The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system. In order to identify the dynamic error model coefficients accurately, the static error model coefficients which la...The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system. In order to identify the dynamic error model coefficients accurately, the static error model coefficients which lay a foundation for compensating while identifying the dynamic error model are identified in the gravity acceleration fields by using angular position function of the three-axis turntable. The angular acceleration and angular velocity are excited on the input, output and spin axis of the gyros when the outer axis and the middle axis of a three-axis turntable are in the uniform angular velocity state simultaneously, while the inner axis of the turntable is in different static angular positions. 8 groups of data are sampled when the inner axis is in 8 different angular positions. These data are the function of the middle axis positions and the inner axis positions. For these data, harmonic analysis method is applied two times versus the middle axis positions and inner axis positions respectively so that the dynamic error model coefficients are finally identified through the least square method. In the meantime the optimal angular velocity of the outer axis and the middle axis are selected by computing the determination value of the information matrix.展开更多
This paper proposes a novel distributed control method for surrounding a noncooperative target that has maneuverability by spacecraft formation.A relative orbit error dynamic model between the target and the formation...This paper proposes a novel distributed control method for surrounding a noncooperative target that has maneuverability by spacecraft formation.A relative orbit error dynamic model between the target and the formation is established dependent on a reference spacecraft under the 2-body assumption.To estimate and compensate for the target’s control input rapidly,a novel finite-time extended state observer is developed.It is stable in the sense of fast finite-time uniformly ultimately bounded stability.A fast terminal sliding mode controller is proposed for finite-time convergence of the system.Simulation examples are implemented to show the effectiveness of proposed algorithm.展开更多
文摘The dynamic errors of gyros are the important error sources of a strapdown inertial navigation system. In order to identify the dynamic error model coefficients accurately, the static error model coefficients which lay a foundation for compensating while identifying the dynamic error model are identified in the gravity acceleration fields by using angular position function of the three-axis turntable. The angular acceleration and angular velocity are excited on the input, output and spin axis of the gyros when the outer axis and the middle axis of a three-axis turntable are in the uniform angular velocity state simultaneously, while the inner axis of the turntable is in different static angular positions. 8 groups of data are sampled when the inner axis is in 8 different angular positions. These data are the function of the middle axis positions and the inner axis positions. For these data, harmonic analysis method is applied two times versus the middle axis positions and inner axis positions respectively so that the dynamic error model coefficients are finally identified through the least square method. In the meantime the optimal angular velocity of the outer axis and the middle axis are selected by computing the determination value of the information matrix.
基金supported by the National Natural Science Foundation of China(nos.62273118,12150008,61973100,and 61876050).
文摘This paper proposes a novel distributed control method for surrounding a noncooperative target that has maneuverability by spacecraft formation.A relative orbit error dynamic model between the target and the formation is established dependent on a reference spacecraft under the 2-body assumption.To estimate and compensate for the target’s control input rapidly,a novel finite-time extended state observer is developed.It is stable in the sense of fast finite-time uniformly ultimately bounded stability.A fast terminal sliding mode controller is proposed for finite-time convergence of the system.Simulation examples are implemented to show the effectiveness of proposed algorithm.
