levels of fault tol- erant governability with respect to actuators＇ failures. Then, a two-stage control approach is devel- oped, leading frst to the inversion of the output dynamics to get nominal values for the virtual inputs and then to the solution of a linear quadratic （LQ） problem to compute the solicitation of each operational actuator. The proposed approach is applied to the control of a transportation air- craft which performs a stabilized roll maneuver while a partial failure appears. Two fault scenarios are considered and the resulting performance of the proposed approach is displayed and discussed.

关键词： Actuator allocation fault tolerant control flight control Linear quadratic (LQ)problem Nonlinear control

Aircraft fault Tolerant Control Based on Active Set Method

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Aircraft Fault Tolerant Control Based on Active Set Method

第25届中国控制与决策会议

作者： Lunlong Zhong félix mora-camino ENAC MAIAA Univ de Toulouse

ISBN: (纸本)9781467355339

This communication considers the case in which an aerodynamic actuator failure occurs to an aircraft while it has to perform a guidance manoeuver. The problem considered deals with the reassignment of the remaining actuators to continue to perform the manoeuver while maintaining the structural integrity of the aircraft. A nonlinear inverse control technique is used to generate online nominal moments along the three main axes of the aircraft. Then, taking into account all material and structural constraints as well as the redundant effects from other actuators, a Mathematical Programming problem to be solved online is introduced. The proposed on line solution method is based on an active set method which appears to provide acceptable response times according to the simulation results. Then new development perspectives are discussed.

关键词： fault tolerant control flight mechanics Quadratic programming Active set method Actuators assignment

Online Actuator Reassignment for fault Tolerant flight Control

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Online Actuator Reassignment for Fault Tolerant Flight Contr...

第26届中国控制与决策会议

作者： Lunlong Zhong félix mora-camino College of Electronic Information Engineering Civil Aviation University of China

This communication considers the case in which some aerodynamic actuator failures occur when an aircraft performs the intended maneuver. The problem considered deals with online reassignment of the remaining effective actuators to continue performing the current maneuver safely. first, through analysis of a general nonlinear system, the concept of virtual inputs and fault tolerance is proposed and analyzed. Taking a pure roll maneuver as an example, the values of its virtual inputs can be computed through nonlinear inverse control approach. Then, a linear quadratic programming problem is formulated for actuator reassignment, to find a best utilization of remaining effective actuators, as well as taking into account various constraints for safety. Three fast solution approaches are studied to solve this reassignment problem. The simulation results show the feasibility of the proposed method. finally, a general conclusion is drawn.

关键词： fault tolerant flight control Linear quadratic problem Interior point method Active set method Neural networks Actuators reassignment

Hamilton-Jacobi-Bellman equations for fuzzy-Dual Optimization 36

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Hamilton-Jacobi-Bellman equations for Fuzzy-Dual Optimizatio...

第36届中国控制会议

作者： Lunlong Zhong felix mora-camino Hakim Bouadi Roger Marcelin faye Key Lab. for Adv.Signal Proc. Civil Aviation University of China Automation Research Group ENACToulouse University

ISBN: (纸本)9781538629185

In this article, after introducing fuzzy-dual numbers, functions and functionals, the optimization of a fuzy-dual functional is considered through an extension of Euler’s condition. Then, once uncertainty is imbedded in a fuzzy-dual dynamical system, the optimization of such systems is considered, leading to an extended Hamilton-Jacobi-Bellman equation to characterize optimal fuzzy-dual solutions.

关键词： fuzzy-dual numbers uncertain systems Euler’s equation optimal control Hamilton-Jacobi-Bellman equation

Are the number and size of scales in Liolaemus lizards driven by climate?

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Integrative Zoology 2018年第5期13卷 579-594页

作者： María JoséTULLI félix BCRUZ Unidad Ejecutora Lillo(UEL-CONICET) Instituto de HerpetologíaFundación Miguel LilloSan Miguel de TucumánTucumánArgentina Instituto de Investigaciones en Biodiversidad y Medioambiente(INIBIOMA)CONICET-UNCOMA BarilocheRío NegroArgentina

Ectothermic vertebrates are sensitive to thermal fluctuations in the environments where they *** buffer these fluctuations,ectotherms use different strategies,including the integument,which is a barrier that minimizes temperature exchange between the inner body and the surrounding *** lizards,this barrier is constituted by keratinized scales of variable size,shape and texture,and its main function is protection,water loss avoidance and *** size of scales in lizards has been proposed to vary in relation to climatic gradients;however,it has also been observed that in some groups of Iguanian lizards it could be related to ***,here,we studied the area and number of scales(dorsal and ventral)of 60 species of Liolaemus lizards distributed in a broad latitudinal and altitudinal gradient to determine the nature of the variation of the scales with climate,and found that the number and size of scales are related to climatic variables,such as temperature and geographical variables as *** evolutionary process that best explained how these morphological variables evolved was the Ornstein–Uhlenbeck *** number of scales seemed to be related to common ancestry,whereas dorsal and ventral scale areas seemed to vary as a consequence of ecological *** fact,the ventral area is less exposed to climate conditions such as ultraviolet radiation or wind and is,thus,under less pressure to change in response to alterations in external *** is possible that scale ornamentation,such as keels and granulosity,may bring some more information in this regard.

关键词： climate variables habitat use Lioalemidae scale traits

Describing failure in geomaterials using second-order work approach

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Water Science and Engineering 2015年第2期8卷 89-95页

作者： franois Nicot félix Darve Institut de Recherche en Sciences et Technologies de l'Environnement et de l'Agriculture(IRSTEA) Erosion Torrentielle Neige et Avalanches (ETNA)Geomechanics GroupGrenoble 38402 France Université Joseph fourier (UJf)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS) Laboratoire SolsSolides Structures et RisquesGrenoble 38041 France

Geomaterials are known to be non-associated materials. Granular soils therefore exhibit a variety of failure modes, with diffuse or localized kinematical patterns. In fact, the notion of failure itself can be confusing with regard to granular soils, because it is not associated with an obvious phenomenology. In this study, we built a proper framework, using the second-order work theory, to describe some failure modes in geomaterials based on energy conservation. The occurrence of failure is defined by an abrupt increase in kinetic energy. The increase in kinetic energy from an equilibrium state, under incremental loading, is shown to be equal to the difference between the external second-order work,involving the external loading parameters, and the internal second-order work, involving the constitutive properties of the material. When a stress limit state is reached, a certain stress component passes through a maximum value and then may decrease. Under such a condition, if a certain additional external loading is applied, the system fails, sharply increasing the strain rate. The internal stress is no longer able to balance the external stress, leading to a dynamic response of the specimen. As an illustration, the theoretical framework was applied to the well-known undrained triaxial test for loose soils. The influence of the loading control mode was clearly highlighted. It is shown that the plastic limit theory appears to be a particular case of this more general second-order work theory. When the plastic limit condition is met, the internal second-order work is nil. A class of incremental external loadings causes the kinetic energy to increase dramatically, leading to the sudden collapse of the specimen, as observed in laboratory.

关键词： failure in geomaterials Undrained triaxial loading path Second-order work Kinetic energy Plastic limit condition Control parameter

Do Rules and Patterns Affect Design Maintainability?

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Journal of Computer Science & Technology 2009年第2期24卷 262-272页

作者： Javier Garzás félix García Mario Piattini Kybele Consulting Madrid Spain Department of Information Technologies and Systems-Escuela Superior de Informáica University of Castilla-La Mancha Alarcos Research Group-Institute of Information Technologies and Systems Department of Information Technologies and Systems-Escuela Superior de Informáica University of Castilla-La Mancha

At the present time, best rules and patterns have reached a zenith in popularity and diffusion, thanks to the software community＇s efforts to discover, classify and spread knowledge concerning all types of rules and patterns. Rules and patterns are useful elements, but many features remain to be studied if we wish to apply them in a rational manner. The improvement in quality that rules and patterns can inject into design is a key issue to be analyzed, so a complete body of empirical knowledge dealing with this is therefore necessary. This paper tackles the question of whether design rules and patterns can help to improve the extent to which designs are easy to understand and modify. An empirical study, composed of one experiment and a replica, was conducted with the aim of validating our conjecture. The results suggest that the use of rules and patterns affect the understandability and modifiability of the design, as the diagrams with rules and patterns are more difficult to understand than non-rule/pattern versions and more effort is required to carry out modifications to designs with rules and patterns.

关键词： design patterns and rules maintainability software quality object-oriented design

Understanding the neighborhoods’in-between spaces on spatial perception,social interaction,and security

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frontiers of Architectural Research 2024年第1期13卷 21-36页

作者： Lizeth félix Mariel Organista Autonomous University of Baja California Ensenada 22860Mexico

This study reflects on the impact that the neighborhoods’in-between spaces have on:spatial perception,social interaction,and *** sites,characterized by their abandonment and deterioration,can also be seen as crucial spaces of opportunity for cities,in the architectural,urban and landscape *** paper aims to analyze the sociospatial relationships in the neighborhoods’in-between spaces and examine the impact of inbetween space configuration on urban *** investigation draws on a survey of perception to residents about the requirements for a suitable social interaction in these *** study was developed in a neighborhood in the city periphery,characterized by their social dynamics and location in a nature conservation *** findings indicate that the appropriation process,activities,and collective practices are dependent on the spatial legibility,in this case when this increases,gives rise to improve the habitability and the rehabilitation of the in-between ***,the lack of design on in-between spaces substantially affects the use of these spaces and the social interaction among residents.

关键词： In-between spaces Socio-spatial relationships Habitability Neighborhoods Security

A 3D Numerical Study of LO_2/GH_2 Supercritical Combustion in the ONERA-Mascotte Test-rig Configuration

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Journal of Thermal Science 2016年第1期25卷 97-108页

作者： Abdelkrim Benmansour Abdelkrim Liazid Pierre-Olivier Logerais Jean-félix Durastanti Laboratory LTE ENP-OranBP 1523 El Mnaouer 31000Oran Algeria Universite de Paris-Est CERTESIUT de Senartrue Georges Charpak77567 LieusaintFrance

Cryogenic propellants LOx/H2 are used at very high pressure in rocket engine combustion. The description of the combustion process in such application is very complex due essentially to the supercritical regime. Ideal gas law becomes invalid. In order to try to capture the average characteristics of this combustion process, numerical computations are performed using a model based on a one-phase multi-component approach. Such work requires fluid properties and a correct definition of the mixture behavior generally described by cubic equations of state with appropriated thermodynamic relations validated against the NIST data. In this study we consider an alternative way to get the effect of real gas by testing the volume-weighted-mixing-law with association of the component transport properties using directly the NIST library data fitting including the supercritical regime range. The numerical simulations are carried out using 3D RANS approach associated with two tested turbulence models, the standard k-Epsilon model and the realizable k-Epsilon one. The combustion model is also associated with two chemical reaction mechanisms. The first one is a one-step generic chemical reaction and the second one is a two-step chemical reaction. The obtained results like temperature profiles, recirculation zones, visible flame lengths and distributions of OH species are discussed.

关键词： Rocket engine non-premixed combustion supercritical regime H2-O2 flame transport properties