Formation flying is a novel concept of distributing the functionality of large spacecraft among several smaller, less expensive, cooperative satellites. Some applications require that a controllable satellite keeps re...Formation flying is a novel concept of distributing the functionality of large spacecraft among several smaller, less expensive, cooperative satellites. Some applications require that a controllable satellite keeps relative position and attitude to observe a specific surface of another satellite among the cluster. Specially, the target space vehicle is malfunctioning. The present paper focuses on the problem that how to control a chaser satellite to fly around an out-of-work target satellite closely in earth orbit and to track a specific surface. Relative attitude and first approximate relative orbital dynamics equations are presented. Control strategy is derived based on feedback linearization and Lyapunov theory of stability. Further, considering the uncertainty of inertia, an adaptive control method is developed to obtain the correct inertial ratio. The numerical simulation is given to verify the validity of proposed control scheme.展开更多
This paper presents a scheme of fault diagnosis for flexible satellites during orbit maneuver. The main contribution of the paper is related to the design of the nonlinear input observer which can avoid false alarm ar...This paper presents a scheme of fault diagnosis for flexible satellites during orbit maneuver. The main contribution of the paper is related to the design of the nonlinear input observer which can avoid false alarm arising from the disturbance from orbit control force. The effects of orbit control force on the fault diagnosis system for satellite attitude control systems, including the disturbing torque caused by the misalignments and the model uncertainty caused by the fuel consumed, are discussed, where standard Lu- enberger observer cannot work well. Then the nonlinear unknown input observer is proposed to decouple faults from disturbance, Besides, a linear matrix inequality approach is adopted to reduce the effect of nonlinear part and model uncertainties on the observer. The numerical and semi-physical simulation demonstrates the effectiveness of the proposed observer for the fault diagnosis system of the satellite during orbit maneuver.展开更多
This paper investigates the attitude and orbit control for the combined spacecraft formed after a target spacecraft without the autonomous control ability is captured by a service spacecraft.The optimal controller of ...This paper investigates the attitude and orbit control for the combined spacecraft formed after a target spacecraft without the autonomous control ability is captured by a service spacecraft.The optimal controller of fully-actuated system is proposed to realize the attitude and orbit stabilization control of combined spacecraft.The stability of the system is proved by introducing Lyapunov function.Numerical simulation of the combined spacecraft and physical experiment based on the combined spacecraft simulator(CSS)are completed.Both simulation and experiment results demonstrate the effectiveness and practicability of the optimal controller of fully-actuated system.展开更多
The inner-formation gravity field measurement satellite(IFS) is a novel pure gravitational orbiter. It aims to measure the Earth's gravity field with unprecedented accuracy and spatial resolution by means of preci...The inner-formation gravity field measurement satellite(IFS) is a novel pure gravitational orbiter. It aims to measure the Earth's gravity field with unprecedented accuracy and spatial resolution by means of precise orbit determination(POD) and relative state measurement. One of the key factors determining the measurement level is the outer-satellite control used for keeping the inner-satellite flying in a pure gravitational orbit stably. In this paper the integrated orbit and attitude control of IFS during steady-state phase was investigated using only thrusters. A six degree-of-freedom translational and rotational dynamics model was constructed considering nonlinearity resulted from quaternion expression and coupling induced by community thrusters. A feasible quadratic optimization model was established for the integrated orbit and attitude control using constrained nonlinear model predictive control(CNMPC) techniques. Simulation experiment demonstrated that the presented CNMPC algorithm can achieve rapid calculation and overcome the non-convexity of partial constraints. The thruster layout is rational with low thrust consumption,and the mission requirements of IFS are fully satisfied.展开更多
基金Project supported by the National Natural Science Foundation of China(No.10672084)the Specialized Research Fund for Doctoral Program of Higher Education(No.20060003097)
文摘Formation flying is a novel concept of distributing the functionality of large spacecraft among several smaller, less expensive, cooperative satellites. Some applications require that a controllable satellite keeps relative position and attitude to observe a specific surface of another satellite among the cluster. Specially, the target space vehicle is malfunctioning. The present paper focuses on the problem that how to control a chaser satellite to fly around an out-of-work target satellite closely in earth orbit and to track a specific surface. Relative attitude and first approximate relative orbital dynamics equations are presented. Control strategy is derived based on feedback linearization and Lyapunov theory of stability. Further, considering the uncertainty of inertia, an adaptive control method is developed to obtain the correct inertial ratio. The numerical simulation is given to verify the validity of proposed control scheme.
基金supported by the National Natural Science Foundation of China (61034005)the Natural Science Foundation of Jiangsu Province (BK2010072)
文摘This paper presents a scheme of fault diagnosis for flexible satellites during orbit maneuver. The main contribution of the paper is related to the design of the nonlinear input observer which can avoid false alarm arising from the disturbance from orbit control force. The effects of orbit control force on the fault diagnosis system for satellite attitude control systems, including the disturbing torque caused by the misalignments and the model uncertainty caused by the fuel consumed, are discussed, where standard Lu- enberger observer cannot work well. Then the nonlinear unknown input observer is proposed to decouple faults from disturbance, Besides, a linear matrix inequality approach is adopted to reduce the effect of nonlinear part and model uncertainties on the observer. The numerical and semi-physical simulation demonstrates the effectiveness of the proposed observer for the fault diagnosis system of the satellite during orbit maneuver.
基金This paper was supported in part by the National Natural Science Foundation of China under Grant Nos.62173255 and 62188101.
文摘This paper investigates the attitude and orbit control for the combined spacecraft formed after a target spacecraft without the autonomous control ability is captured by a service spacecraft.The optimal controller of fully-actuated system is proposed to realize the attitude and orbit stabilization control of combined spacecraft.The stability of the system is proved by introducing Lyapunov function.Numerical simulation of the combined spacecraft and physical experiment based on the combined spacecraft simulator(CSS)are completed.Both simulation and experiment results demonstrate the effectiveness and practicability of the optimal controller of fully-actuated system.
基金supported by the National Natural Science Foundation of China (Grant No. 11002076)the National Defense Pre-Research (Grant No.51320010201)
文摘The inner-formation gravity field measurement satellite(IFS) is a novel pure gravitational orbiter. It aims to measure the Earth's gravity field with unprecedented accuracy and spatial resolution by means of precise orbit determination(POD) and relative state measurement. One of the key factors determining the measurement level is the outer-satellite control used for keeping the inner-satellite flying in a pure gravitational orbit stably. In this paper the integrated orbit and attitude control of IFS during steady-state phase was investigated using only thrusters. A six degree-of-freedom translational and rotational dynamics model was constructed considering nonlinearity resulted from quaternion expression and coupling induced by community thrusters. A feasible quadratic optimization model was established for the integrated orbit and attitude control using constrained nonlinear model predictive control(CNMPC) techniques. Simulation experiment demonstrated that the presented CNMPC algorithm can achieve rapid calculation and overcome the non-convexity of partial constraints. The thruster layout is rational with low thrust consumption,and the mission requirements of IFS are fully satisfied.
