Jean de Lafontaine - Academia.edu (original) (raw)
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Papers by Jean de Lafontaine
IFAC Proceedings Volumes, 1992
Acta Astronautica, Dec 1, 2008
Previous work on autonomous formation flying guidance and control identified three key challenges... more Previous work on autonomous formation flying guidance and control identified three key challenges to overcome in order to obtain a fully autonomous guidance and control loop: an accurate but simple model of relative motion about elliptical and perturbed orbits, an efficient way of performing conflicting requirements trade-off with power-limited on-board computers, and finally an optimal or near-optimal control algorithm easy to implement on a flight computer. This paper first summarizes recent developments on each of these subject that help to overcome these challenges, developments which are then used as building blocks for an autonomous formation flying guidance and control system. This system autonomously performs trade-offs between conflicting requirements, i.e. minimization of fuel cost, formation accuracy and equal repartition of the fuel expenditure within the formation. Simulation results show that a complete guidance and control loop can be established using mainly analytical results and with very few numerical optimization which facilitates on-board implementation.
AIAA Guidance, Navigation, and Control Conference and Exhibit, Jun 15, 2006
This paper proposes four guidance laws aimed at reducing the most significant sources of landing ... more This paper proposes four guidance laws aimed at reducing the most significant sources of landing dispersion during atmospheric entry at Mars. The autonomous guidance algorithms rely on simple analytic and semi-analytic solutions that prescribe segments of constantflightpath angles (FPA's) that match the trajectory constraints in terms of desired final altitude, velocity and downrange. Two one-segment solutions and two two-segment solutions are presented. A nonlinear dynamic inversion of the translational dynamics and a robust attitude controller, designed with the Robust Modal Control technique, complete the guidance and control system whose performance is demonstrated through numerical simulations of a Mars entry scenario.
The Rosetta/Comet Nucleus Sample Return (CNSR) mission is described in terms of scenario, spacecr... more The Rosetta/Comet Nucleus Sample Return (CNSR) mission is described in terms of scenario, spacecraft concept, comet approach, sampling, return to Earth and Earth approach and re-entry phase. The preparatory program of ESA and NASA to provide new technologies is discussed. The prime scientific objective is to return a comet nucleus sample to Earth while preserving such fundamental properties as: the chemical and isotopic composition of the individual molecular species of remaining volatile compounds; the chemical, isotopic and structural state of the individual phases and crystals constituting higher temperature condensates and aggregates; and the preservation of complex hydrocarbon compounds and their aggregates. The sample will allow the study of the most primitive material in the solar system and the physical and chemical processes that marked the system's beginning, and hopefully will establish correspondence between interstellar matter, cometary material and primitive meteo...
IFAC Proceedings Volumes, 2004
Thanks to real-p,-analysis, the (p"Mu)-iteration generalizes the discrete multi-model approach to... more Thanks to real-p,-analysis, the (p"Mu)-iteration generalizes the discrete multi-model approach to a continuum of models, represented by LFT. The present paper proposes and explains how to generalize the (p"Mu)-iteration to take into account robust performance requirements rather than stability. Moreover, it illustrates the advantages of this approach by applying it to reduction, structuration and performance robustness improvement of a high-order controller designed for flexible aircraft robust control.
AIAA Guidance, Navigation, and Control Conference and Exhibit, 2005
AIAA Guidance, Navigation and Control Conference and Exhibit, 2008
In an effort to bridge the gap between software simulation and expensive full-scale hardware-in-t... more In an effort to bridge the gap between software simulation and expensive full-scale hardware-in-the-loop tests, an innovative Landing Dynamic Test Facility was designed and built. This facility reproduces landing trajectories in a lab environment using an industrial robot mounted on a linear rail. The facility was originally designed to validate a Lidar-based autonomous guidance, navigation and control system for Mars landing. However, its time and spatial scaling capabilities make it compatible with a variety of celestial bodies (Moon, asteroids, etc.) and sensors (e.g. camera). This paper presents the design of the facility as well as examples of its use in particular landing applications.
Journal of Guidance Control and Dynamics, May 23, 2012
Canadian Aeronautics and Space Journal, Mar 1, 2003
Journal of Guidance Control and Dynamics, 2007
ABSTRACT A linearized set of equations of relative motion about a J2,-perturbed elliptical refere... more ABSTRACT A linearized set of equations of relative motion about a J2,-perturbed elliptical reference orbit is developed. This model uses analytical relations that are well suited for onboard applications. The inclusion oftheJ2 perturbation in a simple analytical model can lead to formation flying guidance and control algorithms that make use ofthe naturaIJ2induced relative motion to perform maneuvers instead of constantly compensating for this perturbation. The model uses the linearized differential drift rate of mean orbit elements to predict the impact of the J2 perturbation on relative osculating spacecraft motion. tt analytically provides the relative motion in Hill coordinates at any given true anomaly using only the initial osculating relative orbit elements and the initial orbit elements of the reference trajectory. A linear time-varying state-space form of the model is also presented. Simulation results show that relative motion prediction remains accurate over several orbits.
Journal of Guidance Control and Dynamics, 2007
ABSTRACT
The PROBA-2 spacecraft is the second spacecraft designed in the context of the PRoject for On-Boa... more The PROBA-2 spacecraft is the second spacecraft designed in the context of the PRoject for On-Board Autonomy (PROBA) programme supported by the European Space Agency (ESA). Building on the ongoing success of PROBA-1, PROBA-2 will continue the in-flight demonstration of on-board autonomy by performing a Sun observation mission along with many flight and hardware experiments. Now that the Final Acceptance Review (FAR) of the Attitude and Orbit Control System (AOCS) has been completed, this paper will focus on the test activities that were conducted to qualify the software for flight and on some critical test results that were obtained.
Journal of the Astronautical Sciences
ABSTRACT
IFAC Proceedings Volumes, 1992
Acta Astronautica, Dec 1, 2008
Previous work on autonomous formation flying guidance and control identified three key challenges... more Previous work on autonomous formation flying guidance and control identified three key challenges to overcome in order to obtain a fully autonomous guidance and control loop: an accurate but simple model of relative motion about elliptical and perturbed orbits, an efficient way of performing conflicting requirements trade-off with power-limited on-board computers, and finally an optimal or near-optimal control algorithm easy to implement on a flight computer. This paper first summarizes recent developments on each of these subject that help to overcome these challenges, developments which are then used as building blocks for an autonomous formation flying guidance and control system. This system autonomously performs trade-offs between conflicting requirements, i.e. minimization of fuel cost, formation accuracy and equal repartition of the fuel expenditure within the formation. Simulation results show that a complete guidance and control loop can be established using mainly analytical results and with very few numerical optimization which facilitates on-board implementation.
AIAA Guidance, Navigation, and Control Conference and Exhibit, Jun 15, 2006
This paper proposes four guidance laws aimed at reducing the most significant sources of landing ... more This paper proposes four guidance laws aimed at reducing the most significant sources of landing dispersion during atmospheric entry at Mars. The autonomous guidance algorithms rely on simple analytic and semi-analytic solutions that prescribe segments of constantflightpath angles (FPA's) that match the trajectory constraints in terms of desired final altitude, velocity and downrange. Two one-segment solutions and two two-segment solutions are presented. A nonlinear dynamic inversion of the translational dynamics and a robust attitude controller, designed with the Robust Modal Control technique, complete the guidance and control system whose performance is demonstrated through numerical simulations of a Mars entry scenario.
The Rosetta/Comet Nucleus Sample Return (CNSR) mission is described in terms of scenario, spacecr... more The Rosetta/Comet Nucleus Sample Return (CNSR) mission is described in terms of scenario, spacecraft concept, comet approach, sampling, return to Earth and Earth approach and re-entry phase. The preparatory program of ESA and NASA to provide new technologies is discussed. The prime scientific objective is to return a comet nucleus sample to Earth while preserving such fundamental properties as: the chemical and isotopic composition of the individual molecular species of remaining volatile compounds; the chemical, isotopic and structural state of the individual phases and crystals constituting higher temperature condensates and aggregates; and the preservation of complex hydrocarbon compounds and their aggregates. The sample will allow the study of the most primitive material in the solar system and the physical and chemical processes that marked the system's beginning, and hopefully will establish correspondence between interstellar matter, cometary material and primitive meteo...
IFAC Proceedings Volumes, 2004
Thanks to real-p,-analysis, the (p"Mu)-iteration generalizes the discrete multi-model approach to... more Thanks to real-p,-analysis, the (p"Mu)-iteration generalizes the discrete multi-model approach to a continuum of models, represented by LFT. The present paper proposes and explains how to generalize the (p"Mu)-iteration to take into account robust performance requirements rather than stability. Moreover, it illustrates the advantages of this approach by applying it to reduction, structuration and performance robustness improvement of a high-order controller designed for flexible aircraft robust control.
AIAA Guidance, Navigation, and Control Conference and Exhibit, 2005
AIAA Guidance, Navigation and Control Conference and Exhibit, 2008
In an effort to bridge the gap between software simulation and expensive full-scale hardware-in-t... more In an effort to bridge the gap between software simulation and expensive full-scale hardware-in-the-loop tests, an innovative Landing Dynamic Test Facility was designed and built. This facility reproduces landing trajectories in a lab environment using an industrial robot mounted on a linear rail. The facility was originally designed to validate a Lidar-based autonomous guidance, navigation and control system for Mars landing. However, its time and spatial scaling capabilities make it compatible with a variety of celestial bodies (Moon, asteroids, etc.) and sensors (e.g. camera). This paper presents the design of the facility as well as examples of its use in particular landing applications.
Journal of Guidance Control and Dynamics, May 23, 2012
Canadian Aeronautics and Space Journal, Mar 1, 2003
Journal of Guidance Control and Dynamics, 2007
ABSTRACT A linearized set of equations of relative motion about a J2,-perturbed elliptical refere... more ABSTRACT A linearized set of equations of relative motion about a J2,-perturbed elliptical reference orbit is developed. This model uses analytical relations that are well suited for onboard applications. The inclusion oftheJ2 perturbation in a simple analytical model can lead to formation flying guidance and control algorithms that make use ofthe naturaIJ2induced relative motion to perform maneuvers instead of constantly compensating for this perturbation. The model uses the linearized differential drift rate of mean orbit elements to predict the impact of the J2 perturbation on relative osculating spacecraft motion. tt analytically provides the relative motion in Hill coordinates at any given true anomaly using only the initial osculating relative orbit elements and the initial orbit elements of the reference trajectory. A linear time-varying state-space form of the model is also presented. Simulation results show that relative motion prediction remains accurate over several orbits.
Journal of Guidance Control and Dynamics, 2007
ABSTRACT
The PROBA-2 spacecraft is the second spacecraft designed in the context of the PRoject for On-Boa... more The PROBA-2 spacecraft is the second spacecraft designed in the context of the PRoject for On-Board Autonomy (PROBA) programme supported by the European Space Agency (ESA). Building on the ongoing success of PROBA-1, PROBA-2 will continue the in-flight demonstration of on-board autonomy by performing a Sun observation mission along with many flight and hardware experiments. Now that the Final Acceptance Review (FAR) of the Attitude and Orbit Control System (AOCS) has been completed, this paper will focus on the test activities that were conducted to qualify the software for flight and on some critical test results that were obtained.
Journal of the Astronautical Sciences
ABSTRACT