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Table of Content

    25 August 2022, Volume 42 Issue 4 Previous Issue   
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    Intelligent program synthesis framework and key scientific problems for embedded software
    YANGMengfei, GUBin, DUANZhenhua, JINZhi, ZHANNaijun, DONGYunwei,
    2022, 42 (4):  1-7.  doi: 10.16708/j.cnki.1000-758X.2022.0046
    Abstract ( 96 )   PDF (2052KB) ( 264 )   Save
    Program synthesis is an effective way to improve the efficiency of software development and the quality of software,and it is one of the most challenging problems in computer science.Firstly,the research status and existing problems of program synthesis methods were reviewed.Secondly,the concept of software IP(intellectual property)and an embedded software intelligent synthesis development method based on software IP(IP based embedded software intelligent synthesis,IPESIS)with its framework were proposed.Finally,the key scientific problems and main research contents that IPESIS needs to solve were discussed.IPESIS describes software requirement at a higher level of abstraction by defining the domain requirement description language,reduces the program search space with software IP as the granularity,and uses machine learning and other artificial intelligence technologies to automatically synthesize programs.It is expected to break through the limitations of existing methods,and then realize the transition of embedded software development from manual programming to software IP research and development plus intelligent synthesis based on software IP.
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    Analysis on geolocation error of FY-3D MERSI imaging
    HUANG Xuxing, YANG Yong, SHE Yuchen, JING Zhenhua, HU Xiuqing, GAO Xudong, LI Shuang
    2022, 42 (4):  8-18.  doi: 10.16708/j.cnki.1000-758X.2022.0047
    Abstract ( 170 )   PDF (4410KB) ( 102 )   Save
    Accurate geolocation of Fengyun 3D(FY-3D)medium resolution spectral imager(MERSI)images improves the remote sensing performance.Given that the coastline of the images after geolocating generates a periodically oscillating error in this stage,the geolocation error was systemically analyzed based on the attitude and orbit control of satellites.Firstly,the FY-3D satellite′s dynamic model and the imaging model were established.Then,based on real images from the FY-3D/MERSI,the geolocation errors resulting from the attitude and orbit control subsystem were analyzed.Finally,the source of geolocation error was validated in numerical simulations by comparing the results with real images.The study indicates that onboard attitude and orbit propagation errors and payload mounting error of the attitude and orbit control subsystem can cause the deviation of the imaging reference,thereby leading to the periodically oscillating error of the images after geolocating.
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    Inter satellite link planning of high middle low orbit hybrid constellation
    TIAN Lu, MA Dongqing, SUN Jianwei, LI Junping
    2022, 42 (4):  19-26.  doi: 10.16708/j.cnki.1000-758X.2022.0048
    Abstract ( 211 )   PDF (1204KB) ( 156 )   Save
    According to the characteristics of mixed constellation of BeiDou system after adding LEO enhanced constellation,in order to meet the major inter satellite link business requirements of the next generation navigation constellation,a hierarchical planning scheme for inter satellite link planning of hybrid constellation was proposed,and priority was given to the establishment of topology for MEO,LEO and MEO LEO of laser inter satellite link.A grouping topology planning algorithm for TDMA was proposed based on the topology,and two improved routing algorithms were proposed for hybrid inter satellite networks in navigation constellation.Simulation and planning of the hybrid system inter satellite link were carried out,the correctness of the hybrid network planning method was proved,and the data transmission efficiency of the hybrid network in three typical navigation business scenarios of LEO monitoring data backhaul,inter layer data transmission and navigation information injection was verified.The results show that the delay of LEO monitoring data backhaul and continuous system node navigation information injection is less than 1s.There are 5~8 inter layer intersatellite links for 94% of the time,and the TDMA node can complete the navigation information injection in 12s for 92% of the time,which provides reference for the planning and design of the next generation navigation system.
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    Simplification method and application of dynamic analysis model for spacecraft equipment
    LI Xiufeng, BAI Guangming, GAO Lingfei, HAN Shaohuan, ZHOU Jiang
    2022, 42 (4):  27-35.  doi: 10.16708/j.cnki.1000-758X.2022.0049
    Abstract ( 129 )   PDF (5185KB) ( 146 )   Save
    Aiming at the difficult modeling problem of dynamic analysis model caused by complex composition of spacecraft equipment, a method of finite element model simplification based on topology optimization was proposed.In this method, the measured mass characteristics of the spacecraft equipment were taken as the constraint condition, and the material distribution in the feasible design space of the finite element model of the equipment was determined by the topology optimization method.Then the stiffness performance of the structure was simulated, and finally the simplified finite element model of the equipment was obtained to meet the needs of dynamic characteristics analysis.A simplified finite element model of a star sensor was established by using this method.This obtained model is basically consistent with the actual mass, centroid position and moment of inertia of the product, and the maximum frequency deviation of the first two orders between the analysis values and the experimental values is less than 30%.Then, the simplified model was applied to the dynamic response performance evaluation of the support structure.The analysis data of natural frequency and acceleration response trend of the assembly are in line with the test data under the frequency range below 450Hz, and the maximum deviation of natural frequency is about 39%.The application results verify the rationality of the simplified finite element modeling method based on topology optimization technology, which provides a new solution for simplified finite element modeling of complex spacecraft equipment dynamics analysis.
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    Relative pose measurement for non-cooperative target based on monocular vision
    XING Yanjun, WANG Hao, YE Dong, ZHANG Jiaxun
    2022, 42 (4):  36-44.  doi: 10.16708/j.cnki.1000-758X.2022.0050
    Abstract ( 197 )   PDF (5167KB) ( 307 )   Save
    In order to realize the on orbit service and maintenance of the space attitude tumbling spacecraft and the removal of space debris,it is necessary to perform accurate relative pose measurement.Aiming at the problems,a relative pose measurement method based on monocular vision and Kalman filter was proposed.By investigating the feature point matching algorithm,the feature point extraction methods based on the scale invariant feature transform (SIFT) algorithm and the speeded up robust feature (SURF) algorithm with scale invariance and rotation invariance were used.And these two algorithms were further compared to get the working conditions of each other.Through the study of Kalman filter algorithm,the camera bias matrix was introduced,the Kalman filter was designed,the range ambiguity problem of the monocular camera was solved,and the relative pose,main inertia ratio and feature point position information of non-cooperative targets were estimated.According to the simulation,the attitude angle estimation error is less than 0.3° after stabilization,and the relative position estimation error is less than 0.5m.Compared with the true values,the errors are less than 1.67%.The main inertia ratio estimation error is less than 0.01,and the feature point position error is less than 0.005m after stabilization.After introducing the camera bias condition,all the filtering state variables converged,and an estimation with sufficient accuracy was obtained.The problem of the lack of depth information of the monocular camera has been successfully solved.
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    A PPP-RTK atmospheric correction model generation method with fast convergence and high reliability
    TIAN Ye, ZHANG Lixin, BIAN Lang
    2022, 42 (4):  45-53.  doi: 10.16708/j.cnki.1000-758X.2022.0051
    Abstract ( 174 )   PDF (6654KB) ( 291 )   Save
    The key and bottleneck of PPP-RTK application is the generation of atmospheric correction model with fast convergence and high reliability.The PPP-RTK atmospheric correction model generation method mentioned above was investigated.The fast convergence and reliability were ensured by iterative constraints and time domain constraints,and the horizontal 10cm(95%)positioning accuracy was achieved in 45s using Wuhan CORS.On this basis,Hong Kong CORS was used for further validation and analysis.Although increasing the grid density can improve the positioning accuracy,the amount of information is increased.It is necessary to consider the positioning effect and the amount of broadcasted information,and the latitude and longitude of grid size for general users are suggested to be set at 0.5°~0.8°.The spatial distribution of reference stations must be reasonable and uniform,and it was proposed that virtual reference stations can be added within a reasonable range to constrain the generation of atmospheric correction models,thus ensuring their convergence and reliability.
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    Common frequency sharing method for multi channel mission data transmission system of remote sensing satellites
    GAO Weibin, ZHANG Hanqing, SHI Yunchi
    2022, 42 (4):  54-60.  doi: 10.16708/j.cnki.1000-758X.2022.0052
    Abstract ( 131 )   PDF (2133KB) ( 78 )   Save
    In order to save frequency resources,spread spectrum communication is usually used to realize multi-channel mission data transmission sharing the common frequency in remote sensing satellite.Regarding to the mutual interference caused by multi-channel transmission signals,a new common frequency sharing method for two-channel mission data transmission based on direct sequence spread spectrum was proposed.This method calculates the tight jamming margin for balanced Gold sequence spread spectrum system through improved interference estimation model of CDMA.Meanwhile,it also satisfies the ITU′s constraints of emitter power flux density.Simulation results show that the common frequency can be shared in the two signals when the difference of two emitter signals EIRP is less than 8-15dBw in carrier frequency 2GHz.The performance compatibility could be improved if the measures of spread spectrum bandwidth differentiation processing are taken.
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    A high-accuracy measuring method of beam center velocity in continuous wave radar
    NIU Wenbo, ZHANG Aijun, PAN Lin, LI Shuanlao, WANG Zhenxi
    2022, 42 (4):  61-68.  doi: 10.16708/j.cnki.1000-758X.2022.0053
    Abstract ( 145 )   PDF (4472KB) ( 77 )   Save
    For solving the influence of the heterogeneous scattering features of area target and the acceleration in velocity measuring of CW radar for landing navigation,a high-accuracy beam center velocity measuring method was presented.Kalman filter was used for velocity tracking and acceleration compensation after acceleration estimating.ZFFT transform was used for spectrum zoom of target Doppler range.Finally the envelope method was presented for high-precision estimating of beam center velocity.The simulation results verify that the envelope method can obtain higher estimating precision and adaptation than other methods,the standard deviation(3δ)of velocity measuring error is less than 0.15m/s.The process time analysis results of hardware system verify that the algorithm procedure is suitable for real-time processing,and has been successfully used in certain landing navigation radar system.
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    Monitoring of hypervelocity impact damage to honeycomb sandwich structures by using electrical tomography
    SHU Jiajun, ZHOU Deng, YAN Gang, LI Gan, WANG Yongwei
    2022, 42 (4):  69-78.  doi: 10.16708/j.cnki.1000-758X.2022.0054
    Abstract ( 131 )   PDF (8519KB) ( 74 )   Save
    Aiming at the impact problem of spacecraft by micrometeoroid/orbital debris(MMOD)at hypervelocity,monitoring of the hypervelocity impact damage to honeycomb sandwich structures was studied.A method was proposed to co-cure carbon nanotube(CNT)film on the surface of honeycomb sandwich structure to enable it have self-sensing capability to detect and identify hypervelocity impacts and their associated damage by using electrical tomography technique.Experimental studies were conducted with a two-stage light gas gun to perform hypervelocity impacts to the self-sensing honeycomb sandwich structures.By injecting tiny currents into the CNT sensing layers before and after hypervelocity impacts,the conductivity changes caused by hypervelocity impacts were reconstructed by the change of boundary voltages,providing valuable information about the impact and damage.The experimental results show that,the CNT sensing layers have good performance,and the reconstructed images of conductivity changes can reflect the number,locations and approximate sizes of the damage,validating the effectiveness of the proposed method and providing a new technical method for spacecraft to monitor hypervelocity impacts.
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    Review of flexible tensioned thin-film deployable antennas
    ZHOU Xiaotao, MA Xiaofei, LI Huanxiao
    2022, 42 (4):  77-91.  doi: 10.16708/j.cnki.1000-758X.2022.0055
    Abstract ( 298 )   PDF (14136KB) ( 285 )   Save
    The flexible tensioned thin-film deployable antenna is a kind of large-scale deployable antenna with wide application prospects,which integrates flexible electronics,flexible thin-film material,flexible structure and flexible deployable technology.The antenna has the characteristics of lightweight,high spreading ratio,high gain,and flexible beam,which can effectively meet the special needs of remote sensing,communication and deep space exploration satellites.The characteristics and current status of research on flexible tensioned thin-film deployable antennas were described;a survey of the antennas in terms of materials,structures and applications was carried out to provide an overview of the existing structural forms;the basic theory and comprehensive test methods of the development of the thin-film antennas were summarized;the key technical problems to be solved in the development of the large deployable space antennas were discussed in the context of specific engineering problems,and the technical development trend of the thin-film antennas was further analyzed.
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    Interval model updating method for space deployable structure
    WEN Jiangbo, LI Tuanjie, WANG Zuowei, TANG Yaqiong
    2022, 42 (4):  92-101.  doi: 10.16708/j.cnki.1000-758X.2022.0056
    Abstract ( 135 )   PDF (7940KB) ( 184 )   Save
    The traditional model updating method does not take into consideration the uncertainties existing in engineering, such as geometric size, material parameters and gap error, so the prediction accuracy of the updated finite element model is low. In order to improve the prediction accuracy of the finite element model and accurately predict the static and dynamic characteristics of the structure, the model updating method considering the uncertainty of parameters was studied, and an interval model updating method based on Kriging model and universal grey number was proposed. Firstly, the parameters to be updated were determined by sensitivity analysis. Secondly, the interval response objective function based on the Kriging model was constructed with the updated parameters as variables, and the universal grey number was introduced to convert the interval response objective function into two objective functions of the upper limit of the interval and the diameter of the interval. Thirdly,the Kriging model combined with the genetic algorithm was used to give the updated parameter interval. Finally, the proposed method was used to update the model of a space deployable structure with hinge gap. The results show that the parameter interval obtained by the proposed method has a high degree of coincidence with the true interval, and the modified structural response interval is consistent with the true interval, which verifies the effectiveness of the proposed method. The research results provide an effective and feasible way for model updating of large space deployable structures.
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    Study on design and repetitive deployment precision of deployable membrane sunshields
    XU Yan, ZHANG Chao, LI Hongwei, YANG Huxiao
    2022, 42 (4):  102-110.  doi: 10.16708/j.cnki.1000-758X.2022.0057
    Abstract ( 139 )   PDF (8448KB) ( 87 )   Save
    To suppress stray light from the star sensor,a cylindrical deployable membrane sunshield with axial expansion was designed,including inflatable support tubes,membrane skin and vanes.The structure and material design of each component were completed.Kinematic analysis model of the membrane skin was established,and the variation process of the configurations with the dihedral angle was analyzed.The membrane skin can be folded and deployed completely by hexagonal origami pattern.The repetitive deployment precision of the sunshield was studied by experiments,including the axial and radial precision.The prototype model of the sunshield was developed,and the ground deployment test was carried out.Results showed that the sunshield was successfully deployed under the drive of the inflatable support tubes.The work provides a new technical scheme for the engineering application of large size sunshields.
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    Optimization design of mesh antenna considering thermal deformation in service
    HAN Ruoyu, HE Baiyan, NIE Rui, FAN Yesen, MA Xiaofei
    2022, 42 (4):  111-119.  doi: 10.16708/j.cnki.1000-758X.2022.0058
    Abstract ( 148 )   PDF (4947KB) ( 170 )   Save
    Mesh antennas serve in harsh space environments with extreme temperatures and intense radiation.Thermal deformation is an essential factor that affects the performances of mesh antennas.The existing pretension design methods are generally carried out under ambient temperature,which is challenging to consider the influence of the in-orbit service environment on the antenna’s performances. An optimization model was established by introducing the temperature load into the cable net model.In this model,the cable element parameters at ambient temperature were the optimization variables.The surface accuracy and tension distribution under the in-orbit service environment were the optimization objectives and constraint conditions,respectively,which can fully consider the performances of antennas in the service environment at the initial design stage to improve the surface accuracy and uniformity of tension distribution.The in�orbit thermal environment of the antenna was analyzed,and the temperature fields of different orbital positions were calculated.Based on the nonlinear finite element theory,a thermal-structure model of the mesh antenna was established,and a form-finding and optimization design method considering the temperature effect was proposed.The optimization design of the antenna’s service performance was carried out.The optimization results indicate that the proposed method can effectively improve the antenna’s in-orbit performance,which can provide a strategy for the optimal design of the mesh antenna considering the space environment.
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    Mobility analysis of deployable space structures based on group theory group theory
    FAN Linzi, YE Wangjie, CHEN Yao, LU Chenhao
    2022, 42 (4):  120-128.  doi: 10.16708/j.cnki.1000-758X.2022.0059
    Abstract ( 133 )   PDF (3650KB) ( 102 )   Save
    To develop deployable structures with novel geometric configuration,strong vitality,and convenient transportation and storage,mobility and folding analysis on deployable structures is important.As the involved configurations could be effectively deployed or folded,these structures would satisfy the hard conditions of time or space,and meet the needs of some specific tasks.In fact,most existing deployable structures show certain symmetries.From the point of view of symmetry,group theory was introduced to explain the essence of kinematic mobility in-depth.Afterwards,the sufficient condition for evaluating the mobility of symmetric systems was proposed.According to the property of geometric constraints and the variational principle,the compatibility matrix of a typical member in assembling deployable structures was derived.Based on the symmetry subspaces,the symmetry representations of internal mechanisms and self-stress states were deduced.Then,symmetry-adapted mobility analysis on a few closed-loop deployable structures was presented.The study is devoted to promote the design and development of novel symmetric deployable structures,providing a basis for further studies and potential applications on novel deployable structures and kinematically indeterminate structures.
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    Analysis and application of deployment principles of large-scale spacecraft parts
    ZHANG Yuanxun, XU Liping, CHEN Guohui, XIE Gengxin, YANG Xiaojun
    2022, 42 (4):  129-145.  doi: 10.16708/j.cnki.1000-758X.2022.0060
    Abstract ( 227 )   PDF (10794KB) ( 244 )   Save
    Based on the new technology,new material and new structure of the in-orbit deployable mechanism of large-scale spacecraft components involved in the development of spacecraft towards large scale and long distance,the deployable mechanism of large-scale components on the existing spacecraft was analyzed statistically,and the technical parameters,structures and compositions of foldable mechanisms of in-orbit spacecraft were systematically combed.The application of new craft and materials including origami art,self-rebound materials and shape memory alloys in large-scale components,such as solar sails and antennas of spacecraft,was introduced.The characteristics and working principle of new structures including inflatable type,axial rotating type,radial expansion type,reconfigurable type,linear elongation type,etc,were analyzed and combed.Finally,in conjunction with the upcoming moon landing,construction of a lunar base,exploration of solar system and other deep space exploration missions,the trend of development about the large-scale components of in-orbit spacecraft was prospected.
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    Geometric design and motion analysis of Miura-Ori mechanism with thick panels
    CHANG Boyan, XU Xin, LIANG Dong, ZHANG Haonan
    2022, 42 (4):  146-157.  doi: 10.16708/j.cnki.1000-758X.2022.0061
    Abstract ( 253 )   PDF (11832KB) ( 287 )   Save
    Different from the general motion mechanism,the space deployable mechanism is strict with the geometry shape and dimensions of components.Based on the origami theory of thick panels,two kinds of Miura-Ori deployable unit(Bennett unit and spherical 4R unit)were obtained for accommodating material thickness to avoid physical interference.The flat-foldable condition for achieving the compact folding and maximum expansion as well as the requirement of constructing large space deployable mechanism with infinite number of units were considered to deduce components geometry constraints.The process to constructing large deployable Miura-Ori mechanism was explained and corresponding two typical network systems which can maintain the kinematic properties of the origami mechanism were established.Finally,the influence regularity of various factors on folding ratio was analyzed and a general approach for optimum design of Miura-Ori mechanism with thick panels was proposed which can provide reference for practical engineering application of this kind of mechanism.
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