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15 July 2021 Volume 34 Issue 7
  
    Real-Time Tracking Algorithm for Relay Antenna of Spacecraft
    HUANG Kewu,ZHU Ke,ZHANG Wei,QI Xin
    Electronic Science and Technology. 2021, 34(7):  1-6.  doi:10.16180/j.cnki.issn1007-7820.2021.07.001
    Abstract ( 213 )   HTML ( 388 )   PDF (3054KB) ( 67 )  
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    In view of at the problem that the traditional STK simulation algorithm for tracking angle of relay antenna cannot be used in real-time testing processing for spacecraft AIT, a real-time tracking algorithm for relay antenna is proposed and implemented in software. In this method, the orbit of spacecraft, antenna beam and coordinate system are applied to establish the equivalent model of the direction angle for relay antenna. Combining the spacecraft flight attitude and real-time telemetry, the tracking angle algorithm, real-time test result verification and closed-loop control strategy for relay antenna are realized. The experimental results show that the proposed method not only achieve real-time comparison of relay antenna angle tracking during the AIT test process, but also achieves the real-time prediction of TTC coverage under various flight attitude on orbit.The maximum TTC coverage of a single arc is increased by 13.3%. The method described in the study has been already applied to a certain type of spacecraft sub-system test and in orbit flight missions.

    Event-Based Fault Detection Filter with Packet Loss and Time-Varying Delay
    HUANG Yuecheng,TONG Dongbing
    Electronic Science and Technology. 2021, 34(7):  7-12.  doi:10.16180/j.cnki.issn1007-7820.2021.07.002
    Abstract ( 239 )   HTML ( 32 )   PDF (640KB) ( 43 )  
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    In view of at the problem of coordinated design of event-triggered fault detection filters and controllers in continuous-time network control systems, by considering the network induced delay and the packet loss in networked control systems, an output feedback closed-loop model including the event-triggered mechanism and fault detection filter is established. In order to reduce the conservativeness of the system, Jensen's inequality is used. Compared with Wirtinger inequality, Jensen's inequality is not conservative. Thus, the sensitivity of residual signals for faults can be ensured by the designed fault detection filter and the controller. The effectiveness of the proposed event-triggered mechanism is verified by the simulation, and the residual evaluation function curve proves that system faults can be detected quickly by the fault detection filter.

    Hybrid Iteration Method for Number Conformal Mapping of Multi-Connected Domain
    TANG Shengnan,LÜ Yibin,WANG Yingzi,FANG Jinli,WU Dean
    Electronic Science and Technology. 2021, 34(7):  13-18.  doi:10.16180/j.cnki.issn1007-7820.2021.07.003
    Abstract ( 187 )   HTML ( 32 )   PDF (715KB) ( 41 )  
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    For the problem of numerical conformal transformation of unbounded multi-connected domain of the charge simulation method, this study presents a high-precision numerical method, that is, Hybrid iteration method for number conformal mapping of multi-connected domain. This method constructs a constrain equation by charge simulation method, applies preprocessing to the constrain equation, constructs a symmetric positive definite equation, obtains new charge simulation and angle, and constructs an approximate conformal mapping function. In this study, the numerical experiment is carried out by taking the mapping of multiple connected domain into radial slit domain as an example. The maximum modulus principle of the analytic function is used as the error evaluation index, and the error curves of the Amano method and the algorithm of this study are drawn. When the number of charge simulation is N=180 and the Jordan curve is C2, the error of EA2 the algorithm of this study is 1.676 7×10-7, and the error of EA2 in Amano method is 8.597 7×10-4. When the number of charge simulation is N=180 and the Jordan curve is C3, the error of EΘ3 in the algorithm of this study is 5.635 1×10-10, but the error of EΘ3 in Amano method is 1.102 5×10-5.

    Energy Consumption Model of Cyber-Physical System Based on Object-Oriented Fuzzy Petri Net
    YU Jiawei,HU Haiyang
    Electronic Science and Technology. 2021, 34(7):  19-25.  doi:10.16180/j.cnki.issn1007-7820.2021.07.004
    Abstract ( 217 )   HTML ( 5 )   PDF (1121KB) ( 24 )  
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    Cyber-physical system is an advanced embedded system that integrates computing, communication and control functions, and its energy consumption analysis is currently a hot research issue. In view of the modular architecture and the uncertainties of CPS, this study proposes the OFPN as a new energy consumption model of CPS. In OFPN, the modular logical structure and process of CPS are modeled by OFPN, and the uncertainties in CPS is described by using fuzzy mathematics to blur the energy consumption attributes of transitions in OPN. Besides, a CPS component energy consumption analysis algorithm based on the reachability graph of OPFN is proposed, which calculates the fuzzy energy consumptions of each component and then deblur them to get the minimum and maximum numerical results. The availability of the model and analysis method are verified by the modeling and energy consumption analysis of a real-world CPS (an intelligent thick metal plate production line).

    Insulator Nondestructive Testing Based on Feature Fusion CNN
    MA Lixin,DOU Chenfei,SONG Chencan,YANG Tianxiao
    Electronic Science and Technology. 2021, 34(7):  26-30.  doi:10.16180/j.cnki.issn1007-7820.2021.07.005
    Abstract ( 203 )   HTML ( 8 )   PDF (1070KB) ( 43 )  
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    Currently, it is difficult for the electric power transmission and distribution network to detect the insulator's insulation deterioration in operation. In view of this problem, on the basis of the analysis of the insulation deterioration mechanism, this study proposes an intelligent method based on the feature-fused CNN to detect whether the insulator produces the insulation deterioration. Firstly, the flashover experiment is conducted on the insulator to produce three states as follows: no discharge, weak discharge and strong discharge. Subsequently, the ultraviolet imager is applied to collect the CNN insulator's ultraviolet images in different discharge state to form the sample library. Then, the CNN is adopted to extract the sample's features and fuse the extracted shallow and deep features. Finally, the fusion feature map is identified and classified to judge whether the insulator is degraded. The result reveals that this method has a high detection rate, and the highest correct rate reachs 97.4%. Compared to the AlexNet algorithm, this method has a higher accuracy and quicker convergence speed.

    Evaluation Method of Coal Mine Power Quality Based on Improved Entropy Weight Method
    WANG Yumei,LIU Jingyan,LI Ziqiang
    Electronic Science and Technology. 2021, 34(7):  31-36.  doi:10.16180/j.cnki.issn1007-7820.2021.07.006
    Abstract ( 185 )   HTML ( 6 )   PDF (709KB) ( 27 )  
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    In view of the problem of weight distribution and evaluation accuracy in coal mine power quality evaluation, a method of coal mine power quality evaluation based on improved entropy weight method is proposed in the current study. The factors affecting the power quality in coal mines are analyzed, and an evaluation index system is established. The improved entropy weight method and AHP scale expansion method are combined to calculate the index weight, which overcomes the shortcomings of the single method and improves the accuracy of the weight determination. Probability statistics and fuzzy mathematics are utilized to comprehensively evaluate indicators and weights, and a comprehensive assessment of the power quality in coal mine is achieved. The example analysis shows that the proposed method is helpful to distinguish the power quality grade, and it can qualitatively and quantitatively evaluate the power quality.

    Weighted Maximum Network Lifetime Algorithm in Target Coverage
    ZHOU Jia,WANG Ran
    Electronic Science and Technology. 2021, 34(7):  37-42.  doi:10.16180/j.cnki.issn1007-7820.2021.07.007
    Abstract ( 165 )   HTML ( 4 )   PDF (1245KB) ( 36 )  
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    Unlike traditional WSNs, PDSNs is a new type of monitoring network model. The sensor direction in PDSNs is optional, and the monitoring result of the target is a distance-related probability. Due to the limited energy of the sensors, extending the life of the network with limited energy has become a core issue for PDSNs. The ε-directional coverage maximum network lifetime problem is formally defined in the study, which proves that this is an NP-hard problem, and gives a mathematical definition of the optimization goal and constraints. A priority selection algorithm based on target weight is proposed. The target weight is determined by the potential gain of the target, the priority and coverage set of the target are determined according to the weight order, and the network life is extended through multiple rounds of scheduling. Through simulation experiments under different parameters, it is verified that the target weight preference algorithm can extend the network life by about 10%.

    Optimal Coordination Sizing Analysis of Different Entities Interconnected Microgrids Based on Game Theory
    LIANG Longji,ZHANG Jing,HE Yu,ZENG Xixi,CHEN Chaokuan
    Electronic Science and Technology. 2021, 34(7):  43-49.  doi:10.16180/j.cnki.issn1007-7820.2021.07.008
    Abstract ( 227 )   HTML ( 6 )   PDF (1302KB) ( 35 )  
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    In view of the problem of planning and configuration of interconnected microgrids, which is composed of multiple microgrids with mutual power supply, a non-cooperative game model of planning and construction of interconnected microgrids is established based on the non-cooperative synergistic optimization mechanism of game theory. In this model, microgrid belonging to different entities is taken as game participant. The optimization goal of each participant is to maximize the annual value of the profit-cost function of the whole life cycle of investment, construction and operation. The Nash equilibrium of this problem is solved using the particle swarm optimization algorithm of integer programming. The simulation results show that the optimal allocation model of interconnected microgrid proposed in this study can provide decision-making theoretical basis for the planning and construction parties in the case of the interaction of planning decisions of different microgrid owners.

    Chinese Microblog Polarity Classification Based on Hownet and PMI
    HAO Miao,CHEN Linqiang
    Electronic Science and Technology. 2021, 34(7):  50-55.  doi:10.16180/j.cnki.issn1007-7820.2021.07.009
    Abstract ( 223 )   HTML ( 6 )   PDF (1187KB) ( 33 )  
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    To solve the problem of Chinese microblog sentiment classification, a sentiment classification method combining PMI and Hownet based on microblog data is proposed. Through the research on the short and novel features of microblog data, a method of dictionary merging is proposed.The existing dictionaries are merged according to Hownet word similarity, and PMI is used to perform sentiment classification of online words. The network sentiment words are added to construct sentiment dictionary that adapts to the features of microblog text, and sentiment classification models are trained based on the new dictionary combined with supervised learning methods. The experimental results show that using this method for sentiment analysis can effectively identify the impact of new internet words on sentiment analysis, with an accuracy rate of 78.3%. In the sentiment analysis of microblog containing new words on the Internet, the accuracy rate is higher than that of only using dictionaries or supervised learning.

    Metallization of Dopamine Modified Polyphenylene Ether Substrate
    WANG Kang,FENG Zhesheng
    Electronic Science and Technology. 2021, 34(7):  56-60.  doi:10.16180/j.cnki.issn1007-7820.2021.07.010
    Abstract ( 182 )   HTML ( 7 )   PDF (1723KB) ( 27 )  
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    The symmetrical and low activity molecular structure of PPO substrate makes it has very stable chemical properties. Therefore, it is difficult to deposit high quality metal layer on the substrate surface by electroless plating. In order to solve this problem, chemical etched and dopamine grafting are combined to treat the surface of the PPO substrate to adjust the surface roughness and improve the surface hydrophilicity. Meanwhile, the conductivity and adhesion of the deposited metal layer are improved by introducing active functional groups that have an adsorption effect on Ag+. Characterization tests prove that the copper layer prepared by this method shows a continuous, uniform and densely packed morphology, and has high purity, good crystallinity, excellent adhesion and low resistivity.

    Concentric Detection of Micro-Precision Glass Encapsulated Electrical Connectors by Binary and Hole Filling Fusion Differential
    WANG Gaowei,WANG Fuzhong,LIU Qunpo,WANG Manli,GAO Ruxin,WANG Zhenying
    Electronic Science and Technology. 2021, 34(7):  61-66.  doi:10.16180/j.cnki.issn1007-7820.2021.07.011
    Abstract ( 199 )   HTML ( 5 )   PDF (2671KB) ( 16 )  
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    The micro-precision glass encapsulated electrical connector is widely used in the electronic industry. At present, manual detection is mainly used to detect concentricity, but the detection efficiency and accuracy can no longer meet the application needs. To solve the complex surface texture of cylindrical glass-encapsulated electrical connector and the difficulty in determining the boundary contour of high-temperature and low-temperature glass columns, a fusion difference algorithm based on binary and hole-filling is proposed, and clear inner circle image is successfully obtained. The image of the filled hole is processed by the maximum connected area method, the noise caused by the background texture is removed, and the outer circle image of the main body of the electrical connector is obtained. Then, a concentric calculation model is established based on the information of the inner and outer circle coordinates, and the concentricity parameters are obtained. The experimental results show that the time for concentric detection is shortened from more than 6.5 s for manual detection to less than 0.32 s, and the accuracy rate reaches more than 90%.

    An Overview of the Process and Research on the Preparation of FeNiMoCoCrTi High Entropy Alloys by Fiber Laser
    ZHANG Qi,LI Zhongwen,YU Zhishui
    Electronic Science and Technology. 2021, 34(7):  67-72.  doi:10.16180/j.cnki.issn1007-7820.2021.07.012
    Abstract ( 152 )   HTML ( 9 )   PDF (1432KB) ( 28 )  
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    As a new type of high-performance multi-primary alloy series, high-entropy alloy has broken through the traditional alloy category in terms of alloy principle, electronic theory and physical properties, and has the advantages of element addition and controllability of material physical properties. This study evaluates the technological design and physical innovation of high- entropy alloy preparation, focuses on laser cladding and orthogonal experiments for FeNiMoCoCrTi high entropy alloys. The corresponding solutions are proposed to deal with the limitations of the development of high entropy alloys and laser cladding technology, which provides guiding significance for the development of the application field, the research direction of laboratory and industrial production.

    Roll-to-Roll Preparation of Flexible Metal Interconnect Conductor
    CHENG Siyuan,CHENG Pan,XIAO Kuan,FENG Zhesheng
    Electronic Science and Technology. 2021, 34(7):  73-78.  doi:10.16180/j.cnki.issn1007-7820.2021.07.013
    Abstract ( 183 )   HTML ( 7 )   PDF (2094KB) ( 19 )  
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    For the problems of the current flexible metal interconnect conductor based on the inkjet printing-based printed electronics technology, such as easy clogging of nozzles, poor accuracy of conductor lines, and the process requires heating, a reliable and low-cost flexible metal interconnect conductor is proposed, which is the method of preparing metal interconnect conductor by combining the roll-to-roll printing process and the chemical deposition technique. The flexible substrate material used herein is Teslin paper, which has more excellent mechanical strength and water resistance than ordinary paper. A roll-to-roll flexography machine is used to print the metal interconnect conductor pattern on the flexible substrate material. The ink film on the substrate is dried by ultraviolet curing technology, and the metal copper conductor is obtained on the substrate surface by chemical deposition technology. The advantage of this craft is that the prepared metal copper conductor has high accuracy and the process do not require high temperature equipment. In addition, since a roll-to-roll flexography printing machine is utilized, it has the prospect of large-scale flow production in the industry. The SEM, XRD, EDS and adhesion test of the metal layer of the metal interconnect conductor prove that the surface of the metal layer of the interconnect conductor has advantages including dense surface, high crystallinity, good adhesion, low resistivity (2.62×10-8Ω·cm), and excellent mechanical properties (1 000 bending test).

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