A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has ...A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has robustness to uncertainty of frequency, which makes it practical in engineering. Several time optimal and time-fuel optimal control strategies are designed for a kind of single flexible link. Simulation results validate the feasibility of our method.展开更多
Solar sail is a new type of spacecraft for deep space exploration,which flies by the pressure of sunlight.The attitude of the sail determines its orbit,so altitude control plays an important role in the mission.Howeve...Solar sail is a new type of spacecraft for deep space exploration,which flies by the pressure of sunlight.The attitude of the sail determines its orbit,so altitude control plays an important role in the mission.However,the large flexible structure leads to some difficulty in attitude control.This paper establishes the reduced dynamic model of a flexible solar sail with foreshortening deformation,and coupling with its attitude and vibration.As usual,large angle maneuvering will lead to the vibration of flexible structure,so the time optimal control of solar sail maneuvering is considered.Bang-Bang control of the solar sail generates large amplitude and sustained vibration,while the combined control based on input shaping can eliminate the vibration efficiently.With the comparison of two reduced models,it is demonstrated that the choice of two models depends on the attention to the stretching deformation.展开更多
For the control of large angle maneuvers of a spacecraft, variable gain backstepping control is proposed. The controller can make the states of the system converge to the commanded position along the input vector fiel...For the control of large angle maneuvers of a spacecraft, variable gain backstepping control is proposed. The controller can make the states of the system converge to the commanded position along the input vector field orientation. The controller stabilizes the system with the amplitude of the commanded torques decreased. Considering the uncertainty of the disturbance torques and the estimation error of the inertia matrix, the control design is improved to provide strong self-adaptability and robustness of the system. Simulation is conducted, and the results show that the design has good tracking performance and convergence, consistent with the theoretical analysis.展开更多
Earth off\|nadir pointing technology can be used on a small satellite to provide larger nadir earth surface imaging coverage. In this paper, the satellite attitude dynamics equations including the gravity\|gradient ...Earth off\|nadir pointing technology can be used on a small satellite to provide larger nadir earth surface imaging coverage. In this paper, the satellite attitude dynamics equations including the gravity\|gradient torque and wheel motor torque are derived using Euler parameters. The necessary conditions for optimum solutions subject to the performance index are obtained via Pontryagin's principle. The resulting two\|point boundary value problem is solved numerically with an optimal slew illustrated by example.展开更多
基金This project is supported by National 211 Project.
文摘A component synthesis vibration suppression (CSVS) method for flexible structures is put forward. It can eliminate any unwanted orders of flexible vibration modes while achieves desired rigid motion. This method has robustness to uncertainty of frequency, which makes it practical in engineering. Several time optimal and time-fuel optimal control strategies are designed for a kind of single flexible link. Simulation results validate the feasibility of our method.
文摘Solar sail is a new type of spacecraft for deep space exploration,which flies by the pressure of sunlight.The attitude of the sail determines its orbit,so altitude control plays an important role in the mission.However,the large flexible structure leads to some difficulty in attitude control.This paper establishes the reduced dynamic model of a flexible solar sail with foreshortening deformation,and coupling with its attitude and vibration.As usual,large angle maneuvering will lead to the vibration of flexible structure,so the time optimal control of solar sail maneuvering is considered.Bang-Bang control of the solar sail generates large amplitude and sustained vibration,while the combined control based on input shaping can eliminate the vibration efficiently.With the comparison of two reduced models,it is demonstrated that the choice of two models depends on the attention to the stretching deformation.
基金supported by the National Natural Science Foundation of China (Nos. 61174001, 61203185)
文摘For the control of large angle maneuvers of a spacecraft, variable gain backstepping control is proposed. The controller can make the states of the system converge to the commanded position along the input vector field orientation. The controller stabilizes the system with the amplitude of the commanded torques decreased. Considering the uncertainty of the disturbance torques and the estimation error of the inertia matrix, the control design is improved to provide strong self-adaptability and robustness of the system. Simulation is conducted, and the results show that the design has good tracking performance and convergence, consistent with the theoretical analysis.
文摘Earth off\|nadir pointing technology can be used on a small satellite to provide larger nadir earth surface imaging coverage. In this paper, the satellite attitude dynamics equations including the gravity\|gradient torque and wheel motor torque are derived using Euler parameters. The necessary conditions for optimum solutions subject to the performance index are obtained via Pontryagin's principle. The resulting two\|point boundary value problem is solved numerically with an optimal slew illustrated by example.
