Mar 2024, Volume 11 Issue 1
    

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  • Research Progress of Autonomous Navigation and Control Technology for Extraterrestrial Soft Landing
    HUANG Xiangyu, XU Chao, GUO Minwen
    2024, 11(1): 3-15. https://doi.org/10.15982/j.issn.2096-9287.2024.20230178
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    Soft landing exploration is an important method for exploring extraterrestrial objects, and guidance, navigation and control (GNC) is the key to successful soft landing of extraterrestrial objects. Firstly, the development status of soft-landing missions of foreign and domestic celestial bodies such as Moon, Mars, and small celestial bodies was reviewed. On this basis, the typical GNC schemes for soft landing missions of extraterrestrial objects and the main progress of autonomous navigation and control technology were summarized. Finally, the key technologies for autonomous navigation and control that require special attention and development were proposed for future pinpoint soft-landing missions of extraterrestrial objects, in order to provide the experience and reference for future technological development.
  • Trajectory Optimization for Lunar Hover Hop with Multi Constraints
    CHEN Shangshang, GUAN Yifeng, HUANG Xiangyu
    2024, 11(1): 16-23. https://doi.org/10.15982/j.issn.2096-9287.2024.20230005
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    The multi-constrained trajectory of minimal fuel consumption was achieved in this paper for the lunar hover hop without lateral thrusters. The hover hop was divided to 3 phases: the vertical rise, the horizontal traverse and the vertical descent. The optimal control of the vertical rise and the vertical descent was bang-bang function. For the first time the control variable of the horizontal traverse was converted from thrust to angle rate, with position, velocity and angle rate considered. The preliminary form of the optimal angle rate for the horizontal traverse was developed by application of the Pontryagin’s minimum principle. With further study on the continuity of the singular point and the number of switching times of the control variable, it was confirmed that the optimal angle rate program consisted of either the maximum or the minimum and there were 2 switchings. A numerical approach to searching the switching points was presented. Simulation results show that the approach with high accuracy and low complexity can potentially be implemented onboard for trajectory optimization.
  • Intelligent Fusion Autonomous Navigation Method for Mars Precise Landing
    GAO Xizhen, HUANG Xiangyu, XU Chao
    2024, 11(1): 24-30. https://doi.org/10.15982/j.issn.2096-9287.2024.20230041
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    To overcome the difficulty of absolute optical navigation in unknown environments, an intelligent fusion autonomous navigation method for Mars precise landing was proposed. Considering the difficulties of the inability to detect features and the low efficiency of recognition brought by high texture similarity in the extraterrestrial environment and perspective scaling between images, an unsupervised homography network was constructed to estimate the inter frame motion of the lander. Based on the inertial measurement information, a recursive model of the lander state was established. Using the established measurement model and state recursive model, real-time estimation of the lander position, velocity, and attitude was achieved through UKF. The simulation results verify the effectiveness of the proposed method without the need of feature detection and matching.
  • Design of Adaptive Iterative Guidance Scheme for Mars Ascent Vehicle Orbiting Phase
    SONG Chun, GUO Yanning, GUO Minwen, LI Kun
    2024, 11(1): 31-39. https://doi.org/10.15982/j.issn.2096-9287.2024.20230055
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    An adaptive iterative guidance strategy was designed for the guidance of Mars ascent vehicle in the orbiting phase. To reduce the effects of initial state deviation and the uncertainty of the Martian environment, the remaining flight time was calculated iteratively in the guidance coordinate system in each cycle, and the optimal control angle satisfying the constraints of the target point position and velocity vector was solved under the fixed thrust of the ascender, so as to correct the flight trajectory in real time. The simulation results show that compared with the traditional open-loop guidance scheme, the proposed scheme significantly improves guidance accuracy, in which the altitude error is reduced by three orders of magnitude, the maximum velocity error is reduced to one-third of that of the original open-loop guidance, the orbital inclination and eccentricity errors at the entry point satisfy the basic engineering requirements, and it can be used as a reliable scheme for the future guidance of the Mars ascent vehicle in the orbiting phase.
  • Mapped Chebyshev Pseudospectral Convex Optimization for Martian Ascent Trajectory Planning
    XU Yuanjing, LIU Xu, PENG Shengjun, XI Tao, ZHU Yongsheng, XIAO Yao, LI Shuang
    2024, 11(1): 40-46. https://doi.org/10.15982/j.issn.2096-9287.2024.20220113
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    Mapped Chebyshev pseudospectral convex optimization approach was proposed for Martian ascent trajectory optimization. Firstly, the lossless convexification technique was used to convexify the fuel-optimal problem of Martian ascent. Then, the convexified problem was discretized at mapped Chebyshev-Gauss-Lobatto points and interpolated by the barycentric rational interpolation techniques. Finally, the sequential convex optimization method was used to solve the convex problem iteratively to obtain the numerical optimal solution. Simulation results show that the proposed method is superior to the classical sequential convex optimization method in computational efficiency, and effectively improves the ill-condition of standard Chebyshev differential matrices.
  • A Constant-Thrust Guidance Method with Yaw Maneuver for Pinpoint Landing
    LI Ji, ZHANG Honghua, ZHANG Xiaowen, GUAN Yifeng
    2024, 11(1): 47-55. https://doi.org/10.15982/j.issn.2096-9287.2024.20230026
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    To realize all the six components of terminal position and velocity control for pinpoint landing, throttleable engines are usually needed. In order to reduce economic cost and technique risk, a constant thrust guidance method with yaw maneuver for pinpoint landing was proposed in this paper. The range in the flight line was controlled by yaw maneuver which regulated the in-plane component of the thrust. And a strategy to change the sign of heading angle was performed to eliminate the position and velocity errors in the cross direction, which made the trajectory in horizon plane resemble the letter “W”. This method steered the spacecraft to a given target point with a little more fuel consumption. Simulation results show that the method proposed in this paper is easy to use and efficient.
  • Fast Spin Cross-Scale Small-Body Light Invariant Matching Algorithm
    LI Shuai, LI Jinyi, LIU Yanjie, SHAO Wei, HUANG Xiangyu
    2024, 11(1): 56-62. https://doi.org/10.15982/j.issn.2096-9287.2024.20230038
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    During the attachment process of small body spacecraft, there are scale, viewpoint and illumination variations in the image, making it difficult for traditional feature-matching algorithms to obtain accurate matches. In this paper, a small-body cross-scale illumination invariant matching algorithm is proposed. To address the problem of scale changes in the image during the attachment process, the global attention mechanism is combined with the dilated convolution to construct a scale adaptive adjustment module; the viewpoint invariant feature extraction module is designed to solve the problem of low matching accuracy under the large viewpoint changes in the feature matching algorithm; the self-attention mechanism is combined with the inter-attention mechanism to establish the feature dependency relationship, and the illumination invariant features are extracted. Experimental validation is carried out using the real images of Ceres and Bennu, and the results show that the proposed algorithm achieves an accuracy of more than 89% under large scale, view angle and illumination changes.
  • A Method for Estimating Motion State of Small Bodies Based on Fusion of Camera and LIDAR
    CHEN You, GUO Jinrong, LIU Yanjie, SHAO Wei, HUANG Xiangyu
    2024, 11(1): 63-70. https://doi.org/10.15982/j.issn.2096-9287.2024.20230039
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    Only one vision sensor is incompetent for estimating the motion state of small body. In order to solve this problem, a small body motion state estimation method based on the fusion of camera and LIDAR was proposed. Firstly, a fused camera and LIDAR measurement model was built. By tracking image feature points with depth information, extended Kalman filter was used to estimate the spin angular velocity, spin axis direction, position and velocity of small body. Secondly, a feature fusion matrix was designed to achieve real-time updates of image feature points, point clouds, and fused feature points. Thirdly, the effectiveness of this algorithm and the impact of the number of feature points, observation height, and noise on the algorithm were analyzed. Simulation results show that the accuracy of the proposed algorithm is significantly higher than that of the spin parameter estimation algorithm of small bodies based on monocular camera.
  • Hazard Avoidance for Complex Planetary Surface Landing Using Augmented Curvature Guidance Method
    YANG He, YUAN Xu, GE Dantong, ZHU Shengying
    2024, 11(1): 71-78. https://doi.org/10.15982/j.issn.2096-9287.2024.20230053
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    A hazard avoidance strategy based on augmented curvature guidance was presented for complex planetary surface landing. Based on the basic curvature guidance law, a hazard avoidance augmentation term was introduced. The idea of spacecraft landing space division was used and an anti-collision zone was defined in the collision prone zone near the hazards. The continuous analytical hazard avoidance guidance law was derived based on anti-collision zone. While meeting the geometric convex trajectory state constraints, the hazard avoidance guidance law evaluated the relative position relationship between spacecraft and hazards, which can quickly steer the spacecraft away from hazards and increase landing safety. Simulation results reveal that the validity of avoiding terrain hazards on the complex planet surface and achieving pinpoint soft landing is enhanced, with good flexibility and reliability.
  • Study on the Construction Scheme of Mega Interconnected Knowledge Systems in Deep Space Exploration
    LIU Jizhong, GE Ping, KANG Yan, ZHANG Tianxin, JIANG Yichen, MA Ke, SHAO Yanli
    2024, 11(1): 79-89. https://doi.org/10.15982/j.issn.2096-9287.2024.20230169
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    China’s deep space exploration has gradually developed from technology and science-driven to the stage dominated by science, leading to technological advances. Under our demand for high-quality development in deep space exploration, the Mega Interconnected Knowledge System in Deep Space Exploration (MIKSE) was innovatively proposed with its concept and scheme conceiving. Centering around the scientific goals, deep space exploration engineering, science, technology, and big data in the application were collected, techniques including artificial intelligence and cloud computing were utilized to perform organic organization, information association, and knowledge mining on relevant elements, a large model with genealogical associations and networks of connections was built, and an intelligent big knowledge platform was established. With the help of this platform, historical data and its current capabilities can be fully utilized to support generative knowledge and information for the future planning and development of deep space exploration and promote the paradigm shift of data-driven deep space research.
  • Orbital Dynamics of Dust Particles in the Region of the Jovian Irregular Moons
    YE Anqi, CAI Zizhe, CHEN Zhenghan, LIU Xiaodong
    2024, 11(1): 90-99. https://doi.org/10.15982/j.issn.2096-9287.2024.20230096
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    A lot of dust particles are ejected from the surfaces of the Jovian irregular moons by the impact of interplanetary meteoroids. In this paper, the dynamics of dust particles originating from the irregular satellites in the complicated Jupiter system with various perturbation forces were studied, using both the analytical method and the numerical simulation method. By analyzing the conserved effective Hamiltonian quantity and phase portraits in the orbit-averaged model that describes the long-term evolution of motion of dust, it is concluded that dust particles originating from the prograde satellites tend to be distributed in the direction away from the Sun, while dust particles originating from the retrograde satellite are predominantly distributed in the direction towards the Sun. With long-term numerical simulation, it is found that the orbits of particles originating from prograde satellites are more stable than those of particles originating from retrograde satellites, and the orbital stabilities of large-size dust particles are greater than those of small-size particles.
  • Research on Capability of Space Target Detection by Spaceborne Ultraviolet Cameras
    SUN Tianyu, TANG Yi, LIU Wanyu, BIAN Ziyu, ZENG Tianji, XU Wenbin
    2024, 11(1): 100-108. https://doi.org/10.15982/j.issn.2096-9287.2024.20220093
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    The reflection spectra of satellites are shifted to short wavelengths when seasonal scintillation caused by solar wings occurs, and the shorter wavelength UV band has potential advantages in space target solar wing detection. The space target detection signal-to-noise ratio and detection distance models were developed for space target detection. For the most influential material properties in the model, the spectral reflectance of typical satellite materials and solar wing cell materials in the UV and visible bands were measured, and other influencing factors such as detector and deep space background in the model were also analyzed. Using the SJ-5 and Skynet 5D satellites as examples, it was verified that there was indeed a significant advantage of UV in solar wing detection. The results show that compared with the main body visible detection of the satellite, the solar wing UV detection signal-to-noise ratio is enhanced by 1.3~1.6 times, and the detection distance can be increased by 1.5~1.8 times by the combination of UV and visible light. UV has obvious technical advantages over visible light in detection scenes such as Earth’s limb, occultation and engine tail flame detection during satellite deorbiting, thus UV detection has the obvious advantages of cost-efficiency ratio and detection capability in space target detection.