This paper investigates the pose and motion estimation problem using single camera measurement for spacecraft. The leader spacecraft of three-dimensional shape is observed by a calibrated camera fixed on the follower ...This paper investigates the pose and motion estimation problem using single camera measurement for spacecraft. The leader spacecraft of three-dimensional shape is observed by a calibrated camera fixed on the follower spacecraft. Based on dual numbers,an integrated observation model is proposed based on a combination of multiple geometric features including points,lines and circles,which can improve the robustness and accuracy of the estimation algorithm. A six-degree-of-freedom relative motion model is proposed by using the dual quaternion representation,in which the rotation-translation coupling effect due to the points deviating from the center of the mass is described. Employing the proposed observation model and dynamics model,an Extended Kalman Filter is presented to estimate the relative state between the two spacecraft. Numerical simulations are performed to evaluate the proposed approaches,showing the convergence of relative estimation errors and superior estimation performance.展开更多
The optimal guidance problem for an interceptor against a ballistic missile with active defense is investigated in this paper.A class of optimal guidance schemes are proposed based on linear quadratic differential gam...The optimal guidance problem for an interceptor against a ballistic missile with active defense is investigated in this paper.A class of optimal guidance schemes are proposed based on linear quadratic differential game method and numerical solution of Riccati differential equation.By choosing proper parameters, the proposed guidance schemes are able to drive the interceptor to the target and away from the defender simultaneously.Additionally, fuel cost, control saturation,chattering phenomenon and parameters selection were taken into account.Satisfaction of the proposed guidance schemes of the saddle point condition is proven theoretically.Finally, nonlinear numerical examples are included to demonstrate the effectiveness and performance of the developed guidance approaches.Comparison of control performance between different guidance schemes are presented and analysis.展开更多
文摘This paper investigates the pose and motion estimation problem using single camera measurement for spacecraft. The leader spacecraft of three-dimensional shape is observed by a calibrated camera fixed on the follower spacecraft. Based on dual numbers,an integrated observation model is proposed based on a combination of multiple geometric features including points,lines and circles,which can improve the robustness and accuracy of the estimation algorithm. A six-degree-of-freedom relative motion model is proposed by using the dual quaternion representation,in which the rotation-translation coupling effect due to the points deviating from the center of the mass is described. Employing the proposed observation model and dynamics model,an Extended Kalman Filter is presented to estimate the relative state between the two spacecraft. Numerical simulations are performed to evaluate the proposed approaches,showing the convergence of relative estimation errors and superior estimation performance.
文摘The optimal guidance problem for an interceptor against a ballistic missile with active defense is investigated in this paper.A class of optimal guidance schemes are proposed based on linear quadratic differential game method and numerical solution of Riccati differential equation.By choosing proper parameters, the proposed guidance schemes are able to drive the interceptor to the target and away from the defender simultaneously.Additionally, fuel cost, control saturation,chattering phenomenon and parameters selection were taken into account.Satisfaction of the proposed guidance schemes of the saddle point condition is proven theoretically.Finally, nonlinear numerical examples are included to demonstrate the effectiveness and performance of the developed guidance approaches.Comparison of control performance between different guidance schemes are presented and analysis.
