May 2022, Volume 1 Issue 4
    

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  • Review
    Development of New Technology in Deep Space TT&C
    DONG Guangliang
    2014, 1(4): 243-249. https://doi.org/10.15982/j.issn.2095-7777.2014.04.001
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    The TT&C system is an indispensable part of deep space exploration project with its navigation and telecommunication performance being the key factor for mission success and science output. In condition of faraway distance, long delay, feeble signal and easy discontinuity, developing and applying a series of deep space TT&C new technologies, such as antenna array, regenerative pseudo-noise (PN) ranging, connected-element interferometry, phase-referencing interferometry and delay-tolerant network, can provide high precision navigation methods and high rate data transmission capabilities for future deep space exploration missions.
  • Review
    Research Trend of Dynamics in the Gravitational Field of Irregular Celestial Body
    JIANG Yu, BAOYIN Hexi
    2014, 1(4): 250-261. https://doi.org/10.15982/j.issn.2095-7777.2014.04.002
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    Both asteroid and comet exploration are important areas in the deep space exploration. The mass of an asteroid or a comet is not big enough, so its gravitational force is much smaller than the stress to satisfy the hydrostatic equilibrium, which makes the minor celestial body irregular-shaped. The research of dynamical behaviours and mechanisms in the gravitational field of irregular celestial body is the basis of minor celestial body exploration, including the catching of the explorer and the design of the orbit around the minor celestial body. This paper summarizes the research progress of the dynamics in the gravitational field of irregular celestial body through gravitational models and dynamical mechanisms. The research situation of gravitational models such as the Legendre polynomial model, the simple-shaped model and the polyhedron model are presented. In addition, the research situation of dynamical mechanisms such as the periodic orbits and quasi-periodic orbits, equilibrium points, manifolds, bifurcations and resonances, chaos, are also presented. Besides, we have analyzed key points and difficult points of these researches. Finally, the research trend of the dynamics in the gravitational field of irregular celestial body is discussed.
  • Article
    Obstacle Recognition and Safe Area Selection Method in Soft Landing based on a Single Lunar Image
    WU Weiren, WANG Dayi, MAO Xiaoyan, HUANG Xiangyu
    2014, 1(4): 262-268. https://doi.org/10.15982/j.issn.2095-7777.2014.04.003
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    A method of ameliorated Hapke model which is the same with satellite surface covered with deep dust is put forward to satisfy the needs of soft landing on the moon. The linearization method is used to calculate the differential equation and to get the relative three-dimensional height of simulative images for obstacle recognition and selection of safe area during landing phase. It can resolve the problem that is difficult to recognize the slope by texture method. Making use of the simulating lunar images during landing, the model calculation, three-dimensional height rebuilding and safe area selection are realized. The results show the validity of this method using single lunar image.
  • Article
    Risk Theta*: an Any-Angle Path Planning Algorithm based on Terrain Risk
    WANG Qiong, YU Dengyun, JIA Yang
    2014, 1(4): 269-274. https://doi.org/10.15982/j.issn.2095-7777.2014.04.004
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    Risk Theta*: an any-angle path planning algorithm based on terrain risk is proposed in this paper. At first, based on statistical analysis on terrain feature of planetary surface, terrain risk index is proposed and the index map is built. Basic Theta* search is conducted on this index map to seek optimal path of lowest terrain risk. Simulation experiments show that the proposed algorithm could find out any-angle path of much lower terrain risk and comparable path length on grid map than A* and Basic Theta* which can significantly improve the rover safety, as well as satisfy the urgent demand of any-angle travel of planetary roving exploration, therefore it is fairly practical.
  • Article
    Multiple Model Adaptive Estimation Algorithm for SINS/CNS Integrated Navigation System
    FAN Shuangfei, ZHAO Fangfang, LI Xiajing, TANG Zhongliang, HE Wei
    2014, 1(4): 275-281. https://doi.org/10.15982/j.issn.2095-7777.2014.04.005
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    In this paper, a new filtering method based on multiple model adaptive estimation(MMAE) algorithm is proposed, for the problem of poor adaptability of single model filters with unknown or uncertain parameters. In this proposed algorithm, we use improved Kalman filters rather than traditional Kalman filters, such as extended Kalman filter (EKF), unscented Kalman filter (UKF). And EKF and UKF are used as sub filters in MMAE algorithm to realize the state estimation of nonlinear system. Meanwhile, this method is applied to the SINS/CNS integrated navigation system under the motion of ballistic missile. As the simulation result shows, the improved filtering methods have better navigation accuracy, and can solve the problem of poor adaptability of single model filter, when compared with traditional EKF and UKF algorithms.
  • Article
    Fiber Laser Phased Array for Deep-Space Information Transmission
    WANG Tianshu, SUN Hongwei, HAN Jian, ZHANG Peng, HU Yuan, ZHANG Lizhong, LIU Jingjiao, JIANG Huilin
    2014, 1(4): 282-288. https://doi.org/10.15982/j.issn.2095-7777.2014.04.006
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    In this paper, the technology of deep space laser communication and all optical networking based on fiber laser phased array using dynamic connection is proposed. The link power in deep space laser communication from 40 000 km to 35 000 km are simulated. Because the limit of saturation output of erbium-doped fiber amplifier, the safety margin using 1.55 μm laser is much lower than that of 1.064 μm. The far field intensity distribution of 1.064 μm fiber laser phased array in deep space is simulated. It is found that the scanning angle range is different with distance between two adjacent elements. With a 20×20 array, fiber core radius and distance between two adjacent elements are 10 μm and 20 μm respectively, the scanning angle range is ±1.309°. Therefore, the fiber laser phased array of the light source at 1.064 μm is more suitable for deep space communication systems. This study provide a theoretical basis for the realization of a dynamic link for laser phased communication.
  • Article
    A Path-Planning Method for Mars Rovers based on Grid Map
    DONG Yuanyuan, CUI Hutao, TIAN Yang
    2014, 1(4): 289-293. https://doi.org/10.15982/j.issn.2095-7777.2014.04.007
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    Path-planning is one of the major parts for Mars to complete exploration missions. With running slowly and higher computing complexity, traditional path-planning algorithms, such as A* and D* algorithms, are no longer in using. In this paper, a fast and efficient global path-planning method is got through improving the conretional A* algorithm. Then combining with local obstacle avoiding method, a complete rover path-planning method based on grid map is obtained. Finally, by using simulation provefs this method is effective and available.
  • Article
    Statistical Characteristics of Martian Equatorial Ionosphere based on MARSIS
    WANG Mingyuan, PING Jinsong
    2014, 1(4): 294-297. https://doi.org/10.15982/j.issn.2095-7777.2014.04.008
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    In calibrating the Martian ionosphere effects in subsurface detection of MARSIS (Mars advanced radar for subsurface and ionospheric sounding), total electron content (TEC) of the Martian ionosphere is yielded as a by-product. Using these data, the peak electron density and scale height of Martian ionosphere in equatorial region is calculated. The result shows in equatorial region Martian ionosphere is more obvious in winter than in summar and the gradient of eletron density of Martian ionosphere in spring is of the biggest.
  • Article
    Modeling on Autonomous Navigation of Mars Probe with Pulsars and Nonreal-Time Adjustment Methods
    WEI Erhu, YANG Hongzhou, ZHANG Shuai, LIU Jingnan, YI Hui
    2014, 1(4): 298-302. https://doi.org/10.15982/j.issn.2095-7777.2014.04.009
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    To investigate the autonomous navigation of probe orbiting the Mars orbit X-ray pulsars, different real-time adjustment methods are applied in this paper, including the extended Kalman filter (EKF), adaptive extended Kalman filter (AEKF) and robust adaptive extended Kalman filter (RAEKF). Firstly, the observation data, i.e., time of arrival, is simulated according to the principles of pulsars navigation. Secondly, extended Kalman filter (EKF), adaptive extended Kalman filter (AEKF) and robust adaptive extended Kalman filter (RAEKF) are used to get the position and velocity of the probe. Thirdly, the adjustment results are compared with the orbit generated by STK, the results show AEKF and RAEKF performs better than EKF, the result of AEKF is better than the km level of VLBI and can reach the precision level of triple pass Doppler, leveling at 94.1 m in X-axis, 19.5 m in Y-axis and 22.3 m in Z-axis.
  • Article
    Experimental Study on Triple Junction Solar Cells Performance and Dust Removal Efficiency with Mars Dust
    JIA Wei, NI Jiawei, HUANG Sanbo, ZONG Wei, XIAO Jie, WANG Xunchun, CHI Weiying
    2014, 1(4): 303-307. https://doi.org/10.15982/j.issn.2095-7777.2014.04.010
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    In the future manned lunar landing, the solar array output power may be decreased or molfunction when the Mars dust accumulated on the surface of the solar array. In recent years, electric curtain dust removal method is considered an effective means for the Mars dust prevention. In this paper, the performance of triple-junction gallium arsenide solar cell was analysed as Mars dust accumulated on solar cell. From the experimental results, we obtained a trend exponential function between the relative output power and dust deposition mass. Next, the dust removal efficiency of electric curtain under different Mars dust accumulation mass was studied, and the optimum operating point of electric curtain dust removal device was obtained. The research will provide a strong technical support for adaptive dust solar array.
  • Article
    Characteristic Areas Extraction and Tracking Algonthm in the Process of Asteroid Landing
    WEI Ruoyan, RUAN Xiaogang, PANG Tao, Ouattara SIE, WU Xuan, XIAO Yao
    2014, 1(4): 308-314. https://doi.org/10.15982/j.issn.2095-7777.2014.04.011
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    A new algorithm is proposed for the landmark tracking in the process of asteroid soft landing that based on the frame of DIMES. Firstly, a method of luminance equalization is used for highlight the shadow areas and light areas, and convert the image into the binary one to find the connection areas. Secondly, find the high correlation location of the binary areas by template matching. Finally, confirm the characteristic areas by the geometrical relationship of different characteristic areas, and extract the characteristic vectors of the high correlation areas, and analyze the degree of similar between areas and the land mark to find the most similarity location. Two groups of the terrain picture of asteroid are examined in the paper and the result is well.
  • Article
    Non-Fragile Robust Control for Lunar Rotary-Drill Spamling Technology
    ZHENG Yanhong, DENG Xiangjin, ZHAO Zhihui, YAO Meng, ZOU Xin
    2014, 1(4): 315-319. https://doi.org/10.15982/j.issn.2095-7777.2014.04.012
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    Rotatory drilling is a key technology to lunar sampling mission. Model perturbation of rotatory drilling mechanism exists in lunar complex environment. And system disturbance always influences the control system performance. Robust of controller plays an important role in sampling mission. Perturbation and disturbance was analyzed in the state space description. The state feedback non fragile robust controller was induced with linear matrix inequality method. Simulation results proved that the controller is inner stable with bounded model perturbation and has suppression ability to disturbance.