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Design of Optimal Controllers for Spacecraft Formation Flying based on the Decentralized Approach
Jonghee Bae,Youdan Kim 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10
Formation controller for multiple spacecrafts is designed based on a decentralized approach. The objective of the proposed controller is to make each spacecraft fly to the desired waypoints, while keeping the formation shape of multiple spacecrafts. To design the decentralized formation controller, the output feedback linearization technique using error functions for goal convergence and formation keeping is utilized for spacecraft dynamics. The primary contribution of this paper is to propose optimal controller for formation flying based on the decentralized approach. To design the optimal controller, eigenvalue assignment technique is used. To verify the effectiveness of the proposed controller, numerical simulations are performed for three-dimensional waypoint-passing missions of multiple spacecrafts.
Spacecraft Formation Reconfiguration using Impulsive Control Input
Jonghee Bae,Youdan Kim 한국항공우주학회 2013 International Journal of Aeronautical and Space Sc Vol.14 No.2
This paper presents formation reconfiguration using impulsive control input for spacecraft formation flying. Spacecraft in a formation should change the formation size and/or geometry according to the mission requirements and space environment. To modify the formation radius and geometry with respect to the leader spacecraft, the follower spacecraft generates additional control inputs; the two impulsive control inputs are general control type of the spacecraft system. For the impulsive control input, Lambert’s problem is modified to construct the transfer orbit in relative motion, given two position vectors at the initial and final time. Moreover, the numerical simulation results show the transfer trajectories to resize the formation radius in the radial/along-track plane formation and in the along-track/cross-track plane formation. In addition, the maneuver characteristics are described by comparing the differential orbital elements between the reference orbit and transfer orbit in the radial/along-track plane formation and along-track/cross-track plane formation.
Nonlinear Estimation for Spacecraft Attitude using Decentralized Unscented Information Filter
Jonghee Bae,Youdan Kim 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10
This paper presents a spacecraft attitude estimation algorithm using the unscented information filter. The objective of the proposed algorithm is to make the spacecraft attitude accurately estimate with low computational load. The main contribution of this study is to derive the unscented information filter for nonlinear spacecraft attitude dynamics and multiple sensor systems. For the multiple sensor estimation, the decentralized unscented information filter is used in this study. This filter provides accurate attitude estimation from the unscented filtering and less computational time from the information filtering. To verify the effectiveness of the proposed decentralized unscented information filter algorithm, numerical simulations are performed for a spacecraft system with three gyroscopes.
Design of Optimal Controllers for Spacecraft Formation Flying Based on the Decentralized Approach
Jonghee Bae,Youdan Kim 한국항공우주학회 2009 International Journal of Aeronautical and Space Sc Vol.10 No.1
Formation controller for multiple spacecrafts is designed based on a decentralized approach. The objective of the proposed controller is to make each spacecraft fly to the desired waypoints, while keeping the formation shape of multiple spacecrafts. To design the decentralized formation controller, the output feedback linearization technique using error functions for goal convergence and formation keeping is utilized for spacecraft dynamics. The primary contribution of this paper is to proposed optimal controller for formation flying based on the decentralized approach. To design the optimal controller, eigenvalue assignment technique is used. To verify the effectiveness of the proposed controller, numerical simulations are performed for three-dimensional waypoint-passing missions of multiple spacecrafts.
Attitude Estimation for Satellite Fault Tolerant System Using Federated Unscented Kalman Filter
Jonghee Bae,Youdan Kim 한국항공우주학회 2010 International Journal of Aeronautical and Space Sc Vol.11 No.2
We propose a spacecraft attitude estimation algorithm using a federated unscented Kalman filter. For nonlinear spacecraft systems, the unscented Kalman filter provides better performance than the extended Kalman filter. Also, the decentralized scheme in the federated configuration makes a robust system because a sensor fault can be easily detected and isolated by the fault detection and isolation algorithm through a sensitivity factor. Using the proposed algorithm, the spacecraft can continuously perform a given mission despite navigation sensor faults. Numerical simulation is performed to verify the performance of the proposed attitude estimation algorithm.
Bae, Jonghee,Kim, Youdan Elsevier 2012 Journal of the Franklin Institute Vol.349 No.2
<P><B>Abstract</B></P><P>A spacecraft formation flying controller is designed using a sliding mode control scheme with the adaptive gain and neural networks. Six-degree-of-freedom spacecraft nonlinear dynamic model is considered, and a leader–follower approach is adopted for efficient spacecraft formation flying. Uncertainties and external disturbances have effects on controlling the relative position and attitude of the spacecrafts in the formation. The main benefit of the sliding mode control is the robust stability of the closed-loop system. To improve the performance of the sliding mode control, an adaptive controller based on neural networks is used to compensate for the effects of the modeling error, external disturbance, and nonlinearities. The stability analysis of the closed-loop system is performed using the Lyapunov stability theorem. A spacecraft model with 12 thrusts as actuators is considered for controlling the relative position and attitude of the follower spacecraft. Numerical simulation results are presented to show the effectiveness of the proposed controller.</P>
Spacecraft Formation Reconfiguration using Impulsive Control Input
Bae, Jonghee,Kim, Youdan The Korean Society for Aeronautical and Space Scie 2013 International Journal of Aeronautical and Space Sc Vol.14 No.2
This paper presents formation reconfiguration using impulsive control input for spacecraft formation flying. Spacecraft in a formation should change the formation size and/or geometry according to the mission requirements and space environment. To modify the formation radius and geometry with respect to the leader spacecraft, the follower spacecraft generates additional control inputs; the two impulsive control inputs are general control type of the spacecraft system. For the impulsive control input, Lambert's problem is modified to construct the transfer orbit in relative motion, given two position vectors at the initial and final time. Moreover, the numerical simulation results show the transfer trajectories to resize the formation radius in the radial/along-track plane formation and in the along-track/cross-track plane formation. In addition, the maneuver characteristics are described by comparing the differential orbital elements between the reference orbit and transfer orbit in the radial/along-track plane formation and along-track/cross-track plane formation.
Initial Error Dispersion and Midcourse Correction Maneuver Analysis of the Lunar Orbiter
Jonghee Bae,송영주,Young-Rok Kim,Bang-Yeop Kim 한국항공우주학회 2018 International Journal of Aeronautical and Space Sc Vol.19 No.4
The preliminary error analysis is performed to design the midcourse correction (MCC) maneuver of the lunar orbiter. During the trans-lunar trajectory, the lunar orbiter will perform several MCC maneuvers using the on-board propulsion system. The objectives of these maneuvers are to remove the deviation from the nominal trajectory by the injection error of the launch vehicle and to achieve the high accuracy for the lunar orbit insertion (LOI). To design the MCC maneuver, it is required to analyze the dispersion of the trans-lunar injection (TLI) error from the launch vehicle. In addition, the MCC maneuver epoch is also considered to design the MCC maneuver, which is an essential factor to analyze the MCC maneuver. To investigate the effects of the TLI uncertainty and the MCC maneuver epoch on the MCC maneuver, the Monte Carlo simulation is performed for the statistical analysis. The numerical simulation results and analysis provide a guideline to design the trans-lunar trajectory using the MCC maneuver in the presence of various error sources in the preliminary design phase.