Satellite Constellation Design with Adaptively Continuous Ant System Algorithm

The ant system algorithm （ASA） has proved to be a novel meta-heuristic algorithm to solve many multivariable problems. In this paper, the earth coverage of satellite constellation is analyzed and a n ＋ 1^ -fold coverage rate is put forward to evaluate the coverage performance of a satellite constellation. An optimization model of constellation parameters is established on the basis of the coverage performance. As a newly developed method, ASA can be applied to optimize the constellation parameters. In order to improve the ASA, a rule for adaptive number of ants is proposed, by which the search range is obviously enlarged and the convergence speed increased. Simulation results have shown that the ASA is more quick and efficient than other methodV211.71s.     

基于快速性能计算算法和序优化的卫星星座构型设计研究(英文)

卫星星座设计是一个复杂耗时的仿真优化设计问题。本文首先介绍了一种利用Hermite插值算法计算卫星星座性能指标的快速算法,用来减少计算复杂度和时间,并且基于快速算法建立了星座构型优化模型。其次引进了序优化理论,用来缩减搜索空间。针对星座优化问题,详细阐述了序优化所涉及到的精确和粗糙模型、有序性能曲线、选择规则和选择集合。通过对卫星导航星座和天基目标监视星座系统的仿真表明序优化理论对处理卫星星座优化设计问题是有效的。     

基于星座恢复法降低PAPR的性能分析

提出了一种新的降低峰均功率比(Peak-to-average ratio,PAPR)的方法——星座恢复法.在发送端采用软件削波限幅的方法来降低系统的峰均比,其系统结构简单、且可根据系统的要求灵活地改变PAPR值;在接收端根据调制信号的星座特性恢复出被限幅数据的实际值,从而减小了信号的畸变,提高了系统的误码性能.为了使星座恢复法更具实用性,对其算法进行了简化,从而大大地减少了系统的运算量.理论分析和仿真结果表明:与选择性映射法(Selective mapping,SLM)相比,基于星座恢复法的正交频分复用(Orthogonal frequency division multiplexing,OFDM)系统,其误码性能得到了明显的改善,算法较简单,且无需额外信道来传送附加信息.     

基于外包合同网的自治电磁探测卫星群任务规划

针对具有星间通信能力的自治电磁探测卫星群任务及载荷特点,建立了基于MAS (Multi\|Agent System)的电磁探测卫星群自主规划模型,提出了基于外包合同网的电磁探 测卫星群自主规划算法。根据模拟的数据进行仿真实验及分析,该方法能有效解决电磁 探测卫星群自主任务规划问题。
     

考虑燃料消耗均衡性的低轨通信星座在轨星座构型重构方法研究

针对低轨（low earth orbit,LEO）通信星座在轨重构问题,分析了低轨通信星座的特点,提出了4个重构指标,即全球平均覆盖率、燃料消耗均衡性、重构总时间和重构总速度增量,并分析了提高轨道高度的重构方式。采用基于分解的多目标进化算法（multiobjective evolutionary algorithm based on decomposition,MOEA/D）对重构进行建模分析。结果表明,模型优化结果可以得出多组最优解,构成帕累托前沿,并得出燃料消耗均衡性最优的解,针对两种失效模式得出的重构总时间均为3.6×105s,速度增量方差分别为261.4m2/s2和293.4m2/s2,这些解均可恢复星座原有的覆盖性能,并使燃料消耗最为均衡。     

气动力星座保持的最优控制

研究了利用气动力进行星座保持的最优控制问题。首先得到了正则方程，然后针对最优控制问题提出了一种求解算法，利用此算法进行了仿真计算。结果表明，算法简单有效。     

Optimal mission planning of the reconfiguration process of satellite constellations through orbital maneuvers: A novel technical framework

In this paper, a general new methodology is presented for the orbital reconfiguration of satellite constellations on the basis of Lambert targeting theorem. In view of the cost and risk reduction, it is very important to consider the problem of satellite constellation reconfiguration with the two constraints of overall mission cost minimization and the desired final configuration. Hence, the dependent non-simultaneous deployment approach is proposed to minimize overall fuel cost. Despite the fact that the satellites deploy in a non-simultaneous manner, supplementary phasing maneuvers on the target orbital pattern to achieve the desired orbital configuration are avoided. Moreover, a novel idea is presented to optimize the flight of satellites, which plays an important role in complying with the constraint of overall fuel cost minimization as much as possible. In order to achieve the global optimal solution of the satellite constellation reconfiguration problem, the efficient hybrid Particle Swarm Optimization/Genetic Algorithm (PSO/GA) technique, is implemented. Finally, to indicate the superiority of the presented method, a comparison to the simultaneous maneuver viewpoint is made on a number of representative cases. The obtained results imply significant reduction of reconfiguration costs by employing the proposed method.     

具有星间链路的导航星座重构研究

针对具有星间链路的导航星座在卫星节点或链路失效情况下的重构优化设计问题,提出了一种基于遗传算法的设计方法。首先,根据导航星座的功能需求与设计约束,建立了星座综合重构优化设计模型。其次,提出了基于遗传算法的综合优化设计方法,并根据问题特性对遗传算法的具体操作进行了修改。最后,应用该方法对Walker 24/3/2构型星座及网状星间网络在节点和链路混合故障模式下的重构进行了优化设计。结果表明,基于该方法重构后的星座与网络拓扑性能能够得到一定程度的改善,证明了方法的可行性。     

基于改进的NSGA-Ⅱ算法的区域覆盖卫星星座优化

对基于Pareto最优概念的非劣性分层遗传算法(NSGA-Ⅱ)进行了改进，与区域覆盖卫星星座的多目标优化设计相结合，提出基于改进的NSGA-Ⅱ算法的区域覆盖卫星星座优化设计方法，并利用多属性决策中的字典序法，根据目标的重要程度，在得到的Pareto解中进行选择．最后，利用STK和Matlab工具对遥感卫星星座进行了仿真，仿真结果表明该算法可以找到多个Pareto解，避免了传统的多目标优化求解方法的权值选择问题，并且比简单遗传算法具有更好的灵活性，从而解决了多目标优化的星座设计问题。     

Orbit insertion error analysis for a space-based gravitational wave observatory

Constellation is required to be highly stable over several years for a space-based gravitational wave observatory. However, the stability of the constellation can be affected by orbit insertion errors. The effects of orbit insertion errors on the constellation are mainly studied in this paper. Firstly, Monte-Carlo, Unscented Transformation Covariance Analysis Method (UTCAM) and Spherical Simplex Unscented Transformation Covariance Analysis Method (SSUTCAM) are used for simulation. The results indicate that UTCAM and SSUTCAM are highly efficient in calculating, with a relative error of less than 6%. Therefore, it is concluded that because of their accuracy and high efficiency, UTCAM and SSUTCAM can be adequately used in orbit insertion error analysis for a space-based gravitational wave observatory. Secondly, SSUTCAM is used to study the effects of position and velocity errors on the constellation. For the case in this paper, when the position error does not exceed 300 km, and the velocity error does not exceed 4 cm/s, the constellation remains stable.