The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
A T Alouani - One of the best experts on this subject based on the ideXlab platform.
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lqg ltr Pitch Attitude control of an earth orbiting spacecraft
Conference on Decision and Control, 1993Co-Authors: T Lahdhiri, A T AlouaniAbstract:The control of Pitch Attitude and Pitch momentum of an Earth-orbiting spacecraft is considered in this paper. The control approach uses loop shaping techniques based on the linear quadratic-Gaussian and the loop transfer recovery (LQG/LTR) methodology. Attitude is measured by an Earth horizon sensor and control torque is produced by magnetic torquer bars and a Pitch momentum. The controller must achieve good tracking, environmental disturbance rejection, and robustness to modeling errors. Loop shaping filters are used so that the roll and yaw magnetic torquer bars control Pitch Attitude at low frequency, while the Pitch wheel controls Pitch Attitude at high frequency. The controller design and the simulation results are presented and discussed. >
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LQG/LTR Pitch Attitude control of an earth-orbiting spacecraft
Proceedings of 32nd IEEE Conference on Decision and Control, 1993Co-Authors: T Lahdhiri, A T AlouaniAbstract:The control of Pitch Attitude and Pitch momentum of an Earth-orbiting spacecraft is considered in this paper. The control approach uses loop shaping techniques based on the linear quadratic-Gaussian and the loop transfer recovery (LQG/LTR) methodology. Attitude is measured by an Earth horizon sensor and control torque is produced by magnetic torquer bars and a Pitch momentum. The controller must achieve good tracking, environmental disturbance rejection, and robustness to modeling errors. Loop shaping filters are used so that the roll and yaw magnetic torquer bars control Pitch Attitude at low frequency, while the Pitch wheel controls Pitch Attitude at high frequency. The controller design and the simulation results are presented and discussed. >
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LQG/LTR spacecraft Attitude control
1993 (25th) Southeastern Symposium on System Theory, 1993Co-Authors: T Lahdhiri, A T AlouaniAbstract:The control of Pitch Attitude and Pitch momentum of an Earth-orbiting spacecraft using loop-shaping techniques based on the linear-quadratic-Gaussian/loop-transfer-recovery (LQG/LTR) methodology is considered. Attitude is measured by an Earth horizon sensor, and control torque is produced by magnetic torquer bars and a Pitch momentum or reaction wheel. The controller must achieve good tracking, environmental disturbance rejection, and robustness to modeling errors. Loop-shaping filters are used so that the roll and yaw magnetic torquer bars control Pitch Attitude at low frequency, while the Pitch wheel controls Pitch Attitude at high frequency. The controller design and the simulation results are presented and discussed.
Valery D Yurkevich - One of the best experts on this subject based on the ideXlab platform.
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aircraft Pitch Attitude adaptive control via singular perturbation technique
Progress in Flight Dynamics Guidance Navigation Control Fault Detection and Avionics, 2013Co-Authors: Valery D YurkevichAbstract:The problem of aircraft Pitch Attitude control is treated in the presence of uncertain aerodynamics. The proposed design methodology guarantees desired Pitch Attitude transient performance indices by inducing of two-time-scale motions in the closed-loop system where the controller dynamics is a singular perturbation with respect to the system dynamics. The singular perturbation method is used in order to get explicit expressions for evaluation of the controller parameters. Stability of fast-motion transients for a large range of aerodynamic characteristics variations is maintained due to a high-frequency-gain online identi¦cation and gain tuning that are incorporated in the control loop. Numerical example and simulation results are presented.
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PID Adaptive Control Design Based on Singular Perturbation Technique: A Flight Control Example
2011Co-Authors: Valery D YurkevichAbstract:The paper treats a question of proportional-integral-derivative (PID) controller design for aircraft Pitch Attitude in the presence of uncertain aerodynamics. The presented design methodology guarantees desired Pitch Attitude transient performance indices by inducing of two-time-scale motions in the closed-loop system where the controller dynamics is a singular perturbation with respect to the system dynamics. Stability conditions imposed on the fast and slow modes and sufficiently large mode separation rate between fast and slow modes can ensure that the full-order closed-loop nonlinear system achieves the desired properties in such a way that the Pitch Attitude transient performances are desired and insensitive to external disturbances and variations of aerodynamic characteristics. The singular perturbation method is used throughout the paper in order to get explicit expressions for evaluation of the controller parameters. The high-frequency-gain online identification and gain tuning are incorporated in the control loop in order to maintain the stability of the fast-motion transients for a large range of aerodynamic characteristics variations. Numerical example and simulation results are presented.
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aircraft Pitch Attitude control in presence of uncertain aerodynamics
Proceedings. The 9th Russian-Korean International Symposium on Science and Technology 2005. KORUS 2005., 2005Co-Authors: Valery D YurkevichAbstract:The problem of aircraft Pitch Attitude control with guaranteed transient performances in the presence of uncertain aerodynamics is discussed. The fast dynamical controller with the relative highest derivative of aircraft Pitch Attitude in feedback loop is used. Consequently, two-time-scale motions are induced in the closed-loop system and the method of singular perturbation is used to analyze the closed-loop system properties. Stability conditions imposed on the fast and slow modes and sufficiently large mode separation rate can ensure that the full-order closed-loop system achieves the desired properties in such a way that the aircraft Pitch Attitude transient performances are desired and insensitive to external disturbances and variations of aerodynamics properties. The circle criterion is used to ensure the absolute stability of the fast motions in the presence of uncertain aerodynamics.
T Lahdhiri - One of the best experts on this subject based on the ideXlab platform.
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lqg ltr Pitch Attitude control of an earth orbiting spacecraft
Conference on Decision and Control, 1993Co-Authors: T Lahdhiri, A T AlouaniAbstract:The control of Pitch Attitude and Pitch momentum of an Earth-orbiting spacecraft is considered in this paper. The control approach uses loop shaping techniques based on the linear quadratic-Gaussian and the loop transfer recovery (LQG/LTR) methodology. Attitude is measured by an Earth horizon sensor and control torque is produced by magnetic torquer bars and a Pitch momentum. The controller must achieve good tracking, environmental disturbance rejection, and robustness to modeling errors. Loop shaping filters are used so that the roll and yaw magnetic torquer bars control Pitch Attitude at low frequency, while the Pitch wheel controls Pitch Attitude at high frequency. The controller design and the simulation results are presented and discussed. >
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LQG/LTR Pitch Attitude control of an earth-orbiting spacecraft
Proceedings of 32nd IEEE Conference on Decision and Control, 1993Co-Authors: T Lahdhiri, A T AlouaniAbstract:The control of Pitch Attitude and Pitch momentum of an Earth-orbiting spacecraft is considered in this paper. The control approach uses loop shaping techniques based on the linear quadratic-Gaussian and the loop transfer recovery (LQG/LTR) methodology. Attitude is measured by an Earth horizon sensor and control torque is produced by magnetic torquer bars and a Pitch momentum. The controller must achieve good tracking, environmental disturbance rejection, and robustness to modeling errors. Loop shaping filters are used so that the roll and yaw magnetic torquer bars control Pitch Attitude at low frequency, while the Pitch wheel controls Pitch Attitude at high frequency. The controller design and the simulation results are presented and discussed. >
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LQG/LTR spacecraft Attitude control
1993 (25th) Southeastern Symposium on System Theory, 1993Co-Authors: T Lahdhiri, A T AlouaniAbstract:The control of Pitch Attitude and Pitch momentum of an Earth-orbiting spacecraft using loop-shaping techniques based on the linear-quadratic-Gaussian/loop-transfer-recovery (LQG/LTR) methodology is considered. Attitude is measured by an Earth horizon sensor, and control torque is produced by magnetic torquer bars and a Pitch momentum or reaction wheel. The controller must achieve good tracking, environmental disturbance rejection, and robustness to modeling errors. Loop-shaping filters are used so that the roll and yaw magnetic torquer bars control Pitch Attitude at low frequency, while the Pitch wheel controls Pitch Attitude at high frequency. The controller design and the simulation results are presented and discussed.
Akira Iwasaki - One of the best experts on this subject based on the ideXlab platform.
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estimation of satellite Pitch Attitude from aster image data
International Geoscience and Remote Sensing Symposium, 2010Co-Authors: Tetsuya Okuda, Akira IwasakiAbstract:In this study, we demonstrate an automatic methodology for estimating the satellite Pitch vibration by using information of sensors with small parallax and correcting the images taken by the sensors themselves. Consequently, We can get corrected digital elevation model (DEM) from the images disturbed by satellite Pitch vibration. A satellite often vibrates in roll and Pitch directions, and each component has a bad influence on photogrammetry. Since the Pitch component directly deteriorates the accuracy of DEM in case of along-track stereo sensor, we focus on estimating and correcting Pitch vibration. Our methodology is particularly useful for small parallax stereo system, because sub-pixel image matching precision is needed for small parallax stereo system and satellite vibration causes a critical problem.
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IGARSS - Estimation of satellite Pitch Attitude from aster image data
2010 IEEE International Geoscience and Remote Sensing Symposium, 2010Co-Authors: Tetsuya Okuda, Akira IwasakiAbstract:In this study, we demonstrate an automatic methodology for estimating the satellite Pitch vibration by using information of sensors with small parallax and correcting the images taken by the sensors themselves. Consequently, We can get corrected digital elevation model (DEM) from the images disturbed by satellite Pitch vibration. A satellite often vibrates in roll and Pitch directions, and each component has a bad influence on photogrammetry. Since the Pitch component directly deteriorates the accuracy of DEM in case of along-track stereo sensor, we focus on estimating and correcting Pitch vibration. Our methodology is particularly useful for small parallax stereo system, because sub-pixel image matching precision is needed for small parallax stereo system and satellite vibration causes a critical problem.
Sahjendra N Singh - One of the best experts on this subject based on the ideXlab platform.
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Feedback linearization and solar pressure satellite Attitude control
IEEE Transactions on Aerospace and Electronic Systems, 1996Co-Authors: Sahjendra N SinghAbstract:The question of large angle Pitch Attitude maneuver of satellites using solar radiation pressure is considered. For Pitch axis maneuver, two highly reflective control surfaces are used to generate radiation moment. Based on dynamic feedback linearization, a nonlinear control law is derived for large Pitch Attitude control. In the closed-loop system, the response characteristics of the Pitch angle are governed by a fourth-order linear differential equation. Robustness of control system is obtained by the integral error feedback. Simulation results are presented to show that in the closed-loop system, Attitude control of the satellite is accomplished in spite of the parameter uncertainty in the system.
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dynamic feedback linearization and large Pitch Attitude control of satellite using solar radiation pressure
Advances in Computing and Communications, 1995Co-Authors: Sahjendra N SinghAbstract:The question of large angle Pitch Attitude maneuver of satellites using solar radiation pressure is considered. For Pitch axis maneuver, two highly reflective control surfaces are used to generate radiation moment. Based on dynamic feedback linearization, a nonlinear control law is derived for large Pitch Attitude control. In the closed-loop system, the response characteristics of the Pitch angle are governed by a fourth order linear differential equation. Robustness of control system is obtained by the integral error feedback. Simulation results are presented to show that in the closed-loop system, Attitude control of the satellite is accomplished in spite of the parameter uncertainty in the system.