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Shufan Wu Wen Chen Caixia Cao Chuanxin Zhang Zhongcheng Mu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(11):3712-3724
CubeSats has evolved from purely educational tools, to useful platforms for technology demonstration and many practical applications. This paper reviews a CubeSat constellation mission involving 3 CubeSats launched into orbit on Sep. 25th 2015, aiming to demonstrate the integrated application of low-cost CubeSat technologies with distributed payloads using a group of satellites, as well as to demonstrate several new technologies. The mission scenario, the satellite system design, the innovative technologies and instruments or devices used on the CubeSats and the in-orbit experimental results and the payload data analysis, as well as some experiences and lessons learned, are presented and summaried. 相似文献
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The main purpose of the LISA Pathfinder mission is to provide in-orbit validation of the critical technologies necessary for LISA (Laser Interferometer Space Antenna), aiming at detecting gravitational waves generated by very massive objects such as black holes. The spacecraft consists of a Science Module (SCM) and a Propulsion Module (PRM). The former performs the science experiment, and the later provides the propulsive capability to raise the spacecraft from the injection orbit to the operational orbit at around L1 and is then separated from the former. The Spacecraft Attitude and Orbit Control System (AOCS) is actually composed of three distinct systems to fulfill the needs of the whole mission: – Composite AOCS, used to reach L1, aims at raising the Perigee through a succession of about 10 boosts performed with high thrust chemical propulsion; – Micro-propulsion AOCS takes over once the separation of the SCM from PRM has occurred and is based on micro-propulsion systems (micro-Newton electrical thrusters); – Drag-Free Attitude Control System (DFACS) is then used to perform science experiments. This article provides a comprehensive overview of the AOCS architecture, requirements, selected sensors and actuators, system design & evolution, and achieved performances. It focuses in particular on the Composite AOCS and the Micro-propulsion AOCS and will analyze the challenges of using micro-Newton electric propulsion. 相似文献
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The capacity to acquire the relative position and attitude information between the chaser and the target satellites in real time is one of the necessary prerequisites for the successful implementation of autonomous rendezvous and docking. This paper addresses a vision based relative position and attitude estimation algorithm for the final phase of spacecraft rendezvous and docking. By assuming that the images of feature points on the target satellite lie within the convex regions, the estimation of the relative position and attitude is converted into solving a convex optimization problem in which the dual quaternion method is employed to represent the rotational and translational transformation between the chaser body frame and the target body frame. Due to the point-to-region correspondence instead of the point-to-point correspondence is used, the proposed estimation algorithm shows good performance in robustness which is verified through computer simulations. 相似文献
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Baoyu Liu Xingqun Zhan Yang Gao 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(7):2044-2057
The cross-covariances among local sensor estimates are usually unknown or can’t be accurately known in multi-sensor systems. The Covariance Intersection (CI), Convex Combination (CC), Largest Ellipsoid (LE) and Ellipsoidal Intersection (EI) algorithms have been developed for the estimate fusion with unknown cross-covariances. In this contribution, we reveal a strong commonality in principle among CI, CC, LE and EI algorithms after a transformation into a new Euclidean space, although each algorithm is designed based on different criteria. We also assess the consistencies of CC, LE and EI algorithms under different conditions which have been found significantly dependent on the correlation level among local estimates. All the CI, CC, LE and EI algorithms have the capability to enhance consistency or accuracy but at a cost of accuracy or consistency. Based on the commonality and consistency features among different algorithms, an improved algorithm is presented which can significantly improve the consistency performance at a very little expense of accuracy. The theoretical analysis and the fusion algorithm selection strategy are testified through simulated examples and the fusion of GPS and GLONASS horizontal position solutions. 相似文献
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Liqiang Hou Shufan Wu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(11):3638-3653
A new method is proposed for multi-objective optimal control of satellite formation reconfiguration. First, necessary optimality conditions of single-objective fuel-optimal reconfiguration are studied. Problem of initial guess of the costate and control discontinuity are addressed by using a new developed stochastic based method. Terminal conditions of Two Point Boundary Value Problem (TPBVP) of the optimal control equations are relaxed using augmented Gaussian. Variances or bandwidths of the terminal conditions are set to decision variables to be optimized. Responses of varied initial costate are modeled and propagated using Riccati equation. Using quadratic convolution of relaxed terminal conditions, objective function of the fuel-optimal problem is reformulated into a quadratic equation, and a gradient based optimizer is used to search the optimal initial guess. In the second part of the paper, optimal control of format flying reconfiguration with two competitive objectives:fuel and time of flight (ToF) is studied. With Pascoletti-Serafini scalarization, the Multi-objective Optimal Control Problem (MOCP) is scalarized into a set of weighted Single-objective Optimal Control Problems (SOCP). Hamiltonian and switch function for the weighted SOCP are developed and constructed. New developed stochastic based approach is then used to search the optimal Pareto solutions. Verification and performances of proposed algorithms are demonstrated through numerical simulations of single-objective and multi-objective optimal control of low-thrust elliptical orbit formation reconfiguration. Potential applications of the algorithms to some other preliminary space mission designs are also discussed. 相似文献
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