In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated...In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.展开更多
To synchronize the attitude of a spacecraft formation flying system, three novel autonomous control schemes are proposed to deal with the issue in this paper. The first one is an ideal autonomous attitude coordinated ...To synchronize the attitude of a spacecraft formation flying system, three novel autonomous control schemes are proposed to deal with the issue in this paper. The first one is an ideal autonomous attitude coordinated controller, which is applied to address the case with certain models and no disturbance. The second one is a robust adaptive attitude coordinated controller, which aims to tackle the case with external disturbances and model uncertainties. The last one is a filtered robust adaptive attitude coordinated controller, which is used to overcome the case with input con- straint, model uncertainties, and external disturbances. The above three controllers do not need any external tracking signal and only require angular velocity and relative orientation between a spacecraft and its neighbors. Besides, the relative information is represented in the body frame of each spacecraft. The controllers are proved to be able to result in asymptotical stability almost everywhere. Numerical simulation results show that the proposed three approaches are effective for attitude coordination in a spacecraft formation flying system.展开更多
This paper addresses an integrated relative position and attitude control strategy for a pursuer spacecraft flying to a space target in proximity operation missions. Relative translation and rotation dynamics are both...This paper addresses an integrated relative position and attitude control strategy for a pursuer spacecraft flying to a space target in proximity operation missions. Relative translation and rotation dynamics are both presented, and further integratedly considered due to mutual couplings, which results in a six degrees-of-freedom (6-DOF) control system. In order to simultaneously achieve relative position and attitude requirements, an adaptive backstepping control law is designed, where a command filter is introduced to overcome 'explosion of terms'. Within the Lyapunov framework, the proposed controller is proved to ensure the ultimate boundedness of relative position and attitude signals, in the presence of external disturbances and unknown system parameters. Numerical simulation demonstrates the effect of the designed control law.展开更多
This paper investigates a switching control strategy for the altitude motion of a morphing aircraft with variable sweep wings based on Q-learning.The morphing process is regarded as a function of the system states and...This paper investigates a switching control strategy for the altitude motion of a morphing aircraft with variable sweep wings based on Q-learning.The morphing process is regarded as a function of the system states and a related altitude motion model is established.Then,the designed controller is divided into the outer part and inner part,where the outer part is devised by a combination of the back-stepping method and command filter technique so that the’explosion of complexity’problem is eliminated.Moreover,the integrator structure of the altitude motion model is exploited to simplify the back-stepping design,and disturbance observers inspired from the idea of extended state observer are devised to obtain estimations of the system disturbances.The control input switches from the outer part to the inner part when the altitude tracking error converges to a small value and linear approximation of the altitude motion model is applied.The inner part is generated by the Q-learning algorithm which learns the optimal command in the presence of unknown system matrices and disturbances.It is proved rigorously that all signals of the closed-loop system stay bounded by the developed control method and controller switching occurs only once.Finally,comparative simulations are conducted to validate improved control performance of the proposed scheme.展开更多
文摘In this paper,an integrated estimation guidance and control(IEGC)system is designed based on the command filtered backstepping approach for circular field-of-view(FOV)strapdown missiles.The threedimensional integrated estimation guidance and control nonlinear model with limited actuator deflection angle is established considering the seeker's FOV constraint.The boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to constrain the body line-of-sight(BLOS)in IEGC system to fit a circular FOV.Then,the nonlinear adaptive controller is designed to estimate the changing aerodynamic parameters.The generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking accuracy.Furthermore,the command filters are used to solve the"differential expansion"problem during the backstepping design.The Lyapunov theory is used to prove the stability of the overall closed-loop IEGC system.Finally,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.
基金co-supported by the National Natural Science Foundation of China (No. 61174037)the Innovation Found of Chinese Academy of Space Technology (No. CAST20120602)+1 种基金the Foundation for Creative Research Groups of the National Natural Science Foundation (No. 61021002)the National High-tech Research and Development Program of China (No. 2012AA120602)
文摘To synchronize the attitude of a spacecraft formation flying system, three novel autonomous control schemes are proposed to deal with the issue in this paper. The first one is an ideal autonomous attitude coordinated controller, which is applied to address the case with certain models and no disturbance. The second one is a robust adaptive attitude coordinated controller, which aims to tackle the case with external disturbances and model uncertainties. The last one is a filtered robust adaptive attitude coordinated controller, which is used to overcome the case with input con- straint, model uncertainties, and external disturbances. The above three controllers do not need any external tracking signal and only require angular velocity and relative orientation between a spacecraft and its neighbors. Besides, the relative information is represented in the body frame of each spacecraft. The controllers are proved to be able to result in asymptotical stability almost everywhere. Numerical simulation results show that the proposed three approaches are effective for attitude coordination in a spacecraft formation flying system.
基金supported by Innovative Team Program of the National Natural Science Foundation of China (No.61021002)
文摘This paper addresses an integrated relative position and attitude control strategy for a pursuer spacecraft flying to a space target in proximity operation missions. Relative translation and rotation dynamics are both presented, and further integratedly considered due to mutual couplings, which results in a six degrees-of-freedom (6-DOF) control system. In order to simultaneously achieve relative position and attitude requirements, an adaptive backstepping control law is designed, where a command filter is introduced to overcome 'explosion of terms'. Within the Lyapunov framework, the proposed controller is proved to ensure the ultimate boundedness of relative position and attitude signals, in the presence of external disturbances and unknown system parameters. Numerical simulation demonstrates the effect of the designed control law.
基金supported by the National Natural Science Foundation of China(Nos.61873295,61833016)the Aeronautical Science Foundation of China(No.2016ZA51011).
文摘This paper investigates a switching control strategy for the altitude motion of a morphing aircraft with variable sweep wings based on Q-learning.The morphing process is regarded as a function of the system states and a related altitude motion model is established.Then,the designed controller is divided into the outer part and inner part,where the outer part is devised by a combination of the back-stepping method and command filter technique so that the’explosion of complexity’problem is eliminated.Moreover,the integrator structure of the altitude motion model is exploited to simplify the back-stepping design,and disturbance observers inspired from the idea of extended state observer are devised to obtain estimations of the system disturbances.The control input switches from the outer part to the inner part when the altitude tracking error converges to a small value and linear approximation of the altitude motion model is applied.The inner part is generated by the Q-learning algorithm which learns the optimal command in the presence of unknown system matrices and disturbances.It is proved rigorously that all signals of the closed-loop system stay bounded by the developed control method and controller switching occurs only once.Finally,comparative simulations are conducted to validate improved control performance of the proposed scheme.
