The Experts below are selected from a list of 41517 Experts worldwide ranked by ideXlab platform

Christine Fernandez-martin - One of the best experts on this subject based on the ideXlab platform.

  • Sharing the Knowledge: An Open-Source Vision for Flight Dynamics
    SpaceOps 2010 Conference, 2010
    Co-Authors: Luc Maisonobe, Christine Fernandez-martin
    Abstract:

    Flight Dynamics systems have long been considered to be restricted fields inhabited by strange people performing highly complex computation on specific computers with specific languages. These systems did not really embed smoothly with the rest of the ground system. They use their own frameworks, their own GUI, their own database, and are often triggered either manually on dedicated computers or using very low level mechanisms like files dropped in shared folders or scripts wrappers. These systems are costly to maintain and clearly don't scale to today's needs with more demanding space missions and tighter schedules. The use of old technology implies skilled engineers are difficult to find and the few available have high hourly cost. Lots of work is to be done on interfaces because none of the new features brought by web technology is ever used. This paper shows a different approach for Flight Dynamics systems. It explains there is no reason such systems could not benefit from the current technology. The new development paradigms are mature and well known. They have proven useful on many critical fields and a tremendous offer of tools allows to improve code quality, testing, validation, traceability ... The open-source approach has also been time tested by now and is accepted for its unique features in critical systems and when long term maintenance are needed. The Orekit library (http://www.orekit.org/) is an implementation of these ideas. It is an open-source library freely available with a businessfriendly license and using state of the art models and technology. It demonstrates high performance operational products can be embedded in modern control centers to smoothly integrate complex Flight Dynamics functions right within the system. The project also shows the open-source approach is well suited for the Flight Dynamics field and that putting down some fences and sharing the code is a key feature for the success of such a library.

  • an open-source vision for Flight Dynamics
    2010
    Co-Authors: Luc Maisonobe, Christine Fernandez-martin
    Abstract:

    Flight Dynamics systems have long been considered to be restricted fields inhabited by strange people performing highly complex computation on specific computers with specific languages. These systems did not really embed smoothly with the rest of the ground system. They use their own frameworks, their own GUI, their own database, and are often triggered either manually on dedicated computers or using very low level mechanisms like files dropped in shared folders or scripts wrappers. These systems are costly to maintain and clearly don't scale to today's needs with more demanding space missions and tighter schedules. The use of old technology implies skilled engineers are difficult to find and the few available have high hourly cost. Lots of work is to be done on interfaces because none of the new features brought by web technology is ever used. This paper shows a different approach for Flight Dynamics systems. It explains there is no reason such systems could not benefit from the current technology. The new development paradigms are mature and well known. They have proven useful on many critical fields and a tremendous offer of tools allows to improve code quality, testing, validation, traceability ... The open-source approach has also been time tested by now and is accepted for its unique features in critical systems and when long term maintenance are needed. The Orekit library (http://www.orekit.org/) is an implementation of these ideas. It is an open-source library freely available with a businessfriendly license and using state of the art models and technology. It demonstrates high performance operational products can be embedded in modern control centers to smoothly integrate complex Flight Dynamics functions right within the system. The project also shows the open-source approach is well suited for the Flight Dynamics field and that putting down some fences and sharing the code is a key feature for the success of such a library. I. Traditional architecture light Dynamics systems are an essential part of ground systems for space applications, just like those many other essential parts as control center, mission center, tracking stations … Two main architectures have been used in ground systems. The first one considers Flight Dynamics as a self-contained subsystem exchanging data with control center (AOCS and propulsion telemetry, maneuvers commands …), mission center (ephemeris, operational forecasts, visibilities …) and tracking station (localization measurements, pointing data). The second one embed Flight Dynamics within the control center, which acts partly as a data gateway with the other systems. In neither case is Flight Dynamics tightly integrated with the other parts. A general interface is used to shield all computation programs from the rest of the ground system. F

Peter H. Zipfel - One of the best experts on this subject based on the ideXlab platform.

  • Tensors of Rank Two in Tensor Flight Dynamics
    2018
    Co-Authors: Peter H. Zipfel
    Abstract:

    Tensor Flight Dynamics solves Flight Dynamics problems using Cartesian tensors, which are invariant under coordinate transformations, rather than Gibbs’ vectors, which change under time-varying transformations. Three tensors of rank two play a prominent role and are the subject of this paper: moment of inertia, rotation, and angular velocity tensor. A new theorem is proven governing the shift of reference frames, which is used to derive the angular velocity tensor from the rotation tensor. As applications, the general strap-down INS equations are derived, and the effect of the time-rate-of-change of the moment of inertia tensor on missile Dynamics is investigated.

  • The Covariance Principle Applied to Flight Dynamics
    2018
    Co-Authors: Peter H. Zipfel
    Abstract:

    Flight Dynamics is rooted in classical Newtonian Dynamics. We all grew up with Newton’s Second Law, which states that force equals mass times acceleration, and were told that it holds in this form only in inertial coordinates. No doubt, Newton’s law is a fundamental law of physics. Then Einstein introduced the Covariance Principle: “All physical laws are invariant under all coordinate transformations” , which is central to his special and general theories of relativity. Did he contradict Newton? No, he always insisted that Newton’s laws are a subset of his theories. So there must be a formulation of Newton’s second law that abides by the Covariance Principle. This paper retraces the steps that led to the formulation of Newton’s Second Law satisfying Einstein’s Covariance Principle; i.e., Newton’s Second Law maintains the same form under all, even time-dependent, coordinate transformations. The consequences for Flight Dynamics are far reaching. In particular, the modeling and simulation of aerospace vehicles is streamlined by separating the dynamic modeling from the coding of the mathematical equations. Tensors—invariant under coordinate transformations—model the Dynamics, and, after introduction of coordinate systems, are converted to matrices for computer programming. This two-step approach is called Tensor Flight Dynamics . Two new concepts make Newtonian Dynamics compatible with the Covariance Principle: the rotational time derivative and the Euler transformation . A general time operator replaces the ordinary time derivative, and the Euler transformation enables the shifting of reference frames. Both concepts were derived from general space and time properties. The introduction of tensor Flight Dynamics goes back to the early seventies. It was first applied to rotating bodies, called Magnus rotors. Then it entered the mainstream of Flight Dynamics of missiles, aircraft, hypersonic vehicles, and rocket boosters. Today, the object oriented nature of tensor Flight Dynamics has been combined with the object oriented computer language C++ to model and simulate ever more complex aerospace systems. This paper also presents some new, unpublished results. Up to now, the Euler transformation applied only to tensors of rank one. A new theorem extends it to tensors of rank two and is applied to the rotation tensor and the moment-of-inertia tensor of Flight vehicles. With the help of this new Euler transformation the fundamental equations of the strap-down INS are derived, and the effect of the time-variable moment-of-inertia on a short-range air-to-air missile is investigated. Some organizations have adopted the new paradigm of tensor Flight Dynamics, while others remain with the time=tested vector Flight Dynamics. As M&S of aerospace vehicles becomes more complex, the object oriented approach of tensor Flight Dynamics will gain wider acceptance out of necessity.

  • Tensor Flight Dynamics
    AIAA Atmospheric Flight Mechanics Conference, 2011
    Co-Authors: Peter H. Zipfel
    Abstract:

    Tensor Flight Dynamics models Flight Dynamics with Cartesian tensors that are invariant under all coordinate transformations, even time dependent transformations. It elevates Newton’s Second Law to a law that is not only invariant under inertial coordinate transformations, but under all transformations, thus bringing Newtonian mechanics under the umbrella of Einstein’s General Relativity. Its roots go back to the late 1960’s and a paper that was presented at the Second Atmospheric Flight Mechanics Conference in 1972. The Atmospheric Flight Mechanics Committee has selected that paper as most influential for Flight Dynamics of that period. This paper reviews the history and introduces the kinematic and dynamic concepts. The Special and General Theories of Relativity are briefly highlighted with two of Einstein’s favorite examples, and their consequences for classical mechanics are discussed. Recent applications of tensor Flight Dynamics are summarized.

Luiz Carlos Sandoval Góes - One of the best experts on this subject based on the ideXlab platform.

  • Flight Dynamics modeling of a flexible wing unmanned aerial vehicle
    Mechanical Systems and Signal Processing, 2020
    Co-Authors: D.f. Castillo Zúñiga, Alain Souza, Luiz Carlos Sandoval Góes
    Abstract:

    Abstract This paper shows the results of traditional aerodynamic analysis and the flexible Flight Dynamics modeling including the effects of structural motion for a flexible wing unmanned aerial vehicle. The influence of some design parameters such as wing flexibility, horizontal/vertical tail aeroDynamics is investigated for aeroelasticity and Flight Dynamics of flexible aircraft. The research platform is an Unmanned Aerial Vehicle (UAV), made of composite material. Its wing span is 4 m and reaches a high aspect ratio, whose value is 18.9. For a traditional analysis, the Vortex Lattice Method (VLM) was used to obtain conventional aerodynamic and control derivatives. The flexible Flight Dynamics model is based on the work of Waszack and Schmidt. In this approach, it is used the mean-axes reference system and it is assumed that structural deformations is small and described by a set of eigenmodes. The Dynamics model incorporates the first normal modes obtained by Ground Vibration Test (GVT) campaigns. A focus of the paper lies on providing a useful model for Dynamics system identification and in-Flight aeroelastic testing. A developed platform for in-Flight system identification and the acquisition system is described. A Flight path reconstruction process from a Flight test campaign results is shown.

Luc Maisonobe - One of the best experts on this subject based on the ideXlab platform.

  • Sharing the Knowledge: An Open-Source Vision for Flight Dynamics
    SpaceOps 2010 Conference, 2010
    Co-Authors: Luc Maisonobe, Christine Fernandez-martin
    Abstract:

    Flight Dynamics systems have long been considered to be restricted fields inhabited by strange people performing highly complex computation on specific computers with specific languages. These systems did not really embed smoothly with the rest of the ground system. They use their own frameworks, their own GUI, their own database, and are often triggered either manually on dedicated computers or using very low level mechanisms like files dropped in shared folders or scripts wrappers. These systems are costly to maintain and clearly don't scale to today's needs with more demanding space missions and tighter schedules. The use of old technology implies skilled engineers are difficult to find and the few available have high hourly cost. Lots of work is to be done on interfaces because none of the new features brought by web technology is ever used. This paper shows a different approach for Flight Dynamics systems. It explains there is no reason such systems could not benefit from the current technology. The new development paradigms are mature and well known. They have proven useful on many critical fields and a tremendous offer of tools allows to improve code quality, testing, validation, traceability ... The open-source approach has also been time tested by now and is accepted for its unique features in critical systems and when long term maintenance are needed. The Orekit library (http://www.orekit.org/) is an implementation of these ideas. It is an open-source library freely available with a businessfriendly license and using state of the art models and technology. It demonstrates high performance operational products can be embedded in modern control centers to smoothly integrate complex Flight Dynamics functions right within the system. The project also shows the open-source approach is well suited for the Flight Dynamics field and that putting down some fences and sharing the code is a key feature for the success of such a library.

  • an open-source vision for Flight Dynamics
    2010
    Co-Authors: Luc Maisonobe, Christine Fernandez-martin
    Abstract:

    Flight Dynamics systems have long been considered to be restricted fields inhabited by strange people performing highly complex computation on specific computers with specific languages. These systems did not really embed smoothly with the rest of the ground system. They use their own frameworks, their own GUI, their own database, and are often triggered either manually on dedicated computers or using very low level mechanisms like files dropped in shared folders or scripts wrappers. These systems are costly to maintain and clearly don't scale to today's needs with more demanding space missions and tighter schedules. The use of old technology implies skilled engineers are difficult to find and the few available have high hourly cost. Lots of work is to be done on interfaces because none of the new features brought by web technology is ever used. This paper shows a different approach for Flight Dynamics systems. It explains there is no reason such systems could not benefit from the current technology. The new development paradigms are mature and well known. They have proven useful on many critical fields and a tremendous offer of tools allows to improve code quality, testing, validation, traceability ... The open-source approach has also been time tested by now and is accepted for its unique features in critical systems and when long term maintenance are needed. The Orekit library (http://www.orekit.org/) is an implementation of these ideas. It is an open-source library freely available with a businessfriendly license and using state of the art models and technology. It demonstrates high performance operational products can be embedded in modern control centers to smoothly integrate complex Flight Dynamics functions right within the system. The project also shows the open-source approach is well suited for the Flight Dynamics field and that putting down some fences and sharing the code is a key feature for the success of such a library. I. Traditional architecture light Dynamics systems are an essential part of ground systems for space applications, just like those many other essential parts as control center, mission center, tracking stations … Two main architectures have been used in ground systems. The first one considers Flight Dynamics as a self-contained subsystem exchanging data with control center (AOCS and propulsion telemetry, maneuvers commands …), mission center (ephemeris, operational forecasts, visibilities …) and tracking station (localization measurements, pointing data). The second one embed Flight Dynamics within the control center, which acts partly as a data gateway with the other systems. In neither case is Flight Dynamics tightly integrated with the other parts. A general interface is used to shield all computation programs from the rest of the ground system. F

Karen Northon - One of the best experts on this subject based on the ideXlab platform.