Our Solar System contains eight planets and their respective natural satellites excepting the inner two planets Mercury and Venus. A satellite hosted by a given Planet is well protected by the gravitational pertubatio...Our Solar System contains eight planets and their respective natural satellites excepting the inner two planets Mercury and Venus. A satellite hosted by a given Planet is well protected by the gravitational pertubation of much heavier planets such as Jupiter and Saturn if the natural satellite lies deep inside the respective host Planet Hill sphere. Each planet has a Hill radius a<sub>H</sub> and planet mean radius R<sub>P </sub>and the ratio R<sub>1</sub>=R<sub>P</sub>/a<sub>H</sub>. Under very low R<sub>1 </sub>(less than 0.006) the approximation of CRTBP (centrally restricted three-body problem) to two-body problem is valid and planet has spacious Hill lobe to capture a satellite and retain it. This ensures a high probability of capture of natural satellite by the given planet and Sun’s perturbation on Planet-Satellite binary can be neglected. This is the case with Earth, Mars, Jupiter, Saturn, Neptune and Uranus. But Mercury and Venus has R<sub>1</sub>=R<sub>P</sub>/a<sub>H</sub> =0.01 and 5.9862 × 10<sup>-3</sup> respectively hence they have no satellites. There is a limit to the dimension of the captured body. It must be a much smaller body both dimensionally as well masswise. The qantitative limit is a subject of an independent study.展开更多
在传统星座自主定轨中,SST(satellite to satellite tracking)可以同时提供轨道的大小、形状和星座相对方位信息,但不能确定星座的绝对定向。针对这一亏秩问题,联合圆型限制性三体模型CRTBP(circle restricted three bodyproblem)下的...在传统星座自主定轨中,SST(satellite to satellite tracking)可以同时提供轨道的大小、形状和星座相对方位信息,但不能确定星座的绝对定向。针对这一亏秩问题,联合圆型限制性三体模型CRTBP(circle restricted three bodyproblem)下的一种平动点周期轨道-Halo轨道飞行器,与二体问题轨道卫星组成扩展星座。利用两种力模型的特性差异,可以去除星座系统上的相关性,避免星座的整体旋转,从而确定星座的全部轨道状态参量。分析Halo轨道的力模型及性态特点,从系数矩阵的相关性角度讨论引进Halo轨道对定轨法矩阵正定性的改善作用,利用地月系L1平动点附近的Halo轨道与月球低轨卫星(LMO)的星间链路,在理想CRTBP框架下进行自主定轨仿真。初步验证了LMO-Halo星座定轨可行性,为开展附加平动点轨道的星座SST定轨提供了参考依据。展开更多
In this paper, we use Port-Hamiltonian framework to stabilize the Lagrange <span style="font-family:Verdana;">points in the Sun-Earth three-dimensional Circular Restricted Three-Body Problem (CRTBP). T...In this paper, we use Port-Hamiltonian framework to stabilize the Lagrange <span style="font-family:Verdana;">points in the Sun-Earth three-dimensional Circular Restricted Three-Body Problem (CRTBP). Through rewriting the CRTBP into Port-Hamiltonian framework, we are allowed to design the feedback controller through ener</span><span style="font-family:Verdana;">gy-shaping and dissipation injection. The closed-loop Hamiltonian is </span><span style="font-family:Verdana;">a candidate of the Lyapunov function to establish nonlinear stability of the designed equilibrium, which enlarges the application region of feedback controller compared with that based on linearized dynamics. Results show that th</span><span style="font-family:Verdana;">e Port-Hamiltonian</span><span style="font-family:Verdana;"> a</span><span style="font-family:Verdana;">pproach allows us to successfully stabilize the Lagrange points, where the Linear Quadratic Regulator (LQR) may fail. The feedback </span><span style="font-family:Verdana;">system based on Port-Hamiltonian approach is also robust against whit</span><span style="font-family:Verdana;">e noise in the inputs.</span>展开更多
The current methods for designing periodic orbits in the elliptic restricted three-body problem(ERTBP)have the disadvantages of targeting limited orbits and ergodic searches and considering only symmetric orbits.A uni...The current methods for designing periodic orbits in the elliptic restricted three-body problem(ERTBP)have the disadvantages of targeting limited orbits and ergodic searches and considering only symmetric orbits.A universal method for designing periodic orbits is proposed in this paper.First,the homotopy classes of orbits are structured based on their topological structures.Second,a dynamic model based on homotopy classes,ranging from the circular restricted three-body problem(CRTBP)to the ERTBP,can be built using the homotopy method.Third,a multi-and a single-period orbit were selected based on the resonance ratios.Finally,the corresponding orbit in the ERTBP was computed by modifying the initial condition of the orbit in the CRTBP.This method,without an ergodic search,can extend to any orbit,including an asymmetric orbit in the CRTBP,to the ERTBP model,and the two orbits are of the same homotopy class.Examples of the Earth–Moon ERTBP are presented to verify the efficiency of this method.展开更多
文摘Our Solar System contains eight planets and their respective natural satellites excepting the inner two planets Mercury and Venus. A satellite hosted by a given Planet is well protected by the gravitational pertubation of much heavier planets such as Jupiter and Saturn if the natural satellite lies deep inside the respective host Planet Hill sphere. Each planet has a Hill radius a<sub>H</sub> and planet mean radius R<sub>P </sub>and the ratio R<sub>1</sub>=R<sub>P</sub>/a<sub>H</sub>. Under very low R<sub>1 </sub>(less than 0.006) the approximation of CRTBP (centrally restricted three-body problem) to two-body problem is valid and planet has spacious Hill lobe to capture a satellite and retain it. This ensures a high probability of capture of natural satellite by the given planet and Sun’s perturbation on Planet-Satellite binary can be neglected. This is the case with Earth, Mars, Jupiter, Saturn, Neptune and Uranus. But Mercury and Venus has R<sub>1</sub>=R<sub>P</sub>/a<sub>H</sub> =0.01 and 5.9862 × 10<sup>-3</sup> respectively hence they have no satellites. There is a limit to the dimension of the captured body. It must be a much smaller body both dimensionally as well masswise. The qantitative limit is a subject of an independent study.
文摘在传统星座自主定轨中,SST(satellite to satellite tracking)可以同时提供轨道的大小、形状和星座相对方位信息,但不能确定星座的绝对定向。针对这一亏秩问题,联合圆型限制性三体模型CRTBP(circle restricted three bodyproblem)下的一种平动点周期轨道-Halo轨道飞行器,与二体问题轨道卫星组成扩展星座。利用两种力模型的特性差异,可以去除星座系统上的相关性,避免星座的整体旋转,从而确定星座的全部轨道状态参量。分析Halo轨道的力模型及性态特点,从系数矩阵的相关性角度讨论引进Halo轨道对定轨法矩阵正定性的改善作用,利用地月系L1平动点附近的Halo轨道与月球低轨卫星(LMO)的星间链路,在理想CRTBP框架下进行自主定轨仿真。初步验证了LMO-Halo星座定轨可行性,为开展附加平动点轨道的星座SST定轨提供了参考依据。
文摘In this paper, we use Port-Hamiltonian framework to stabilize the Lagrange <span style="font-family:Verdana;">points in the Sun-Earth three-dimensional Circular Restricted Three-Body Problem (CRTBP). Through rewriting the CRTBP into Port-Hamiltonian framework, we are allowed to design the feedback controller through ener</span><span style="font-family:Verdana;">gy-shaping and dissipation injection. The closed-loop Hamiltonian is </span><span style="font-family:Verdana;">a candidate of the Lyapunov function to establish nonlinear stability of the designed equilibrium, which enlarges the application region of feedback controller compared with that based on linearized dynamics. Results show that th</span><span style="font-family:Verdana;">e Port-Hamiltonian</span><span style="font-family:Verdana;"> a</span><span style="font-family:Verdana;">pproach allows us to successfully stabilize the Lagrange points, where the Linear Quadratic Regulator (LQR) may fail. The feedback </span><span style="font-family:Verdana;">system based on Port-Hamiltonian approach is also robust against whit</span><span style="font-family:Verdana;">e noise in the inputs.</span>
文摘The current methods for designing periodic orbits in the elliptic restricted three-body problem(ERTBP)have the disadvantages of targeting limited orbits and ergodic searches and considering only symmetric orbits.A universal method for designing periodic orbits is proposed in this paper.First,the homotopy classes of orbits are structured based on their topological structures.Second,a dynamic model based on homotopy classes,ranging from the circular restricted three-body problem(CRTBP)to the ERTBP,can be built using the homotopy method.Third,a multi-and a single-period orbit were selected based on the resonance ratios.Finally,the corresponding orbit in the ERTBP was computed by modifying the initial condition of the orbit in the CRTBP.This method,without an ergodic search,can extend to any orbit,including an asymmetric orbit in the CRTBP,to the ERTBP model,and the two orbits are of the same homotopy class.Examples of the Earth–Moon ERTBP are presented to verify the efficiency of this method.