WorldWideScience

Sample records for anti-jamming

  1. Electromagnetic anti-jam telemetry tool

    Science.gov (United States)

    Ganesan, Harini; Mayzenberg, Nataliya

    2008-02-12

    A mud-pulse telemetry tool includes a tool housing, a motor disposed in the tool housing, and a magnetic coupling coupled to the motor and having an inner shaft and an outer shaft. The tool may also include a stator coupled to the tool housing, a restrictor disposed proximate the stator and coupled to the magnetic coupling, so that the restrictor and the stator adapted to generate selected pulses in a drilling fluid when the restrictor is selectively rotated. The tool may also include a first anti-jam magnet coupled to the too housing, and an second anti-jam magnet disposed proximate the first anti-jam magnet and coupled to the inner shaft and/or the outer shaft, wherein at least one of the first anti-jam magnet and the second anti-jam magnet is an electromagnet, and wherein the first anti-jam magnet and the second anti-jam magnet are positioned with adjacent like poles.

  2. Anti-Jam GPS Antennas for Wearable Dismounted Soldier Navigation Systems

    Science.gov (United States)

    2016-06-01

    Jam GPS Systems 6 3. Materials and Fabrication Methods for Wearable Anti-Jam GPS Antennas 8 3.1 Textile- Integrated Antennas 9 3.2 Flexible Polymer...Element and Array Design for Anti-Jam GPS Systems The antenna element design for a CRPA is also of critical importance , particularly for a wearable...ARL-TR-7670 ● JUNE 2016 US Army Research Laboratory Anti-Jam GPS Antennas for Wearable Dismounted Soldier Navigation Systems

  3. Studies on Novel Anti-jamming Technique of Unmanned Aerial Vehicle Data Link

    Institute of Scientific and Technical Information of China (English)

    Huang Wenzhun; Wang Yongsheng; Ye Xiangyang

    2008-01-01

    Based on the M-ary spread spectrum (M-ary-SS), direct sequence spread spectrum (DS-SS), and orthogonal frequency division multiplex (OFDM), a novel anti-jamming scheme, named orthogonal code time division multi-subchannels spread spectrum modulation (OC-TDMSCSSM), is proposed to enhance the anti-jamming ability of the unmanned aerial vehicle (UAV) data link. The anti-jamming system with its mathematical model is presented first, and then the signal formats of transmitter and receiver are derived. The receiver's bit error rate (BER) is demonstrated and anti-jamming performance analysis is carried out in an additive white Ganssian noise (AWGN) channel. Theoretical research and simulation results show the anti-jamming performance of the proposed scheme better than that of the hybrid direct sequence frequency hopping spread spectrum (DS/FH SS) system. The jamming margin of the OC-TDMSCSSM system is 5 dB higher than that of DS/FH SS system under the condition of lUcian channel and full-band jamming, and 6 dB higher under the condition of Rician channel environment and partial-band jamming.

  4. Anti-JAM-C therapy eliminates tumor engraftment in a xenograft model of mantle cell lymphoma.

    Science.gov (United States)

    Doñate, Carmen; Vijaya Kumar, Archana; Imhof, Beat A; Matthes, Thomas

    2016-11-01

    Junctional adhesion molecule (JAM)-C is a member of the JAM family, expressed by a variety of different cell types, including human B lymphocytes and some B-cell lymphoma subtypes-in particular, mantle cell lymphoma (MCL). Treatment with anti-JAM-C pAbs reduces homing of human B cells to lymphoid organs in a NOD/SCID mouse model. In the present study, the role of JAM-C in the engraftment of human lymphoma B cells in mice was investigated. Administration of novel anti-JAM-C mAbs reduced tumor growth of JAM-C(+) MCL cells in bone marrow, spleen, liver, and lymph nodes of mice. Treatment with anti-JAM-C antibodies significantly reduced the proliferation of JAM-C-expressing lymphoma B cells. Moreover, the binding of anti-JAM-C antibodies inhibited the phosphorylation of ERK1/2, without affecting other signaling pathways. The results identify for the first time the intracellular MAPK cascade as the JAM-C-driven signaling pathway in JAM-C(+) B cells. Targeting JAM-C could constitute a new therapeutic strategy reducing lymphoma B-cell proliferation and their capacity to reach supportive lymphoid microenvironments.

  5. Self-Encoded Spread Spectrum Modulation for Robust Anti-Jamming Communication

    Science.gov (United States)

    2009-06-30

    0000 AFOSR / RSE 875 North Randolph Street, Suit 325 | Room 3112 Arlington, Virginia 22203-1768 AFOSR/ RSE AFRL-OSR-VA-TR-2012-0505 1) DISTRIBUTION...SESS), SESS technique, Jam-Resistant or Anti-Jamming (AJ), Pseudo-Random Noise (PN) U U U UU Jon Sjogren, RSE (Program Manager) 703.696.6564 Defense

  6. Reduced-Rank Space-Time Processing for Anti-Jamming GPS Receivers

    Institute of Scientific and Technical Information of China (English)

    ZHUANG Xuebin; CUI Xiaowei; LU Mingquan; FENG Zhenming

    2009-01-01

    In a jamming environment with multiple wideband and narrowband jammers, global positioning system (GPS) receivers can use space-time processing to efficiently suppress the jamming. However, the computational complexity of space-time algorithms restricts their application in practical GPS receivers. This paper describes a reduced-rank multi-stage nested Wiener filter (MSNWF) based on subspace decomposi-tion and Wiener filter (WF) to eliminate the effect of jamming in anti-jamming GPS receivers. A general sidelobe canceller (GSC) structure that is equivalent to the MSNWF is used to facilitate calculation of the optimal weights for the space-time processing. Simulation results demonstrate the satisfactory performance of the MSNWF to cancel jamming and the significant reduction in computational complexity by the re-duced-rank processing. The technique offers a feasible space-time processing solution for anti-jamming GPS receivers.

  7. Jamming/anti-jamming game with a cognitive jammer in space communication

    Science.gov (United States)

    Tian, Xin; Tian, Zhi; Pham, Khanh; Blasch, Erik; Shen, Dan

    2012-06-01

    In this paper a basic cognitive jamming/anti-jamming problem is studied in the context of space communication. The scenario involves a pair of transmitter and receiver, and a cognitive jammer. The cognitive jammer is assumed to have powerful spectrum sensing capability that allows it to detect data transmission from the transmitter to the receiver over the communication channels. Accordingly the jammer uses a "detect and jam" strategy; while the transmitter-receiver side uses the direct frequency hopping spread spectrum approach to mitigate the jamming impact. The basic jamming/anti-jamming problem is formulated as a two-side zero sum game between the jammer and the transmitterreceiver sides. For spectrum sensing, it is assumed that the jammer uses the energy detection in a sliding window fashion, namely, sliding window energy detection. As a conservative strategy of the transmitter-receiver side, Maxmin solutions to the jamming/anti-jamming game are obtained under various conditions. The impacts of factors such as signal propagation delay, channel bandwidth, and jammer/receiver side signal noise ratio on the game results are discussed. The results show the potential threats of cognitive jammers and provide important information for the configuration of jamming resistant space communication networks.

  8. [A new method of anti-jamming ability improvement for Michelson Interferometer].

    Science.gov (United States)

    Li, Yang-Jun; Lian, Su-Jie; Shi, Jia; Guo, Ya-Fei; Wang, Gao

    2014-05-01

    In order to improve anti-jamming capability of Michelson interferometer system, replace the traditional structure of the moving mirror scanning was replaced, an interference system based on electro-optic modulation of crystal refractive index was designed to achieve optical path scanning. The system modulated voltage signal on the variable refractive crystal, to generate cyclical changes, changed the refractive index to control optical path difference in the original optical path system. Using electronic scanning to replace of mechanical scanning, improved the system's noise immunity was improved. In the electro-optic modulation process, computed the maximum optical path difference of the system was computed, and analyzed of the crystal thickness and crystal diffraction efficiency of the modulation process were analyzed. The simulation experiment shows that, with the modulation voltage range increasing, the available range of the optical path is also increased, and the system spectrum resolving power will also increase accordingly. Meanwhile, in the modulation process set the modulation range was set to make the energy of diffraction energy losses less than 10% of the total energy, so as to ensure a better signal to noise ratio. Experimental results show that, as the modulation voltage changes, interference fringes occurred continuously moved. When the voltage is further increased, the nonlinear error appears. After non-linear error correction for the system, spectrum resolution reached to 7. 2 cm-1, slightly lower than the original system. But its anti-jamming capability is greatly enhanced, as in the absence of experimental platform for seismic conditions, conventional interferometer relative error is more than 20%, while the relative error of the system is less than 5%, in line with the design requirements. It was proved that the anti-jamming capability of the system was enhanced greatly, when the static electro-optical modulation was used.

  9. Combined algorithm of acquisition and anti-jamming based on SFT

    Institute of Scientific and Technical Information of China (English)

    Ying Ma; Xiangyuan Bu; Hangcheng Han; Qiaoxian Gong

    2015-01-01

    A communication and navigation receiver is required to remove hostile jamming signals and synchronize receiving signals effectively especial y for satel ite communication and navigation whose resources are becoming more and more limited. This paper proposes a novel signal receiving method by combining the pro-cesses of anti-jamming and synchronization to reduce the overal computational complexity at the expense of slightly affecting the detection probability, which is analyzed in detail by derivations. Furthermore, this paper introduces sparse Fourier transformation (SFT) into the proposed algorithm to replace fast Fourier transfor-mation (FFT) so as to further reduce the calculation time especial y in large frequency offset environments.

  10. Collaborative Anti-jamming in Cognitive Radio Networks Using Minimax-Q Learning

    Directory of Open Access Journals (Sweden)

    Sangeeta Singh

    2013-10-01

    Full Text Available Cognitive radio is an efficient technique for realization of dynamic spectrum access. Since in the cognitive radio network (CRN environment, the secondary users (SUs are susceptible to the random jammers, the security issue of the SU’s channel access becomes crucial for the CRN framework. The rapidly varying spectrum dynamics of CRN along with the jammer’s actions leads to challenging scenario. Stochastic zero-sum game and Markov decision process (MDP are generally used to model the scenario concerned. To learn the channel dynamics and the jammer’s strategy the SUs use reinforcement learning (RL algorithms, like Minimax-Q learning. In this paper, we have proposed the multi-agent multi-band collaborative anti-jamming among the SUs to combat single jammer using the Minimax-Q learning algorithm. The SUs collaborate via sharing the policies or episodes. Here, we have shown that the sharing of the learned policies or episodes enhances the learning probability of SUs about the jammer’s strategies but reward reduces as the cost of communication increases. Simulation results show improvement in learning probability of SU by using collaborative anti-jamming using Minimax-Q learning over single SU fighting the jammer scenario.

  11. GPS抗干扰技术发展趋势%Development Trend of GPS Anti-jamming Technique

    Institute of Scientific and Technical Information of China (English)

    刘海波; 吴德伟; 董成喜; 卢艳娥

    2011-01-01

    随着信息技术的深入发展,研究复杂电磁环境下的GPS干扰和抗干扰,对打赢未来信息化条件下的局部战争,具有十分重要的意义.从GPS工作的基本原理出发,在卫星、地面监控系统、接收系统等方面分析了对GPS的干扰措施,阐明了GPS抗干扰技术的现状,指出了几个未来重点发展方向,并提出了提高北斗导航系统导航保障能力的建议.%With the development of communication technologies, researching on the interference and anti-jamming issues of GPS under complex electromagnetic circumstances has become very important in winning aftertime information-age local warfares.The existing interference and anti-jamming methods aimed at the GPS satellites, ground monitoring and control system and the receiving terminals were analyzed, and the interference and anti-jamming development tendency was forecasted.Suggestions were given in improving the anti-jamming capability of BD Satellite Navigation System.

  12. AntiJam: Efficient Medium Access despite Adaptive and Reactive Jamming

    CERN Document Server

    Richa, Andrea; Schmid, Stefan; Zhang, Jin

    2010-01-01

    Intentional interference constitutes a major threat for communication networks operating over a shared medium and where availability is imperative. Jamming attacks are often simple and cheap to implement. In particular, today's jammers can perform physical carrier sensing in order to disrupt communication more efficiently, specially in a network of simple wireless devices such as sensor nodes, which usually operate over a single frequency (or a limited frequency band) and which cannot benefit from the use of spread spectrum or other more advanced technologies. This paper proposes the medium access (MAC) protocol \\textsc{AntiJam} that is provably robust against a powerful reactive adversary who can jam a $(1-\\epsilon)$-portion of the time steps, where $\\epsilon$ is an arbitrary constant. The adversary uses carrier sensing to make informed decisions on when it is most harmful to disrupt communications; moreover, we allow the adversary to be adaptive and to have complete knowledge of the entire protocol history....

  13. An SDR-Based Real-Time Testbed for GNSS Adaptive Array Anti-Jamming Algorithms Accelerated by GPU

    Directory of Open Access Journals (Sweden)

    Hailong Xu

    2016-03-01

    Full Text Available Nowadays, software-defined radio (SDR has become a common approach to evaluate new algorithms. However, in the field of Global Navigation Satellite System (GNSS adaptive array anti-jamming, previous work has been limited due to the high computational power demanded by adaptive algorithms, and often lack flexibility and configurability. In this paper, the design and implementation of an SDR-based real-time testbed for GNSS adaptive array anti-jamming accelerated by a Graphics Processing Unit (GPU are documented. This testbed highlights itself as a feature-rich and extendible platform with great flexibility and configurability, as well as high computational performance. Both Space-Time Adaptive Processing (STAP and Space-Frequency Adaptive Processing (SFAP are implemented with a wide range of parameters. Raw data from as many as eight antenna elements can be processed in real-time in either an adaptive nulling or beamforming mode. To fully take advantage of the parallelism resource provided by the GPU, a batched method in programming is proposed. Tests and experiments are conducted to evaluate both the computational and anti-jamming performance. This platform can be used for research and prototyping, as well as a real product in certain applications.

  14. An SDR-Based Real-Time Testbed for GNSS Adaptive Array Anti-Jamming Algorithms Accelerated by GPU.

    Science.gov (United States)

    Xu, Hailong; Cui, Xiaowei; Lu, Mingquan

    2016-03-11

    Nowadays, software-defined radio (SDR) has become a common approach to evaluate new algorithms. However, in the field of Global Navigation Satellite System (GNSS) adaptive array anti-jamming, previous work has been limited due to the high computational power demanded by adaptive algorithms, and often lack flexibility and configurability. In this paper, the design and implementation of an SDR-based real-time testbed for GNSS adaptive array anti-jamming accelerated by a Graphics Processing Unit (GPU) are documented. This testbed highlights itself as a feature-rich and extendible platform with great flexibility and configurability, as well as high computational performance. Both Space-Time Adaptive Processing (STAP) and Space-Frequency Adaptive Processing (SFAP) are implemented with a wide range of parameters. Raw data from as many as eight antenna elements can be processed in real-time in either an adaptive nulling or beamforming mode. To fully take advantage of the parallelism resource provided by the GPU, a batched method in programming is proposed. Tests and experiments are conducted to evaluate both the computational and anti-jamming performance. This platform can be used for research and prototyping, as well as a real product in certain applications.

  15. Anti-jam technique research for GPS%全球定位系统的抗干扰技术研究

    Institute of Scientific and Technical Information of China (English)

    齐志强

    2011-01-01

    This paper introduces the jam source and jam methods, it expounds the principle and implementation of the routine anti-jam method from both the constellation of GPS satellites in transmitting system and the GPS receiver. The methods of the anti-jam from the GPS receiver are classified and all the anti-jam methods are analyzed from the implementation and the principle, the background of the application and defects of every kind of the anti-jam methods are also given out, it points out that we should choose the right anti-jam technique in view of actual application.%介绍了全球定位系统(GPS)的干扰来源和方法,从GPS卫星星座发射端和用户接收端两方面介绍了常用的抗干扰措施的原理和实现方法。对用户接收端实现的抗干扰技术进行了分类,详细分析了各种抗干扰技术的实现方法和原理,应用背景及局限性,指出了在实际应用中应根据需要灵活选取抗干扰实现方法。

  16. A Real-Time Capable Software-Defined Receiver Using GPU for Adaptive Anti-Jam GPS Sensors

    Directory of Open Access Journals (Sweden)

    Dennis Akos

    2011-09-01

    Full Text Available Due to their weak received signal power, Global Positioning System (GPS signals are vulnerable to radio frequency interference. Adaptive beam and null steering of the gain pattern of a GPS antenna array can significantly increase the resistance of GPS sensors to signal interference and jamming. Since adaptive array processing requires intensive computational power, beamsteering GPS receivers were usually implemented using hardware such as field-programmable gate arrays (FPGAs. However, a software implementation using general-purpose processors is much more desirable because of its flexibility and cost effectiveness. This paper presents a GPS software-defined radio (SDR with adaptive beamsteering capability for anti-jam applications. The GPS SDR design is based on an optimized desktop parallel processing architecture using a quad-core Central Processing Unit (CPU coupled with a new generation Graphics Processing Unit (GPU having massively parallel processors. This GPS SDR demonstrates sufficient computational capability to support a four-element antenna array and future GPS L5 signal processing in real time. After providing the details of our design and optimization schemes for future GPU-based GPS SDR developments, the jamming resistance of our GPS SDR under synthetic wideband jamming is presented. Since the GPS SDR uses commercial-off-the-shelf hardware and processors, it can be easily adopted in civil GPS applications requiring anti-jam capabilities.

  17. A real-time capable software-defined receiver using GPU for adaptive anti-jam GPS sensors.

    Science.gov (United States)

    Seo, Jiwon; Chen, Yu-Hsuan; De Lorenzo, David S; Lo, Sherman; Enge, Per; Akos, Dennis; Lee, Jiyun

    2011-01-01

    Due to their weak received signal power, Global Positioning System (GPS) signals are vulnerable to radio frequency interference. Adaptive beam and null steering of the gain pattern of a GPS antenna array can significantly increase the resistance of GPS sensors to signal interference and jamming. Since adaptive array processing requires intensive computational power, beamsteering GPS receivers were usually implemented using hardware such as field-programmable gate arrays (FPGAs). However, a software implementation using general-purpose processors is much more desirable because of its flexibility and cost effectiveness. This paper presents a GPS software-defined radio (SDR) with adaptive beamsteering capability for anti-jam applications. The GPS SDR design is based on an optimized desktop parallel processing architecture using a quad-core Central Processing Unit (CPU) coupled with a new generation Graphics Processing Unit (GPU) having massively parallel processors. This GPS SDR demonstrates sufficient computational capability to support a four-element antenna array and future GPS L5 signal processing in real time. After providing the details of our design and optimization schemes for future GPU-based GPS SDR developments, the jamming resistance of our GPS SDR under synthetic wideband jamming is presented. Since the GPS SDR uses commercial-off-the-shelf hardware and processors, it can be easily adopted in civil GPS applications requiring anti-jam capabilities.

  18. 基于FPGA的GNSS接收机抗干扰的设计%Anti-jamming Design of FPGA-based GNSS Receiver

    Institute of Scientific and Technical Information of China (English)

    何訸; 张旭东

    2012-01-01

    Due to the signal of GNSS arriving at the ous kinds of interference. Especially in the war, the surface is so weak that the GNSS receiver is vulnerable to vari- high power interference transmitted by the enemy would impact the GNSS receiver severely, and the GNSS receiver cannot work normally if we do not use any ant-jamming tech- nique. An anti-jamming scheme uniting frequency domain and space domain is proposed. The simulation result demonstrates that anti-jamming algorithm uniting frequency domain and space domain is better than frequency domain and space domain anti-jamming algorithms, and it can be implemented on FPGA by using Verilog language.%由于到达地面的GNSS信号很微弱,导致GNSS接收机极易受到干扰。特别是在作战时,敌方发射的强干扰对GNSS接收机影响很大,如果不施以抗干扰措施,接收机将无法正常工作。本文提出了频域——空域联合抗干扰的技术方案,仿真结果表明频域——空域联合抗干扰的算法比频域抗干扰算法和空域抗干扰算法性能更优越,在FPGA中用Verilog语言实现了该联合域抗干扰的算法。

  19. 空间信息传输智能化抗干扰技术研究%Research on the intelligent anti jamming technology in spatial information transmission

    Institute of Scientific and Technical Information of China (English)

    叶曦; 雷鸣; 金晔; 陈煜; 应忍冬; 王亚鸣

    2016-01-01

    面向未来“天地一体的空间信息感知与传输”的安全需求,重点讨论了空间信息传输中的智能化抗干扰技术。分析了空间信息传输系统与网络的应用特点,在此基础上对空间信息传输系统中的干扰威胁和安全防护策略进行了分析,开展了星载智能抗干扰系统的总体设计,并对星载智能频谱监测技术和星载智能天线技术进行了论述。%To meet the future security requirements of spatial information perception and transmission, the intelligent anti jamming technology in spatial information transmission is discussed. Based on the analysis of the characteristics of the spatial information transmission system and the network, the paper analyzes the jamming threat and the security strategy of the spatial information transmission system. The overall design of the space-borne intelligent anti- jamming system is carried out, and the intelligent spectrum monitoring technology and the satellite borne smart antenna technol-ogy are discussed.

  20. 利用机体遮挡实现机载抗干扰通信%Airborne Anti-jamming Communication by Airframe Antenna Shading

    Institute of Scientific and Technical Information of China (English)

    曹劲; 彭笠

    2014-01-01

    According to the engineering requirement of airborne anti-jamming communication design,the airframe shading effect on typical forward,rear,left and right distributed VHF/UHF and L-band antennas on the airplane is analyzed. Based on the principle of signal suppression by airframe shading,an anti-jam-ming communication method is proposed by smartly using the left or right wing mounted antenna which faces the communication signal when communication and interference signal comes from different sides of the airplane respectively. The method can be realized easily in engineering because it only needs two new installed wing mounted antennas and two RF switches. The simulation result shows that the method can ef-fectively suppress the interference signal reception from the side of the airplane and the maximal suppres-sion can reach 35 dB. The method provides a new technical solution and theoretical implemental guide for airborne anti-jamming communication design.%结合机载通信抗干扰设计的工程应用需求,分析了机体遮挡对机身前后左右典型安装位置VHF/UHF和L频段通信天线的影响程度,提出了一种当通信信号和干扰信号分别位于机身两侧时,应用机体遮挡对信号接收的抑制原理,通过选择指向通信信号一侧的左或右机翼天线实现抗干扰通信的方法。该方法仅需新增两副机翼天线和两个射频开关,具备较强的工程可实现性。仿真结果表明该方法能够有效抑制来自机身侧面干扰信号的接收,最大抑制达到35 dB,为机载通信抗干扰能力提升设计提供了新的技术途径和理论指导。

  1. Study of Simulation Algorithm of Adaptive Nulling Antenna Aray for Anti-Jamming in Satellite Positioning Systems%自适应调零天线卫星定位抗干扰算法仿真研究

    Institute of Scientific and Technical Information of China (English)

    初明阳

    2014-01-01

    自适应阵列天线是国内外GPS抗干扰研究的主要方向,自适应调零抗干扰算法是成功应用的抗干扰技术之一。介绍了自适应调零抗干扰的原理,建立了天线阵列的数学模型,基于LMS算法介绍了4个天线单元的自适应调零算法的原理和实现过程,并对算法进行了仿真。结果显示该算法对单干扰、双干扰及三干扰均有较强的抗干扰能力。%Adaptive antenna array is the main research direction of GPS anti j-amming home and a -board, and adaptive nulling anti -jamming algorithm is one of the anti-jamming technologies which uses in practice successfully .This paper introduces the adaptive nulling anti-jamming theory and builds the math-ematical model of the antenna array .And based on LMS , the adaptive nulling algorithm for four antenna elements and its implementation are discussed as well .The algorithm is simulated and its results show that it features relatively strong anti-jamming capability to the mono-tone , dual-tone and triple-tone interfer-ence.

  2. V波段引信反侦察抗干扰性能研究%Anti-reconnaissance and Anti-jamming Performance Research of V-band Fuze

    Institute of Scientific and Technical Information of China (English)

    王虹; 李兴国

    2011-01-01

    Based on the attenuation characteristic of non-atmospheric window V-band, by calculating the reconnaissance aircraft received power of the V-band fuze from different rang, the ant-reconnaissance performance of V band fuze is analyzed ; By simulating the jamming-signal-ratio of the fuze from different range and power active interference based on the relationship between jamming-signal-ratio and effective jamming boundary, o the window band is compared and the jamming effect of the fuze is analyzed. At last by subscale experiment the anti-jamming performance of V-band fuzes verified. The simulation and experiment result indicate that the V-band MMW fuze has better performance in concealment and anti-jamming, although its ranging scale is limited .%根据非大气窗口V波段大气衰减特性,通过仿真计算侦察机接收到的来自不同距离V波段引信的探测信号,分析V波段引信反侦察性能;仿真来自不同距离和功率有源干扰对于V波段引信的干信比值,并根据干信比值与有效干扰界之间的关系,对比窗口频段分析对引信实施干扰的效果.最后通过缩比试验验证V波段引信的抗干扰能力.通过仿真和实验,结果表明V波段毫米波引信虽探测距离受限,但隐蔽性好,抗有源干扰能力强.

  3. Raptor码在卫星通信中抗干扰性能研究%Anti-jamming Performance in Satellite Communications Based on Raptor Codes

    Institute of Scientific and Technical Information of China (English)

    刘琴涛; 刘宏波; 马俊凯

    2013-01-01

    In order to improve the anti-jamming performance of satellite communications,the Raptor codes program of erasure codes used in satellite communications systems is proposed,based on satellite communications channel characteristics analysis.In this paper,the LDPC code and LT code serial concatenated coding is used to achieve a bit rate of 0.95 Raptor code,and the decoding algorithm of Raptor code is studied in the carrier noise interference channel,via system simulation,the satellite communication system model of the Raptor codes was set up based on optimization distribution,and analyze and study the performance of anti-jamming.%为了提高卫星通信抗干扰性能,在对卫星通信的信道特性分析基础上,提出一种将Raptor码作为纠删码应用于卫星通信系统的方案.文中采用了LDPC码+LT码串行级联编码来实现一个码率为0.95的Raptor码,并对在载波噪声干扰信道中传输的Raptor码的译码算法进行了研究,通过系统仿真,搭建一种基于最优化度分布Raptor码的卫星通信系统模型,并对其抗干扰的性能进行分析及研究.

  4. Research on Anti-Jamming Technology of UAV Data-Link Based on TDC%基于TDC的无人机数据链抗干扰技术研究

    Institute of Scientific and Technical Information of China (English)

    韦乃棋; 陈自力; 朱安石; 郑百源

    2013-01-01

    针对目前无人机数据链系统中传统扩频等技术在抗干扰性能上的局限,研究了基于变换域通信(TDC)的无人机数据链抗干扰技术.在研究变换域通信基本原理的基础上,结合无人机数据链的特点,给出了基于TDC的无人机数据链系统发射机和接收机模型,并通过仿真与常规直扩系统在窄带干扰中的误码率性能比较,结果表明基于TDC的数据链系统抗窄带干扰性能明显优于常规直扩系统.研究表明变换域通信技术应用于无人机数据链可有效提高数据链抗干扰能力.%As the anti -jamming performance of conventional spread spectrum technology used on present UAV (unmanned aerial vehicle ) data-link is limited, an anti-jamming technology for UAV data-link based on trans form domain communication( TDC) is studied. The fundamental principles of TDC is studied firstly. Then the transmitter model and receiver model of UAV data-link based on TDC are proposed according to the character istics of UAV data-link. The bit error rate performances of TDC and DSSS under narrow band jamming are sim ulated and compared. The result shows that the anti-jamming performance of UAV data-link based on TDC is evidently better than DSSS. The reasearch shows that the application of TDC to UAV data-link can improve its anti-jamming ability effectively.

  5. Large Uav Electronic Communication Signal Anti-jamming Method Study and Simulation%大型无人机电子通讯信号抗干扰方法研究仿真

    Institute of Scientific and Technical Information of China (English)

    赵利芳; 荆丽丽

    2015-01-01

    进行大型无人机电子通讯信号抗干扰方法研究与仿真,通过GPS系统确定信号的来源与方向定位,利用GPS定位信息准确计算最小均方、最大信噪比与最小方差,依据选择最优准则,实现对复杂抗干扰信号的削弱与排除.仿真实验表明,针对干扰信号,该种自适应滤波抗干扰算法具有较强的抑制与削弱能力,并扩大了干扰信号搜索范围,有效抵抗复杂的干扰信号,与常规抗干扰算法比较更为可靠,为无人机电子通讯抗干扰方法研究提供更好的保障.%Large uavs electronic communication signal anti-jamming method research and simulation, through the GPS posi-tioning system to determine the signal source and direction, using GPS positioning information to calculate the minimum mean square accurately, and maximum signal-to-noise ratio and minimum variance, on the basis of choosing the optimal criterion, implementation of complex interference signals and ruled out. Simulation results show that, in view of the interfer-ence signal, this kind of adaptive filter anti-jamming algorithm has strong inhibition and weaken the ability, and expand the search range of the interference signal, effective against complex jamming signal, compared with conventional anti-jam-ming algorithm is more reliable, for unmanned aerial vehicle (uav) electronic communication anti-jamming method re-search for better security.

  6. Overview of research on key techniques for anti-jamming of UAV data link%UAV数据链抗干扰的关键技术研究综述

    Institute of Scientific and Technical Information of China (English)

    李思佳; 毛玉泉; 郑秋容; 李波

    2011-01-01

    无人机(unmanned aerial vehicle,UAV)数据链抗干扰功能的增强是UAV实现战时信息资源共享的核心目标.在分析现有无人机数据链研究现状的基础上,重点综述了UAV数据链抗干扰功能的两类方案:一是在单链路方面,对现有UAV数据链的信道编/解码技术作了比较,并对其他抗干扰现状进行了研究;二是多链路方面,对多链路组网的抗干扰技术进行了深入分析,综述了协同通信在多链路UAV数据链中的应用.抗干扰关键技术的综述为下一代UAV数据链的研发提供一定的理论与技术基础.%The key goal of sharing martial information resources is to enhance the anti-jamming function of UAV data link.Based on analyzing actuality of UAV data link, overviewed two issues for anti-jamming of UAV data link.Firstly, made a comparison of methods for channel code of current UAV data link and performed an overview of researches on anti-jamming techniques.Secondly, analyzed a review of anti-jamming techniques using in multi-link network.Lastly, presented an overview of application research on cooperative communication in the multi-link network of the UAV data link.Provided some kinds of foundation for next generation UAV data link through the overview of research on theoretic and techniques.

  7. A novel role for junctional adhesion molecule-A in tumor proliferation: modulation by an anti-JAM-A monoclonal antibody.

    Science.gov (United States)

    Goetsch, Liliane; Haeuw, Jean-François; Beau-Larvor, Charlotte; Gonzalez, Alexandra; Zanna, Laurence; Malissard, Martine; Lepecquet, Anne-Marie; Robert, Alain; Bailly, Christian; Broussas, Matthieu; Corvaia, Nathalie

    2013-03-15

    To identify new potential targets in oncology, functional approaches were developed using tumor cells as immunogens to select monoclonal antibodies targeting membrane receptors involved in cell proliferation. For that purpose cancer cells were injected into mice and resulting hybridomas were screened for their ability to inhibit cell proliferation in vitro. Based on this functional approach coupled to proteomic analysis, a monoclonal antibody specifically recognizing the human junctional adhesion molecule-A (JAM-A) was defined. Interestingly, compared to both normal and tumor tissues, we observed that JAM-A was mainly overexpressed on breast, lung and kidney tumor tissues. In vivo experiments demonstrated that injections of anti-JAM-A antibody resulted in a significant tumor growth inhibition of xenograft human tumors. Treatment with monoclonal antibody induced a decrease of the Ki67 expression and downregulated JAM-A levels. All together, our results show for the first time that JAM-A can interfere with tumor proliferation and suggest that JAM-A is a potential novel target in oncology. The results also demonstrate that a functional approach coupled to a robust proteomic analysis can be successful to identify new antibody target molecules that lead to promising new antibody-based therapies against cancers.

  8. 电视制导系统抗干扰性能评估%A Research on Anti jamming Performance of TV-Command-Guided System

    Institute of Scientific and Technical Information of China (English)

    潘勃; 冯金富; 陶茜; 李骞

    2012-01-01

    The anti-amming evaluation frame of TV-command-guided image transmission system of air-to-ground missile is put forward. Then space model of anti-jamming performance evaluation is built under the electronic jamming exercises. By Finite State Machine theory, the mode transition model' s recognising of the TV-Command-Guided missile is deduced, and the influence of typical jamming in TV-guided system' s image data link is discussed in detail. Finally, by the computer simulation technology, this paper gets the missile' s longest tactics available distance and image jamming effect in different Signal-to-Noise.%提出了一种空地电视制导导弹图像传输系统抗干扰评估的总体框架,建立了电磁干扰条件下系统的抗干扰评估的空间模型.而后基于有限状态机理论,建立了电视制导导弹图像识别模态转换模型,详细讨论了典型干扰对电视图像数据链的影响.最后,应用计算机仿真技术,得到制导系统在不同信噪比条件下导弹的最大作用距离和图像干扰效果.

  9. 基于限制波尔兹曼机的GPS空时抗干扰降维方法%Study on Dimension-reduced Method Based on Restricted Boltzmann Machine for GPS Space-time Anti-jam

    Institute of Scientific and Technical Information of China (English)

    李文元; 葛大江; 梁茂国; 田相轩

    2015-01-01

    In the study on space-time anti-jam in GPS receiver,dimension-reduced methods become one of the most critical issues because of the great amount of computions.After the model of space-time adaptive filter is offered,A kind of dimension-reduced methods based on Restricted Boltzmann Machine is proposed in this paper. It is compared with some general dimension-reduced methods for Mean Square Error(MSE)performance.The simulation result validates its validity.Good result is achieved when this kind of dimension-reduced method based on restricted boltzmann machine is applied in GPS space-time anti-jam.%空时二维GPS接收机抗干扰技术的主要瓶颈是算法的复杂度高、计算量大,研究如何降维是抗干扰处理技术最关键的问题之一。一种基于限制波尔兹曼机的降维方法被提出,使复杂度降低,并与一般的降维方法进行了均方误差(MSE)性能对比,仿真实验验证了该方法的有效性。

  10. 电力系统中的 PLC 抗电磁干扰技术探讨%Investigation of PLC Anti-Jamming Technique in Electric Power System

    Institute of Scientific and Technical Information of China (English)

    孙延岭; 彭文才; 刘国敏

    2014-01-01

    可编程控制器(PLC)广泛应用在电力系统中,本文分析了电力系统中电磁干扰的来源和影响因素,详细介绍了 MB 系列 PLC 开发过程中的抗电磁干扰技术,并结合工程应用经验介绍了 PLC 系统中电源、I/O 以及通信的抗干扰措施,对于 PLC 的开发尤其是工程应用具有一定的借鉴意义。%Programmable logic controller(PLC)has been widely used in electric power system.Analysis to source and influen-cing factor of electromagnetic interference in electric power system.is shown.Anti-Jamming technique to electromagnetic inter-ference in development of MB series PLC is introduced.And the Anti-Jamming measure of power,I/O and communication in PLC system is introduced according to engineering application experience.This has certain referenced effect to PLC develop-ment especially engineering application.

  11. 支援干扰下火控雷达反干扰能力分析磁%Anti-jamming Capability of Fire Control Radar in Support-jamming

    Institute of Scientific and Technical Information of China (English)

    余巍; 申文峰; 张树杰; 赵勇; 王晓东

    2014-01-01

    Support-jamming is the main jamming tactics pattern that fire control radars are facing .This paper analyzes the characteristics of three different types of support-jamming .As a part of air defense system ,fire control radars should meet the needs of air defense fire system .The paper establishes an anti-jamming capability assessment model for support jamming ,on the basis of calculating the self-protection distance of fire control radars .In the hypothetical combat back-ground ,the anti-jamming capability of fire control radars are calculated and analyzed by the assessment model .The assess-ment model considers the influences of technological measures ,such as fixed multiple frequency hopping ,random data coding frequency hopping and pulse compress .The paper has value in anti-jamming capability of fire control radars .%支援干扰是火控雷达面临的主要干扰战术样式。分析了三种不同类型支援干扰的特点,根据火控雷达配属于防空火力系统,必须满足火力系统对空射击的需要,在计算火控雷达自卫距离基础上,建立了支援干扰下火控雷达反干扰能力评估模型。在想定作战背景下,应用评估模型对火控雷达抗支援干扰的能力进行了计算和分析。评估模型考虑了采取固定多点跳频、随机数字编码跳频和脉冲压缩等技术措施后对火控雷达反干扰能力的影响,具有一定的应用价值。

  12. 基于调频率捷变的抗移频干扰 SAR 成像方法%SAR Imaging Method of Shift-Frequency Anti-Jamming Based on Chirp Rate Agility

    Institute of Scientific and Technical Information of China (English)

    蒋思源; 吕幼新

    2015-01-01

    针对固定移频 SAR 干扰,提出一种基于调频率极性捷变的抗干扰处理方法,通过改变发射信号中的调频率,改变信号波形,使干扰机很难使用先前侦获的雷达信号参数来干扰雷达工作。理论分析表明,该方法可以有效抑制固定移频干扰对合成孔径雷达带来的影响。在高干信比的情况下,还可以采用调频率极性捷变与限幅相结合的方法来提高抗干扰性能,该方法在处理流程上仅对距离脉冲压缩进行改变,在成像算法中需要对二维频域使用调频率极性捷变与幅度限制相结合的方法。仿真结果表明,事先在雷达发射信号中改变发射信号的调频率,通过改变信号波形进行抗干扰是能达到抗干扰目的的。%Aiming at fixed-shift-frequency SAR jamming,an anti-jamming processing method based on chirp rate polarity agility has been proposed.Through changing the chirp rate of transmit signal to change signal waveform,the difficulty is increased for jammer using the previous radar signal parameters to interfere the radar.Theoretical analysis shows that the method can restrain the influence of fixed-shift-frequency jamming on synthetic aperture radar effectively.In high jamming-to-signal ratio circumstance,using the method of chirp rate polarity agility and combing with amplitude limitation can improve anti-jamming performance.The meth-od only makes change in range pulse compression and uses an imaging algorithm combing chirp rate polarity agility and amplitude limitation in two-dimensional frequency domain.Simulation result shows that through changing chirp rate of transmit signal to change waveform in advance can achieve the target of anti-jamming.

  13. Numerically controlled oscillator phase truncation effect on performance of frequency domain anti-jamming%数控振荡器相位截断对频域抗干扰性能影响分析

    Institute of Scientific and Technical Information of China (English)

    李建; 聂俊伟; 李柏渝; 王飞雪

    2015-01-01

    Numerically controlled oscillator is usually adopted in current GNSS(Global Navigation Satellite System)frequency domain anti-jamming receiver.Constrained by hardware,numerically controlled oscillator phase truncation is needed.But,whether numerically controlled oscillator phase is truncated reasonably influences anti-jamming performance greatly.Aiming at the problem,its effect on mixing and frequency domain anti-jamming was analyzed theoretically based on local oscillator spur caused by numerically controlled oscillator phase truncation.A theoretical computing module of numerically controlled oscillator look-up table width was brought forward.Thus,carrier noise loss approximated that of receiver with non-truncated phase numerically controlled oscillator.Simulations show that numerically controlled oscillator look-up table width computed by that module is no more than 10bit,when suppressing narrow band interference whose band is above 100kHz and jam-signal-ratio is below 80dBc.When adopting that width,carrier noise loss of receiver with numerically controlled oscillator phase truncation increases 0.6dB at most,compared to that of receiver with non-truncated numerically controlled oscillator phase.%全球导航卫星系统频域抗干扰接收机中,普遍采用数控振荡器生成本振信号。由于硬件约束,通常需要对数控振荡器进行相位截断。而数控振荡器相位截断是否合理对抗干扰性能影响较大。针对该问题,从数控振荡器相位截断导致的本振杂散着手,从理论上分析其对混频和频域抗干扰环节的影响。在此基础上,给出一种数控振荡器查找表地址位宽的理论计算模型,使得接收机的载噪比损耗接近无数控振荡器相位截断的频域抗干扰接收机。仿真结果表明,抑制带宽大于100kHz、干信比小于80dBc的窄带干扰时,计算的数控振荡器查找表地址位宽不超过10bit。与无数控振荡器相位截断的频域抗干

  14. Anti -jamming design for diven control power of Stirling cryocooler%分置式斯特林制冷机驱动控制源的抗干扰设计

    Institute of Scientific and Technical Information of China (English)

    杨玉玲; 胥春茜

    2011-01-01

    Jamming from electromagnetism is an important factor to effect the cabability of Stifling cryocooler. This paper presented the anti -jamming design for driven and control power of Stirling cryocooler through hardware and software. In hardware we installed LC filter in the output of driven and control power. The monopole control of electromotor replaced the ambipolar control of electromotor and we installed partition of photoelectricity in the part of testing the temperature etc. In software we used the way of digital filtering for the sampled signal.%电磁干扰问题一直是影响斯特林制冷机性能的重要因素,文中分别从硬件和软件两方面对斯特林制冷机驱动控制源的抗干扰设计作介绍.本设计的硬件方面主要采用驱动控制器的输出部分加装LC滤波器、电机的单极性驱动代替传统的双极性驱动和测温部分装光电隔离器等措施;软件部分主要是对采样到的信号进行数字滤波.

  15. Anti-jamming design of sensor signal sampling system in captive balloon%抗干扰设计在系留气球传感器信号采集中的应用

    Institute of Scientific and Technical Information of China (English)

    段玲琳; 谭剑波

    2009-01-01

    This paper analyzes all kinds of interference sources in the sensor signal sampling system that works in the complicated electromagnetic environment of captive balloons. Some anti-jamming measures are put forward from the perspectives of both hardware and software aiming at the characteristics of each interference source, namely, shielding, isolation, grounding and digital filtering. The actual effect of the design is proved with the help of the stress sensor.%文章分析了在系留气球复杂的电磁工作环境中传感器信号采集系统潜在的各种干扰源,并针对干扰源的特点分别从硬件和软件2方面设计抗干扰措施:屏蔽、隔离、接地和软件滤波,最后以拉力传感器为例,证明了抗干扰设计的实施效果.

  16. 联合空时滤波算法在接收机抗干扰中的应用%Application of Method Based on Space Time Adaptive Filtering Algorithm to Anti-Jamming Receiver

    Institute of Scientific and Technical Information of China (English)

    乐四海; 杨睿峰; 李保东

    2013-01-01

      从空时自适应滤波技术出发,结合数字多波束天线实际应用,提出了一种改进的联合空时滤波算法,解决了当干扰信号与卫星信号空间角接近时,传统的空时滤波算法在抑制干扰信号的同时,极大衰减该卫星有用信号,从而降低了接收机抗干扰性能的问题。仿真和实测结果表明,在卫星信号与干扰信号夹角接近10o和多干扰信号存在的条件下,改进的联合空时滤波算法明显优于传统的空时滤波算法。%Based on the space time adaptive processing technology and in combination with the practical application of digital multi-beam faggot antenna, an improved space time adaptive processing algorithm is put forward. The method is used to solve the problem—that is—traditional space time filtering algorithm can suppress jamming signals, but, at the same time, it can lead to attenuate the signals available of the satellite when the angle between jamming signal and satellite signal is close enough, so that this affects the anti-jamming capability of receiver. The simulation and actual results show the improved space time adaptive processing algorithm is better than the traditional method while the angle between satellite signal and jamming signal is close to 10 degrees and there exists jamming signals.

  17. 低压电力线载波通信与抗干扰解决途径%Solutions for low-voltage power line carrier communication and anti-jamming

    Institute of Scientific and Technical Information of China (English)

    赵新正; 姚发久; 白崇乾; 王阳

    2014-01-01

    Since the power grid is the largest,most popular and reliable network,data transmission through low-voltage power line is the most economical way to use the existing resource. The technology for low-voltage power line multi-frequency self-adaption DSSS carrier communication was created by Shaanxi Kaistar Company,in which the development of IC chip and thick film circuit were included. The jamming from low-voltage power line was completely solved on the basis of the data concentrator, data acquisition unit,data controller and anti-jamming products. The application of power line carrier communication in the energy resources measurement and monitoring platform is superior to the other technologies.%电网是最大、最普及、最可靠的供电网,利用低压电力线实现数据传输,具有利用现有资源、减少投资的现实意义。陕西凯星公司独创了低压电力线多频段自适应直接序列展频载波通信技术,从IC芯片、厚膜电路的研发,从电力线载波数据集中器、采集器、控制器及抗干扰硬件产品入手,彻底解决了低压电力线上的干扰问题。该技术应用在能源计量监控平台方面,是其他技术无法比拟的。

  18. 基于阵列天线的认知抗干扰 MAC 协议%A MAC Protocol for Cognitive Anti-jamming Communication with Antenna Array

    Institute of Scientific and Technical Information of China (English)

    孔得凯; 韩方景; 韩方剑; 刘伟

    2013-01-01

      应用认知无线电技术和阵列天线技术,提出了一个军事通信中认知抗干扰通信的 MAC 协议.把整个通信频段分为控制信道和业务信道两层信道,并由控制信道支撑业务信道.每个通信终端装备一部感知天线和一部4元天线阵.4元天线阵有两种工作方式:多天线独立方式和阵列天线方式.以多天线方式在控制信道完成交会,以阵列天线方式定向发射或定向接收控制信息和业务信息.通过对交会算法研究和改进,提出了多天线交会算法,并验证了此算法性能非常优越.%With the application of CR and antenna array techniques, a MAC protocol for cognitive Anti-jamming communication is proposed. In this protocol, the whole communication band is divided into two layers, namely the control channel layer and the traffic channel layer, and the traffic channel is supported by the control channel. Each communication terminal is equiped with a sensing antenna and a four-element antenna array. The four-element antenna array works in multi-antenna way or AAA way at different stages of the communication. For the multi-antenna rendezvous, the array quorum-based system algorithm by K. Bian and J. Park is studied, and thus multi-antenna rendezvous algorithm proposed. Analysis indicates that the proposed algorithm is of excellent performance.

  19. Anti-jamming scheme of pilot modification MLD based on superimposed spread spectrum for UAV-MIMO%基于叠加扩频的无人机 MIMO 导频修正 MLD 抗干扰

    Institute of Scientific and Technical Information of China (English)

    陈自力; 高喜俊

    2015-01-01

    The remote control link of unmanned aerial vehicle (UAV)is often cluttered by interference, which results in performance degradation or losing lock.The technologies of multiple input multiple output (MIMO)space time block codes and direct spread are combined to suppress the common interference in the re-mote control link.The superimposed spread spectrum is presented to eliminate multiple access interference in the fusion technology,combat against narrow-band jamming and avoid deception jamming.The maximum likeli-hood decoding (MLD)based on the subspace projection of noise is adopted to suppress the noise interference of natural and strong wideband.The disturb deviation of MLD caused by channel estimation deviation is analyzed. Then the pilot modification is set up to reduce the effect of channel estimate error on MLD performance.The theoretical analysis and system simulation show that the scheme has better communication privacy and great ro-bustness which can suppress multi-population interferences.It can provide a scheme for achieving the intelligent anti-jamming of UAV in the future.%针对无人机遥控链路常受干扰的影响导致性能下降甚至失锁,研究将多输入多输出(multiple input multiple output,MIMO)空时分组编码与直扩技术相结合实现对链路常见干扰抑制。提出叠加扩频的方法消除融合技术中存在的多址干扰、对抗窄带干扰并预防欺骗干扰;采用基于噪声子空间投影的简化最大似然译码(maximum likelihood decoding,MLD)抑制自然以及强宽带噪声干扰,通过分析由信道估计误差引起的 MLD 扰动误差,并利用导频修正来降低信道估计误差对 MLD 性能影响。理论分析及仿真表明,该方案通信保密性好、鲁棒性强,能够实现对多种干扰的抑制,为未来无人机智能抗干扰的实现提供方案。

  20. Anti-jamming in a fungal transport network

    CERN Document Server

    Hickey, Patrick C; Foshe, Sierra; Roper, Marcus

    2016-01-01

    Congestion limits the efficiency of transport networks ranging from highways to the internet. Fungal hyphal networks are studied as an examples of optimal biological transport networks, but the scheduling and direction of traffic to avoid congestion has not been examined. We show here that the Neurospora crassa fungal network exhibits anticongestion: more densely packed nuclei flow faster along hyphal highways, and transported nuclei self-organize into fast flowing solitons. Concentrated transport by solitons may allow cells to cycle between growing and acting as transport conduits.

  1. Anti-Jamming with Adaptive Arrays Utilizing Power Inversion Algorithm

    Institute of Scientific and Technical Information of China (English)

    MENG Dawei; FENG Zhenming; LU Mingquan

    2008-01-01

    The convergence rate of the power inversion (PI) algorithm is quite sensitive to the power of the interference with the used fixed parameters in the PI algorithm leading to degradation of its ability to handle interference. This paper presents a normalized PI algorithm that traces the stochastic characteristics of the interference. The algorithm adaptively adjusts the recursive step size to determine the constrained optimized parameters for the Iowpass filter. Simulations show that the normalized PI algorithm achieves faster con-vergence and produces deeper nulls. The algorithm makes GPS receivers more robust in environments with large variations in the interference strength.

  2. Low Cost Anti-Jam Digital Data-Links Techniques Investigations. Volume III.

    Science.gov (United States)

    1979-05-01

    PHIOJ. GAIDJ. OAMOJ COMMON/ODD /ENODB. SJRDB COt’WON/PLLFLT/BNP. ESP. DELF COMMON/FREJ/FJ COMPION/PHASIN/HO. P. Z.K!.KG, PHASP, PHASG REAL KI#KQ COMMON...COMMON/OPTION/NOS COMMON/DELAY/DELPHI. DELMEG COMMON/PHASE/PHEES. PHEEO COMMON/FREGJ/FJ CO)MMON/ODD /ENODB. SJRDB COMMON/PLLFLT/BNP. ESP. DELF COMMON...ENODD. SJRDB COMMON/PLLFLT/DNP, ESP, DELF COMMON/FREQJ/FJ COMMON/COLRD/PHIDJ.PHIOJ, OAMOJ. OAMOJ COPMN/PHASE/PHEES. PHEEO COMMON/PHASIN/HO. P.Z

  3. GPS抗干扰方法综述%REVIEW ON GPS ANTI-JAM METHOD

    Institute of Scientific and Technical Information of China (English)

    胡永生

    2001-01-01

    全球定位系统提供的低能级信号易受干扰.这些干扰或对抗导致GPS丢失信息,因而成为威胁GPS的严重问题.本文探讨对抗或干扰对GPS的威胁,从策略、干扰源和GPS接收机角度谈抗干扰方法,侧重分析减少GPS干扰的技术.

  4. Study of Optimum Simulation Techniques for the Design and Evaluation of Anti-Jam Communication Systems

    Science.gov (United States)

    1976-03-01

    TT (1+A +2Acos@) (l/nr) f dA I+ AcosO (The latter expression follows from the even symmetry cf the integrand.) 9 It is convenient to write the...numerator in this integrand as 1+ AcosO = (1/2) (2+2AcosO) = (1/2) (I+A2+2AcosO + 1-A2), (II) so that v = (1/2r) fd( 1+A +2AcosO) 0 + [(1-A )/( 27)]T d (1

  5. TDCS抗干扰技术研究%Study on Anti-Jamming Technique-Transform Domain Communication System

    Institute of Scientific and Technical Information of China (English)

    栗靖; 张婷; 李洪力; 刘冰

    2012-01-01

    随着通信抗干扰技术的发展,TDCS系统以其独特的躲避干扰理念将成为未来抗干扰研究的一个重要方向.本文简要地介绍了TDCS系统的发展历史和抗干扰的机理,并从TDCS系统抗干扰性能和特点出发,提出了TDCS系统的主要研究内容与关键技术,包括伪随机相位生成技术、变换域信号处理技术等,最后展望了TDCS系统技术的应用和发展趋势.

  6. Application and Discussion of Anti-Jamming Technology for HF Communication%短波通信抗干扰技术应用与探讨

    Institute of Scientific and Technical Information of China (English)

    辛登松

    2015-01-01

    短波通信通过大气层进行传播,不需要中间设备,具有较强的抗毁能力,适用于各种复杂环境下的远距离通信.因此在通信领域特别是军事领域得到了广泛的应用,并在军用通信领域占有重要地位.随着短波通信技术的不断发展,短波通信应用领域越来越宽,空间电磁频谱日趋复杂,短波通信面临的干扰越来越多、越来越复杂.短波信号的传播过程是一个在电离层内多次反射的过程,因此容易受到空间环境的干扰.为了抵抗通信干扰,人们提出了自适应技术、跳频技术、差错控制技术和分集技术等抗干扰技术,增强短波通信抗干扰能力,提高短波通信传输的稳定性和可靠性.

  7. Miniaturized Broadband 3-dB / 90 deg and 180 deg Power Splitters for GPS/GNSS Anti-Jam Systems

    Science.gov (United States)

    2010-02-01

    Eatock Brian Eatock Chairman DRP c© Her Majesty the Queen in Right of Canada as represented by the Minister of National Defence, 2010 c© Sa Majesté la...surface de la géométrie miniaturisée représente 31% de la surface du circuit hy- bride 180◦ à deux sections. Les performances obtenues sont aussi

  8. A Preliminary Study on CSAMT Anti-jamming Transmitter System%CSAMT发射系统抗干扰供电技术初步研究

    Institute of Scientific and Technical Information of China (English)

    李荡; 王珺璐; 李勇; 李建华; 林品荣

    2016-01-01

    在伪随机编码信号的相关辨识理论基础上,根据可控源音频大地电磁法(CSAM T )测量频率范围及受环境电磁干扰影响的程度,将 CSAM T 测量划分为三个频段,对易受工频及其谐波成分干扰的频段采用伪随机编码发射,高频和低频段采用单频方波发射。发射系统的人机交互和供电波形的产生基于虚拟仪器 LabVIEW(Laboratory Virtual Instrumentation Engineer‐ing Workbench ,实验室虚拟仪器工程平台)软件平台,操作方便、控制灵活。%On the basis of the relevant identification theory of pseudo‐random code signal ,the signals of CSAM T ( Con‐trolled Source Audio‐Frequency Magneto Tellurics) are divided into three parts according frequency range and the extent affect ‐ed by environmental electromagnetic interference .The signals are susceptible to 50Hz interference signal and its harmonic com‐ponents should be set by pseudo‐random code way .Others are set by single square waveform way .The human‐computer inter‐action and waveform generated software of the transmitter system is built on the advanced virtual instrument platform ,Lab‐VIEW (Laboratory Virtual Instrumentation Engineering Workbench ) .The software is easy to operation and flexible to control .

  9. 高速无线局域网室外信号抗干扰探讨%Exploring on Anti-jamming of Outdoor Signals in High-Speed Wireless Local Area Network

    Institute of Scientific and Technical Information of China (English)

    陈国先

    2011-01-01

    为了使高速无线局域网(IEEE.11n技术)室外部分发射天线和接收天线之间的信号损耗和干扰最小,对信号传播反射损耗、绕射损耗、多径信道衰落、自然环境损耗等干扰进行了定量定性分析,提出了正确进行覆盖设计、频率规划、容量规划等措施,使高速无线局域网室外的干扰最小化。%In order to minimize the signal loss and disturbance of the transmitting and receiving antenna in high-speed wireless local area network (IEEE. lln technology) in the outdoor, this article analyzes the quota qualitative problems of the reflection loss for the ground dissemination, diffraction loss, the multi-diameter channel declination, natural environment loss and so on. And at the same time it proposes the relative measures, such as the cover design frequency plan, and the capacity planning to deal with them. In this way, we can minimize the disturbance to high speed wireless local area network in the outdoor

  10. A Study of Medium-sized Group of Soccer Robots Anti-jamming System%中型组足球机器人抗干扰系统的研究

    Institute of Scientific and Technical Information of China (English)

    钱晟; 毛丽民; 张亚飞; 浦宇欢

    2012-01-01

      提出了结合RGB和HSI色彩空间的颜色算法以减少光照干扰,基于HSI颜色模型对图像进行二值处理消除噪声;根据实际现场环境,选取最佳方案消除场周围的颜色干扰。实际运行测试表明了该方法的有效性。%  The vision subsystem is one of the most important parts in the football robot system. The vision sub⁃system mainly includes real-time, accuracy and adaptability. This paper completes the anti-interference process⁃ing mainly from three aspects. The First is light interference. The paper uses a color extract algorithm which combines RGB color space and HSI color space. Using RGB color model to collect image, it is transformed into HSI color model immediately. The HSI color model is not sensitive to light, so it can be used for color calibra⁃tion. The second is the color impurity. Based on the HSI color model, the picture is dealt with to eliminate the noise by erosion and dilation. The authors of this paper select the most appropriate spatial color model conver⁃sion to reduce impurities interference effects. The third is some color interference surrounding the match field. Some solutions have been reached in this paper. According to the actual environment, the best one is selected to eliminate environmental interference. The actual running tests show the effectiveness of the image process method.

  11. Anti-Jamming Modulation/Demodulation Technology of Atmospheric Laser Communication System%一种大气激光通信系统抗干扰调制/解调技术

    Institute of Scientific and Technical Information of China (English)

    刘丹; 刘智; 王璞瑶; 姜会林

    2012-01-01

    空间光通信以大气为介质进行信息传输时,不可避免地受到大气散射、大气湍流及背景光等因素的影响.针对大气信道对通信质量的影响,提出了基于激光偏振态参数的调制与解调技术,设计了一种基于偏振移位键控(PolSK)的大气激光通信系统并对其原理进行了简要分析.该通信系统采用偏振移位键控的调制方式,即利用圆偏振光的两种旋态(左旋和右旋)进行编码、调制从而实现数据的传输,接收端采用平衡探测方法进行光信号解调.对系统性能进行仿真分析,结果表明,基于激光偏振态参数的调制与解调技术在抗大气环境干扰、提高数据传输速率和降低误码率等方面具有优越性,在未来的空间激光通信领域有广阔的发展空间和应用前景.%When free space optical communication system uses the atmosphere as a medium for information transmission, received signals are inevitably influenced by the atmospheric environment, atmospheric turbulence, background light factors, and so on. Considering that the atmosphere channel has a great influence on the laser atmosphere communication quality, a modulation/demodulation technology based on polarization parameters is proposed, and an atmospheric laser communication system based on polarization shift keying (PolSK) is designed. This system uses polarization shift keying modulation. In this modulation, two rotation states of circle polarization (left and right) are used for information transmission. In the receiver, the optical signal is detected with balance detection method. At the same time, the performance of the system is simulated. The results show that the modulation/demodulation techniques based on polarization parameters have unique advantages, such as anti-atmospheric interference, high data rate and low bit error rate. It will have broad prospects for development and application in future space laser communication.

  12. Influence of inconsistence of GNSS anti-jamming antenna array on MUSIC algorithm%GNSS抗干扰天线阵不一致性对MUSIC算法的影响

    Institute of Scientific and Technical Information of China (English)

    俞立宏; 秦红磊; 李武涛; 郎荣玲

    2016-01-01

    由于天线阵元位置、射频(RF)放大器和模数转换器(ADC)等因素的影响,全球卫星导航系统(GNSS)抗干扰天线阵各通道间不可避免地存在着不一致性.首先,利用矩阵中的子空间理论分析了通道的幅度不一致性和相位不一致性对多重信号分类(MUSIC)算法的影响.理论分析结果表明:单干扰情况下通道幅度不一致性会降低MUSIC算法方向图的零陷深度,但不影响零陷位置,相位不一致性对MUSIC算法方向图零陷位置和零陷深度均有影响;多干扰情况下通道幅度不一致性和相位不一致性对MUSIC算法方向图零陷位置零陷和深度都有影响.因此在通道不一致性慢变化的条件下,MUSIC算法利用方向图进行性能评估时需要测出通道幅相偏差矩阵进行方向图纠正.然后,利用仿真的方法对不一致性的影响进行了实验分析,实验分析结果与理论分析结果一致.

  13. Design and Practice of Anti-jamming Optimization for Radar Servo System%雷达伺服系统抗干扰优化设计与实践

    Institute of Scientific and Technical Information of China (English)

    万霞

    2011-01-01

    随着雷达机动性的不断提高,雷达的伺服系统涵盖的内容也越来越全面、复杂。包括天线转动平台的自动调平,天线旋转和定位,天线展开和撤收,方位角度转换及与上位机进行信息交换,强电、弱电综合,数字信号、模拟信号汇集等功能。因此要求综合全面地考虑各种因素,采取多种措施,解决其电磁兼容性问题,保证雷达及其伺服系统稳定可靠地运行。%With the improvement of radar mobility,what involved in the radar servo subsystem is more and more complicated.It includes functions such as automatic leveling of antenna rotary platform,rotation and location of antenna,deployment and dismantling of antenna,azimuth angle conversion and information exchange with master computer,integration of weak power and strong power,collection of digital signal and analog signal.Therefore,all factors should be considered and several measures should be taken to meet the requirements of electromagnetic compatibility and to ensure reliable operation of the radar system and its servo subsystem.

  14. Anti-jamming Performance Analysis of Communication Based on Leakage Current Meter%基于泄漏电流仪通讯的抗干扰性能分析

    Institute of Scientific and Technical Information of China (English)

    夏弘毅; 钱晓耀; 张忆汝; 金叶丹

    2016-01-01

    In order to design computer to control leakage current meter, connection of RS232 communication is established. But it is found that there is interference in the electromagnetic compatibility test, therefore, the comparison of the wired and wireless communication between host computer and leakage current meter is carried out. The communication capability evaluation from the view of anti-disturbance is designed to evaluate the anti-interference test platform of intelligent leak current instrument set up at the present stage, so as to ensure the reliability of the communication between host computer and leakage current meter.%为设计计算机对泄漏电流仪的控制,建立了RS232通讯的连接,但发现在进行电磁兼容测试时有干扰,因此开展了对计算机上位机和泄漏电流仪间有线、无线通讯的测试比较,从抗干扰情况角度进行通讯能力评价,旨在评价现阶段所搭建的智能泄漏电流仪的抗干扰测试平台,从而以保证计算机上位机与泄漏电流仪通讯的可靠性。

  15. Anti-jamming network architecture self-adaption technology based on cooperation and cognition%基于协同认知的抗干扰网络结构自适应技术

    Institute of Scientific and Technical Information of China (English)

    王海军; 李佳迅; 赵海涛; 王杉

    2016-01-01

    针对现有协同认知无线网络工作在固定结构导致灵活性低、对复杂环境适应力不足的问题,以提高其抗干扰和抗毁能力为目标,提出了一种基于协同认知的网络结构自适应技术.该技术能够使协同认知无线网络在集中控制、自组织和协同中继三种结构之间灵活、自主切换,从而应对电磁干扰、设备故障和通信链路遮挡等问题,极大增强了网络的稳健性.详细介绍了切换方案设计和节点协议实现,并通过搭建基于GNU Radio和二代通用软件无线电外设(USRP2)的协同认知无线网络测试床对其切换耗时以及吞吐量性能进行实际测试验证.结果表明,相比单一、固定的网络结构,该技术能够显著增强网络抗毁性、连通性,提高服务质量(QoS).

  16. The Anti-jamming Measures of Low Voltage Power Line Carrier Communication%低压电力线载波系统中的抗干扰措施

    Institute of Scientific and Technical Information of China (English)

    马宏锋; 陈金鹏

    2001-01-01

    According to the noises and interference in low power line, thispaper takes the measures from hardware and software. And it fits very well for restraining the noises and interference. It has been applied to the low vol tage power line carrier communication system, and obtained the anticipated effect.%根据低压电力线路存在的各种噪声和干扰,从硬件和软件等方面提出了相应的解决方案,并在低压电力线载波数据传输系统中得以应用,取得了预期的效果。

  17. 复用2 Mb/s通道抗干扰性能降低造成保护不正确动作原因分析%Analysis on Protection Malfunction Caused by Multiplex 2 Mb/s Channel Anti-jamming Performance Decrease

    Institute of Scientific and Technical Information of China (English)

    崔运海; 田晓龙; 王大勇

    2013-01-01

    介绍了光纤纵联保护复用2 Mb/s通道现状,通过对2起由于继电保护复用2 Mb/s通道继电保护接口设备接地及等电位接地网未严格执行相关规程,接地设置不正确造成继电保护拒动或误动原因分析,指出保证光纤纵联保护复用2 Mb/s通道接口设备抗干扰性能的重要性,提出有针对性技术及管理措施.

  18. Tracking Launch Vehicles in Interference and Jamming Project

    Data.gov (United States)

    National Aeronautics and Space Administration — MARK Resources proposes to develop a method for combining a set of distributed FRPAs into a network that provides high GPS anti-jam/interference capability. Like a...

  19. [A wireless mobile monitoring system based on bluetooth technology].

    Science.gov (United States)

    Sun, Shou-jun; Wu, Kai; Wu, Xiao-Ming

    2006-09-01

    This paper presents a wireless mobile monitoring system based on Bluetooth technology. This system realizes the remote mobile monitoring of multiple physiological parameters, and has the characters of easy use, low cost, good reliability and strong capability of anti-jamming.

  20. Decision feedback equalizer based on non-singleton fuzzy regular neural networks

    Institute of Scientific and Technical Information of China (English)

    Song Heng; Wang Chen; He Yin; Ma Shiping; Zuo Jizhang

    2006-01-01

    A new equalization method is proposed in this paper for severely nonlinear distorted channels. The structure of decision feedback is adopted for the non-singleton fuzzy regular neural network that is trained by gradient-descent algorithm. The model shows a much better performance on anti-jamming and nonlinear classification, and simulation is carried out to compare this method with other nonlinear channel equalization methods. The results show the method has the least bit error rate (BER).

  1. Advancements on Radar Polarization Information Acquisition and Processing

    Directory of Open Access Journals (Sweden)

    Dai Dahai

    2016-04-01

    Full Text Available The study on radar polarization information acquisition and processing has currently been one important part of radar techniques. The development of the polarization theory is simply reviewed firstly. Subsequently, some key techniques which include polarization measurement, polarization anti-jamming, polarization recognition, imaging and parameters inversion using radar polarimetry are emphatically analyzed in this paper. The basic theories, the present states and the development trends of these key techniques are presented and some meaningful conclusions are derived.

  2. 变频器中单片机人机交互系统的设计%Design of Single-chip Human-machine Interface in Converter

    Institute of Scientific and Technical Information of China (English)

    陈林; 侯志雄; 熊有伦

    2000-01-01

    介绍了一种采用80196设计的变频器人机交互系统,包括系统的硬件、软件设计和抗干扰设计。%A human-machine system of converter is described in this paper, and the hardware, software and anti-jamming design of this singlechip system are discussed.

  3. Department of the Navy Supporting Data for Fiscal Year 1984 Budget Estimates Descriptive Summaries Submitted to Congress January 1983. Research, Development, Test and Evaluation, Navy. Book 2. Tactical Programs

    Science.gov (United States)

    1983-01-01

    EQUIPMENT ----------------------------------------------------------------------------- 9-.7 6 451 O N C O M M UN IC A T IO N S SY S T E MS ...34masage processinx, Anti-Jam performance and Time Division Multipla Access backward compatibility consistent with both stated requirements ed analytic...Research Facility, Monterey, CA; and Naval Ocean Research and Development Activity, Ray St. Louis, MS . CONTRACTORS: None. OTHERS: Applied Research

  4. Global Positioning System III (GPS III)

    Science.gov (United States)

    2015-12-01

    Military Operations in Urban Terrain; Defense-Wide Mission Support; Air Mobility; and Space Launch Orbital Support. For military users, the GPS III...program provides Precise Positioning Service (PPS) to military operations and force enhancement. It also provides increased anti-jam power to the earth ...to be modified . On January 31, 2016, USD(AT&L) signed the GPS III revised APB. This Change 1 to the APB was due to both cost and schedule breaches

  5. Intelligent cognitive radio jamming - a game-theoretical approach

    Science.gov (United States)

    Dabcevic, Kresimir; Betancourt, Alejandro; Marcenaro, Lucio; Regazzoni, Carlo S.

    2014-12-01

    Cognitive radio (CR) promises to be a solution for the spectrum underutilization problems. However, security issues pertaining to cognitive radio technology are still an understudied topic. One of the prevailing such issues are intelligent radio frequency (RF) jamming attacks, where adversaries are able to exploit on-the-fly reconfigurability potentials and learning mechanisms of cognitive radios in order to devise and deploy advanced jamming tactics. In this paper, we use a game-theoretical approach to analyze jamming/anti-jamming behavior between cognitive radio systems. A non-zero-sum game with incomplete information on an opponent's strategy and payoff is modelled as an extension of Markov decision process (MDP). Learning algorithms based on adaptive payoff play and fictitious play are considered. A combination of frequency hopping and power alteration is deployed as an anti-jamming scheme. A real-life software-defined radio (SDR) platform is used in order to perform measurements useful for quantifying the jamming impacts, as well as to infer relevant hardware-related properties. Results of these measurements are then used as parameters for the modelled jamming/anti-jamming game and are compared to the Nash equilibrium of the game. Simulation results indicate, among other, the benefit provided to the jammer when it is employed with the spectrum sensing algorithm in proactive frequency hopping and power alteration schemes.

  6. Digital Synthetic-heterodyne Interferometric Demodulation Based on Embedded System

    Institute of Scientific and Technical Information of China (English)

    MENG Ju; WANG Jin-hai; CHEN Cai-he; ZHANG Cheng

    2006-01-01

    Optical fiber acceleration seismometer as an important instrument can offer high sensitivity,anti-jamming and non-touched advantage which has an extensive application field. Its signal processing ability will decide whole system's performance to some extent because it will affect directly the factors such as resolving power,precision and dynamic range. The signal processing is usually realized by analog circuits which was more inferior in stability,flexibility and anti-jamming to digital processing system. A digital processing system of optical fiber acceleration seismometer has been designed based on the embedded system design scheme. Synthetic-heterodyne demodulation has been studied,and signal processing has been realized. The double processors of ARM and DSP are employed to implement respectively the system control and signal processing,and to provide the output interfaces such as LCD,DAC and Ethernet interface. This system can vary with the measured signal in real time and linearly,and its work frequency bandwidth is between 10 Hz and 1 kHz. The system has better anti-jamming ability and can work normally when the SNR is 40 dB.

  7. Homing of human B cells to lymphoid organs and B-cell lymphoma engraftment are controlled by cell adhesion molecule JAM-C.

    Science.gov (United States)

    Doñate, Carmen; Ody, Christiane; McKee, Thomas; Ruault-Jungblut, Sylvie; Fischer, Nicolas; Ropraz, Patricia; Imhof, Beat A; Matthes, Thomas

    2013-01-15

    Junctional adhesion molecule C (JAM-C) is expressed by vascular endothelium and human but not mouse B lymphocytes. The level of JAM-C expression defines B-cell differentiation stages and allows the classification of marginal zone-derived (JAM-C-positive) and germinal center-derived (JAM-C-negative) B-cell lymphomas. In the present study, we investigated the role of JAM-C in homing of human B cells, using a xenogeneic nonobese diabetic/severe combined immunodeficient mouse model. Treatment with anti-JAM-C antibodies in short-term experiments reduced migration of normal and malignant JAM-C-expressing B cells to bone marrow, lymph nodes, and spleen. Blocking homing to the spleen is remarkable, as most other antiadhesion antibodies reduce homing of B cells only to bone marrow and lymph nodes. Long-term administration of anti-JAM-C antibodies prevented engraftment of JAM-Cpos lymphoma cells in bone marrow, spleen, and lymph nodes of mice. Plasmon resonance studies identified JAM-B as the major ligand for JAM-C, whereas homotypic JAM-C interactions remained at background levels. Accordingly, anti-JAM-C antibodies blocked adhesion of JAM-C-expressing B cells to their ligand JAM-B, and immunofluorescence analysis showed the expression of JAM-B on murine and human lymphatic endothelial cells. Targeting JAM-C could thus constitute a new therapeutic strategy to prevent lymphoma cells from reaching supportive microenvironments not only in the bone marrow and lymph nodes but also in the spleen.

  8. 地面情报雷达抗有源干扰能力的定量描述%Quantitative Description of Anti-active Jamming Ability for Ground Information Radar

    Institute of Scientific and Technical Information of China (English)

    胡进; 李建勋; 刘笑

    2015-01-01

    在概述地面情报雷达面临的典型有源电子干扰场景和干扰样式的基础上提出了通用化、系统化定量描述雷达总体抗干扰能力的思路. 基于主瓣干扰、副瓣干扰和组合干扰三种场景构建了不针对具体干扰样式和抗干扰措施并用于系统定量描述雷达总体抗干扰能力的若干战术、技术指标,给出了相关定义、边界条件与适用范围,并进一步提炼构建了不针对具体干扰场景的雷达总体抗干扰能力通用化定量描述措施.%The unitized and systematized quantitative description of radar's overall anti-jamming ability is proposed , which is based on the summary of typical active electronic jamming scenario and jamming pattern of the ground information radar .The tactical and tech-nical index for quantitative describing radar's overall anti-jamming ability is constructed based on three scenarios , i.e., main lobe jamming, side lobe jamming and combined jamming , which is also independent of particular jamming pattern and anti-jamming meas-ures.The definitions, boundary conditions and application scope of the constructed index are provided , based on which the universal quantitative description of the jamming scenario irrelevant radar's overall anti-active jamming ability is extracted and purified .

  9. Effects of Follower Jamming to FH Communication%跟踪干扰对跳频通信性能影响

    Institute of Scientific and Technical Information of China (English)

    全厚德; 闫云斌; 崔佩璋

    2012-01-01

    In this paper, the follower jamming and the jamming ellipse are analyzed. After studying the jamming ellipse and combining the mathematical model of FH signal, the mathematical model of follower jamming is built. The MFSK modulation was be adopted to the FH system,and then the performance of FH-MFSK system under the follower jamming is analyzed. The simulation results show that, when the FH-MFSK system is jammed by the follower jamming, the bit error rate (BER) of FH-MFSK communication system is bigger, and the anti-jamming performance of FH-MFSK system is degradation, and the anti-jamming performance of follower jamming in the FH-MFSK system is increased obviously, when the MFSK modulation is adopted. Finally, the anti-jamming measures of follower jamming are proposed.%针对跳频通信中跟踪干扰的问题,分析了跟踪干扰及其对应的干扰椭圆,结合跳频信号的数学模型建立了跟踪干扰的数学模型;在调制方式为MFSK的情况下,给出了跟踪干扰对FH-MFSK通信系统的误码率性能.仿真结果表明,当跳频通信系统遭受跟踪干扰时,系统的误码率升高,抗干扰性能下降明显,而采用多进制频移键控调制可以提高系统的抗跟踪干扰能力;最后给出了抗跟踪干扰的一些措施.

  10. A Robust Acquisition Scheme for FH Signal in Adverse Environments

    Institute of Scientific and Technical Information of China (English)

    Ya-Ding Chen; Shao-Qian Li; Yu-Fan Cheng; Gang Wu

    2009-01-01

    Both partial-band jamming and multi- tone jamming have severe effect on the acquisition of frequency-hopping (FH) signal in adverse environments. In this paper, an anti-jamming FH signal acquisition scheme based on cognitive correlation process is proposed to boost the robustness of acquisition. The main idea of this scheme is to utilize a priori knowledge of FH speed and FH pattern to distinguish jamming signal from received signal. Furthermore, theoretic analysis on detection probability and false probability is given to demonstrate the robust performance of the FH signal acquisition method compared with conventional acquisition scheme without any prior information on FH speed and pattern in adverse environments.

  11. A substitute for BOC modulation based on SS-CPM

    Science.gov (United States)

    Su, Chengeng; Guo, Shuren; Zhou, Hongwei

    2013-03-01

    CPM (continuous phase modulation) has been widely used in the field of satellite communication, which has high spectrum efficiency and constant envelope. This paper explores the applicability of CPM to satellite navigation. A SS-CPM (Spread-Spectrum CPM) modulation is investigated. The SS-CPM with tuned parameters can resemble the spectrum of Binary Offset Carrier (BOC) modulation and yields comparable performance in terms of tracking accuracy, multipath mitigation, anti-jamming, and compatibility. The BOC-like SS-CPM signal maintains the constant envelope at transmission and less out-band emission in radio determination satellite service (RDSS) band, which provides a reference modulation for COMPASS satellite navigation signal.

  12. Application of watersheds algorithms to train wheel tread check and measure systems

    Science.gov (United States)

    Shen, Bangxing; Zhang, Haibo; Wang, Wei

    2006-11-01

    A image system and a new kind of image processing algorithm (watersheds algorithm) are introduced; First, we get the prime wheel tread data by a Charge Coupled Device (CCD), after the pretreatment of the data, we use the watersheds algorithm to get the trail wheel abrasion and peel off strips, than we will get the numerical value of the damage. The result of the experiment shows that the system can obtain the edge of the trail wheel abrasion and peel off strips; the algorithm is fast, stable and anti-jamming; the recognition system can satisfy the manufactory requirements.

  13. Jamming in the Internet of Things: A Game-Theoretic Perspective

    OpenAIRE

    Namvar, Nima; Saad, Walid; Bahadori, Niloofar; Kelley, Brian

    2016-01-01

    Due to its scale and largely interconnected nature, the Internet of Things (IoT) will be vulnerable to a number of security threats that range from physical layer attacks to network layer attacks. In this paper, a novel anti-jamming strategy for OFDM-based IoT systems is proposed which enables an IoT controller to protect the IoT devices against a malicious radio jammer. The interaction between the controller node and the jammer is modeled as a Colonel Blotto game with continuous and asymmetr...

  14. Application of the Algorithm of Fractional Dimension to Extraction Image Edge

    Institute of Scientific and Technical Information of China (English)

    Qiang Luo; Qingli Ren

    2006-01-01

    The idea of fractional dimension was stated in brief firstly. Then, adopting the fractional statistical similar principle,the method of the least square minimum error was applied to evaluate the fractional dimension of per image pixel depending on the fractional property of image. And the image edge is extracted by magnitude of fractional dimension of image pixel. We presented the algorithm of the local fractional dimension, which made the rule of window size and sentencing the fractional dimension of edge. Although this algorithm was waste time, it is better than the classical ones in extraction edge and anti-jamming.

  15. River Regulation Problems and Solutions%河道整治存在问题与解决方法研究

    Institute of Scientific and Technical Information of China (English)

    孙丽娜; 刘晓敏; 陈星

    2011-01-01

    总结了河道整治在理念、规划、技术、管理等方面存在的问题;提出健康河流的新理念,对河道结构、社会服务功能、抗干扰能力等进行了全面规划.%The paper summarizes the ideological, planning, technical and management problems of river regulation, brings forward the new concept of healthy river,and carries out an overall planning on the structure, social function and anti-jamming capacity of the channel.

  16. A method of initial welding position guiding for arc welding robot based on visual servo control

    Institute of Scientific and Technical Information of China (English)

    郭振民; 陈善本; 邱涛; 吴林

    2003-01-01

    In order to solve the visual guiding task of initial welding position for arc welding robot, this paper presents a practice-prone image-based visual servo control strategy without calibration, and we perform validating experiments on a nine-DOF arc welding robot system. Experimental results illustrate presented method has the function to fulfill the task of welding robot initial positioning with certain anti-jamming ability. This method provides a basis for guiding welding gun to initial welding pose with real typical seam's image properties to replace flag block properties, and is a significant exploit to realize visual guiding of initial welding position and seam tracing in robot welding system.

  17. STUDY ON MECHANISM OF HYDRODYNAMIC OSCILLATION IN VORTEX PRECESSION METER USING LARGE EDDY SIMULATION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to improve the anti-jamming performance of a vortex precession meter, the disciplinarian of the vortex precession and the mechanism of hydrodynamic oscillation inside the vortex precession meter are numerically investigated by using the large eddy simulation. The results show that the periodical eccentric motion of the vortexes initiates a hydrodynamic oscillation inside the vortex precession meter. The visualized time dependent flow fields indicate that the pressures at axisymmetric points oscillate with a same intensity and frequency but 180° phase shift. By using differential sensing technique,a new prototype of double-sensor vortex precession meter,aimed to improve measurement accuracy, is developed.

  18. Command, Control, Communications And Intelligence (C3I) Project Book, Fiscal Year 1993

    Science.gov (United States)

    1992-10-30

    TEST SET, AN/PPM-4 26-6 COMMUNICATIONS CENTRAL, AN/TSC-122 26-7 PSYCHOLOGICAL WARFARE PRCGRAMMING CENTER, AN/TSQ-171 26-8 TAnLE OF CONTENTS BY... Tecnical Data Packages to Government at no cost. Mar 90 - Three-year Production contract awarded to ITT and EOS. EVENT SCHEDULE: FISCAL YEAR 92 9 94 95 96 97... COMUNICATION SYSTEA WHICH HAS LIMITED ANTI-JAM CAPABILITY AND ON-LINE ENCRYPTION. TVE A.N/GSC-40 IS THE COtMMAND POST TERMINAL FOR NETWORKS MADE UP OF AN/MSC

  19. 一种基于混沌序列的短时猝发水声通信方法%Short Burst Underwater Acoustic Communication Method Based on Chaotic Sequence

    Institute of Scientific and Technical Information of China (English)

    黄富良; 黄华贵; 苏军

    2014-01-01

    Traditional underwater acoustic communication signal has long duration ,and poor covert performance and anti-jamming .In this paper ,a short burst of spread spectrum communication method is designed .Chaotic sequence is opti-mized as a pseudo random sequence for M-ary spread spectrum communication ,and the synchronization signal and the data are placed in different sub-channels ,which greatly reduce emission signal duration .The simulation results show that this method can greatly improve the anti-jamming and covert performance of underwater acoustic communication .%传统的水声通信发射信号持续时间长,隐蔽性差和抗干扰能力差。文中设计了一种短时猝发的扩频通信方法,用优选后的混沌序列作为多进制扩频通信的伪随机序列,并将同步信号和数据信息分别放置在不同的子通道上,极大地压缩了发射信号时长。仿真结果表明该方法能大大提高水声通信的抗扰和隐蔽性能。

  20. Communication and control technology of underwater vehicle%水下机器人通信与控制技术研究

    Institute of Scientific and Technical Information of China (English)

    杨薇

    2015-01-01

    Research the development process of underwater vehicle, this article proposed vehicle system design with a track and designed the automotive module and algorithm control. Then contrast pulse modulation, differential pulse modulation, made use of improved underwater communication DPPM. Finally, experiments show that this method improves the data transfer rate. Add white noise to simulation experiment. When the signal is superimposed, anti-jamming capability of system would first become strong, with the increase in data, anti-jamming capability was weakened.%通过调研水下机器人的发展历程,提出了带有履带机器人的系统设计方案,并对其车载模块进行设计以及算法控制。然后通过对脉冲调制、差分脉冲调制进行对比,提出利用改进的 DPPM 进行水下通信,最后通过实验说明此种方法提高了数据的传输速率,添加白噪声进行实验仿真,说明当信号因延迟为叠加时,系统抗干扰能力会先变强,然后随着叠加数据的增多,抗干扰性减弱。

  1. The Development of Intelligent Detector for Train Longitudinal Impact

    Institute of Scientific and Technical Information of China (English)

    TIAN E; MO Yimin; NIU Wei

    2006-01-01

    This paper introduces a new kind of train impact detecting system that detect the train impact through detecting the train running acceleration, proposes that uniting the train running acceleration and the change rate of acceleration to token the train impact. The detector takes the portable computer as platform of data processing, utilizes the database technology to process data, making instrument Pc true, and improving the data processing ability of the instrument. The detector can show the train running acceleration on-line and real-timely, indicating the train impact situation directly,and uses the method that the software and hardware unifies to strengthen the system anti-jamming ability. At present, this detector has been tryout in some locomotive depots, each design function and the performance index conforms to request of the scene; the anti-jamming ability is strong, the monitor precision is reasonable, the detector can carry out the on-line examination to the train impact and monitoring the train running condition.

  2. 阀控液压马达速度伺服系统仿真分析%Simulation of the Hydraulic Motor of Speed Servo System Controlled by Valve

    Institute of Scientific and Technical Information of China (English)

    贾文铜; 周瑞祥; 张忠

    2012-01-01

    针对干扰力矩对阀控液压马达速度伺服系统的影响,利用结构不变性原理给系统加入了补偿器来消除干扰力矩的影响,同时利用PID控制来提高系统的抗干扰性.仿真表明,在利用结构不变性原理后再通过PID控制可以有效提高系统抗干扰能力和控制精度.%Aiming at the interfere moment affecting the hydraulic motor of speed servo system controlled by valve,the structure unchangeable principle was applied to eliminate the effect of the interfere moment and PID control was also managed to enhance the anti-jamming of the system, The simulation indicates that the application of the PID controll after the application of structure unchangeable principle can effectively improve the anti-jamming ability and control precision.

  3. Band Selection for Aircraft Targets Detection%面向飞机目标探测的波段选择方法

    Institute of Scientific and Technical Information of China (English)

    祁鸣; 刘德连; 张二磊

    2011-01-01

    针对飞机目标的探测与抗干扰问题,提出一种新的面向飞机目标探测的波段选择方法,通过耦合分析飞机目标、背景、大气、成像系统和干扰的特性,建立目标和背景的信噪比模型,确定出探测波段的中心.在此基础上,不断扩展探测波段,并分析信噪比的变化,得到探测波段的宽度.随后,根据干扰目标的辐射特性,添加抗干扰波段,有效解决了目标探测和抗干扰的结合.将所选择的探测波段应用于飞机目标的探测,仿真结果表明我们给出的波段选择方法得到的探测波段能够提高系统探测距离,同时具有一定的抗干扰能力.%To improve the performance of detection and anti-jamming of aircraft targets, a new band selection method is proposed. Base on the coupling analysis of the characteristics of aircraft targets, background, atmosphere, detection systems, and infrared-decoy, a signal to noise model (SNR) is build. And the center of the selected band is determined. Next, the width of the selected band is enlarged step by step to show the change of the SNR. As the SNR grows slowly and flatly, the width of the selected band is the final selected band. Subsequently, the characteristics of infrared-decoy are also analyzed. And a supplement band is got for anti-jamming. We test the band selection method by applying our selected bands to aircraft targets detection. The results indicate that the selected bands obtained by our new band selection method can improve the detection performance of aircraft targets and have good ability for Anti-jamming.

  4. Cutting edge: JAM-C controls homeostatic chemokine secretion in lymph node fibroblastic reticular cells expressing thrombomodulin.

    Science.gov (United States)

    Frontera, Vincent; Arcangeli, Marie-Laure; Zimmerli, Claudia; Bardin, Florence; Obrados, Elodie; Audebert, Stéphane; Bajenoff, Marc; Borg, Jean-Paul; Aurrand-Lions, Michel

    2011-07-15

    The development and maintenance of secondary lymphoid organs, such as lymph nodes, occur in a highly coordinated manner involving lymphoid chemokine production by stromal cells. Although developmental pathways inducing lymphoid chemokine production during organogenesis are known, signals maintaining cytokine production in adults are still elusive. In this study, we show that thrombomodulin and platelet-derived growth factor receptor α identify a population of fibroblastic reticular cells in which chemokine secretion is controlled by JAM-C. We demonstrate that Jam-C-deficient mice and mice treated with Ab against JAM-C present significant decreases in stromal cell-derived factor 1α (CXCL12), CCL21, and CCL19 intranodal content. This effect is correlated with reduced naive T cell egress from lymph nodes of anti-JAM-C-treated mice.

  5. Security against jamming in imaging with partially-distinguishable photons

    Science.gov (United States)

    Roga, Wojciech; Jeffers, John

    2016-10-01

    We describe a protocol in which we detect intercept-resend jamming of imaging and can reverse its effects. The security is based on control of the polarization states of photons that are sent to interrogate an object and form an image at a camera. The scheme presented here is a particular implementation of a general anti-jamming protocol established by Roga and Jeffers in Ref. 5. It is applied here to imaging by photons with partially distinguishable polarisation states. The protocol in this version is easily applicable as only single photon states are involved, however the efficiency is traded off against the intrusion detectability because of a leak of information to the intruder.

  6. Analysis of interference of QPSK and QDPSK modulation signals by mathematical

    Science.gov (United States)

    Li, Dairuo; Xu, Kai

    2017-03-01

    In today's society, with the rapid development and extensive application of the information technology of the network central station and the integrated information system technology, information plays an important role in the military communication, mastering the information right to the competition Important role, how to protect one's own security, smooth access to and transmission of information, and to maximize the elimination of interference has become an important issue at home and abroad. QPSK modulation and its improved QPSK modulation as the mainstream signal modulation, the most widely used. In this paper, the principle of QPSK and QDPSK modulation and demodulation are introduced in this paper. Then, how to interfere with QPSK modulation signal is analyzed, and the interference of QPSK modulation signal is simulated by Matlab scripting program, which can be used in the next step. And to study the next step of anti-jamming measures provided the basis and preparatory work.

  7. Research and application of visual location technology for solder paste printing based on machine vision

    Institute of Scientific and Technical Information of China (English)

    Luosi WEI; Zongxia JIAO

    2009-01-01

    A location system is very important for solder paste printing in the process of surface mount technology (SMT). Using machine vision technology to complete the location mission is new and very efficient. This paper presents an integrated visual location system for solder paste printing based on machine vision. The working principle of solder paste printing is introduced and then the design and implementation of the visual location system are described. In the system, two key techniques are completed by secondary development based on VisionPro.One is accurate image location solved by the pattern-based location algorithms of PatMax. The other one is camera calibration that is achieved by image warping technology through the checkerboard plate. Moreover, the system can provide good performances such as high image locating accuracy with 1/40 sub-pixels, high anti-jamming, and high-speed location of objects whose appearance is rotated, scaled, and/or stretched.

  8. The risk early-warning of gas hazard in coal mine based on Rough Set-neural network

    Institute of Scientific and Technical Information of China (English)

    TIAN Shui-cheng; WANG Li

    2007-01-01

    This article proposed the risk early-warning model of gas hazard based on Rough Set and neural network. The attribute quantity was reduced by Rough Set, the main characteristic attributes were withdrawn, the complexity of neural network system and the computing time was reduced, as well. Because of fault-tolerant ability, parallel processing ability, anti-jamming ability and processing non-linear problem ability of neural network system, the methods of Rough Set and neural network were combined. The examples research indicate: applying Rough Set and BP neural network to the gas hazard risk early-warning coal mines in coal mine, the BPNN structure is greatly simplified, the network computation quantity is reduced and the convergence rate is speed up.

  9. Design of new seismometer based on laser Doppler effect

    Institute of Scientific and Technical Information of China (English)

    Zhenhui Du(杜振辉); Fuxiang Huang(黄福祥); Chengzhi Jiang(蒋诚志); Zhifei Tao(陶知非); Hua Gao(高华); Lina Lü(吕丽娜)

    2004-01-01

    In order to improve the resolution of seismic acquisition, a new seismic acquisition system based on tangential laser Doppler effect with an optimized differential optical configuration is proposed. The relative movement of the inertia object and the immobile frame is measured by laser Doppler effect, which can avoid the electromagnetic and thermometric interference, and the adoption of frequency-modulated (FM)transmission can improve the ability of anti-jamming. The frequency bandwidth is properly determined by analyzing the frequency of the Doppler signal. The velocity, displacement, acceleration, and frequency to be measured can be real-time acquired by frequency/velocity (F/V) converting the FM Doppler signal.A 100-dB dynamic range and the linear frequency range of 1.0 to 1000 Hz are realized.

  10. Strategy and Consider for Hosting Type Data Center Users%托管数据中心用户的策略和考虑

    Institute of Scientific and Technical Information of China (English)

    陈宇通

    2012-01-01

    主要阐述了用户如何决策使用托管型的数据中心。并从安全性、节能、抗干扰、高效安装等几方面对布线设计和方案实施提出了合理化建议,以给数据中心用户决策提供参考。%The user to how to carry on the decision-making for use hosting type data center was mainly discussed. And some rational suggestions for wiring design and plan implementation were given, from the aspects of safety, energy saving, anti-jamming, high efficiency installation. It can provide references for users' decision making.

  11. Mathematic principle of active jamming against wideband LFM radar

    Institute of Scientific and Technical Information of China (English)

    Shixian Gong; Xizhang Wei; Xiang Li; Yongshun Ling

    2015-01-01

    The inherent mathematic principle of active jamming against the wideband linear frequency modulated (LFM) radar is investigated. According to different generation strategies, the active jamming methods are reclassified into three groups, i.e., non-coherent jamming (NCJ), convolution jamming (CJ) and mul-tiplying jamming (MJ). Based on the classification, the mathematic principles of different active jamming groups are put forward, which describe the relationships between the modulated signals and the jamming results. The advantages and disadvantages of different groups are further analyzed, which provides a new perspective for the study of jamming/anti-jamming methods and a potential for engineers to integrate similar jamming methods into one jam-mer platform. The analyses and simulation results of some typical active jamming methods prove the validity of the proposed mathe-matics principle.

  12. Power Transformer Intelligence Monitor System

    Institute of Scientific and Technical Information of China (English)

    Sun Jianshe; Shi Lei

    2006-01-01

    An auto-monitoring system has been created that could monitor the main parameter of power transformers. It reads data of V&I by precision rectifier circuit and amplifier, and converted electric energy into pulse signal by means of sensor technique and pulse converter circuit, it is sent into microcomputer to process, completed monitoring to power transformer parameters and running state by software system. It can register all kinds of key data, and provide all kinds of virtual technical data for managing sections and can auto-form all kinds of electric annual reports and monthly reports analysis graphs such as managing graphs. It notably improves the safety and reliability of transformer, with strong anti-jamming technique and unique function, it can be used on the transformers in railway' s self-closing lines and all kinds of transformer stations.

  13. Resilience of LTE networks against smart jamming attacks

    KAUST Repository

    Aziz, Farhan M.

    2014-12-08

    Commercial LTE networks are being studied for mission-critical applications, such as public safety and smart grid communications. In this paper, LTE networks are shown vulnerable to Denial-of-Service (DOS) and loss of service attacks from smart jammers, who may employ simple narrowband jamming techniques to attack without any need to hack the network or its users. We modeled the utilities of jamming and anti-jamming actions played by the jammer and the network under the framework of single-shot and repeated Bayesian games. In a single-shot game formulation the only Nash Equilibria (NE) are pure strategy equilibria at which network utility is severely compromised. We propose a repeated-game learning and strategy algorithm for the network that outperforms single-shot games by a significant margin. Furthermore, all of our proposed actions and algorithms can be implemented with current technology.

  14. Isothermal amplification detection of nucleic acids by a double-nicked beacon.

    Science.gov (United States)

    Shi, Chao; Zhou, Meiling; Pan, Mei; Zhong, Guilin; Ma, Cuiping

    2016-03-01

    Isothermal and rapid amplification detection of nucleic acids is an important technology in environmental monitoring, foodborne pathogen detection, and point-of-care clinical diagnostics. Here we have developed a novel method of isothermal signal amplification for single-stranded DNA (ssDNA) detection. The ssDNA target could be used as an initiator, coupled with a double-nicked molecular beacon, to originate amplification cycles, achieving cascade signal amplification. In addition, the method showed good specificity and strong anti-jamming capability. Overall, it is a one-pot and isothermal strand displacement amplification method without the requirement of a stepwise procedure, which greatly simplifies the experimental procedure and decreases the probability of contamination of samples. With its advantages, the method would be very useful to detect nucleic acids in point-of-care or field use.

  15. Direct GPS P-Code Acquisition Method Based on FFT

    Institute of Scientific and Technical Information of China (English)

    LI Hong; LU Mingquan; FENG Zhenming

    2008-01-01

    Recently, direct acquisition of GPS P-code has received considerable attention to enhance the anti-jamming and anti-spoofing capabilities of GPS receivers. This paper describes a P-code acquisition method that uses block searches with large-scale FFT to search code phases and carrier frequency offsets in parallel. To limit memory use, especially when implemented in hardware, only the largest correlation result with its position information was preserved after searching a block of resolution cells in both the time and frequency domains. A second search was used to solve the code phase slip problem induced by the code frequency offset. Simulation results demonstrate that the probability of detection is above 0.99 for carrier-to-noise density ratios in excess of 40 dB- Hz when the predetection integration time is 0.8 ms and 6 non-coherent integrations are used in the analysis.

  16. Research on Image processing in laser triangulation system

    Energy Technology Data Exchange (ETDEWEB)

    Liu Kai; Wang Qianqian; Wang Yang; Liu Chenrui, E-mail: qqwang@bit.edu.cn [School of Optoelectronics, Beijing Institute of Technology, 100081 Beijing (China)

    2011-02-01

    Laser Triangulation Ranging is a kind of displacement distance measurement method which is based on the principle of optical triangulation using laser as the light source. It is superior in simple structure, high-speed, high-accuracy, anti-jamming capability and adaptability laser triangulation ranging. Therefore it is widely used in various fields such as industrial production, road test, three-dimensional face detection, and so on. In current study the features of the spot images achieved by CCD in laser triangulation system were analyzed, and the appropriate algorithms for spot images were discussed. Experimental results showed that the precision and stability of the spot location were enhanced significantly after applying these image processing algorithms.

  17. Circular object recognition based on shape parameters

    Institute of Scientific and Technical Information of China (English)

    Chen Aijun; Li Jinzong; Zhu Bing

    2007-01-01

    To recognize circular objects rapidly in satellite remote sensing imagery, an approach using their geometry properties is presented.The original image is segmented to be a binary one by one dimension maximum entropy threshold algorithm and the binary image is labeled with an algorithm based on recursion technique.Then, shape parameters of all labeled regions are calculated and those regions with shape parameters satisfying certain conditions are recognized as circular objects.The algorithm is described in detail, and comparison experiments with the randomized Hough transformation (RHT) are also provided.The experimental results on synthetic images and real images show that the proposed method has the merits of fast recognition rate, high recognition efficiency and the ability of anti-noise and anti-jamming.In addition, the method performs well when some circular objects are little deformed and partly misshapen.

  18. Design of object surveillance system based on enhanced fish-eye lens

    Institute of Scientific and Technical Information of China (English)

    Jianhui Wu; Kuntao Yang; Qiaolian Xiang; Nanyang Zhang

    2009-01-01

    A new method is proposed for the object surveillance system based on the enhanced fish-eye lens and the high speed digital signal processor (DSP). The improved fish-eye lens images an ellipse picture on the charge-coupled device (CCD) surface, which increases both the utilization rate of the 4:3 rectangular CCD and the imaging resolution, and remains the view angle of 183°. The algorithm of auto-adapted renewal background subtraction (ARBS) is also explored to extract the object from the monitoring image. The experimental result shows that the ARBS algorithm has high anti-jamming ability and high resolution, leading to excellent object detecting ability from the enhanced elliptical fish-eye image under varies en-vironments. This system has potential applications in different security monitoring fields due to its wide monitoring space, simple structure, working stability, and reliability.

  19. Reed Solomon Coding for Frequency Hopping Spread Spectrum in Jamming Environment

    Directory of Open Access Journals (Sweden)

    Othman Sidek

    2008-01-01

    Full Text Available Frequency hopping spread spectrum with noncoherent M-ary frequency shift keying system is considered. In this study Reed Solomon codes RS (255, 223 are employed in a standard error correction role to provide some Anti-Jamming (AJ capability with 8-bit symbols. Noise has been added to RS encoded data, which is demodulated at RS decoder perfectly. Matlab simulations have been implemented for numerical results. Graphical results have been plotted between the probability of an erasure versus ρ using RS (255, 223 code for 1 and 2 kHz frequencies. The simulation results have proved that system having RS (255, 223 code with M = 32 require substantially less signal to jammer power ratio to achieve the same bit error probability.

  20. Area Efficient Rapid Signal Acquisition scheme for High Doppler DSSS Signals

    Directory of Open Access Journals (Sweden)

    D. Karunakar Reddy

    2013-04-01

    Full Text Available The Direct Sequence Spread Spectrum (DSSS communication system is widely used in ground to airmissile links due to its anti-jam and low Signal to Noise Ratio (SNR requirement advantages. The paperpresents the challenges in achieving fast signal acquisition in this scenario and brings out theimplementation challenges for achieving simultaneous Doppler estimation and phase delay of PseudoNoise (PN code. A new scheme for PN code phase delay estimation with correlation of differential signals,followed by precise Doppler estimation using Fast Fourier Transform (FFT is presented. The areaoptimized Field Programmable Gate Array (FPGA friendly architecture is utilized for rapid signalacquisition by combining both time and frequency domain approaches. The advanced design practices inFPGAs are used to achieve resource sharing and high clock speed of operation. The architecture issynthesized for Virtex-6 LX240T FPGA, resulting in 52% of area occupancy and 134 MHz of maximumallowed clock frequency value.

  1. Guiding the welding robot to the initial welding position with visual method

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhenyou; Lin Tao; Chen Shanben

    2008-01-01

    Using step pattern match technology with variational resolution can recognize the position and orientation of the weld seam in the image. According to using the image segmentation method based on pattern match, not only advanced the speed and anti-jamming capability, but also captured the edge information of the weld seam and the edge of the workpiece, and the image coordinate of the initial welding position can be obtained. The matrix for hand-eye relationship of the robot can be calculated by adopting the rapid calculation method. According to the depth calculating principle with the special point matching using binocular stereovision, the initial welding position can be confirmed by calculating the middle point of the perpendicular line of two radials in the space, and the function to guide the welding robot to the initial welding position can be realized.

  2. Mathematical principle and characteristics of polarization transform

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The precise definition of polarization transform is proposed from the viewpoint of polarization domain transform for the first time. The mathematical principle,char-acteristics and physical meanings of polarization transform are analyzed. Two typical kinds of polarization transforms which are called unitary matrix polarization transform (UMPT) and diagonal matrix polarization transform (DMPT) are put for-ward. The gain property and the change property of polarization state distance are presented in detail. Thereby,the concept of serial polarization transform is pro-posed. A general polarization transform can be realized by two steps: changing the location of polarization states in polarization domain by UMPT; and expanding or compressing the density of polarization states by DMPT. The result is meaningful to many applications including polarization filtering,detection,enhancement,anti-jamming,discrimination and so on.

  3. Brushless DC Motor Control System Design Based on DSP2812

    Directory of Open Access Journals (Sweden)

    Wei Min

    2016-01-01

    Full Text Available By comparison various control methods currently for permanent magnet brushless DC motor, on the basis of motor principle analysis, a current smallest and most real-time all-digital rare earth permanent magnet brushless DC motor control system is designed. The high-speed digital signal processor DSP2812 is applied as the main control unit. The fuzzy PID control algorithm is used to control rectifier regulator and speed, which the speed and current is double closed loop in the system. The principle of control system, control strategy and software is analyzed in this paper. The system has some features such as less overshoot, rapid response speed, good performance of anti-jamming, simple structure, high control precision, flexible in changing control policies and so on. Validity of the design is verified by prototype test.

  4. Performance Evaluation of the New Compound-Carrier-Modulated Signal for Future Navigation Signals

    Directory of Open Access Journals (Sweden)

    Ruidan Luo

    2016-01-01

    Full Text Available Navigation Signal based on Compound Carrier (NSCC, is proposed as the potential future global navigation satellite system (GNSS signal modulation scheme. NSCC, a kind of multi-carrier (MC signal, is generated by superposition and multi-parameter adjustment of sub-carriers. Therefore, a judious choice of parameter configation is needed. The main objective of this paper is to investigate the performance of the NSCC which is influenced by these parameters and to demonstrate its structure characteristics and superiority, employing a comprehensive evaluation system. The results show that the proposed NSCC signal processes full spectral efficiency and limited out of band (OOB emissions, satisfying the demands of crowed frequency resources. It also presents better performance in terms of spectral separation coefficients (SSCs, tracking accuracy, multipath mitigation capability and anti-jamming reduction compared with the legacy navigation signals. NSCC modulation represents a serious candidate for navigation satellite augmentation systems, especially for signals applied in challenging environments.

  5. Design of Intelligent Control System of Transformer Oil Temperature

    Directory of Open Access Journals (Sweden)

    Caijun Xu

    2016-02-01

    Full Text Available in working process of power transformer, which directly affects the safe operation of transformer oil temperature as well as the stability of the network, so vital to transformer oil temperature detection and control. Based on single chip and chip design of digital temperature measurement transformer oil temperature of an intelligent control system. The system uses a digital temperature sensor DS18B20 collection transformer oil temperature, improves the accuracy of the system. The low power consumption, strong anti-jamming ability of the SCM STC89C51 as the main controller to achieve control and real-time monitoring of transformer oil temperature, and input control module is designed for different transformer oil temperature preset control during normal operation, improving system usability and human-computer interaction.

  6. 基于分布云和Logistic方法的微格录播系统%System Design of Micro Recording System Based on Distribution Cloud and Logistic Method

    Institute of Scientific and Technical Information of China (English)

    郭志军

    2014-01-01

    提出一种基于分布云和Logistic方法的强抗干扰微格录播系统,采用分布式云计算的思想,将微格录播系统的多种资源分布存储在云平台的各个分布式节点中,实现资源存储和计算的高度均衡性,微格录播系统中,采用Logistic方法实现数据域的精确映射,在数据映射的基础上,保证系统数据的强抗干扰性。最后采用一组微格录播系统图像进行测试实验,结果显示,采用基于Logistic方法的微格录播系统,系统的抗干扰性能平均提升了约20%,具有很好的工程应用价值。%The strong anti jamming system design of micro recording system was proposed based on distribution cloud and logistic method, the idea of distributed cloud computing was used in micro broadcasting system, the resource was distribut-ed in the cloud platform to achieve the high degree of balance, in micro recording system, the logistic method was used to achieve accurate mapping data fields in the data mapping. Finally, a team of micro-grid image recording and broadcasting was used to test the ability, and the result shows that with logistic method, the anti-jamming performance of system was im-proved about 20%, so it has good engineering application value.

  7. Design and realization of a wireless dual modulus interphone%无线双模数字对讲机的设计与实现

    Institute of Scientific and Technical Information of China (English)

    朱理辰; 刘德康; 张序琦; 卢继华

    2013-01-01

    传统模拟对讲机由于频谱利用率低、抗干扰性能差、频道开放、不具有保密性等原因已经很难满足需求.介绍的无线双模对讲机用于改善传统模拟对讲机抗干扰及保密性差的缺点,所提双模对讲机设计方案综合了集群和无中心两种工作模式功能,具有灵活设置与抗干扰性强的优点.重点设计了对讲机的软硬件结构,还对音频编解码进行了讨论分析.经测试,可实现距离350米内误码率低于10-4,文中所设计的无线双模对讲机可提供良好的性能.%Traditional analog interphone has been difficult to meet the increasing applicable demands for its low spectrum utilization rate, bad anti-jamming ability, unsafe channel and bad confidentiality. This paper introduces wireless dual modulus interphone, which is used to improve the weakness such as bad anti-jamming ability and bad confidentiality of traditional analog interphone. The design of dual modulus interphone integrated the function of two modes, cluster and no center, which has advantages of flexible and robust. The realization of the hardware and software structure of wireless interphone is focused and discussed in detail. We also make experiments and analysis of voice encoding and decoding. Through the measurements, it realizes that bit error rate is below 10 -4 in 350 meters. So the wireless dual modulus interphone can provide good performance.

  8. Function of Jam-B/Jam-C interaction in homing and mobilization of human and mouse hematopoietic stem and progenitor cells.

    Science.gov (United States)

    Arcangeli, Marie-Laure; Bardin, Florence; Frontera, Vincent; Bidaut, Ghislain; Obrados, Elodie; Adams, Ralf H; Chabannon, Christian; Aurrand-Lions, Michel

    2014-04-01

    The junctional adhesion molecules Jam-b and Jam-c interact together at interendothelial junctions and have been involved in the regulation of immune response, inflammation, and leukocyte migration. More recently, Jam-c has been found to be expressed by hematopoietic stem and progenitor cells (HSPC) in mouse. Conversely, we have reported that Jam-b is present on bone marrow stromal cells and that Jam-b-deficient mice have defects in the regulation of hematopoietic stem cell pool. In this study, we have addressed whether interaction between Jam-b and Jam-c participates to HSPC mobilization or hematopoietic reconstitution after irradiation. We show that a blocking monoclonal antibody directed against Jam-c inhibits hematopoietic reconstitution, progenitor homing to the bone marrow, and induces HSPC mobilization in a Jam-b dependent manner. In the latter setting, antibody treatment over a period of 3 days does not alter hematopoietic differentiation nor induce leukocytosis. Results are translated to human hematopoietic system in which a functional adhesive interaction between JAM-B and JAM-C is found between human HSPC and mesenchymal stem cells. Such an interaction does not occur between HSPC and human endothelial cells or osteoblasts. It is further shown that anti-JAM-C blocking antibody interferes with CD34(+) hematopoietic progenitor homing in mouse bone marrow suggesting that monoclonal antibodies inhibiting JAM-B/JAM-C interaction may represent valuable therapeutic tools to improve stem cell mobilization protocols.

  9. Junctional adhesion molecule-A, JAM-A, is a novel cell-surface marker for long-term repopulating hematopoietic stem cells.

    Science.gov (United States)

    Sugano, Yasuyoshi; Takeuchi, Masaki; Hirata, Ayami; Matsushita, Hirokazu; Kitamura, Toshio; Tanaka, Minoru; Miyajima, Atsushi

    2008-02-01

    Junctional adhesion molecule-A (JAM-A/JAM-1/F11R) is a cell adhesion molecule expressed in epithelial and endothelial cells, and also hematopoietic cells, such as leukocytes, platelets, and erythrocytes. Here, we show that JAM-A is expressed at a high level in the enriched hematopoietic stem cell (HSC) fraction; that is, CD34(+)c-Kit(+) cells in embryonic day 11.5 (E11.5) aorta-gonod-mesonephros (AGM) and E11.5 fetal liver (FL), as well as c-Kit(+)Sca-1(+)Lineage(-) (KSL) cells in E14.5 FL, E18.5FL, and adult bone marrow (BM). Although the percentage of JAM-A(+) cells in those tissues decreases during development, the expression in the HSC fraction is maintained throughout life. Colony-forming assays reveal that multilineage colony-forming activity in JAM-A(+) cells is higher than that in JAM-A(-) cells in the enriched HSC fraction in all of those tissues. Transplantation assays show that long-term reconstituting HSC (LTR-HSC) activity is exclusively in the JAM-A(+) population and is highly enriched in the JAM-A(+) cells sorted directly from whole BM cells by anti-JAM-A antibody alone. Together, these results indicate that JAM-A is expressed on hematopoietic precursors in various hematopoietic tissues and is an excellent marker to isolate LTR-HSCs.

  10. Research Status and Development of Transform Domain Communication System%变换域通信系统研究现状与发展*

    Institute of Scientific and Technical Information of China (English)

    王杰; 毛玉泉; 张衡阳; 郭尧; 李波

    2013-01-01

    This paper reviewes the development course of Transform Domain Communication System(TDCS),intro-duces basic principle and key technology of TDCS,analyzes its unique anti-jamming way,and illustrates the strong anti-interference ability,high spectrum efficiency and the Low Probability of Intercept/Low Probability De-tect(LPI/LPD)characteristics of TDCS. It also summarizes the research directions and open problems in TDCS area,and finally prospects the good prospect of TDCS,which points out the direction for further study of TDCS.%  回顾了变换域通信系统(TDCS)的发展历程,介绍了TDCS的基本原理及关键技术,分析了其独特的抗干扰方式,并揭示了TDCS具有极强的抗干扰能力、较高频谱利用率和低截获概率/低检测概率( LPI/LPD)特性的特点。对目前TDCS投入实际应用存在的难点问题进行了分析和总结,最后展望了其良好的应用前景,为TDCS的深入研究指明了方向。

  11. Convolutive Frequency-Domain Blind Interference-Signal Separation Algorithm Based on IVA%基于IVA的卷积混合频域盲扰信分离算法研究

    Institute of Scientific and Technical Information of China (English)

    文威; 张杭

    2012-01-01

    Blind interference-signal separation technique is the application of Blind Source Separation (BSS) in anti-jamming. This paper introduced a frequency-domain convolutive blind interference-signal separation algorithm based on Independent Vector Analysis (IVA), which prevents permutation ambiguity and acquires better separation performance. Simulation results indicate that this algorithm can separate BPSK signal and a variety of interference, and has cer- tain anti-interference ability.%盲扰信分离是盲源分离算法在无线通信抗干扰中的应用。文章将独立向量分析(IVA)引入到卷积混合频域盲扰信分离算法中,克服了频域方法存在顺序不确定性和分离效果不佳的缺陷。仿真实验表明该算法的有效性,采用该算法实现了卷积混合条件下BPSK信号与多种干扰的扰信分离,具有一定的抗干扰能力。

  12. Noninvasive blood pressure measurement scheme based on optical fiber sensor

    Science.gov (United States)

    Liu, Xianxuan; Yuan, Xueguang; Zhang, Yangan

    2016-10-01

    Optical fiber sensing has many advantages, such as volume small, light quality, low loss, strong in anti-jamming. Since the invention of the optical fiber sensing technology in 1977, optical fiber sensing technology has been applied in the military, national defense, aerospace, industrial, medical and other fields in recent years, and made a great contribution to parameter measurement in the environment under the limited condition .With the rapid development of computer, network system, the intelligent optical fiber sensing technology, the sensor technology, the combination of computer and communication technology , the detection, diagnosis and analysis can be automatically and efficiently completed. In this work, we proposed a noninvasive blood pressure detection and analysis scheme which uses optical fiber sensor. Optical fiber sensing system mainly includes the light source, optical fiber, optical detector, optical modulator, the signal processing module and so on. wavelength optical signals were led into the optical fiber sensor and the signals reflected by the human body surface were detected. By comparing actual testing data with the data got by traditional way to measure the blood pressure we can establish models for predicting the blood pressure and achieve noninvasive blood pressure measurement by using spectrum analysis technology. Blood pressure measurement method based on optical fiber sensing system is faster and more convenient than traditional way, and it can get accurate analysis results in a shorter period of time than before, so it can efficiently reduce the time cost and manpower cost.

  13. Coupled Integration of CSAC, MIMU, and GNSS for Improved PNT Performance.

    Science.gov (United States)

    Ma, Lin; You, Zheng; Liu, Tianyi; Shi, Shuai

    2016-05-12

    Positioning, navigation, and timing (PNT) is a strategic key technology widely used in military and civilian applications. Global navigation satellite systems (GNSS) are the most important PNT techniques. However, the vulnerability of GNSS threatens PNT service quality, and integrations with other information are necessary. A chip scale atomic clock (CSAC) provides high-precision frequency and high-accuracy time information in a short time. A micro inertial measurement unit (MIMU) provides a strap-down inertial navigation system (SINS) with rich navigation information, better real-time feed, anti-jamming, and error accumulation. This study explores the coupled integration of CSAC, MIMU, and GNSS to enhance PNT performance. The architecture of coupled integration is designed and degraded when any subsystem fails. A mathematical model for a precise time aiding navigation filter is derived rigorously. The CSAC aids positioning by weighted linear optimization when the visible satellite number is four or larger. By contrast, CSAC converts the GNSS observations to range measurements by "clock coasting" when the visible satellite number is less than four, thereby constraining the error divergence of micro inertial navigation and improving the availability of GNSS signals and the positioning accuracy of the integration. Field vehicle experiments, both in open-sky area and in a harsh environment, show that the integration can improve the positioning probability and accuracy.

  14. Analysis of bistable inductive micro-switch based on surface micro size effect

    Science.gov (United States)

    Tian, Wenchao; Chen, Zhiqiang

    2015-04-01

    The inductive micro-switch can not only induce an external acceleration, but also be controlled by the external acceleration to realize a trigger action. It is an integrative device of a sensor and an actuator. However, little work has been done to develop a comprehensive model to accurately analyze the micro size effect during micro-switch contact process. So its malfunctions related to "fail-to-closure" and "transient-closure" result in low reliability and weak anti-jamming capability. A bistable inductive micro-switch is presented based on nano electro-mechanical system (NEMS) technology and micro size effect. And the sine-model is used to describe the rough contact surface of the micro-switch. Micro size forces such as the Casimir force and van der Waals (vdW) force are analyzed in detail using the principles of vacuum energy and the Wigner-Seitz micro-continuum media. The vdW force includes the repulsive force. The simulation results of the Casimir force varied with the gap are obtained, which is compared with the relative experimental result. The dynamic equation of the bistable inductive micro-switch is established. Dynamic simulation results are shown to be in agreement with experimental results. The threshold acceleration is 6.8 g, and the response time is 17.5 μs.

  15. Identifying opinion leaders by improved algorithm based on Leader- Rank%改进LeaderRank算法的意见领袖挖掘

    Institute of Scientific and Technical Information of China (English)

    徐郡明; 朱福喜; 刘世超; 朱碧颖

    2015-01-01

    Opinion leader mining is an important topic of social network research which is of great significance in terms of internet public opinion control and information dissemination. LeaderRank is an effective opinion leader mining algorithm. This paper proposes a new algorithm based on LeaderRank with sentiment analysis and user’s liveness to identify the opinion leaders in comment network to achieve a better performance. Experiments based on SIR model show that both accuracy and anti-jamming capability of the proposed algorithm have been effectively improved.%意见领袖挖掘是社会网络研究的重要课题,对于舆情控制、信息传播等方面具有重要意义。LeaderRank算法是一个有效的意见领袖挖掘算法。为提高LeaderRank算法的准确性和抗干扰能力,在LeaderRank算法基础上,加入用户之间的情感倾向、用户活跃程度,提出了改进的LeaderRank算法。基于SIR模型的实验验证表明,改进算法的准确性和抗干扰能力均得到了有效提升。

  16. 基于FPGA的数字心率监测仪设计%Design of Digital Heart Rate Monitor Based on FPGA

    Institute of Scientific and Technical Information of China (English)

    徐宏祥; 田丰; 刘国权; 于东阳; 曹祎

    2011-01-01

    This paper introduces a method to design a digital heart rate monitor based on field - programmable gate array (FPGA). The electrical signal of pulse is collected by the pulse transducer, after the pre - processing and A/D conversion, the signal is given to the FPGA for data storage and processing. The monitor has the functions of real - time monitoring and displaying the heart rate parameters, automatic alarm. The system has advantages in anti -jamming and integration with easy expansion.%提出了一种基于现场可编程门阵列( FPGA)的数字心率监测仪的设计方案.由脉搏传感器采集到的脉搏信号经过预处理和模/数转换,送给FPGA进行数据存储及处理,实现实时监测与显示心率参数、自动报警等功能,具有抗干扰性好、集成度高和易于扩展的优点.

  17. Status and Development Trend of the Military GPS Receiver%军用卫星导航接收机现状及发展趋势

    Institute of Scientific and Technical Information of China (English)

    任小伟

    2014-01-01

    本文总结了GPS接收机在军事应用上的优点及不足,并探讨了军用卫星导航接收机技术的发展趋势。详细介绍了多模卫星导航接收机系统的兼容与互用技术、抗干扰滤波技术、环路滤波技术、组合导航技术、以及相对定位技术,并对相关卫星导航接收机新技术进行了总结和展望。%The advantages and disadvantages of GPS receivers on the military application are summarized and the development trend of military satellite navigation technology is discussed in this paper. Compatibility and interoperability technology, anti-jamming filter technology, loop filter technology, integrated navigation technology, and relative positioning technology of multimode satellite system are introduced. Finally, the new technology of the correlative satellite navigation is summarized and prospected.

  18. 智能插座在高校节能减排工程中的设计和应用%The Design and Application of Intelligent Electrical Outlet for Campus ’s Electricity Saving and Emission Reduction

    Institute of Scientific and Technical Information of China (English)

    马艳

    2013-01-01

    高校用电浪费现象十分突出,本文研究的智能插座能有效计量和控制供电线路,通过控制不必要时段的电器电源供电,达到节能减排的目的,且智能插座还具有安全、可靠、防电磁辐射和抗干扰等优点。%The electrical energy waste phenomenon on colleges and universities’campuses is very severe. This paper introduces the design and application of intelligent electrical outlet, which can measure effectively electricity data and control power supply line on-off, cut off electrical appliance ’s power at nonessential time interval, thus achieves the goal of electricity saving and emission reduction. This intelligent outlet is also safe, reliable, anti-electromagnetic radiation and anti-jamming.

  19. The isothermal amplification detection of double-stranded DNA based on a double-stranded fluorescence probe.

    Science.gov (United States)

    Shi, Chao; Shang, Fanjin; Pan, Mei; Liu, Sen; Ma, Cuiping

    2016-06-15

    Here we have developed a novel method of isothermal amplification detection of double-stranded DNA (dsDNA) based on double-stranded fluorescence probe (ds-probe). Target dsDNA repeatedly generated single-stranded DNA (ssDNA) with polymerase and nicking enzyme. The ds-probe as a primer hybridized with ssDNA and extended to its 5'-end. The displaced ssDNA served as a new detection target to initiate above-described reaction. Meanwhile, the extended ds-probe could dynamically dissociate from ssDNA and self-hybridize, converting into a turn-back structure to initiate another amplification reaction. In particular, the ds-probe played a key role in the entire experimental process, which not only was as a primer but also produced the fluorescent signal by an extension and displacement reaction. Our method could detect the pBluescript II KS(+) plasmid with a detection limit of 2.3 amol, and it was also verified to exhibit a high specificity, even one-base mismatch. Overall, it was a true isothermal dsDNA detection strategy with a strongly anti-jamming capacity and one-pot, only requiring one ds-probe, which greatly reduced the cost and the probability of contamination. With its advantages, the approach of dsDNA detection will offer a promising tool in the field of point-of-care testing (POCT).

  20. Models in frequency-hopping-based proactive jamming mitigation for space communication networks

    Science.gov (United States)

    Shen, Dan; Chen, Genshe; Pham, Khanh; Blasch, Erik; Tian, Zhi

    2012-06-01

    In this paper, we consider a cognitive radio based space communication system in a game-theoretical framework, where players dynamically interact through wireless channels to utilize the wideband spectrum for their objectives. The performance indices include data rate, covertness, jamming, and anti-jamming; each of which relate to an effective signal-nose-ratio (SNR). The game players have different intents and asymmetric and hierarchical information about the frequency spectrum which are modeled as three different types of players: primary users, secondary users, and hostile active jammers. We consider the informational asymmetry in two situations: (1) different information sets for friendly users and jammers and (2) even among the friendly sensors; some sensors may only have partial or little information about others due to jammed observations. Such an asymmetric information pattern naturally partitions the sensors into leaders and followers. In our hierarchical anti-jammer approach, a two level approach includes a pursuit-evasion game and a Stackelberg game. At the higher-level, a non-cooperative pursuit-evasion game is constructed to model the interactions between jammer and primary users in the frequency-location domains. At the lower level, primary and secondary users play a dynamic Stackelberg game in the presence of jammers. Theoretical game solutions are provided to demonstrate the proposed proactive jamming mitigation strategy.

  1. 高温超导滤波器用斯特林制冷机温度控制算法设计%Design of temperature controlling algorithm for Stirling cryocooler used in high temperature superconducting filters

    Institute of Scientific and Technical Information of China (English)

    魏广; 马少君; 闫春杰

    2012-01-01

    In the domain of deep space communications, using of high temperature superconducting technology can significantly improve the receivers performance in sensitivity, signal noise ratio and anti -jamming. As the need for high temperature superconducting filter's low temperature working environment, a Stirling cryocooler for cooling was required. The stability of Stirling cryocoolers temperature will directly affect the performance of high temperature superconducting filter. This topic mainly focused on the temperature controlling algorithm s analysis and design for Stirling cryocooler used in high temperature superconducting filters, the temperature controlling curve based on tester of high temperature superconducting filters were proved at last.%在深空通信领域,利用高温超导滤波技术,可大幅提高接收机的灵敏度、信噪比和抗干扰能力.由于高温超导滤波器工作温度较低,需要斯特林制冷机进行制冷.斯特林制冷机温度的稳定性将直接影响高温超导滤波器的性能,文章对高温超导滤波器用斯特林制冷机温度控制算法进行了分析和设计,并给出了基于高温超导滤波器试验装置的温度控制曲线.

  2. 高精度陀螺稳定平台稳定回路设计%Design of Stabilized Loop for High Precision Gyro-stabilized Platform

    Institute of Scientific and Technical Information of China (English)

    王巾; 王凯

    2012-01-01

      The working principle of the two-axis gyro-stabilized platform for isolating the carrier disturbance is introduced. The mathematical model is analyzed and designed for the stabilized loop of the gyro-stabilized plat⁃form. A dual rate-loop control structure is chosen, so the servo system has the better anti-jamming ability and ro⁃bustness than the single rate-loop control structure. The experimental data from the prototype show that this gy⁃ro-stabilized platform has a better stabilized precision.%  介绍了两轴陀螺稳定平台隔离载体扰动的原理,对陀螺稳定平台的稳定回路进行了数学建模分析和设计。选择了双速度环控制方法,使稳定伺服系统较传统的单速度环方法具有更好的抗干扰性和鲁棒性,并通过样机测试数据表明,该稳定平台具有较高的稳定精度

  3. An Onboard Transmitting Antenna of Cruise Missile%一种飞航导弹弹载发射天线设计

    Institute of Scientific and Technical Information of China (English)

    何兵; 刘刚; 南楠; 王园园

    2011-01-01

    以飞航导弹弹载数据链为应用背景,通过综合分析、比较、优化和仿真,设计了一种与飞航导弹共形、具有大角域覆盖能力的弹载发射天线。仿真结果说明了该天线性能满足飞航导弹卫星通信需求,在解决工程实际问题的同时,为此类应用提供了一种新型天线方案,为相关设计提供了一种思路。%In the paper,we designed a kind of onboard transmitting antenna of cruise missile through integrated comparison,analysis,optimization and simulation.The antenna is conformal with the cruise missile,and has wide coverage domain and certain anti-jamming capability.The simulation result shows that the designed antenna satisfies all requirements of satellite communication of cruise missile.The paper provides a new antenna designning method and new idea for similar application.

  4. 多微处理器在管道焊接自动控制系统中的应用研究%Study on Application of Multi Microcomputer in Automatic Control System of Pipeline Welding Process

    Institute of Scientific and Technical Information of China (English)

    韩赞东; 都东; 陈强; 隋永莉; 程辉

    2001-01-01

    Based on multi-microcomputer,the automatic control system ofpipeline all-position welding process is developed.The system structure,working principle and software design are described.By serial communication,the cooperative control of welding parameters is realized between PLC and microcontroller.The hardware circuit of serial communication,PLC system configuration and the anti-jamming measure are also introduced. Experiments show that the system is reliable and can improve production efficiency,and has important engineering value and widely application foreground.%建立了基于多微处理器的管道全位置焊接自动控制系统,描述了其系统结构、工作原理和软件设计。通过串行通信,PLC和单片机之间实现了对焊接参数的协调控制。还介绍了串行通信的硬件电路、PLC系统设置和系统抗干扰措施等。实验表明,该系统运行可靠,能有效提高生产效率,具有重要的工程应用前景。

  5. FIJI: Fighting Implicit Jamming in 802.11 WLANs

    Science.gov (United States)

    Broustis, Ioannis; Pelechrinis, Konstantinos; Syrivelis, Dimitris; Krishnamurthy, Srikanth V.; Tassiulas, Leandros

    The IEEE 802.11 protocol inherently provides the same long-term throughput to all the clients associated with a given access point (AP). In this paper, we first identify a clever, low-power jamming attack that can take advantage of this behavioral trait: the placement of a low-power jammer in a way that it affects a single legitimate client can cause starvation to all the other clients. In other words, the total throughput provided by the corresponding AP is drastically degraded. To fight against this attack, we design FIJI, a cross-layer anti-jamming system that detects such intelligent jammers and mitigates their impact on network performance. FIJI looks for anomalies in the AP load distribution to efficiently perform jammer detection. It then makes decisions with regards to optimally shaping the traffic such that: (a) the clients that are not explicitly jammed are shielded from experiencing starvation and, (b) the jammed clients receive the maximum possible throughput under the given conditions. We implement FIJI in real hardware; we evaluate its efficacy through experiments on a large-scale indoor testbed, under different traffic scenarios, network densities and jammer locations. Our measurements suggest that FIJI detects such jammers in real-time and alleviates their impact by allocating the available bandwidth in a fair and efficient way.

  6. Electromagnetic Compatibility about Backpack Type Inverter & Motor Structure%背包式变频器与电机集成结构的电磁兼容探讨

    Institute of Scientific and Technical Information of China (English)

    秦立新; 刘洋

    2012-01-01

    变频器与电机的集成结构——背包式的电磁兼容问题是个技术问题.由于采用了背包式结构,变频器和电机型式试验将作为一台电机整体来进行考核.变频器的使用,提高了电机系统效率,但是,变频器背包却带来了较为复杂的电磁兼容问题.介绍了背包式变频器+电机的原理和结构,分析了此结构的电磁兼容问题,并提出了系统抗干扰的实际办法.%In the integration structure of the inverter and motor, the electromagnetic compatibility of backpack type is a technical problem. Because of the backpack type structure, type test assessment of motor & inverter will be as a motor overall. Backpack type inverter improves the efficiency of motor system, but brings complex electromagnetic compatibility problems . The principle and structure about backpack type inverter & motor was introduced, the electromagnetic compatibility problems was analyzed, and practical measures of anti-jamming system was put forward.

  7. CPM Signals for Satellite Navigation in the S and C Bands.

    Science.gov (United States)

    Xue, Rui; Sun, Yanbo; Zhao, Danfeng

    2015-06-05

    Frequency allocations in the L band suitable for global navigation satellite system (GNSS) services are getting crowded and system providers face an ever tougher job when they try to bring in new signals and services while maintaining radio frequency compatibility. With the successive opening of the S and C bands to GNSS service, the multi-band combined navigation is predicted to become a key technology for future high-precision positioning navigation systems, and a single modulation scheme satisfying the requirements in each band is a promising solution for reducing user terminal complexity. A universal modulation scheme based on the continuous phase modulation (CPM) family suitable for the above bands' demands is proposed. Moreover, this paper has put forward two specific CPM signals for the S and C bands, respectively. Then the proposed modulation schemes, together with existing candidates, are comprehensively evaluated. Simulation results show that the proposed CPM signals can not only satisfy the constraint condition of compatibility in different bands well and reduce user terminal complexity, but also provide superior performance in terms of tracking accuracy, multi-path mitigation and anti-jamming compared to other candidate modulation schemes.

  8. Discussion of the target-missile control scheme with supersonic speed at minimum altitude

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    An antiship missile with supersonic speed at minimum altitude is an effective weapon to break through a defense line. The former Soviet Union was a leader in this field since it had developed several kinds of antiship missiles which obtained supersonic speed at minimum altitudes. To counter this kind of missile,many countries have been developing corresponding antimissiles. For the purpose of verifing the antimissile missile's effectiveness in intercepting antiship missiles, a target-missile is needed. A target-missle is cheaper and can imitate the main characteristics of antiship missiles with supersonic speed at minimum altitude. In this paper, the control scheme of a target missile flying with supersonic speed at minimum altitude is studied. To counter the problem of hedgehopping over the sea, a control scheme utilizing a SINS + altimeter was proposed.In this scheme, both the quick response ability of altitude control and the anti-jamming problem were considered. A simulation experiment shows that when an integrated altitude control system is used, the anti-disturbance ability of the integrated altitude is good and the response speed of altitude control system can be dramatically improved.

  9. Applications of digital IF receivers and under-sampling technique in ladar

    Science.gov (United States)

    Song, Zhi-yuan; Zhu, Shao-lan; Dong, Li-jun; Feng, Li; He, Hao-dong

    2011-06-01

    The traditional technique of phase laser range finder is mixing high frequency signals with analog circuits and filtering them to obtain the useful signal with low frequency. But the analog mixing circuits are susceptible to interference and will bring amplitude attenuation, phase jitter and offset and this way has difficulties in achieving high precision ranging and fast speed ranging at the same time. The method of this paper is based on under-sampling technique with digital synchronous detection and referring to Digital down converter technique of digital IF receiver in radar system. This method not only reduces the complexity of data processing, improves the speed and accuracy of phase detection at the same time, but also reduces requirements for ADC devices and DSP chips in the ladar system by a lower sampling rate. At the same time, the structure of electronic system is global simplified compared with traditional analog ladar system and the anti-jamming is greatly enhanced. So this method has important research value.

  10. Subarray-based FDA radar to counteract deceptive ECM signals

    Science.gov (United States)

    Abdalla, Ahmed; Wang, Wen-Qin; Yuan, Zhao; Mohamed, Suhad; Bin, Tang

    2016-12-01

    In recent years, the frequency diverse array (FDA) radar concept has attracted extensive attention, as it may benefit from a small frequency increment, compared to the carrier frequency across the array elements and thereby achieve an array factor that is a function of the angle, the time, and the range which is superior to the conventional phase array radar (PAR). However, limited effort on the subject of FDA in electronic countermeasure scenarios, especially in the presence of mainbeam deceptive jamming, has been published. Basic FDA is not desirable for anti-jamming applications, due to the range-angle coupling response of targets. In this paper, a novel method based on subarrayed FDA signal processing is proposed to counteract deceptive ECM signals. We divide the FDA array into multiple subarrays, each of which employs a distinct frequency increment. As a result, in the subarray-based FDA, the desired target can be distinguished at subarray level in joint range-angle-Doppler domain by utilizing the fact that the jammer generates false targets with the same ranges to each subarray without reparations. The performance assessment shows that the proposed solution is effective for deceptive ECM targets suppression. The effectiveness is verified by simulation results.

  11. 舵机加载系统的自适应滑模控制策略研究%Research for adaptive sliding mode control in aircraft rudder electric loading system

    Institute of Scientific and Technical Information of China (English)

    史本杰; 王易炜

    2012-01-01

    舵机加载系统主要用于模拟导弹在飞行过程中舵面受到的各种气动力矩,但存在力矩效率低,多余力较多,干扰复杂等特点.为使电动加载系统的仿真度和力矩精度进一步提高,采用自适应滑模控制对多余力矩和其他位置干扰进行抑制,同时对滑模控制的切换函数进行改进,以削弱系统存在的抖振.仿真结果显示,加载系统的精度和抗干扰能力有进一步提高.%The steering mechanism loading system is used to simulate various aerodynamic torques that the missile rudder suffers from flying, but it has some characteristics, such as low efficiency, much redundant torque and complex disturbance. In order to improve the precision and reliability of the steering mechanism loading system, adaptive sliding mode control was used and the switch function of sliding mode control (SMC) was modified to weaken system chattering. The simulation result indicates that the precision and anti-jamming of the loading system are improved.

  12. 对称式双电位扩展键盘设计%Design of Double Potential Symmetrical Extended Keyboard

    Institute of Scientific and Technical Information of China (English)

    姜磊

    2013-01-01

    本设计是基于MCU的一款高效率键盘输入系统。通过对分立按键和普通二极管的合理布局,实现了一种利用N个双向I/O端口确定N2+N个键值的键盘电路设计。实验证明,该键盘电路结构简单、抗干扰能力强、稳定性好,具有很高的使用价值。%Based on the MCU,a high-effifiency keyboard input system is designed in this paper. Through the rational distribu-tion of discrete buttons and ordinary diodes, implements a use of N bidirectional I/O port identified N 2+N key keyboard circuit design. Experiments show that the keyboard circuit structure has the simple control circuit,good anti-jamming ability,good stabil-ity and high practical value.

  13. Research on the measurement of belt speed by video in coal mine based on improved template matching algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHU Ai-chun; HUA Wei; WANG Chun; WANG Yong-xing

    2011-01-01

    In order to improve the intelligence of video monitoring system of belt and make up the deficiency of higher failure rate and bad real-time performance in the traditional systems of measurement of belt speed,according to the fact that the light of coal mine is uneven,the strength of light changes greatly,the direction of belt movement is constant,and the position of camera was fixed,various algorithms of speed measurement by video were studied,and algorithm for template matching based on sum of absolute differences(SAD)and correlation coefficient was proposed and improved,besides,the tracking of feature regions was realized.Then,a camera calibration method using the invariance of the cross-ratio was adopted and the real-time measurement of belt speed by the hardware platform based on DM642 was realized.Finally,experiment results show that this method not only has advantages of high precision and strong anti-jamming capability but also can real-time reflect the changes of belt speed,so it has a comprehensive applicability.

  14. A compound control strategy combining velocity compensation with ADRC of electro-hydraulic position servo control system.

    Science.gov (United States)

    Gao, Bingwei; Shao, Junpeng; Yang, Xiaodong

    2014-11-01

    In order to enhance the anti-jamming ability of electro-hydraulic position servo control system at the same time improve the control precision of the system, a compound control strategy that combines velocity compensation with Active Disturbance Rejection Controller (ADRC) is proposed, and the working principle of the compound control strategy is given. ADRC controller is designed, and the extended state observer is used for observing internal parameters uncertainties and external disturbances, so that the disturbances of the system are suppressed effectively. Velocity compensation controller is designed and the compensation model is derived to further improve the positioning accuracy of the system and to achieve the velocity compensation without disturbance. The compound control strategy is verified by the simulation and experiment respectively, and the simulation and experimental results show that the electro-hydraulic position servo control system with ADRC controller can effectively inhibit the external disturbances, the precise positioning control is realized after introducing the velocity compensation controller, and verify that the compound control strategy is effective.

  15. Chaotic CDMA watermarking algorithm for digital image in FRFT domain

    Science.gov (United States)

    Liu, Weizhong; Yang, Wentao; Feng, Zhuoming; Zou, Xuecheng

    2007-11-01

    A digital image-watermarking algorithm based on fractional Fourier transform (FRFT) domain is presented by utilizing chaotic CDMA technique in this paper. As a popular and typical transmission technique, CDMA has many advantages such as privacy, anti-jamming and low power spectral density, which can provide robustness against image distortions and malicious attempts to remove or tamper with the watermark. A super-hybrid chaotic map, with good auto-correlation and cross-correlation characteristics, is adopted to produce many quasi-orthogonal codes (QOC) that can replace the periodic PN-code used in traditional CDAM system. The watermarking data is divided into a lot of segments that correspond to different chaotic QOC respectively and are modulated into the CDMA watermarking data embedded into low-frequency amplitude coefficients of FRFT domain of the cover image. During watermark detection, each chaotic QOC extracts its corresponding watermarking segment by calculating correlation coefficients between chaotic QOC and watermarked data of the detected image. The CDMA technique not only can enhance the robustness of watermark but also can compress the data of the modulated watermark. Experimental results show that the watermarking algorithm has good performances in three aspects: better imperceptibility, anti-attack robustness and security.

  16. 海底光缆安全研究%Study on security in submarine optical fiber cable

    Institute of Scientific and Technical Information of China (English)

    陈利明; 邵芳; 邵平

    2009-01-01

    It has dominated in international communication for submarine optical fiber cable because its large-capacity,reliability and stabilization in quality of service(QoS),high-eonfidentiality, outstanding ability in anti-destruction and anti-jamming and so on.This paper firstly introduced the composing of submarine optical fiber cable system,and then analyzed mostly ingredient that influences its security in transmission line and in-formation.Finally we brought forward some protective measures such as optical fiber cable quality and con-struction, fault positioning and eliminating, enhancing transmission information security and so on.%海底光缆通信具有大容量、通信质量稳定可靠,隐蔽性好,抗毁、抗干扰能力强等特点,成为现代洲际通信的主力.从介绍海底光缆通信系统的组成入手,分析了影响海底光缆传输线路安全和光缆所传输信息安全的主要因素,提出了光缆质量与施工、故障定位与排除和加强信息传输安全等防护措施.

  17. Analysis of Current Status and Future Trend of UV Communication System%紫外光通信系统现状及发展趋势分析

    Institute of Scientific and Technical Information of China (English)

    吴忠良; 梁菁; 任杰; 王绍昱

    2011-01-01

    紫外光通信系统作为一种新型的军事通信系统,具有抗干扰能力强、保密性好、非视距通信以及全方位通信等优点。它可作为一种专用局域军事保密通信手段,或在特定条件下作为其它通信手段的一种补充,可广泛应用于海陆空三军,对未来战争、现代化国防具有特殊的使用价值和实际意义。文中主要介绍了国内外紫外光通信系统的发展现状,并分析了其未来发展趋势。%As a new type optical communication system,ultraviolet communication system has the potential advantages of good security,high powerful anti-jamming,capability of non-line of sight(NLOS) and omni directional.It can be used as a dedicated local military se

  18. 基于DVB-S2系统APSK信号的分析与干扰仿真%Analysis and Simulation of Jamming APSK Signals Based on DVB-S2 System

    Institute of Scientific and Technical Information of China (English)

    田上成; 王可人; 焦传海; 王喜风

    2012-01-01

    针对DVB-S2系统采用的幅度相位键控(APSK)等高阶调制方式,分析了APSK信号的调制与解调原理,推导了16APSK信号的误比特率(BER)。仿真讨论了基于DVB-S2系统APSK信号在受不同噪声调制干扰和数字调制信号干扰时的误比特率及干扰效果。结果表明:在低干信比(J/s)时数字调制干扰信号干扰效果更好。研究结果可为APSK信号的抗干扰性能研究提供参考。%The principles of APSK modulation and demodulation were analyzed for the high-order digital modulation in DVB-S2 system in this paper. The bit error rate (BER) for 16APSK was theoretically derived. The BER and effects of various noise modulation jamming and the digital modulation jamming for APSK based on DVB- $2 system were obtained through simulation. The simulation results were showed that the digital modulation jamming was efficient under the situation of low signal interference rate. The results could provide references to the study of anti-jamming.

  19. Study on interception technique to airborne LPI radar with high probability%对机载LPI雷达的高概率截获技术研究

    Institute of Scientific and Technical Information of China (English)

    邹顺; 胡元奎; 张海黎

    2011-01-01

    The anti-reconnaissance ability and anti-jamming ability of airborne radars can be improved greatly through flexible beam control technique and advanced waveform design technique.A kind of reconnaissance method is put for ward by comprehensively using reconnaissance technique based on digital array,channelized detecting technique based on poly-phase filtering and signal sorting technique based on fuzzy clustering,and the method is hopeful to intercept airborne LPI radar with high probability.%采用先进的功率管理技术和灵活的波形设计技术,能大大提高机载雷达的反侦察和抗干扰能力。提出了一种综合利用数字阵列侦察技术、基于多相滤波的信道化检测技术以及基于模糊聚类的信号分选技术的侦察截获方法,有望实现对机载LPI雷达的高概率截获。

  20. Test results judgment method based on BIT faults

    Institute of Scientific and Technical Information of China (English)

    Wang Gang; Qiu Jing; Liu Guanjun; Lyu Kehong

    2015-01-01

    Built-in-test (BIT) is responsible for equipment fault detection, so the test data correct-ness directly influences diagnosis results. Equipment suffers all kinds of environment stresses, such as temperature, vibration, and electromagnetic stress. As embedded testing facility, BIT also suffers from these stresses and the interferences/faults are caused, so that the test course is influenced, resulting in incredible results. Therefore it is necessary to monitor test data and judge test failures. Stress monitor and BIT self-diagnosis would redound to BIT reliability, but the existing anti-jamming researches are mainly safeguard design and signal process. This paper focuses on test results monitor and BIT equipment (BITE) failure judge, and a series of improved approaches is proposed. Firstly the stress influences on components are illustrated and the effects on the diagnosis results are summarized. Secondly a composite BIT program is proposed with information integra-tion, and a stress monitor program is given. Thirdly, based on the detailed analysis of system faults and forms of BIT results, the test sequence control method is proposed. It assists BITE failure judge and reduces error probability. Finally the validation cases prove that these approaches enhance credibility.

  1. Monitoring technique for seepage line of tailings dam

    Institute of Scientific and Technical Information of China (English)

    李夕兵; 蒋卫东

    2003-01-01

    An automatic monitoring technique of the seepage line, including the monitoring design, the automatic monitoring system and the backfill technique of the measuring probe of pore-water pressure, was used in a tailings dam, and a shallow refractive seismic method was investigated for obtaining the seepage line of those areas outside the monitoring zone. The results show that the automatic monitoring has the error within ± 3 % relative to piezometric tube method and improves monitoring efficiency greatly, and the shallow refractive seismic method has the error within ± 10% but expands the area of monitoring. Both of them can be used for a daily measurement in monitoring the seepage line. The result of the automatic monitoring also shows that not only the design of the survey line and the backfill technique of the measuring probe of pore-water pressure are reasonable and economic but also the reliability and safety of the automatic monitoring system are better. Testing result by the shallow refractive seismic method in tailings reveals that the energy excited by hammering iron sheet-pole is strong enough and safe, and that the character of anti-jamming by the detectors with long tailcone is better.

  2. On the Online Testing Technology Based on RGB Tricolor Theory%基于RGB三基色原理在线监测技术研究

    Institute of Scientific and Technical Information of China (English)

    赵宇; 农永光; 郭炜; 于哲

    2014-01-01

    研究三基色RGB在线检测技术,通过与传统光电比色法进行比对分析,得出两种完全不同的结构原理,RGB在线检测技术在抗干扰能力具有很明显的优势,完全可以将该技术应用于在线检测中,将来可以替代传统的光电比色技术,可以实现小型化设计。%By researching tricolor RGB online testing technology with the comparison analysis of traditional photoelectric colorimetry, the two completely different structural principles are obtained, RGB online testing technology has obvious advantages in anti-jamming capability, which can be applied in online testing technology, and replace traditional photoelectric colorimetry in the future, to realize miniaturized design.

  3. Gear Box State Detection System Based on Fiber Grating Sensor%基于光纤光栅传感器的齿轮箱状态监测系统

    Institute of Scientific and Technical Information of China (English)

    陈亮; 王其林; 李旭松

    2011-01-01

    It is hard to measure gear abrasion of certain type artillery collimator gear box. Therefore design a real time detection system of gear box. The system hardware uses fiber grating sensor as measuring node and adopts fiber as signal transmission medium. The signal is inputted into virtual instrument platform through demodulation system and carried out data processing and displaying. The system software functions include fiber grating demodulation, oscillation signal revivification and gear state estimation. Characteristic of the system is anti-jamming, anti-erosion, small type and easy to integrating.%针对某舰舰炮瞄准机齿轮箱齿轮磨损程度不易测量的问题,设计一种齿轮箱状态实时监测系统.系统硬件以光纤光栅传感器为测量节点,光纤为信号传输介质,信号经解调系统输入虚拟仪器平台,进行数据处理与显示.系统软件功能包括光纤光栅解调、箱体振动信号还原和齿轮状态评估.该系统具有抗干扰、抗腐蚀性强,体积小巧,便于管理,易于集成的特点.

  4. GPS Interference Mitigation Using Derivative-free Kalman Filter-based RNN

    Directory of Open Access Journals (Sweden)

    W. L. Mao

    2016-09-01

    Full Text Available The global positioning system (GPS with accurate positioning and timing properties has become integral part of all applications around the world. Radio frequency interference can significantly decrease the performance of GPS receivers or even completely prohibit the acquisition or tracking of satellites. The approaches of system performances that can be further enhanced by preprocessing to reject the jamming signal will be investigated. A recurrent neural network (RNN predictor for the GPS anti-jamming applications will be proposed. The adaptive RNN predictor is utilized to accurately predict the narrowband waveform based on an unscented Kalman filter (UKF-based algorithm. The UKF algorithm as a derivative-free alternative to the extended Kalman filter (EKF in the framework of state-estimation is adopted to achieve better performance in terms of convergence rate and quality of solution. The adaptive RNN filter can be successfully applied for the suppression of interference with a number of different narrowband formats, i.e. continuous wave interference (CWI, multi-tone CWI, swept CWI and pulsed CWI, to emulate realistic circumstances. Simulation results show that the proposed UKF-based scheme can offer the superior performances to suppress the interference over the conventional methods by computing mean squared prediction error (MSPE and signal-to-noise ratio (SNR improvements.

  5. 多模式化数字语音录放显示系统创新设计%lnnovative Design of Multi-mode Digital Voice Recording System

    Institute of Scientific and Technical Information of China (English)

    钱丹浩; 刘萍萍

    2015-01-01

    This paper using STM32 microcontrol er core,designs a multi-mode digital voice recording system,which consti-tuted by the foundation of the recording-platform and the monitoring-module,and a digital-voice recording system of the Multi-mode,and givens its hardware circuit and discusses the course of their work.Designing the program's main work pro-cesses and algorithms,the system is simple,good anti-jamming.%以STM32微控制器为核心,设计出由基础录放平台和功能测控模块构成的多模式化数字语音录放和显示系统,给出了其硬件电路并论述其工作过程,设计了程序的主要工作流程和算法。该系统结构简单,抗干扰性好。

  6. Blocking junctional adhesion molecule C enhances dendritic cell migration and boosts the immune responses against Leishmania major.

    Science.gov (United States)

    Ballet, Romain; Emre, Yalin; Jemelin, Stéphane; Charmoy, Mélanie; Tacchini-Cottier, Fabienne; Imhof, Beat A

    2014-12-01

    The recruitment of dendritic cells to sites of infections and their migration to lymph nodes is fundamental for antigen processing and presentation to T cells. In the present study, we showed that antibody blockade of junctional adhesion molecule C (JAM-C) on endothelial cells removed JAM-C away from junctions and increased vascular permeability after L. major infection. This has multiple consequences on the output of the immune response. In resistant C57BL/6 and susceptible BALB/c mice, we found higher numbers of innate immune cells migrating from blood to the site of infection. The subsequent migration of dendritic cells (DCs) from the skin to the draining lymph node was also improved, thereby boosting the induction of the adaptive immune response. In C57BL/6 mice, JAM-C blockade after L. major injection led to an enhanced IFN-γ dominated T helper 1 (Th1) response with reduced skin lesions and parasite burden. Conversely, anti JAM-C treatment increased the IL-4-driven T helper 2 (Th2) response in BALB/c mice with disease exacerbation. Overall, our results show that JAM-C blockade can finely-tune the innate cell migration and accelerate the consequent immune response to L. major without changing the type of the T helper cell response.

  7. Blocking junctional adhesion molecule C enhances dendritic cell migration and boosts the immune responses against Leishmania major.

    Directory of Open Access Journals (Sweden)

    Romain Ballet

    2014-12-01

    Full Text Available The recruitment of dendritic cells to sites of infections and their migration to lymph nodes is fundamental for antigen processing and presentation to T cells. In the present study, we showed that antibody blockade of junctional adhesion molecule C (JAM-C on endothelial cells removed JAM-C away from junctions and increased vascular permeability after L. major infection. This has multiple consequences on the output of the immune response. In resistant C57BL/6 and susceptible BALB/c mice, we found higher numbers of innate immune cells migrating from blood to the site of infection. The subsequent migration of dendritic cells (DCs from the skin to the draining lymph node was also improved, thereby boosting the induction of the adaptive immune response. In C57BL/6 mice, JAM-C blockade after L. major injection led to an enhanced IFN-γ dominated T helper 1 (Th1 response with reduced skin lesions and parasite burden. Conversely, anti JAM-C treatment increased the IL-4-driven T helper 2 (Th2 response in BALB/c mice with disease exacerbation. Overall, our results show that JAM-C blockade can finely-tune the innate cell migration and accelerate the consequent immune response to L. major without changing the type of the T helper cell response.

  8. Communication Control of PLC and Inverter Based on Extended Memory%基于扩展存储器的PLC与变频器的通讯控制

    Institute of Scientific and Technical Information of China (English)

    阮友德; 许小华

    2011-01-01

    本文针对PLC与变频器的通讯控制,详细介绍了一种基于FX2N-ROM-E1的通讯控制系统,并且给出了系统的硬件组成和程序梯形图,阐述了PLC的通讯格式和变频器的通讯参数及指令代码.实践证明,系统具有抗干扰能力强、传输速率高、编程简便、造价低廉等特点.%Aiming at communication control of PLC and inverter,this article introduces the communication control system which is based on FX2N-ROM-E1, and gives the hardware's composition and program ladder of the system. also elaborates the communication format of PLC and communication parameters and instruction codes of inverter. Facts have proved that the system is not only possessing powerful anti-jamming capability, high transmission speed, but also simple programming.

  9. Research of PPM-based Reed-solomon concatenate codes modulation in optical wireless communications%无线光通信中PPM的RS级联编码调制研究

    Institute of Scientific and Technical Information of China (English)

    李精华

    2012-01-01

    在脉冲位置调制(PPM)直接检测光通信系统中插入RS级联编码构成一种新的PPM光通信系统(RS-PPM),该方式对PPM直接检测光通信系统进行了改进,并用Matlab对编码系统和未编码系统的误比特率进行了仿真比较,仿真结果表明,基于RS级联编码的PPM系统具有较好纠错和抗干扰能力.%In the direct detection optical PPM communication systems into the RS coding constitute a new cascade PPM optical communication system (RS-PPM), the direct detection method for PPM optical communication system has been improved, and with Matlab coding system and the uncoded system bit error rate of the simulation compared to simulation ,the results show that based on the RS coded PPM system cascade has good error correction and anti-jamming capability.

  10. 基于FPGA的扩频信号发生器的研究与设计%Study and Design of Spread-Spectrum Signal Generator Based on FPGA

    Institute of Scientific and Technical Information of China (English)

    王茂林; 杨合圣

    2012-01-01

    扩频通信技术具有抗干扰,抗多径,保密性好,不易被截获以及可以实现码分多址等优点。信号发生器是一种十分重要的仪器,在通信、测控、导航、雷达、医疗等领域有着广泛的应用。文章以直接频率合成和伪随机码的设计与实现为中心,对扩频通信的基本理论,载波调制等问题进行分析与研究。%Spread-spectrum communication has many advantages such as anti-jamming,anti-multipath,confidentiality,difficult to be intercepted,code division and multiple access,and so on.Signal generator is so important a device that it is applied to communication,monitoring and control,navigation,radar,medical and other abroad fields.In this paper,the design and achievement of direct digital frequency synthesize and pseudo-random code is central work,with basic theory of spread-spectrum communication and carrier modulation analyzed and studied.

  11. Research on Hardware Performance for Thermocouple Temperature Measurement Modules%热电偶温度测量模块硬件性能研究

    Institute of Scientific and Technical Information of China (English)

    陈名宝

    2012-01-01

    Thermocouple is an important measurement tool in thermal detection measurement. Researching the antijamming ability of the Thermocouple temperature sensor module has the great significance. This paper,begin with the performance index of thermocouple temperature sensor module,and combining the theory analysis and experimental cases,design a kind of high precision,strong anti-jamming performance of hardware. Developed the products with the cold junction compensation and thread break detector function,can through a series of electromagnetic compatibility test,can satisfy most of the industrial application.%热电偶是热工检测中重要的计量工具,研究热电偶测温模块的抗干扰性能具有重大意义.该文从热电偶测温模块性能指标出发,结合理论分析和实验案例,设计出精度高,抗干扰性能强的硬件.开发出来的产品具有冷端补偿和断线检测功能,能通过一系列电磁兼容性测试,可以满足绝大部分工业场景应用要求.

  12. Two-layer wireless distributed sensor/control network based on RF

    Science.gov (United States)

    Feng, Li; Lin, Yuchi; Zhou, Jingjing; Dong, Guimei; Xia, Guisuo

    2006-11-01

    A project of embedded Wireless Distributed Sensor/Control Network (WDSCN) based on RF is presented after analyzing the disadvantages of traditional measure and control system. Because of high-cost and complexity, such wireless techniques as Bluetooth and WiFi can't meet the needs of WDSCN. The two-layer WDSCN is designed based on RF technique, which operates in the ISM free frequency channel with low power and high transmission speed. Also the network is low cost, portable and moveable, integrated with the technologies of computer network, sensor, microprocessor and wireless communications. The two-layer network topology is selected in the system; a simple but efficient self-organization net protocol is designed to fit the periodic data collection, event-driven and store-and-forward. Furthermore, adaptive frequency hopping technique is adopted for anti-jamming apparently. The problems about power reduction and synchronization of data in wireless system are solved efficiently. Based on the discussion above, a measure and control network is set up to control such typical instruments and sensors as temperature sensor and signal converter, collect data, and monitor environmental parameters around. This system works well in different rooms. Experiment results show that the system provides an efficient solution to WDSCN through wireless links, with high efficiency, low power, high stability, flexibility and wide working range.

  13. CPM Signals for Satellite Navigation in the S and C Bands

    Directory of Open Access Journals (Sweden)

    Rui Xue

    2015-06-01

    Full Text Available Frequency allocations in the L band suitable for global navigation satellite system (GNSS services are getting crowded and system providers face an ever tougher job when they try to bring in new signals and services while maintaining radio frequency compatibility. With the successive opening of the S and C bands to GNSS service, the multi-band combined navigation is predicted to become a key technology for future high-precision positioning navigation systems, and a single modulation scheme satisfying the requirements in each band is a promising solution for reducing user terminal complexity. A universal modulation scheme based on the continuous phase modulation (CPM family suitable for the above bands’ demands is proposed. Moreover, this paper has put forward two specific CPM signals for the S and C bands, respectively. Then the proposed modulation schemes, together with existing candidates, are comprehensively evaluated. Simulation results show that the proposed CPM signals can not only satisfy the constraint condition of compatibility in different bands well and reduce user terminal complexity, but also provide superior performance in terms of tracking accuracy, multi-path mitigation and anti-jamming compared to other candidate modulation schemes.

  14. A hierarchical model for structure learning based on the physiological characteristics of neurons

    Institute of Scientific and Technical Information of China (English)

    WEI Hui

    2007-01-01

    Almost all applications of Artificial Neural Networks (ANNs) depend mainly on their memory ability.The characteristics of typical ANN models are fixed connections,with evolved weights,globalized representations,and globalized optimizations,all based on a mathematical approach.This makes those models to be deficient in robustness,efficiency of learning,capacity,anti-jamming between training sets,and correlativity of samples,etc.In this paper,we attempt to address these problems by adopting the characteristics of biological neurons in morphology and signal processing.A hierarchical neural network was designed and realized to implement structure learning and representations based on connected structures.The basic characteristics of this model are localized and random connections,field limitations of neuron fan-in and fan-out,dynamic behavior of neurons,and samples represented through different sub-circuits of neurons specialized into different response patterns.At the end of this paper,some important aspects of error correction,capacity,learning efficiency,and soundness of structural representation are analyzed theoretically.This paper has demonstrated the feasibility and advantages of structure learning and representation.This model can serve as a fundamental element of cognitive systems such as perception and associative memory.Key-words structure learning,representation,associative memory,computational neuroscience

  15. 基于RFID的冷库管理信息系统%RFID -based Management Information System for Cold Storage

    Institute of Scientific and Technical Information of China (English)

    张庆英; 何宁英

    2011-01-01

    As an advanced technique of automatic identification, radio frequency identification ( RFID) has many ad vantages, such as excellent adaptability, high abilities of anti -jamming, high read convenience of hig amount data. The RFID was applied in the cold storage management and a cold storage management information system was designed on the ASP. NET platform. The level of automation of cold storage inventory management was improved and the accuracy and efficiency of cold storage were enhanced.%无线射频识别技术(radio frequency identification,RFID)作为一种自动识别技术的高级形式,具有适应环境能力强、抗干扰强、读取方便和读取数量大等诸多优点.将RFID核心技术应用于冷库的库存管理中,在ASP.NET网络平台上开发了冷库管理信息系统,以提高冷库库存管理各环节的自动化水平和冷库的效率.

  16. Software Implementation of Hydraulic Cylinder Position PID Closed Loop Control in Proportional Valve Control System Using PLC%比例阀控液压缸位置PID闭环控制的PLC软件实现

    Institute of Scientific and Technical Information of China (English)

    李艳杰; 崔天宇; 王海; 马鹤; 苗鑫超

    2013-01-01

    A software implementation method of hydraulic cylinder position PID closed loop control in proportional valve control system using Siemens S7-200 was proposed.The block diagram and ladder program was given,and experimental studies in Festo TP701 proportional hydraulic test bed was done.Experimental studies have shown that the proportion of open-loop control system,using software methods can achieve the closed-loop control of position and other physical quantities,to control the performance of precision and anti-jamming capability to meet the demand of general industrial applications.%提出一种利用西门子S7-200实现比例阀控制系统中液压缸位置PID闭环控制的软件实现方法,给出了程序框图及梯形图程序,并在Festo TP701比例液压试验台上进行实验研究.实验研究表明,开环比例控制系统中,利用软件的方法可实现位置等物理量的闭环控制,控制精度和抗干扰能力等性能可满足一般工业应用的需求.

  17. A Novel Monopulse Angle Estimation Method for Wideband LFM Radars

    Directory of Open Access Journals (Sweden)

    Yi-Xiong Zhang

    2016-06-01

    Full Text Available Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, the challenge lies in the accumulation of energy from the high resolution range profile (HRRP of monopulse. In wideband radars, linear frequency modulated (LFM signals are frequently utilized. In this paper, we investigate the monopulse angle estimation problem for wideband LFM signals. To accumulate the energy of the received echo signals from different scatterers of a target, we propose utilizing a cross-correlation operation, which can achieve a good performance in low signal-to-noise ratio (SNR conditions. In the proposed algorithm, the problem of angle estimation is converted to estimating the frequency of the cross-correlation function (CCF. Experimental results demonstrate the similar performance of the proposed algorithm compared with the traditional amplitude comparison method. It means that the proposed method for angle estimation can be adopted. When adopting the proposed method, future radars may only need wideband signals for both tracking and imaging, which can greatly increase the data rate and strengthen the capability of anti-jamming. More importantly, the estimated angle will not become ambiguous under an arbitrary angle, which can significantly extend the estimated angle range in wideband radars.

  18. Research progress in SAW filter banks

    Institute of Scientific and Technical Information of China (English)

    HE Shi-tang

    2005-01-01

    SAW (Surface Acoustic Wave) filter bank is a single input, single or multi-output device consisting of multi-SAW-filters with input interconnection network or switch circuits, and can be divided into two categories: channelizer (multi-output) and switchable (programmable, single output). The former is mainly used in military channelized receiver for spectrum analysis;the latter has wide application in frequency synthesizer and frequency-hopping radar and communication system receiver as anti-jamming filter, and has been widely used in various military electronic equipments ever since the 1970s.Research abroad was done mainly by Americans, few documents on related work done by Japan and Russia are available. Domestic research started in the 1980s, mainly by No. 26 Research Institute, China Electronics Technology Group Co., Institute of Acoustics, Chinese Academy of Sciences, No. 23 and No. 25 Research Institute, China Spaceflight Tech. Group Co. This paper first briefly introduces Chinese and foreign research on SAW filter banks;then discusses research progress in device design, the input interconnection network or switch circuit and miniaturization;and ends in a brief perspective of developing trends in future.

  19. 浅析OFDM的通信技术%Analysis of OFDM communication technology

    Institute of Scientific and Technical Information of China (English)

    刘巧平

    2014-01-01

    正交频分复用(OFDM)是一种具有巨大潜力的传输技术。OFDM技术最突出的优点是频谱利用率高、抗干扰、抗信道衰落。本文首先介绍了OFDM技术的基本原理,接着分析了OFDM技术的优势以及需要克服的缺陷,最后讨论了OFDM的几种关键技术。%OFDM(Orthogonal Frequency Division Multiplexing)is a kind of transmission technology having huge potential.It has prominent advantages in high spectrum utilization,anti-jamming and anti-fading channel. This paper introduces the key techniques of OFDM and then analyzes the advantages of OFDM and the need to overcome the defects,and finally it focuses on studying several key techniques of OFDM.

  20. MIMO Bistatic Radar and Its Application Expectation%MIMO双基地雷达及其应用展望

    Institute of Scientific and Technical Information of China (English)

    高节; 宋苏杭

    2015-01-01

    MIMO bistatic radar is a new conception in recent years,and the research for its theory and technique has become one of hot problem in the domain of radar. Since it has both character of MIMO technique and the bistatic radar, the MIMO bistatic radar is provided with the potential ability of the anti-reconnaissance,anti-jamming,anti-stealth and anti-radiation attack, and can be widely found application in the future. This paper introduces the principle and advantages of MIMO bistatic radar, and expects its application in the future with military requirement and the character of radar self.%MIMO双基地雷达是近年来提出的新概念,对其理论和技术的研究已成为雷达领域的热点课题之一.由于结合了MIMO技术和双基地雷达的特点,MIMO双基地雷达具有反侦察、抗干扰、反隐身、对抗反辐射导弹的潜在优势,在未来雷达中具有广阔的应用前景.文章介绍了MIMO双基地雷达的基本原理和优势,并结合军事需求与雷达自身特点对其应用前景做了展望.

  1. Whole inactivated avian Influenza H9N2 viruses induce nasal submucosal dendritic cells to sample luminal viruses via transepithelial dendrites and trigger subsequent DC maturation.

    Science.gov (United States)

    Qin, Tao; Yin, Yinyan; Wang, Xiaoqing; Liu, Haofei; Lin, Jian; Yu, Qinghua; Yang, Qian

    2015-03-10

    Nasal mucosal barrier is a key impediment for the absorption of influenza whole inactivated virus (WIV) intranasal vaccine. Yet it is still unclear how WIV cross the epithelial cells (ECs) in nasal cavity. Here, in vitro, a coculture system was well established, consisting of surrogate nasal ECs (Calu-3) and dendritic cells (DCs). After adding H9N2 WIV on the apical side of ECs, we found that submucosal DCs extended their transepithelial dendrites (TEDs) and sampled luminal viruses. However, ECs were not involved in the transepithelial transport of viruses. Subsequently, the phenotypic and functional maturation of DCs were also enhanced, whereas they were attenuated after blocking of TED formation by anti-JAM1 antibody. In vivo, we confirmed that H9N2 WIV were capable of inducing nasal submucosal DCs to sample luminal viruses via TEDs in the nasal passage but not nasal-associated lymphoid tissue (NALT). CD103(+) and CD103(-) DC subsets participated in this process. Of note, chemokine CCL20, released from the H9N2 WIV-induced ECs, played a vital role in DC recruitment and TED formation. Taken together, our findings indicated that TEDs played a critical role in facilitating viral transport across the epithelial barrier, which may guide the design of novel nasal mucosal vaccine strategies.

  2. A novel cognitive ISAR imaging method with random stepped frequency chirp signal

    Institute of Scientific and Technical Information of China (English)

    ZHU Feng; ZHANG Qun; LUO Ying; LI KaiMing; GU FuFei

    2012-01-01

    The random stepped frequency chirp signal (RSFCS) has better performance in anti-jamming than that of conventional stepped frequency chirp signal (SFCS).In combination with the theory of compressing sensing (CS),a novel ISAR imaging method is proposed based on RSFCS,in which the high resolution range profile (HRRP) is reconstructed by using the conventional OMP algorithm,whereas the cognitive approach is introduced to further reduce the number of sub-pulse in RSFCS.In the proposed method,via cognizing the characteristics of moving targets,the number of sub-pulse in each burst can be adjusted adaptively.Finally,in the cross-range direction,the accurate reconstruction of ISAR image by using CS theory is implemented,which can effectively accomplish unwrapping.With the proposed method,high quality HRRP and ISAR image can be achieved with fewer sub-pulses of RSFCS and lower burst repetition frequency (BRF).Some simulation results are given to validate the effectiveness and robustness of the proposed algorithm.

  3. Bistatic weak target detection method using non-cooperative air surveillance radar

    Institute of Scientific and Technical Information of China (English)

    Zengping Chen

    2015-01-01

    At present, most of the passive radar system re-searches utilize FM radios, TV broadcasts, navigation satel ites, etc. as il uminators. The transmitted signals are not specifical y de-signed radar waveforms. In this work, the frequency agile, phased array air surveil ance radar (ASR) is used as the il uminator of opportunity to detect the weak target. The phased array tech-nology can help realize beam agility to track targets from diffe-rent aspects simultaneously. The frequency agility technology is widely employed in radar system design to increase the ability of anti-jamming and increase the detection probability. While the fre-quency bandwidth of radar signals is usual y wide and the range resolution is high, the range cel migration effect is obvious during the long time integration of non-cooperative bistatic radar. In this context, coherent integration methods are not applicable. In this work, a parametric non-coherent integration algorithm based on task de-interweaving is proposed. Numerical experiments verify that this is effective in weak target detection.

  4. A Real Orthogonal Space-Time Coded UWB Scheme for Wireless Secure Communications

    Directory of Open Access Journals (Sweden)

    Zhang Yanbing

    2009-01-01

    Full Text Available Recent research reveals that information security and information-hiding capabilities can be enhanced by proper exploitation of space-time techniques. Meanwhile, intrinsic properties of ultra-wideband (UWB signals make it an outstanding candidate for secure applications. In this paper, we propose a space-time coding scheme for impulse radio UWB systems. A novel real orthogonal group code is designed for multi-antenna UWB signals to exploit the full spatial diversity gain and achieve the perfect communication secrecy. Its performance in a frequency-selective fading channel is analyzed. The transmission secrecy, including low probability of detection (LPD, low probability of intercept (LPI, and anti-jamming performance, is investigated, and some fundamental tradeoffs between these secrecy metrics are also addressed. A comparison of the proposed scheme with the direct sequence spread spectrum (DSSS technique is carried out, which demonstrates that proper combination of UWB and space-time coding can provide substantial enhancement to wireless secure communications over other concurrent systems.

  5. Study of a control strategy for grid side converter in doubly- fed wind power system

    Science.gov (United States)

    Zhu, D. J.; Tan, Z. L.; Yuan, F.; Wang, Q. Y.; Ding, M.

    2016-08-01

    The grid side converter is an important part of the excitation system of doubly-fed asynchronous generator used in wind power system. As a three-phase voltage source PWM converter, it can not only transfer slip power in the form of active power, but also adjust the reactive power of the grid. This paper proposed a control approach for improving its performance. In this control approach, the dc voltage is regulated by a sliding mode variable structure control scheme and current by a variable structure controller based on the input output linearization. The theoretical bases of the sliding mode variable structure control were introduced, and the stability proof was presented. Switching function of the system has been deduced, sliding mode voltage controller model has been established, and the output of the outer voltage loop is the instruction of the inner current loop. Affine nonlinear model of two input two output equations on d-q axis for current has been established its meeting conditions of exact linearization were proved. In order to improve the anti-jamming capability of the system, a variable structure control was added in the current controller, the control law was deduced. The dual-loop control with sliding mode control in outer voltage loop and linearization variable structure control in inner current loop was proposed. Simulation results demonstrate the effectiveness of the proposed control strategy even during the dc reference voltage and system load variation.

  6. Broadcable^TM技术及其在三网融合中的应用%BroadcableTM Technology and Its Application in the Triple Play

    Institute of Scientific and Technical Information of China (English)

    管佩森

    2012-01-01

    BroadcableTM技术是东方广视公司针对我国有线电视网络现状开发的一项适合国情的双向网络改造技术,其主要特点在于应用独特的射频调制、解调技术,极大提升了网络双向通讯的抗干扰能力。简单介绍了Broadcable州技术的技术体系、基于Broadcable州的兀TrB组网方案和业务承载能力与QoS保证,利用本技术可以很好地实现基于有线电视网的三网融合。%BroadcableTM technology is a suitable network bidirectional transformation technology to Chinas cable TV network. Its main characteristic is the application of unique RF modulation and demodulation techniques, which greatly enhance the network two-way communication anti jamming ability. This paper briefly introduces the BroadcableTM technology system, BroadcableTM technology based on FTTB network solutions and business capacity and QoS guarantee, using this method can well realize triple play based on cable television network.

  7. Optimal Identification Algorithm for Virus Attack in Super Dense Network%超密集网络中病毒攻击优化识别算法

    Institute of Scientific and Technical Information of China (English)

    田关伟

    2016-01-01

    bandwidth parameters are selected. The simulation results show that the proposed algorithm has better performance of anti jamming performance and better anti jamming performance, and has good application value in the field of network security.

  8. Simulink Simulation and Jamming Effect Evaluation of Digital Communication Links%数字通信链路的Simulink仿真和干扰效果评估

    Institute of Scientific and Technical Information of China (English)

    吴玲玲

    2014-01-01

    对于干扰而言,选择干扰体制和设置合适的干扰参数一直是通信对抗的重点。客观、准确、定量地分析和评价对抗装备对数字通信链路的干扰效果对于提高干扰和抗干扰能力具有重要意义。仿真了对常用数字通信链路信号的干扰效果评估,采用的干扰样式有单音干扰、相关干扰、同步扰动干扰等,对各种干扰的干扰效果进行评估和比较,为优化干扰样式提供了基础。%For jamming ,selecting the jamming system and setting suitable jamming parameters al-ways is the focal point of communication countermeasure .It has important meaning for improving jamming and anti-jamming capbility to analyze and evaluate the jamming effect of communication countermeasure equipments on digital communication links objectively ,accurately and quantitative-ly .T his paper simulates the jamming effect evaluation of common digital communication link sig-nals ,the adopted jamming modes includes single-tone jamming ,interrelated jamming ,synchroniza-tion disturbance jamming and so on ,evaluates and compares the effect of each jamming ,w hich pro-vides the base for optimizing the jamming mode .

  9. 基于Stribeck摩擦模型的无刷直流电机控制系统设计与仿真%Design and Simulation of Brushless DC Motor Control System Based on Stribeck Friction Model

    Institute of Scientific and Technical Information of China (English)

    许宏; 张怡; 王凌; 陈锡爱

    2011-01-01

    针对无刷直流电机(BLDCM)控制系统在实际运行中存在摩擦负载的问题,利用模糊PID控制的优点,提出了系统基于Stribeck摩擦模型的模糊PID控制方案.在分析BLDCM数学模型的基础上,运用MATLAB/Simulink对BLDCM速度、电流双闭环调速系统进行建模和系统仿真,并与采用常规PID算法的系统进行了比较.仿真结果表明基于Stribeck摩擦模型的模糊PID控制系统具有较好的给定适应性和抗干扰性,优于常规PID控制系统的性能.%Taking account of the presence of friction load in actual operation of brushless DC motor (BLDCM)control system, used the advantages of fuzzy PID control, the scheme of fuzzy PID control algorithm for the system was proposed based on the Stribeck friction model.Based on the BLDCM math model, the system of double-closed loop control of current and speed for BLDCM was modeled and simulated based on the use of MATLAB/ Simulink,and compared with normal PID's.The simulation results demonstrated that the system which adopt fuzzy PID control algorithm based on the Stribeck friction model had good adaptability and anti-jamming ability, which was better than PID' s.

  10. 基于AD8302的高精度幅相检测系统的设计%Design of Magnitude and Phase Measuring System with High Precision Based on AD8302

    Institute of Scientific and Technical Information of China (English)

    刘静; 马彦恒

    2011-01-01

    In order to raise the accuracy of the magnitude and phase measuring, predigest the circuit, enlarge the range of the frequence, the paper introduces the chip of AD8302, which is used to measure the RF/IF gain/ loss and phase.Then compose the magnitude and phase measuring system with high precision based on AD8302 and MCU, to realize the measurement of the magnitude and phase of the two simulated input signals, and compose the judgement circuit of phase polarity with Schmitt trigger and D trigger, enlarge the range of the frequence test to 0- 360°.The system can measure the magnitude and phase accurately of the input signal.The results shows that magnitude and phase measuring system based on AD8302 has the advantages of precision and strong anti-jamming.%为了提高幅相测量精度、简化电路,扩展频率范围,介绍了一种用于RF/IF幅度和相位测量的AD8302芯片;并利用此芯片和单片机组成高精度幅相检测系统,主要是以实现两路模拟输入信号的相位差和幅度比测量为目的;并利用分频器、施密特触发器和D触发器组成相位极性判断电路,扩展相位测量范围为0~360°;该系统能精确测量两输入信号的幅度比和相位差,测试结果表明基于AD8302的幅相检测系统具有精度高、抗干扰能力强等优点.

  11. The Test Principle and Method of Power Wave Trap Coil and Coupling Filter%电力线阻波器、结合滤波器测试原理及方法

    Institute of Scientific and Technical Information of China (English)

    江均; 钱牛牛; 汪池

    2012-01-01

    电力线阻波器、结合滤波器是电力线载波通道的重要组成部分,对其特性参数的准确测量是保证电力载波通信正常工作、保证电力系统正常运行的重要保障.本文分析了测试装置的特点,提出了一套实用的特性参数的计算公式.详细介绍了电力线阻波器、结合滤波器主要参数的测量原理.在硬件上,采用AD公司的AD8302为主测量芯片.由于利用了阻抗测量专用芯片,使得整个系统结构简单、抗干扰性能好、测量精度高、测量速度快.%Power wave trap coil and coupling filler is the important element in power line carrier systems.The accurate measurement for the characteristic parameter is security of the power line carrier communication and power system proper functioning.lt analyzed the characteristic of test equipment in this article,and brought up a series of formula for characteristic parameter measurement.lt introduced the key parameter measurement principle for the wave trap coil of power line and the combining wave filter in details.In aspect of hardware, it used AD8302 from AD company as main measurement chip.Thanks to the usage of impedance measurement chip.the whole system become simply structured, strongly anti-jamming,aecurale measurement and rapidly measurement.

  12. 基于铁路无线通信环境下改进的PSO算法在多用户检测中的应用%Application of Improved Particle Swarm Optimization Algorithm to Multi-user Detection Based on Railway Wireless Communication Environment

    Institute of Scientific and Technical Information of China (English)

    刘子轶; 张荣新; 郭景武

    2016-01-01

    随着无线通信技术在铁路系统中迅猛发展和广泛应用,对通信系统装备的抗干扰能力提出更高更新的要求,因此必须研究有效的抗干扰技术以对付日益严重的干扰威胁。在粒子群算法中采用量子力学和经典力学的理论,将量子离散粒子群算法应用于多用户检测技术。在铁路无线通信系统中,可以提高铁路信道质量,降低数据通信误码率,解决列车与调度指挥中心之间的高数据通信中误码率高的问题,并且在抗多址干扰能力明显优于传统检测器。%With the rapid development of railway wireless communication, more rigorous requirements for anti-interference ability of the communication system devices are put forward. Therefore, it is necessary to study the effective anti-jamming technology to deal with the growing threat of interference. Quantum mechanics and classical mechanics are used in particle swarm optimization algorithm and quantum discrete particle swarm algorithm is applied to multi-user detection. In the wireless railway communication system, it improves the quality of the channel, reduce bit error rate, and solve the problem of high bit error rate in high data communication between the train and the dispatch command center, and proves superior to traditional detectors in terms of anti multiple access interference.

  13. 基于磁感线圈的车流量检测的研究%Traffic flow detection based on magnetic coils

    Institute of Scientific and Technical Information of China (English)

    章冠; 李栋; 郭建强

    2012-01-01

    为了解决车辆计数问题,将环形线圈作为传感器,铺设在公路行车道上.当车辆通过线圈上面时,由于电感L发生变化,引起振荡电路的频率发生变化;通过锁相环芯片检测频率的变化,使模拟信号转化成数字信号,将锁相环产生的输出信号传入单片机;当单片机检测到锁相环的输出电平由高变到低时,便计数一次,从而完成对车流量的检测.在检测模型的测试中,该系统表现出较快的检测速率和较低的误检率,具有一定的抗干扰能力.%The ring coil taken as a sensor is laid on the highway to count the vehicles passed by. When vehicles run through above the coil, the variation of inductance L causes the frequency of the oscillating circuit changes. The frequency variation is detected by the chip on the phase-locked loop. The analog signal is converted to digital signal. The output signal produced by the phase-locked loop is transmitted to the microcomputer. It counts once when output electrical level changes from high to low, thus the traffic flow detection is completed. In the detection model testing, this system showed a fast detection rate and low false alarm rate. It has a certain anti-jamming capability.

  14. Design and realization of a real-time processing system for radar network fusion%一种雷达组网融合实时处理系统设计与实现

    Institute of Scientific and Technical Information of China (English)

    杨科技; 郑成波; 傅其祥; 王伟

    2011-01-01

    Radar network is an important method to improve the target detecting and anti-jamming ability of radar system.It designed and fulfilled a real-time processing system using ADSP TS201 for the data fusion of netted radar.It mainly described the configuration of a parallel processing system which used two ADSP TS201s,and also analyzed the algorithm calculate burden and result of it.The system could content the real-time processing need of both centralized and distributed netted radar fusion.The diversity of netted radar signal processing could be sufficed by the system because of its flexibility and scalability.%雷达组网对于提高雷达系统目标探测及抗干扰能力具有重要的意义。设计并实现了一种基于ADSPTS201的组网雷达数据融合实时处理系统。主要阐述了双ADSPTS201并行处理系统的结构、算法量的估计与结果分析。系统可满足集中式组网融合和分布式组网融合的实时处理需求。该系统还具有灵活性和可扩展性,可满足组网雷达信号处理的多样性要求。

  15. Design and Implement of System the Electromagnetic Launcher Based on DSP%基于DSP电磁轨道炮控制系统设计与实现

    Institute of Scientific and Technical Information of China (English)

    牛颖蓓

    2012-01-01

    In order to achieve autocontroL This report designs hardware and software about control system of electromagnetism rail gun with corresponding data analysis during emitting. The system adopts time sequence control mode of synchronization triggering and collects discharging current waves. Then this report analyzes the whole system performance with comparisons between electromagnetism rail guns with different lengths. The result shows that with different charging voltage the electromagnetism rail is longer and the discharging pulse is wider, the system efficiency is better. The system with DSP autocontrol has high response speed, high anti-jamming and high accuracy of test data.%在电磁轨道炮发射过程中,为了实现自动控制并结合相应数据分析电磁发射过程中各系统的运行状态和整体系统性能;从硬件和软件两个部分设计实现了电磁轨道炮控制系统,采用同步触发时序控制方式,进行放电电流波形采集;通过对比轨道炮的不同长度分析整个系统性能;实验结果表明,电磁轨道炮充电电压变化时,电磁轨道越长,放电脉宽增加,系统的整体效率得到提高;采用DSP控制系统对电磁轨道炮进行自动控制,具有反应速度快、抗干扰能力强、试验数据精度高等优点.

  16. 涡旋电磁波在军事无线通信中的应用%Application of Vortex Electromagnetic Wave in Military Wireless Communication

    Institute of Scientific and Technical Information of China (English)

    晋军; 邵尉; 孟凡秋

    2014-01-01

    涡旋电磁波的OAM复用是一种把量子力学中的轨道角动量理论应用到无线通信领域的新型技术,拥有高效频谱利用和抗干扰两项引人注目的特性。介绍了国内外研究现状,对涡旋电磁波的产生与接收、OAM复用对通信容量的影响、OAM模式的复用和解复用、大气的非均匀性和电离层对涡旋电磁波的影响、涡旋电磁波抗干扰能力等研究热点进行了概括。指出了研究、分析OAM复用和抗干扰性能以及探索有效的OAM通信方法的重要意义。%Vortex electromagnetic wave OAM multiplexing is a kind of the application of the theory of quan-tum mechanics to the new technology of the wireless communication field. It has two attractive properties of high spectrum utilization and anti-interference. The present development situation both at home and abroad is introduced. The vortex electromagnetic wave's generating and receiving, OAM multiplexing of the com-munication capacity of OAM mode, the multiplexing and demultiplexing, atmospheric inhomogeneity and i-onosphere to scroll the effects of electromagnetic waves, electromagnetic vortex wave anti-interference abili-ty, etc. , are summarized. Finally,the research and analysis of the OAM multiplexing and anti-jamming per-formance,and the significance in exploring effective methods of OAM communication,are also pointed out.

  17. 嵌入式技术的智能车系统设计与实现研究%Intelligent Vehicle System Based on Embedded Systems

    Institute of Scientific and Technical Information of China (English)

    任肖丽; 黄婉刁; 卢孙平; 王骥

    2014-01-01

    基于 MC9 S12 XS128的智能车,通过对道路图像进行采集和处理,再利用算法控制策略、PID控制原理和 PWM控制技术对智能车转向和速度进行控制,使小车能够自主行驶,通过使用 CodeWarrior 软件编程和 BDM调试实现小车行驶控制。本文基于 PID算法提出了改进的算法,经实物验证,所设计的智能车系统能有效循迹,保持在道路中间快速行驶,可以实现提前转弯,且系统具有较好的抗干扰能力。%The intelligent vehicle based on MC9S12XS128 collects and processes image information by the camera,and then uses algo-rithm control strategy,PID control principle and PWM control technology to control the steering and speed of intelligent vehicle,so that the car is capable of road self-identification,independent drive,and finally the car driving control using CodeWarrior software program-ming and BDM debugging.In this paper,an improved algorithm based on the PID algorithm is proposed.By physical verification,the design of the intelligent vehicle system can effectively track,keep moving fast in the middle of the road,turn in advance,and the system has better anti-jamming capability.

  18. 一种与整车联动的残疾人踏板设计与研究%A linkage of disabled people and vehicle pedal design and research

    Institute of Scientific and Technical Information of China (English)

    赵理想

    2014-01-01

    to provide a linkage of disabled people and vehicle pedal, reliable work, the pedal is not affected by the external factors driving, can be a very good and linkage of the vehicle. Perception of persons with disabilities by electromagnetic switch pedal opening, and the signal transmitted to the vehicle controller, so as to judge whether the vehicle can be started, because the electromagnetic switch can not inlfuenced by following the closure of the pedal clearance, also not affected by the vibration of vehicle, real-time and accurate will can accurate sent to the vehicle control unit, has the characteristics of high reliability, strong anti-jamming capability, improve the performance of the vehicle safety and reliability.%提供一种与整车联动的残疾人踏板,该踏板工作可靠,不受行驶中的外界因素影响,能很好的与整车联动。通过电磁式开关来感知残疾人踏板的开度,并将信号传递给整车控制器,从而判断整车是否可以启动行驶,由于电磁式开关可以不受踏板关闭后的间隙影响,也不受车辆行驶中的震动影响,可以实时将准确的信号发送给整车控制单元,具有可靠性高、抗干扰能力强的特点,提高整车安全性和可靠性。

  19. LOCATING VEHICLE LICENSE PLATE BASED ON CORNER DETECTION AND REGIONAL COLOUR COHERENCE%基于角点检测与颜色连贯性分析的车牌定位算法

    Institute of Scientific and Technical Information of China (English)

    胡振邦; 蔡之华

    2012-01-01

    针对低分辨率视频图像,提出一种基于角点检测与颜色连贯性分析的快速车牌定位算法.考虑到车牌具备固定的颜色连贯性特点,首先由车牌背景颜色与车牌字体颜色得出分析掩膜;然后使用较小的阈值和最小角点间距计算得出掩膜内角点;最后对角点进行颜色加权,选择权值最大的分析区域.该方法对图像噪声具有极好的抗干扰性,适用于分辨率较低的视频图像数据.实验表明与其他方法相比,该方法的车牌定位准确率高,平均耗时短.%Considering the problems with regard to low resolution video images, a vehicle license plate locating method based on comer detection and regional colour coherence is put forward. First, taking into acount the characteristic of fixed colour coherence the vehicle license plate has, the analysis mask is obtained from background colour and fonts colour of the license plate, and then the smaller threshold and minimum corner points spacing are employed to calculate comer points within the mask. At last, the corner points are weighted with colour, and the analysis region with largest weights is chosen. This method has excellent performance for image noise in anti-jamming and is suitable for low resolution video image data. Experimental results show that, comparing with other methods, this one locates the vehicle plates with higher accuracy and less time cost.

  20. Study on the determination of molybdate content in industrial circulating cooling water%工业循环冷却水中钼酸盐含量测定研究

    Institute of Scientific and Technical Information of China (English)

    白莹; 邵宏谦; 杨裴; 李琳

    2012-01-01

    A method for determinating the molybdate content in industrial circulating cooling water,i.e. thiocyanate spectrometry,is introduced. The molybdate is reduced to Mo5+ by adding 6.0 mL of sulfuric acid solution, 1.0 mL of ferrous ammonium sulphate solution, 10.0 mL of ammonium thiocyanate solution and 1.0 mL ascorbic acid solution, and forms orange complex with thiocyanate. The absorbency of the complex is determined at 460 run and the molybdate content is figured out by the calibration curve. This method is scientific and stable,and having strong capacity of anti-jamming. Its determination range is suitable for circulating cooling water.%介绍了一种测定工业循环冷却水中钼酸盐含量的方法——硫氰酸盐分光光度法.在待测水样中加入6.0 mL硫酸溶液,1.0 mL硫酸亚铁铵溶液,10.0 mL硫氰酸铵溶液以及1.0 mL抗坏血酸溶液,此时钼酸盐被还原成Mo5+,并与硫氰酸盐形成橙色络合物,在460m波长处测定该络合物的吸光度并通过标准曲线计算出钼酸盐含量.该方法科学、稳定,抗干扰能力强,测定范围适用于循环冷却水中钼酸盐含量的测定.

  1. 基于模糊控制的光伏发电系统MPPT设计%Design of MPPT in photovoltaic generation system based on fuzzy control

    Institute of Scientific and Technical Information of China (English)

    荆红莉; 赵鹏

    2016-01-01

    为了提高光伏发电的效率 ,分析了光伏发电系统最大功率点跟踪控制的原理 ,选出了实现最大功率跟踪的硬件电路.针对光伏电池输出的非线性特点 ,提出了将模糊控制应用于光伏发电的 MPPT 控制中 ,设计了模糊控制器 ,并在正常光照及光照强度变化的条件下对模糊算法控制系统和扰动观察算法控制系统进行了仿真实验 ,得出两种算法控制下系统输出的电压波形.通过对波形的对比分析 ,进一步证明了模糊 MPPT 控制系统响应快 ,抗干扰能力强 ,系统稳定性好.%In order to improve the efficiency of the photovoltaic power generation ,this paper analyzed the photovoltaic maximum power point tracking control system principle ,choosed the hardware circuit to achieve maximum power track-ing .According to the nonlinear characteristics of photovoltaic cells output ,fuzzy control is put forward to the application of photovoltaic power generation MPPT(maximum power point tracking) control ,the fuzzy controller is designed ;and under the condition of the normal illumination and the disturbance of light intensity observed output voltage waveforms of fuzzy system and P&O system by simulation experiment .Through comparison and analysis of waveforms proved that the fuzzy MPPT control system has faster response speed ,better stability and stronger anti-jamming ability .

  2. Application of fiber Bragg grating sensing technology in long-distance detection of temperature in weapon depots

    Science.gov (United States)

    Xu, Jianguo; Zhang, ZhiLi; Zhao, Bing; Fu, Zhulin

    2010-10-01

    Incessantly long-term real-time detection of temperature is demanded in weapon depots, where the weapon equipment is stored in, to realize the self-regulation of temperature. Long-Distance intellectualized control can be actualized by setting sensor-net which is composed by several temperature sensors to simultaneously detect multi-point and multi- parameter. The temperature sensors based on Fiber Bragg Grating Technology are more suitable for long-term detection for their preponderance in high sensitivity, small volume, anti-jamming and so on. The temperature sensing system, which is composed by several Fiber Bragg Grating sensors in one light-cable, can accomplish Quasi-Distributed measurement and is suitable for multi-point and multi- parameter detection. Basal principle of Fiber Bragg Grating sensing technology is expounded in the article, with a sensing system applied to the long-distance detection of temperature in the depots is designed based on F-P Scanning Method. Besides, DSP and FPGA are adopted pre-treat the transformed data from AD such as filter and determine threshold. The main modules of this demodulation system such as 1550nm exact photoelectric detection module and trigonal wave voltage scan module are designed in this paper to realize demodulation. Proved by the analysis of the testing data, the Fiber Bragg Grating temperature sensing system, whose testing precision achieved the design purpose, has advantages of real-time measure and long-term stability. The system, which provides guarantee to realize the auto-control of temperature, can be generalized and will provide favorable foundation for the broad using of Fiber Bragg Grating sensing technology in the army.

  3. Design of Fingerprint Attendance System Based on MCU%基于单片机的指纹考勤系统设计

    Institute of Scientific and Technical Information of China (English)

    杜新法; 崔陆军

    2016-01-01

    In order to record the employee or students’attendance status in a simple,rapid,efficient way,a attendance management system is proposed based on the STC89C52RC single-chip.The system takes optical fingerprint sensor to collect information and be matched with the fingerprint database built by users be-fore.If there is a match,microcontroller will communicate with fingerprint sensor,read the attendance infor-mation and sent it to host machine for processing that implemented the record and display of attendance infor-mation and time.The test shows that the fingerprint attendance system works well,with the advantages of low cost,simple operation,strong anti-jamming capability,etc.%为了快捷、高效地记录员工或者学生的出勤情况,提出了一种以 STC89 C52 RC 单片机为核心的考勤管理系统。该系统采用光学指纹传感器采集指纹,将采集到的指纹与提前建好的指纹库中指纹信息匹配,若匹配成功,单片机会与指纹传感器通信,读出考勤信息并将信息发送到上位机进行处理,实现了被考勤人员身份及时间的记录和显示。测试表明,该指纹考勤系统工作良好,具有成本低、操作简单、抗干扰能力强等优点。

  4. Improvement of clustering algorithm FEC for signed networks%符号网络聚类算法FEC的改进

    Institute of Scientific and Technical Information of China (English)

    孔令旗; 杨梦龙

    2011-01-01

    The Finding and Extracting Community (FEC) algorithm has some disadvantages as the algorithm stability is not enough, and the quality of extracting community needs to be improved.To solve these problems, some improvements were made from the following aspects: Add the function of selecting target vertex before random walk; cancel the parameter of random walk steps of the original algorithm by using a method of detecting steps automatically; supplement the quality evaluation of the link between the communities on the base of the original community extraction; achieve the controllability of particle size of community by introducing the threshold parameter.The results show that the improved algorithm has some improvements at the aspects of stability, anti-jam performance and clustering analysis.%针对FEC算法存在的稳定性不够、网络簇抽取质量亟待提高等问题,从以下几个方面对原算法进行了改进:在随机游走前添加了选择目标顶点功能;采用自动步数探测法取消了原算法的随机游走步数参数;在原有的簇抽取评价条件的基础上补充了簇间连接权重评价;通过引入阈值参数实现了簇抽取粒度的可控性.测试结果表明,改进后的算法在稳定性、抗干扰性和聚类分析质量等方面比原算法都有所提高.

  5. Research on the FFT Fast Acquisition Method to Suppress Repeater Spoofing Interferences%抗转发干扰FFT快速捕获方法研究

    Institute of Scientific and Technical Information of China (English)

    龚文飞; 孙昕

    2011-01-01

    The problem of suppressing the repeater spoofing interferences effectively has become a must for the design of military anti-jamming satellite navigation receivers. By analyzing the code phase characteristic of satellite signals and repeater spoofing interferences, this research proposes a method of FFT fast acquisition of long code based on delay-waiting strategy. The method distinguishes satellite signals from repeater spoofing interferences according to the code phase information of the correlation peak whose amplitude is above the threshold. Thus the acquisition performance in the scene of repeater spoofing interferences can meet the demand without degradation in normal conditions. The theory analysis and simulation results validate the effectiveness of proposed method.%为了解决有效抑制转发式干扰问题,根据转发干扰信号的码相位滞后于卫星导航信号的特点,结合快速傅里叶变换(FFT)快速捕获的二维搜索策略,提出基于延迟-等待捕获策略的抗转发干扰FFT快速捕获方法.该方法根据过门限峰值的码相位信息来区分判别卫星导航信号和转发干扰信号,在不影响接收机在无转发干扰正常工作的条件下,保证了接收机在转发干扰下的捕获性能.理论分析和仿真实验验证了该方法的有效性.

  6. Robust Control of Six-linkage Walking Assistance Rehabilitation Robot%六连杆助行康复机器人鲁棒控制

    Institute of Scientific and Technical Information of China (English)

    张立勋; 伊蕾; 白大鹏

    2011-01-01

    为帮助老年人及偏瘫患者恢复自然步态的行走,提出了一种六连杆助行康复机器人机构模型.考虑患者体重差异及助行康复训练过程中下肢肌张力的变化,在机器人动力学分析的基础上设计了一种具有抗干扰性能的鲁棒控制器.基于李亚普诺大理论证明了该控制器可有效地抑制外界干扰信号的影响,并进行了鲁棒控制实验研究.研究结果表明,鲁棒控制器能够抑制负载突变及不确定性干扰,保证控制系统工作的稳定性,满足患者对助行训练安全性的要求.%A mechanism model of a six-linkage walking assistant rehabilitation robot is presented to help the aged and hemiplegic patients walk with natural gait. Considering the weight difference among patients and the changes in muscular tension of lower limbs during assisted-walking training, a robust controller with anti-jamming performance is designed based on the robot dynamics analysis. It is proved by Lyapunov theory that the controller can suppress the influence from external interference signals effectively. The robust control experiment results show that the controller can suppress the influence of load variations and uncertain disturbance.

  7. 联合空情预警能力评估研究%Capability evaluation of joint air intelligence early warning systems

    Institute of Scientific and Technical Information of China (English)

    董长清; 李凌鹏; 周一蛟; 王海林

    2014-01-01

    为合理构建联合空情预警体系、优化兵力部署结构,从能力评估的角度,分析信息化条件下构建联合空情预警体系的新要求,根据作战任务将联合空情预警能力分解为预警探测能力、引导保障能力、抗毁抗扰能力、机动作战能力和空情处理能力,建立了指标体系的层次结构,给出了13个底层指标的数学模型,并运用综合加权方法进行了评估分析。计算结果表明,该指标体系对科学构建联合空情预警体系具有一定的参考作用。%To establish the joint air situation early-warning systems (JASEAS) reasonably and optimize the configuration of force deployment, this paper analyzes the new requirements for building up a joint air situation early-warning system in the case of informatization, at the angle of capability evaluation, resolves the capabilities of JASEAS into the early warning detection, guidance and support, anti-damage and anti-jamming, mobile operations and air intelligence processing ones in accordance with combat tasks, sets up the hierarchic structure of the index system, and presents the mathematic models for 13 ground layer indices, and finally carries out an evaluation analysis using comprehensive weighting method. Computation results indicate that this proposed index system possesses a certain reference for constructing the joint air intelligence early-warning systems, scientifically.

  8. A Survey of Security for Satellite Communication System%卫星通信系统安全技术综述

    Institute of Scientific and Technical Information of China (English)

    关汉男; 易平; 俞敏杰; 李建华

    2013-01-01

    The security mechanisms for terrestrial network are not appropriate for satellite communication due to the particularity of space environment.The state of the art in security for satellite communication systems was surveyed.Firstly,the security vulnerabilities of satellite communication systems were presented.Secondly,various possible threats and countermeasures were analyzed among physical layer,data link layer,network layer and transport layer.Particularly,representative solutions for survivability,anti-jamming,authentication and key management were illustrated,and a comparison and assessment of their merits and faults were made.Finally,the research was presented which was still worth to do in the future.%由于空间环境的特殊性,地面网络中的安全机制不能直接用于卫星通信.介绍了卫星通信系统安全技术的最新进展.首先从空间信道环境、卫星节点能力、星座网络结构等方面指出了卫星通信系统的安全弱点.然后总结了物理层、数据链路层、网络层和传输层所面临的安全威胁和防护对策.着重介绍了抗损毁技术、抗干扰技术、认证机制和密钥管理协议,并对有代表性的安全策略进行了分析、对比和讨论.最后对卫星通信系统安全技术发展方向做出预测.

  9. Neural Network Predictive Control of the Medium Density Fiberboard Glue System%中密度纤维板施胶系统的神经网络预测控制1)

    Institute of Scientific and Technical Information of China (English)

    孙丽萍; 曹军; 王颖

    2014-01-01

    According to the characteristics of the sizing process of medium density fiberboard ( MDF) , we proposed a gluing con-trol strategy with neural network predictive control principle.By regarding MDF glue system as a control, we used BP neu-ral network to identify model and multi-step recursive to obtain the prediction model .We made some simulations and real-time control experiments for MDF gluing system and validates the effect compared with the PID control.The glue system brings MDF system a good tracking performance and anti-jamming capability, and realizes the fast track of glue consump-tion in dynamic changes of fiber amount with obvious advantages compared with the PID control .%针对中密度纤维板( MDF)施胶过程的特点,提出一种基于神经网络预测控制原理的施胶控制方法。将MDF施胶系统作为被控对象,利用BP神经网络辨识其模型,并采取多步递推的方式得到被控对象的预测模型。为验证所提方法的控制效果,对MDF施胶系统进行了仿真和实时控制试验,并与PID控制进行比较。结果表明:设计的控制方案,为MDF施胶系统获得良好的控制品质和抗干扰能力,实现施胶量对纤维量动态变化的快速跟踪,比PID控制具有明显的优势。

  10. Study of RSSI Ranging Optimization Techniques by Using Artificial Neural Networks%利用人工神经网络的RSSI测距优化技术研究

    Institute of Scientific and Technical Information of China (English)

    贲伟; 王敬东

    2012-01-01

    Ranging technology based on RSS1 (received signal strength indication) is a distance measurement technique with the features of low cost and low complexity. It is widely used in indoor wireless location. Ranging error is relatively large with the impact of NLOS indoor and multipath transmission. For this reason this paper presents a screening strategy, which successfully combined recursive average filter and Gaussian models. A measuring method of artificial neural network distance has been proposed as well. According to the result of the Experiments, RSSI ranging accuracy and anti-jamming capability have been significantly improved by this method.%基于RSSI(接收信号强度指示)的测距技术是一项低成本和低复杂度的距离测量技术,被广泛应用于基于测距的无线传感器网络的定位技术中.由于室内环境中存在非视距和多径传输的影响,测距误差比较大.针对这个问题,本文提出了一种递推平均滤波和高斯模型相结合的R值筛选策略以及一种利用人工神经网络的距离估计方法.实验表明:通过合理的R值筛选策略和距离估计算法,RSSI测距的精度和抗干扰能力得到了明显的提高.

  11. 磁悬浮开关磁阻球体电机的数学模型及其仿真%Spherical switched reluctance motor with magnetic levitation

    Institute of Scientific and Technical Information of China (English)

    戴敏; 曾励

    2011-01-01

    针对双绕组无轴承开关磁阻电机的绕组结构复杂、绝缘程度要求高及加工成本高的缺陷,结合悬浮原理和磁阻最小原理,提出一种磁悬浮开关磁阻球体电机.分析了磁悬浮开关磁阻球体电机的基本组成和运行机理,采用磁路分割法对各部分磁路进行推导与计算,建立了球体电机的数学模型.利用Matalab/simunik软件进行仿真,结果表明电机能够实现动子快速稳定悬浮和旋转,并且具有良好的抗干扰性能.%In view of the bearingless switched reluctance motor with double windings, which has a complicated structure, an absolute insulation, and expensive manufacture cost, the paper presents a spherical switched reluctance motor with magnetic levitation on the basis of suspension theory and minimum reluctance principle. It analyses elements and machanism of the spherical switched reluctance motor with magnetic levitation, deduces and calculates the magnetic conduction of the gap by means of the magnetic segmentation. It obtaines a model building of spherical electric machines.With the Matalab/simunik model, simulation results show that the rotor realizes quick stable suspension and rotation, it has excellent anti-jamming performance as well.

  12. 模糊无模型自适应控制器在CFB锅炉主蒸汽压力控制中的仿真研究%EMULATION STUDY ON MAIN STEAM PRESSURE CONTROL OF CFB BOILER BASED ON FUZZY MFAC COTROLLER

    Institute of Scientific and Technical Information of China (English)

    梁留涛; 陈铁军; 崔丹丹

    2009-01-01

    Directing against the features of large inertia and large delay in main steam pressure control system of circulating fluidized bed (CFB) boilers in thermal power plants, using the advantages of stronger adaptability to inertia and delay of the model-free adaptive controller (MFAC) ,a MFAC has been designed and an emulation of said control system being carried out by adopting Matlab emulation software. Results show that the fuzzy MFAC has little amount of calculation, and rapid response speed. Compared with basic MAFC, the fuzzy MAFC has good robustness, better anti-jamming capa-bility, and strong adaptability to the loads.%针对火电厂循环流化床(CFB)锅炉主蒸汽压力控制系统大惯性和大滞后的特点,利用无模型自适应控制(MFAC)对大惯性、延迟适应性和模糊控制适应性强的优点,设计了模糊无模型自适应控制器,并采用Matlab仿真软件对该控制系统进行了仿真.结果表明,模糊MFAC方法计算量小,响应速度快.与基本无模型控制器相比,模糊无模型自适应控制器具有鲁棒性好、抗干扰能力及对负荷的适应性强等优点.

  13. 基于SPWM的小型风电逆变系统的建模与仿真研究%Modeling and Simulation of Small Wind Power Inverter System Based on SPWM

    Institute of Scientific and Technical Information of China (English)

    赵钢; 胡凯

    2011-01-01

    Taking the small wind power system as an object for studies, this paper focuses on the design of the inverter link.Through comparisons and analyses, the high frequency transformer form is chosen for the main circuit while the instantaneous voltage feedback control for the control circuit.The wind turbine inverter system circuit model is established by MATLAB/Simulink software. producing the system design and simulation of the voltage feedback based on SPWM (Sinusoidal PWM). With interferences abruptly added, the circumstance simulation model can quickly get stable, indicating the model has strong anti-jamming ability. The simulation results verify the feasibility of the system design. On this hasis, the hardware design scheme is completed for the wind power inverter control system based chips TLA94, IR2110 and SG3525A.%以小型风力发电系统为研究对象,重点研究其逆变环节的设计,通过比较分析,主电路选择高频变压器形式,控制电路采用电压瞬时值反馈控制.利用MATI,AB/Simulink软件建立了风电逆变系统的电路模型,给出了基于SPWM(Sinusoidal PWM)电压反馈控制的系统设计与仿真.在突加干扰的情况下仿真模型能很快稳定,具有较强的抗干扰能力,仿真结果验证了系统设计的可行性.在此基础上,完成了基于芯片TI494、IR2110和SG3525A的风电逆变控制系统的硬件设计方案.

  14. Vehicle Load Detection System Based on Differential Capacitance Sensor%基于差动式电容传感器的车辆载荷检测系统

    Institute of Scientific and Technical Information of China (English)

    陈梅

    2011-01-01

    针对传统车辆载荷检测系统存在的不足,提出了一种电容式车辆载荷检测系统,该系统的载荷检测传感器采用差动式结构,大大提高了测量的灵敏度和非线性,电容测量线路采用差动脉冲宽度调制集成测量电路,数据的采集和处理采用自带A/D转换器的STC89LE516AD单片机芯片,数据通信采用无线通信模式.这种载荷检测系统结构简单、成本低廉、安装方便、性能可靠、测量电路简单、抗干扰性好,可用于交通数据的采集和便携式测量,具有良好的使用前景.%Aiming at the shorrage of present vehicle load detection system, a capacitive vehicle load detection system is introduced. In the system, the load detection sensor used differential structure, which greatly improved the measurement sensitivity and non-linear, the capacitance measurement circuit used differential pulse width modulation integrated circuit, data acquisition and processing used STC89LE516AD single chip which has its own A / D converter, data communication used wireless communication mode. This load detection system has simple structure, low cost, easy installation, reliable performance,simpLe measurement circuit and good anti-jamming. The system can be used for traffic data collection and portable measurement, and has good application prospects.

  15. 低冗余灰度成像技术在反舰导弹末制导中的应用%An Application of Low-redundancy Gray-scale Imaging Technology in the Terminal Guidance of Anti-ship Missile

    Institute of Scientific and Technical Information of China (English)

    李伟; 芮震峰; 孥树军

    2012-01-01

    在对反舰导弹特点和主要几种反舰导弹末制导干扰与反干扰原理进行分析的基础上,提出了基于灰度成像技术的导弹末制导控制办法。在参阅已有文献的基础上,从可行性方面进行了论证,给出了系统设计流程图,列出了相应的数据转换公式,进行了时间处理上的对比验证。这种"低冗余"的红外灰度图像作为信息源具有信息处理所需时间短、排除干扰效率高的优点,有利于提高现代反舰导弹的突防命中能力。%According to analysis the features of anti-ship missile and the contrast for several main guidance and anti-guided ways,a gray-scale imaging based terminal guidance method was put forward.With the help of extant literature achievements,the feasibility of the programe was discussed,the sysyem design flow and the corrresponding data conversion formula were showed,then,the contrast verification on the time processing was carried out.Such a so called "low-redundancy" infrared gray imaging technology witnessed an advantage of shorter information processing time and higher anti-jamming efficiency,which can serve as a reference for the overall design of the modern anti-ship missiles.

  16. A Novel Approach to Beam Steering Using Arrays Composed of Multiple Unique Radiating Modes

    Science.gov (United States)

    Labadie, Nathan Richard

    Phased array antennas have found wide application in both radar and wireless communications systems particularly as implementation costs continue to decrease. The primary advantages of electronically scanned arrays are speed of beam scan and versatility of beamforming compared to mechanically scanned fixed beam antennas. These benefits come at the cost of a few well known design issues including element pattern rolloff and mutual coupling between elements. Our primary contribution to the field of research is the demonstration of significant improvement in phased array scan performance using multiple unique radiating modes. In short, orthogonal radiating modes have minimal coupling by definition and can also be generated with reduced rolloff at wide scan angles. In this dissertation, we present a combination of analysis, full-wave electromagnetic simulation and measured data to support our claims. The novel folded ring resonator (FRR) antenna is introduced as a wideband and multi-band element embedded in a grounded dielectric substrate. Multiple radiating modes of a small ground plane excited by a four element FRR array were also investigated. A novel hemispherical null steering antenna composed of two collocated radiating elements, each supporting a unique radiating mode, is presented in the context of an anti-jam GPS receiver application. Both the antenna aperture and active feed network were fabricated and measured showing excellent agreement with analytical and simulated data. The concept of using an antenna supporting multiple radiating modes for beam steering is also explored. A 16 element hybrid linear phased array was fabricated and measured demonstrating significantly improved scan range and scanned gain compared to a conventional phased array. This idea is expanded to 2 dimensional scanning arrays by analysis and simulation of a hybrid phased array composed of novel multiple mode monopole on patch antenna sub-arrays. Finally, we fabricated and

  17. Target tracking algorithm based on gray scale coexistence matrix and Mean Shift%基于灰度共生矩阵和Mean Shift的目标跟踪算法

    Institute of Scientific and Technical Information of China (English)

    张永; 刘巧玲

    2013-01-01

    针对运用单一颜色特征描述运动目标时抗干扰性较差的问题,提出一种融合灰度共生矩阵和颜色特征的Mean-Shift目标跟踪算法.采用灰度共生矩阵推导的6个纹理特征参数和颜色特征分别表征跟踪目标,引入马氏距离计算纹理特征的相似度,并结合Bhattacharyya系数计算颜色特征的相似度,同时利用Mean Shift算法进行目标定位.实验表明,改进算法能在复杂背景下,有效、准确地实现目标跟踪.%Aimed at the problem that there is poor anti-jamming ability when the single color feature is used to describe the moving target,a target tracking algorithm was proposed based on Mean Shift which mixed gray level co-occurrence matrix (GLCM) and color feature together.Six parameters of texture deduced with GLCM and color feature parameters were used to characterize the tracking target.The similarity of texture feature was calculated by introducing Mahalanobis distance,and the Bhattacharyya coefficient was applied to calculate color feature similarity.Meantime,Mean Shift algorithm was used for target positioning.Experimental result showed that the improved algorithm could be used to track moving target effectively and accurately on a complex background.

  18. The design of an ultra-wideband miniaturized GPR antenna%一种超宽带小型化探地雷达天线的设计

    Institute of Scientific and Technical Information of China (English)

    彭宇; 王蕾; 郭福强; 胡通海

    2014-01-01

    通过对蝶形偶极子天线复合加载的方式形成一种小型化的探地雷达天线,多种加载方式的引入不但使天线具有宽频带的性能,而且设计的天线尺寸与理论计算尺寸相比也大大减小。在天线后方引入背腔设计,增加了天线的方向性和抗干扰能力。所设计的天线具有1.5~4 GHz的频带宽度,且天线的方向性良好。设计的天线已成功应用于LTD探地雷达2.2 GHz天线系统和3 GHz的液态危险品检测天线系统中。%A kind of miniaturized GPR antenna was designed through complex loading to the bow-tie dipole. The introduction of multi-ple loading methods not only makes the antenna acquire the performance of broadband but also greatly decreases the size of antenna compared with the theoretical calculation size. By introducing back cavity behind the antenna, the directivity and anti-jamming capabili-ty of the antenna are enhanced. The designed antenna possesses a 1.5 GHz~4 GHz frequency band width and a good direction. The de-signed antenna is successfully applied to the antenna system of 2.2 GHz LTD series of GPR. This designed antenna can be also used in the dangerous liquid goods inspection system of 3 GHz LTD series of GPR.

  19. Infrared Image Mosaicing in Power System Based on Phase Correlation%基于相位相关的电力红外热像拼接

    Institute of Scientific and Technical Information of China (English)

    王福田; 吴福虎; 罗斌; 汤进

    2012-01-01

    Because of passive work, strong anti-jamming and target recognition ability, around the clock in infrared imaging and so on, infrared detection and diagnosis technology came into being. Most developed countries have been used for military,industrial and other industries. Image mosaic is processing two or more overlapping image to a large scale image. It introduces several methods and development processing of image mosaic technology, and aiming at infrared diagnostics technology of power system, combined with the characteristics of infrared on-line detection,use phase correlation method for seamless mosaicing of infrared image, which makes the diagnosis more accurate, more convincing,and the experiment illustrates the feasibility and effectiveness.%由于红外成像具有被动工作、抗干扰性强、目标识别能力强、全天候工作等特点,红外检测诊断技术应运而生.已被多数发达国家用于军事、工业等各行各业.图像拼接是把两幅有重叠的图像叠加成一幅大尺度图像的过程.文中介绍了图像拼接技术的几种基本方法和发展历程,并针对电力系统红外诊断技术,结合红外在线检测的特点,应用相位相关方法对红外图像进行无缝拼接,使得诊断结果更精确、更有说服力,并且实验说明了方法的可行性和有效性.

  20. 基于89C51智能交通灯系统的设计与仿真%Design and Simulation of an Intelligent Traffic Light System Based on 89C51

    Institute of Scientific and Technical Information of China (English)

    莫小琴; 李钟慎

    2013-01-01

    基于AT89C51单片机为核心控制器,采用ISD2560作为语音录放模块,以及MAX692“看门狗”模块提高抗干扰能力,设计十字路口的交通灯智能化控制系统。实现正常时段交通信号灯的轮换,车辆闯红灯实时监控报警、紧急通行控制、语音录放、数码管倒计时等功能。利用Proteus和Keil软件对系统进行了仿真,结果表明对实现交通的快捷以及缓解交通压力具有较强的可靠性。%The paper introduces an intelligent control system of crossroads based on AT89C51 microcontroller as the core control device, using ISD2560 as voice recording module and MAX692“watchdog”module to improve the anti-jamming capability. The system completes the normal rotation of trafifc lights, real-time monitoring and alarming of vehicles running red lights, emergency trafifc control, voice recording and digital tube countdown function. Proteus and Keil software simulation results show that the designed system has strong reliability on the shortcut trafifc and ease trafifc pressure.

  1. A shutter pulse generator for high speed camera%一种用于高速摄影仪的快门脉冲发生器

    Institute of Scientific and Technical Information of China (English)

    刘春平; 李爽; 李景镇

    2013-01-01

    A shutter pulse generator was designed, which is based on the metal oxide semiconductor field effect transistor (MOSFET). By using the N-channel level shifter for driving switch groups, which consist of Series MOSFETs and controlled by programmable logic device FPGA (field programmable gate array), a high-voltage pulse is achieved with high-speed front edge and back edge, after processing by pulse forming circuit. Experimental results showed that with a load of 1. 1 μF the amplitude of pulse is 800 V and the width of pulse is 81 jxs, both its front edge and back edge lasted less than 1 (μs. The system is anti-jamming and reliable.%设计基于绝缘栅型场效应管(metal-oxide-semiconductor field-effect transistor,MOSFET)的快门脉冲发生器,将MOSFET串联作为开关组,采用电平移位法对其进行驱动,由可编辑逻辑器件FPGA控制延时触发,经过脉冲形成电路分别得到高压脉冲的快前沿与快后沿.结果表明,在1.1 μF的负载下,可获得幅值为800 V、前后沿均小于1μs、脉宽为81μs的高压快脉冲,该系统抗干扰能力强,可靠性好.

  2. Blockade but not overexpression of the junctional adhesion molecule C influences virus-induced type 1 diabetes in mice.

    Directory of Open Access Journals (Sweden)

    Selina Christen

    Full Text Available Type 1 diabetes (T1D results from the autoimmune destruction of insulin-producing beta-cells in the pancreas. Recruitment of inflammatory cells is prerequisite to beta-cell-injury. The junctional adhesion molecule (JAM family proteins JAM-B and JAM-C are involved in polarized leukocyte transendothelial migration and are expressed by vascular endothelial cells of peripheral tissue and high endothelial venules in lympoid organs. Blocking of JAM-C efficiently attenuated cerulean-induced pancreatitis, rheumatoid arthritis or inflammation induced by ischemia and reperfusion in mice. In order to investigate the influence of JAM-C on trafficking and transmigration of antigen-specific, autoaggressive T-cells, we used transgenic mice that express a protein of the lymphocytic choriomeningitis virus (LCMV as a target autoantigen in the β-cells of the islets of Langerhans under the rat insulin promoter (RIP. Such RIP-LCMV mice turn diabetic after infection with LCMV. We found that upon LCMV-infection JAM-C protein was upregulated around the islets in RIP-LCMV mice. JAM-C expression correlated with islet infiltration and functional beta-cell impairment. Blockade with a neutralizing anti-JAM-C antibody reduced the T1D incidence. However, JAM-C overexpression on endothelial cells did not accelerate diabetes in the RIP-LCMV model. In summary, our data suggest that JAM-C might be involved in the final steps of trafficking and transmigration of antigen-specific autoaggressive T-cells to the islets of Langerhans.

  3. COMPASS/CAPS组合导航接收机设计与实现%Design and Implementation of COMPASS/CAPS-Based Integrated Navigation Receiver

    Institute of Scientific and Technical Information of China (English)

    闫舟

    2013-01-01

      As an innovative system on our own, the COMPASS navigation system and the CAPS navigation system complement each other perfectly in practical applications. The COMPASS/CAPS-based receiver is designed based on the characteristics of COMPASS and CAPS system described in the paper. The acquisition and tracking algorithm are presented and the test of the receiver is implemented. The test result shows that the COMPASS/CAPS-based receiver has higher performance and more perfect functions, in such special applications as anti-jamming, than a single COMPASS system receiver.%  COMPASS系统和CAPS系统作为我国自主研发的卫星导航系统,它们在实际使用时具有较强互补的特性。本文研究了 COMPASS 系统和 CAPS 系统的特点,利用 CAPS 系统和COMPASS系统的特性设计了COMPASS/CAPS接收机,详细给出捕获、跟踪算法设计,并对设计的接收机进行了测试。测试表明,设计的COMPASS/CAPS接收机性能良好,相对单COMPASS系统,COMPASS/CAPS接收机在抗干扰特性,特定的应用场合上的功能和性能有了较大的提高。

  4. Anti Interference Mining of Web Data Stream Based on Kalman Filtering%基于Kalman滤波的Web数据流抗干扰挖掘算法

    Institute of Scientific and Technical Information of China (English)

    密海英

    2015-01-01

    提出一种基于变维Kalman滤波的Web海量数据流抗干扰挖掘算法.构建Web环境下的海量数据挖掘数据流信息模型和噪声干扰模型,结合现代信号处理方法,设计变维Kalman滤波算法进行海量数据流信号滤波预处理,把Web海量数据流映射为一组非线性宽带调频信号模型,采用信号检测算法实现Web海量数据的抗干扰挖掘.仿真结果表明,采用该算法进行Web海量数据信息的抗干扰挖掘,具有较高的数据检测精度和准确挖掘性能,具有较高的抗干扰性和鲁棒性.%An anti jamming mining algorithm for Web massive data stream based on the variable dimension Kalman filter-ing is proposed.. Construct the massive amount of data in the web data mining information flow model and noise model, com-bined with modern signal processing methods to design the variable dimension Kalman filtering algorithm of massive data flow signal filtering pre processing, the web massive data flow is mapped to a set of nonlinear wideband FM signal model and uses the signal detection algorithm is to achieve a large amount of Web data anti-interference mining. Simulation re-sults show that by using the algorithm of Web data information of magnanimity anti-interference mining, it has higher preci-sion of measured data and accurate mining performance and has high anti-interference and robustness.

  5. Performance Analysis and Simulation of M-ary Direct Sequence Spread Spectrum System%多进制直接序列扩频系统性能分析及仿真

    Institute of Scientific and Technical Information of China (English)

    夏高峰; 罗宇; 金哲仕

    2015-01-01

    Spread spectrum system can effectively improve the anti-jamming capability of communication systems;and it has been widely applied in military communication systems as well as in civilian communication systems. M-ary direct sequence spread spectrum system has its unique advantages and is proven widely applicable. This paper studies on M-ary Direct Sequence Spread Spectrum System, and introduces the theory, the performance and channel coding. Results of performance analysis and simulation indicate that the M-ary direct sequence spread spectrum system has good performance and can be applied to bandwidth constrained systems.%扩频技术能有效提高通信系统抗干扰能力,因此在军事通信及民用通信领域得到了广泛应用。多进制直接序列扩频相对于直接序列扩频具有其特有的优势和较强的实际应用背景。本文对多进制正交扩频系统进行研究,介绍了多进制直接序列扩频的原理、分析了多进制直接扩频系统的误码性能,并研究了适合多进制直接扩频系统的信道编解码。仿真结果表明,多进制扩频具有良好的性能,适合带宽受限系统。

  6. Spread spectrum communication based on hardware encryption%硬件加密的扩频通信方案

    Institute of Scientific and Technical Information of China (English)

    萧宝瑾; 仝海丽; 张建忠; 张朝霞; 王云才

    2011-01-01

    提出了一个利用混沌激光源产生1Gbit/s的随机序列作为扩频码的方案.理论分析表明,该随机序列克服了伪随机序列的周期性,在扩大扩频码容量的同时实现了扩频码可变,提高了通信安全性.利用Simulink软件对该扩频系统进行仿真.结果表明,当信息速率一定时,扩频增益越大,误码率越低,与理论结果相符.与传统的扩频系统相比,该方案在提高系统抗干扰能力的同时也增强了保密性.%The scheme of 1 Gbit/s random sequence generated by chaotic laser as spreading code is proposed.Theoretical analysis indicates that the pseudo random sequence exhibited periodic behavior is eliminated by the random sequence and the capability of spreading code is enlarged.Meanwhile,the communication security can be improved by variable spreading code.The corresponding spread spectrum system is numerically simulated by Simulink software and the results demonstrate that the greater the used spreading gain,the lower the obtained error rate will be when the information speed is constant,which is consistent with the theoretical results.The anti-jamming ability of the spread spectrum system is strengthened and the security is enhanced compared with those of the traditional spreading system.

  7. Technology Status and Developing Trends of Satellite Phased Array%星载相控阵天线的技术现状及发展趋势

    Institute of Scientific and Technical Information of China (English)

    阎鲁滨

    2012-01-01

    星载相控阵天线采用现代微波集成技术,在有限的卫星平台空间条件下,实现独立控制的多个点波束,满足未来通信的需求。相控阵天线可以实现波束间通信容量的调整,还可以根据需要改变波束形状,使用自适应调零的抗干扰技术,这些技术已在国外星上设备中广泛采用,具有广阔的发展前景。文章介绍了星载相控阵天线的研究现状、关键技术,以及发展趋势,并对我国星载相控阵天线技术的发展提出了建议。%Satellite phased array with modern microwave integrated circuit technology takes limit space on satellite and is able to independently control many beams to satisfy the demands ofmod- ern communication. The power ration between beams of phased array is adjustble. The radiation beam shape is variable and adaptive anti-jamming technology is easy to apply. Satellite phased ar- ray has been applied in wide domain and has increasing developing future. This paper gives the research status of satellite phased array, the key technologies and prospects the developing trends of satellite phased array.

  8. Laser positioning of four-quadrant detector based on pseudo-random sequence

    Science.gov (United States)

    Tang, Yanqin; Cao, Ercong; Hu, Xiaobo; Gu, Guohua; Qian, Weixian

    2016-10-01

    Nowadays the technology of laser positioning based on four-quadrant detector has the wide scope of the study and application areas. The main principle of laser positioning is that by capturing the projection of the laser spot on the photosensitive surface of the detector, and then calculating the output signal from the detector to obtain the coordinates of the spot on the photosensitive surface of the detector, the coordinate information of the laser spot in the space with respect to detector system which reflects the spatial position of the target object is calculated effectively. Given the extensive application of FPGA technology and the pseudo-random sequence has the similar correlation of white noise, the measurement process of the interference, noise has little effect on the correlation peak. In order to improve anti-jamming capability of the guided missile in tracking process, when the laser pulse emission, the laser pulse period is pseudo-random encoded which maintains in the range of 40ms-65ms so that people of interfering can't find the exact real laser pulse. Also, because the receiver knows the way to solve the pseudo-random code, when the receiver receives two consecutive laser pulses, the laser pulse period can be decoded successfully. In the FPGA hardware implementation process, around each laser pulse arrival time, the receiver can open a wave door to get location information contained the true signal. Taking into account the first two consecutive pulses received have been disturbed, so after receiving the first laser pulse, it receives all the laser pulse in the next 40ms-65ms to obtain the corresponding pseudo-random code.

  9. Research on intelligent algorithms DC brushless speed control system cutting machine%应用于裁断机中无刷直流电机调速系统的智能算法研究

    Institute of Scientific and Technical Information of China (English)

    王法龙; 郑明辉

    2015-01-01

    针对常规PI在无刷电机调速中控制精度低及动态性能差,无法满足裁断机对动力辊电机速度控制要求,本文提出了一种自适应模糊PI控制方法。该方法应用于无刷直流电机双闭环控制的速度外环控制,提高了无刷直流电机的控制精度和动态响应性能。通过Matlab进行仿真,仿真结果表明,采用自适应模糊PI控制相对常规PI控制,无刷直流电机的调速系统具有很好的动态和静态性能,快速响应,超调量小,抗干扰能力强,鲁棒性好。%In the conventional PI control of brushless motor speed low precision and dynamic performance is poor, unable to meet the power roller cutting machine for motor speed control requirements, we propose an adaptive fuzzy PI control method. The method is applied to double-loop control of brushless DC motor speed outer control, improved control accuracy and dynamic response performance brushless DC motor. Through Matlab simulation results show that the adaptive fuzzy PI speed control system to control relative to conventional PI control, brushless DC motor has a good dynamic and static performance, fast response, small overshoot, and strong anti-jamming capability, robustness.

  10. 电力系统中基于FPGA的高精度IRIG-B解码模块的设计%The design of IRIG-B decoder based on FPGA in power system

    Institute of Scientific and Technical Information of China (English)

    张明磊; 马先明; 陈志列; 陈超

    2016-01-01

    The Time Synchronization Technique play a vital role in power system’s normal operation and fault diagnosis.In Time Synchronization System,many devices do not support IRIG-B code.Therefore,we need to decode IRIG-B code when the GPS time server provides only a IRIG-B code and the device does not support IRIG-B code.This paper puts forward a method of decoding IRIG-B code based on FPGA,it has features such as high precise,low power consumption,stable performance,strong anti-jamming capability.%时间同步技术对于电力系统的正常运行和故障诊断都起着至关重要的作用,在时间同步系统中有很多设备并不支持IRIG‐B码对时,因此当现场GPS时钟服务器只提供IRIG‐B码对时信号而二次设备又不支持B码对时,就需要将对IRIG‐B(DC)码进行解码。本文提出了一种基于的FPGA的高精度IRIG‐B解码设计方法,具有精度高,功耗低,性能稳定等优点,并实现较强的抗干扰能力。

  11. Influence of jaundice on immune transmission turbidimetry in detection of serum albumin%黄疸因素对免疫透射比浊法检测血清白蛋白的影响

    Institute of Scientific and Technical Information of China (English)

    曾迎春; 王立军; 邹前福

    2013-01-01

    Objective To investigate the influence of jaundice on the detection of serum albumin by immune transmission turbidimetry. Methods Pure bilirubin was added to two samples of serum with known albumin concentrations (low and high values) in order to make the jaundice serum with different bilirubin concentration gradients. Then the immune transmission turbidimetry was used to determine the albumin content and the influence of jaundice on serum albumin detection was analyzed. Results Common jaundice (with a bilirubin concentration of less than 400 umol/L) had no significant influence on the albumin detection results (P>0.05). Conclusion Immune transmission turbidimetry has strong anti-jamming capability against jaundice in the detection of serum albumin.%目的探讨免疫透射比浊法中黄疸对检测血清白蛋白结果的影响。方法将双份已知白蛋白浓度(低、高值)的血清中分别加入胆红素纯品,制成含不同胆红素浓度梯度的黄疸血清,再用免疫透射比浊法测定其白蛋白含量,比较分析黄疸因素对血清白蛋白检测的影响。结果普通黄疸(胆红素浓度低于400 umol/L)对白蛋白检测结果无显著性差异(P>0.05)。结论选用免疫透射比浊法检测血清白蛋白对黄疸的抗干扰能力较强。

  12. Temperature monitored control system for high-frequency welded pipe and analysis of its influencing factors%高频焊管温度监控系统及其影响因素分析

    Institute of Scientific and Technical Information of China (English)

    何世权; 徐德怀; 樊丁; 徐德茹; 田禾

    2011-01-01

    针对高频焊管生产测量环境恶劣以及依靠经验观察来控制焊接温度的特点,提出高频焊管温度监控系统.该系统利用抗干扰强、测量精度高的比色测温仪采集焊接温度,通过LabVIEW控制高频电源的输出功率,实现温度调整,通过PID控制实现闭环控制.实验证明,监控系统能够准确检测高频焊管的焊接温度,并有效地提高温度的稳定性.最后提出影响高频焊管温度监控系统的因素.%Aimed at the poor measurement and production environment and dependence on empirical observation and control of welding temperature in the production of high-frequency welded pipe, a high-frequency welded pipe temperature monitored control system was proposed. In this system, a colorimetric pyrometer with strong anti-jamming and high measurement precision was used. By using software IabVIEW, the high-frequency power output was controlled to achieve temperature adjustment and closed-loop control. It was verified by test that the system could accurately detect the high-frequency welded pipe temperature, and effectively improve the temperature stability. Finally, the factors that influence the monitore control system of temperature of high-frequency welded pipe were suggested.

  13. Cycle Shift Spread Spectrum Technology in Underwater Acoustic Communication%循环移位扩频水声通信技术研究磁

    Institute of Scientific and Technical Information of China (English)

    王喜龙; 张琳琳; 郭小宇

    2014-01-01

    Direct sequence spread spectrum communication system can work reliably in low SNR conditions ,and has great ability of anti multipath and anti -jamming because of its excellent related performance .This is extremely valuable for information transmission without error in underwater acoustic communication .However ,the communication rate of routine direct sequence spread spectrum underwater acoustic communication system is very low ,according to this characteristic ,this article studies the mode of cycle shift spread spectrum underwater acoustic communication ,and it increases communication rate of direct sequence spread spectrum communication system in the proposition of to promise a certain anti-interference abil-ity .%直接序列扩频通信系统因为其优良的相关性能,能够在较低的信噪比条件下进行可靠地工作,而拥有良好的抗多径和抗干扰的能力。这对于水声通信信息的无误码传输都是极为可贵的。可是,常规的直接序列扩频水声通信系统的通信速率很低,针对这一特点,论文研究了循环移位扩频水声通信方式,它在保证一定抗干扰能力的前提下成倍数提高直接序列扩频通信系统的通信速率。

  14. Sliding mode predictive control for nonlinear systems based on lazy learning%一种基于即时学习的非线性系统滑模预测控制方法

    Institute of Scientific and Technical Information of China (English)

    李庆良; 雷虎民; 杨志峰; 邵雷

    2011-01-01

    针对复杂非线性系统的控制问题,采用数据驱动的控制策略,将具有本质自适应能力的即时学习算法与具有强鲁棒性的滑模预测控制相结合,设计了一种基于即时学习的滑模预测(LL-SMPC)控制方法.该方法在在线局部建模的基础上,采用滑模预测控制律求取最优控制量,具有较强的自适应和抗干扰能力,并采用分层递阶搜索策略,避免了求解Diophantine方程,有效减少了计算量,提高了搜索效率.仿真结果验证了所提出算法的有效性.%To solve the control problem of complex nonlinear system, a sliding mode predictive control based on lazy iearning(LL-SMPC) is proposed. The LL-SMPC builds the local model on-line based on lazy learning algorithm and obtains the optimal control law by solving the quadratic optimization problem formulated in sliding mode predictive control framework, therefore it has strong adaptive and anti-jamming ability. Furthermore, the searching efficiency is improved by using hierarchical searching strategy, and the computation complexity is decreased by avoiding the solving of Diophantine equation. Simulation results show the effectiveness of the proposed method.

  15. Sliding mode predictive control for MIMO systems via lazy learning%基于即时学习的MIMO系统滑模预测控制方法

    Institute of Scientific and Technical Information of China (English)

    李庆良; 雷虎民; 邵雷; 陈治湘

    2011-01-01

    To solve the control problem of MIMO nonlinear system, we propose a sliding mode predictive control based on lazy learning(LL-SMPC) method. The LL-SMPC builds the local model online based on the lazy learning algorithm and obtains the optimal control law by solving the quadratic optimization problem formulated in sliding mode predictive control framework; therefore it has strong adaptive ability and anti-jamming ability. Furthermore, the computation complexity is reduced by avoiding solving of Diophantine equation. Simulation results show that the proposed method is effective.%针对MIMO非线性系统的控制问题,采用数据驱动的控制策略,将具有本质自适应能力的即时学习算法与具有强鲁棒性的滑模预测控制相结合,设计了一种基于即时学习的滑模预测(LL-SMPC)控制方法.该方法在在线局部建模的基础上,采用滑模预测控制律求取最优控制量,具有较强的自适应和抗干扰能力,并避免TDiophantine方程的求解,有效减少了计算量.通过仿真研究,验证了算法的有效性.

  16. 一种新的不变矩与神经网络玉米病害识别系统%New system about moment invariant and neural network used in maize disease recognition

    Institute of Scientific and Technical Information of China (English)

    付立思; 何荣卜; 刘朋维

    2012-01-01

    According to the invariant moment theory, the binary and normalized maize disease images are obtained. A new and better RBF-BP neural network recognition system with the approximation and the fault tolerance is proposed. The Hu invariant moment' s advantages that contain translation, proportion, rotation invariant and good anti-jamming are all used to deal with the complex and changeful maize disease images. According to the invariant moment's reliability, independence, and little number of those characteristics, it can get a better convergence of recognition system to extract the maize image' s features and the training and recognition of RBF-BP neural network. The results of simulation show that the maize disease recognition of RBF-BP neural network has high accuracy and efficiency.%基于不变矩理论,对玉米病害图像进行二值化,图像归一化处理,提出一种新的、具有较好逼近能力和较强容错能力的RBF-BP神经网络识别系统.利用Hu不变矩特征的平移不变性、比例不变性、旋转不变生和对目标良好的抗干扰性等特性,处理复杂、多变的玉米病害图像,形成不变矩特征矢量样本库.根据Hu不变矩在提取图像特征过程中的可靠性、独立性及数目小的特点和RBF-BP神经网络在识别过程中较好收敛性特点,对玉米病害图像进行特征提取、网络训练和病害特征的识别.仿真实验结果表明RBF-BP神经网络系统的有效性.

  17. Design of Multi-channel and High-precision Magnitude and Phase Measuring Module%多通道高精度幅相检测模块的设计

    Institute of Scientific and Technical Information of China (English)

    王耀磊; 许国宏; 徐林峰

    2015-01-01

    相控阵雷达为了保证空间功率合成精度和天线波束指向需要各雷达通道激励信号拥有严格的相位关系,根据需求设计了一种基于AD8302的多通道高精度幅度相位检测模块。分析了AD8302的特点以及工作原理,给出了由AD8302、AD9852和CPCI总线接口等组成的幅相检测模块具体设计,并重点阐述了模块自我校准的工作原理和流程,最终实现多路射频输入信号的相位差和幅度差的精确测量。现场使用结果表明,幅相检测模块具有检测精度高、工作频率范围宽、抗干扰能力强、系统稳定及实用性强等优点。%In order to ensure precision of power synthesize and antenna beam steering in phased array radar, there is need of strict phase relation in multi-channel radar, According as requirement, a kind of the magnitude and phase measuring module with multi-channel and high precision based on AD8302 is designed. This paper analyse the AD8302 Character and the working principle, and give a specific design of the magnitude and phase measuring module that consist of AD8302, AD9852 and CPCI bus, It focuses on the working principle and process of the module self-calibration, Finally realized the measurement of the magnitude and phase of the multi-channel input signal. The results shows that magnitude and phase measuring module has the advantages of high preci⁃sion, wide work frequency band, strong anti-jamming, good stable performance, good practicability and so on.

  18. 高精度幅相检测系统的设计%Design of high-precision magnitude and phase measuring system

    Institute of Scientific and Technical Information of China (English)

    李星; 许国宏; 王耀磊

    2012-01-01

    In order to raise the accuracy of the magnitude and phase measuring,predigest the circuit,enlarge the range of the frequence,a kind of the magnitude and phase measuring system with high precision based on AD8302 is designed.This paper analysed the AD8302 Character and the working principle,and presented several methods to improved high-precision phase measuring.Then compose the magnitude and phase measuring system with high precision based on AD8302 DDS and MCU,It is successful to resolve problem of double value,nolinear,phase shift and calibrate in AD8302 phase measuring system,to realize the measurement of the magnitude and phase of the two simulated input signal.The results shows that magnitude and phase measuring system based on AD8302 has the advantages of precision and strong anti-jamming.%为了提高幅相检测精度、简化电路、扩展频率范围,设计了一种基于AD8302高精度幅度相位检测系统。通过分析AD8302的特点以及工作原理,提出了几种提高相位检测精度的方法,并设计采用AD8302、DDS和单片机组成高精度幅相检测系统,成功地解决了AD8302相位检测过程中存在的二值性、非线性、移相以及校准问题,实现两路模拟输入信号的相位差和幅度差的精确测量。测试结果表明基于AD8302的幅相检测系统具有精度高、抗干扰能力强等优点。

  19. 地球同步轨道双基SAR成像方法%Imaging Algorithm for GEO-LEO Bistatic SAR

    Institute of Scientific and Technical Information of China (English)

    宋舒; 马仑; 廖桂生

    2013-01-01

    GEO-LEO distributed spaceborne SAR systems,in which GEO satellite is used as illuminator and LEO satellite only used as signal receiver,have many advantages over conventional spaceborne SAR systems,such as wide observation range,strong anti-jamming and antidestruction ability and flexible networking.However,traditional monostatic SAR imaging algorithms are not applicable to such systems since the echo time delay is coupled with the azimuth position of the target.By analyzing the Doppler history of echo in detail,a novel SAR imaging algorithm for GEO-LEO bistatic spaceborne SAR systems is presented.According to the relationship between geometric distortion of target image and relative position of LEO satellite,the method divides the SAR echo into many patches along the range and the azimuth direction,respectively.For each patch,new range migration correction and matching functions are constructed to focus on the echo.Finally,geometric distortions of target images in each patch are corrected uniformly.The feasibility of the proposed method is verified by experimental results of simulation data.%地球同步轨道发射、低地球轨道接收体制的天基雷达系统具有观测范围广、抗摧毁和抗干扰能力强、组网灵活等优点.分析发现,该系统中回波的包络不仅与地表场景的斜距有关,还与其方位位置有关,传统的单基SAR成像方法不再适用.本文分析了回波包络的历程,给出了适用于该系统的SAR成像方法.该方法根据多普勒参数以及目标像的几何形变量随接收卫星与发射卫星几何位置关系的变化特征对数据沿方位以及距离向进行分块,并重新构造距离徙动校正和方位匹配函数对回波信号聚焦,最后进行几何形变校正.仿真数据的成像结果证明了方法的可行性.

  20. Design of High-Speed Data and Long-Distance Transmission System Based on FPGA%基于FPGA的高速数据长线传输系统的设计

    Institute of Scientific and Technical Information of China (English)

    郭宝锋; 韩壮志; 何强; 尚朝轩; 曾慧燕; 马少闯

    2012-01-01

    Design scheme of high-speed and long-distance transmission system is proposed, whose core is Cyclone II series FPGA chip EP2C5T144, based on low voltage differential signals (LVDS) interface technology. The scheme implements serial-to-parallel conversion, parallel-to-serial conversion, LVDS' driving and receiving through FPGA, it solves some problems such as the voltage conversion of different interface standards, impedance matching, the signals' attenuation and resumption in the process of long-distance transmission. The scheme has advantages of simple design, strong anti-jamming ability, small size, low cost and high integration. Experimental results show that the system works steadily, the serial data transmitting at the speed of 50 Mb/s on the 100 m unshielded twisted pair with the perfect transmission effect, which fully meet the need of design.%提出了以CycloneⅡ系列FPGA芯片EP2C5T144为核心,基于低压差分信号(LVDS)接口技术的高速数据长线传输系统的设计方案,该方案利用FPGA实现数据的串/并、并/串转换以及LVDS信号的驱动和接收,解决了不同接口标准的电平转换、阻抗匹配以及信号长线传输过程中的衰减与恢复等问题,具有设计简单、抗干扰能力强、体积小、成本低、集成度高等优点.通过实验表明,该系统工作稳定,实现了串行数据在100m非屏蔽双绞线上以50 Mb/s的速率传输,并且具有良好的传输效果,完全满足系统设计要求.

  1. 一种基于VDFLL和CaKFPLL的INS/GNSS超紧耦合方法%INS/GNSS ultra-tight coupling based on VDFLL and CaKFPLL

    Institute of Scientific and Technical Information of China (English)

    李传军; 李兴城

    2013-01-01

    为了提高复杂电磁环境下的GNSS抗干扰能力,针对低成本制导武器的导航需求特点,提出了一种基于矢量延迟锁定环和锁频环并级联卡尔曼滤波锁相环的INS/GNSS超紧耦合的改进算法。分析了 INS 辅助矢量跟踪结构,给出了基于鉴别器的低复杂度基带预处理滤波器和基于 EKF 锁相环滤波器的详细设计方法。此外,设计了干扰环境下的高动态飞行轨迹,用于验证INS/GNSS超紧耦合算法,动态仿真试验结果表明,在干扰环境下INS/GNSS超紧耦合系统的导航能力相对于独立式高动态跟踪技术的接收机有明显优势,跟踪GPS L1 C/A情况下,可容忍干信比为48.6 dB,比独立式接收机的干扰抑制能力提高了约12 dB。%In order to improve GNSS’s anti-jamming ability under complex electromagnetic environment, an improved algorithm of INS/GNSS ultra-tight coupling(UTC) based on vector DLL(delay locked loop) and FLL(frequency locked loop) as well as cascade loop filter of phase-locked loop is proposed for low cost guided weapon navigation. The architecture of INS-aided GNSS vector tracking is analyzed, a discriminator-based pre-processing filter for vector tracking is devised to reduce the computational complexity, and an extended Kalman filter for PLL is given. A ballistic trajectory under jamming condition is also designed to test the UTC algorithm. Dynamic simulation test shows that the performance of UTC is better than that of stand-alone high dynamic tracking under interference environment. The UTC can lock GPS L1 C/A signal at J/S level of 48.6 dB which is about 12 dB bigger than stand-alone receiver.

  2. 表面增强拉曼散射基底的研究进展%Review on surface enhanced Raman scattering substrates

    Institute of Scientific and Technical Information of China (English)

    薛向欣; 许东铎; 常立民

    2015-01-01

    表面增强拉曼光谱(SERS)由于其高的灵敏度、抗干扰能力强等优点,被广泛应用在表面科学、分析化学、物理学等领域,是研究表面和界面过程的重要工具,是定性鉴定化学组成相近化合物的有力手段。因此,高品质、高活性的SERS基底一直是科研工作者们追求和研究的重点。本文对SERS活性基底的发展进行了介绍,从金、银金属纳米粒子作为基底的拉曼效应的科学研究,又进一步总结了非金属纳米粒子ZnO、TiO2、ZnS、Cu2O、CdTe、CdS等SERS基底。今后,将贵金属与半导体纳米材料复合将是SERS基底的研究热点。SERS光谱目前可以在液相色谱分析的检测器、医学检测仪器、刑侦分析检测等众多领域得到应用。%Due to its high sensitivity and strong anti-jamming ability,surface-enhanced Raman spectroscopy (SERS) is widely used in surface science,analytical chemistry,physics and other fields, and is a powerful tool for qualitative identification of compounds with similar chemical composition. Therefore,SERS substrates with high-quality and high-activity have always been a focus of researchers. Gold and silver metallic nano-particles based on the Raman effect were first introduced; and non-metallic nanoparticle,ZnO,TiO2,ZnS,Cu2O,CdTe,CdS etc,as surface-enhanced Raman substrate were then summarized in terms of the SERS signal enhancement. Surface-enhanced Roman spectroscopic is currently applied in the liquid phase chromatographic detectors,medical instrumentation,forensic analysis and testing,and many other fields. In the future,the substrates of the complex of metal/semiconductor materials shall be focused on.

  3. Study on the Control Strategy of the Offshore Wind Energy Flexible Direct Current Transmission Using VSC-HVDC%采用VSC-HVDC的海上风电场柔性直流输电系统控制策略研究

    Institute of Scientific and Technical Information of China (English)

    蒋辰晖; 王志新; 吴定国

    2012-01-01

    Taking the three phase two-level voltage source current converter widely used in the actual offshore wind power transmission project as the research objective, this paper establishes a two—phase rotating dq system mathematical model in the two-phase rotating dq system by the coordinate transformation of the main converter circuit topology; and for the control system, uses the PI control method with a dual closed loop, and uses the current decoupling control to achieve the constant active/reactive power control which improves the system's dynamic performance and anti-jamming capability; and uses the space vector PWM modulation (which reduces the switching loss and harmonic content) for converting the current. The final matlab/Simulink simulation results and the 3.5 kW test show that the program has good control effects with voltage and current waveform stable, harmonic content low and response speedy. It is suitable for the offshore wind farm with the HVDC-Flexible system.%以实际应用于海上风电输电工程中的三相两电平电压源换流器为研究对象,通过对换流器主电路拓扑结构进行坐标变换,建立了便于解析的两相旋转dq坐标系下的数学模型;换流器控制系统采用了双闭环PI控制方法,并引入电流解耦控制,实现了一侧定有功、一侧定直流电压控制,提高了系统的动态性能和抗干扰能力;采用了SVPWM调制方式进行调制,有效地降低了谐波含量和开关损耗;采用Matlab/Simulink仿真,并搭建了3.5 kW试验验证平台.结果表明该方案控制效果良好,电压、电流波形稳定、谐波含量少且响应速度较快.因此,适用于海上风电场柔性直流输电系统.

  4. GPS P码接收机本地信号发生器的FPGA实现%Implementation of Local GPS P Code Generation in GPS Receiver Based on FPGA

    Institute of Scientific and Technical Information of China (English)

    曹进; 李荣冰; 徐昭; 谢非

    2013-01-01

    As the military use of GPS,P code is famous for its characteristic of high precise,long period and complex structure. The software receiver based on P code is not only of high position precision, but also of high level of anti-jamming and anti-spoofing. It is of great importance for direct P code acquisition and the tracking if we can generate any bits of P Code in its period. After doing research on the mechanism and structure of P Code generation, we designed some algorithm of P code and realize it through MATLAB. Then we propose the algorithm for FPGA by modules including register module, delay module,period module and register phase module. The result shows that P Code of any time or any satellite can be generated by it without time delay.%P码作为GPS军用伪码,具有结构复杂、周期长且码速率快的特点,这使得使用P码的软件接收机不仅定位精度高,且具有很强的抗干扰和反欺骗能力.能够实现任意卫星的任意时刻P码的产生,对于实现P码直接捕获和跟踪有很重要的意义.对于P码的产生原理和结构进行了分析,基于MATLAB设计了相应的P码发生算法并进行简单的算法仿真.之后针对FPGA硬件平台对P码发生器进行了相应的模块设计,包含寄存器模块、延时模块、周期控制模块和寄存器相位模块等.测试实验结果表明P码发生器可以基本无延迟地生成任意卫星、任意时刻的P码.

  5. Research progress of automatic navigation technology for orchard mobile robot%移动机器人自动导航技术研究进展

    Institute of Scientific and Technical Information of China (English)

    蒋浩然; 陈军; 王虎; 雷王利; 袁池

    2011-01-01

    针对目前果园移动机器人自动导航技术研究现状,综合分析现有的有关文献,依据环境感知方式的不同,分别讨论了以激光、视觉、机械、电磁、GPS、超声波为感知系统的导航方法的研究进展,分析了现有几种导航方法在精度、实时性、抗干扰能力及系统适应性等方面的优缺点,认为多传感器融合技术可为果园移动机器人的导航提供更高的精度和稳定性。在此基础上,提出了未来果园移动机器人自动导航技术的发展趋势,即多传感器融合技术是果园移动机器人感知环境的主要手段,满足果园移动机器人精度和稳定性要求的导航系统将是今后研究的重点。%The existing related literatures were analyzed based on the current research progress of the orchard mobile robot's automatic navigation technology.According to the different environmental perception methods,the current research status of the navigation methods with perception systems based on laser,vision,machinery,electromagnetism,ultrasonic and GPS were discussed respectively;the advantages and disadvantages of each method in terms of navigation accuracy,real time,anti-jamming capability and the flexibility of the system were also discussed.Then we believe that the multi-sensor fusion technology could provide higher precision and stability for the orchard mobile robots' automatic navigation.On that basis,this paper proposed the development tendency of automatic navigation technology for orchard mobile robot in the future,multi-sensor fusion technology would become the main method of the environment perception for orchard mobile robot.Therefore,the development of the navigation system with required accuracy and stability for the orchard mobile robot would be the emphasis of the future research.

  6. W-band technology applying for radar seeker%W波段雷达导引头技术分析

    Institute of Scientific and Technical Information of China (English)

    郭玲红; 吴卫山

    2012-01-01

    由于电子对抗技术的飞速发展,低频段电子干扰设备已经非常完善,低频段主动雷达的工作效能相应地大幅度降低。为了提高雷达系统的抗干扰能力,通过对国内外雷达技术发展趋势的研究,以及影响雷达系统抗干扰能力主要因素的分析。说明了采用更高频段的雷达导引头技术发展的重要性。以W波段雷达导引头技术发展及应用为前提,对其中需要解决的关键技术进行了分解,论述了W波段雷达导引头的基本实现方案、关键技术解决途径,得出W波段雷达导引头技术发展具有策略上的必要性和技术上的可行性的结论。%Because of the rapid development of electronic against technology, low frequency band jamming devices have very perfect, the low frequency active radar's performance is greatly reduced accordingly. In order to improve the anti-interference ability of radar system, through the domestic and international technical development trend of radar, and the impact the radar system of the main factors of anti-jamming ability is analyzed to show the higher frequency band radar seeker technology on the importance of development. With W-band radar seeker technology development and application for the premise, the need to solve the key technologies used in the decomposition, discusses the W-band radar seeker of basic implementation scheme, key technology solutions, draw the W-band radar seeker technology with the necessity of the development strategies and technical feasibility conclusion.

  7. Judgement of Direction of Movement Based on Active RFID%基于有源RFID的运动方向判断

    Institute of Scientific and Technical Information of China (English)

    喻剑; 杨卫

    2011-01-01

    RFID is one of the crucial technology of the IOT (Internet of things) , and it has been applied to the fields of manufacture, logistics, public security, and etc. Active RFID is one of RFID, and the striking features of active RFID are low power consumption, stable signals, long-distance reading and anti-jamming ability. Therefore, active RFID is widely used in the areas of long-range identification of personnel and vehicles and Real Time Location System. In the various application of active RFID, the judgement of direction of movement is a vital technical matter. A new method is put forward to judge. In other words, with several directional antennas, it forms several reading areas, picks up events of the tag entering or exiting and then realizes the judgement of direction by the order of events. In this way, I could not only judge the direction of movement of tags accurately, but also judge other complicated logic, e. g. the midway return of tags.%RFID技术是物联网相关的重要技术之一,已经在生产制造、物流管理、公共安全等众多领域得到了应用.有源RFID技术是RFID技术的一种,具有低功耗、信号稳定、读取距离远、抗干扰性能好等特点,被广泛地应用于车辆、人员的远距离标识与RTLS定位等.在有源RFID各种应用中,对于标签运动方向的判断是一个重要的技术问题.提出一种使用多个定向天线读写设备,形成多个读取区域,提取标签在各区域中的事件,通过事件逻辑顺序实现对运动方向的判断.采用这种方法不但可以准确判断标签运动方向,而且可以判断标签中途返回等一些复杂逻辑.

  8. Research of ZigBee-based Medical Monitoring Network Oriented to Family%面向家庭的ZigBee医疗监护网络研究

    Institute of Scientific and Technical Information of China (English)

    赵锦萌; 吴效明; 张莉莉

    2012-01-01

    ZigBee无线医疗监护能够让广大民众在家中享受个性化医疗卫生服务,有效地缓解医疗卫生资源紧缺等严峻的社会问题;研究通过ZigBee传感器网络在普通家庭环境下的抗干扰能力测试、最大通信距离测试、网络自恢复能力测试、耗电量测试等,阐述了ZigBee短距离通信技术在实际应用中的优缺点以及在医疗监护中应用的可行性,为面向家庭的的无线医疗做了理论依据,并且设计了协调器与上位机、路由节点、传感器节点的通信协议;通过各种测试,研究得出结论:ZigBee短距离通信技术在家庭环境中,能够有效地克服各种家用设备的干扰,数据传输准确率高,正常情况下,准确率达到100%,在增加路由节点的情况下,能够完全覆盖家庭环境,满足无线医疗监护的要求.%Wireless medical monitoring based on ZigBee technology meets personalized medical and health services of people who stay at hornet which eases severe social problems such as the shortage of health care resources. Tests for the anti-jamming capability, maximum communication distance, self-healing capabilities, power consumption are held in the smart home environment, so that we can know the advantages and disadvantages of ZigBee technology and the feasibility of the application in wireless medical monitoring. We developed communication protocol of COORD. ROUTER, RFD. So in the home environment. ZigBee short -range communications technology can overcome the interference of home appliances effectively, and the data transmission is accurate . If increase the routing node , it can cover a family environment, meet the requirements of wireless medical monitoring.

  9. 反隐身与发展先进米波雷达∗%Anti-Stealth and Development of Advanced Metric-Wave Radar

    Institute of Scientific and Technical Information of China (English)

    吴剑旗

    2015-01-01

    米波雷达具有反隐身优势,通过有效克服传统米波雷达的主要缺陷,可以大幅提高米波雷达的性能。对此提出“先进米波雷达”这种新型米波雷达的概念。首先,从频段和功率孔径积两方面优势分析了米波雷达反隐身的有效性。然后,分析了传统米波雷达的主要缺陷及其根本原因。最后,通过米波雷达发展历程的介绍,重点提出空域覆盖、测量精度、抗干扰和目标识别等是先进米波雷达要解决的主要问题,同时分别阐述了解决这些问题的基本方法。指出用先进米波雷达反隐身是经济高效的反隐身路径。%Metric-wave radar has anti-stealth advantages,and its performance can be improved greatly by overcoming the major drawbacks of the traditional metric-wave radar.The concept of the advanced metric-wave radar is proposed.Firstly,the effectiveness of metric-wave radar detecting stealth targets is analyzed from its frequency band and power-aperture product advantages.Secondly,the major drawbacks of the tradi-tional metric-wave radar and their reasons are analyzed.Lastly,the development history of the metric-wave radar is introduced and the main problems to be solved by the advanced metric-wave radar are presented,such as airspace coverage,measurement accuracy,anti-jamming,and target identification.And the basic methods to solve these problems are given respectively.The paper points out that the advanced metric-wave radar is a cost-effective way for stealth target detection.

  10. 机载GNSS掩星观测反演大气折射率廓线研究%Profiling the Atmosphere Refractivity Using the Airborne GNSS Radio Occultation Sounding

    Institute of Scientific and Technical Information of China (English)

    李潇; 张训械; 李烨; 王烁; 李兴国; 吕铁军

    2011-01-01

    作为星载掩星技术的推广,基于飞机平台的无线电掩星技术备受关注.为了将机载掩星技术更好地应用到工程实践中,文章通过介绍机载掩星探测的基本原理和主要特点、模拟仿真,对机载掩星的反演算法进行了探讨,并给出模拟结果:包括利用STK仿真软件生成仿真场景;采用3维射线追踪技术模拟机载无线电掩星,预报掩星事件出现的时间、仰角,模拟信号传播特征;详细研究大气层内折射率反演技术并给出反演结果.研究结果表明,模拟仿真对机载掩星工程化实现是有益的.最后展望了机载掩星探测的发展趋势,提出了弱掩星信号的捕获跟踪、飞机平台的精度定位测速以及反射信号的抗干扰三项技术及工程化中需解决的技术难点.%As an extended technique of GNSS radio occultation (RO), the airborne RO sounding has attracted much wider attention. In order to apply it in practical engineering, this paper firstly introduces some keystone and main features of airborne RO sounding. Then the simulation of the refractivity reversed is done and the reversed results are presented, including: establishing simulated scene by STK software; simulating airborne RO by 3D radial tracing technique to predict occultation occurring time, elevation and signal propagation feature; investigating refractivity reversed technique within the atmosphere. The simulated result is useful to airborne RO engineering. Some conclusions and prospect of airborne RO sounding are discussed. Finally, the paper points out that three technical difficulties in application are tracking weak RO signal, precisely measuring speed of airborne, and anti-jamming of reflection.

  11. Analysis of BOC Modulation and Receiver Technique for Satellite Navigation System%卫星导航系统中的BOC调制和接收技术分析

    Institute of Scientific and Technical Information of China (English)

    袁润平; 翟建勇; 王伟

    2013-01-01

    BOC调制是一种新的调制方式,能够实现频谱分离并能够充分利用整个频带,比传统的BPSK调制拥有更好的自相关特性,以至于能够改善定位精度。由于BOC调制信号在载波频率点处有较低的功率谱密度,因而,在未来的卫星导航系统中使用 BOC 调制信号将能够减少信号间的干扰。本文详细地分析了BOC调制信号的特点,通过对功率谱密度函数、自相关函数、Gabor带宽和码跟踪精度等参数的分析和仿真,验证了BOC调制信号在相关特性、抗干扰能力和码跟踪精度方面的优越性。并针对 BOC 调制信号自相关峰的多峰带来的跟踪不确定性会使捕获复杂度增加和带来跟踪误差的问题,本文介绍了几种BOC调制信号的接收技术,可为我国自主研发的导航系统的信号体制设计和系统优化提供技术支撑。%BOC modulation is a type of new modulation method, which realizes the split of spectrum to make full use of the available frequency bands, and possesses better autocorrelation property than the classic BPSK modulation, so can improve the precision of the positioning. Thus, the use of the Binary Offset Carrier (BOC) modulated signal in incoming satellite navigation systems can reduce the interference as it has low PSD at carrier frequency. the signal characteristic of BOC is analyzed in detail. BOC modulation signal has the advantages of correlate characteristics, code tracking accuracy and anti-jamming ability which are validated by the analysis and simulation of the power spectral density function, correlation function, Gabor bandwidth, and code tracking accuracy. According to the problems which can be brought by the tracking uncertainty of BOC modulation signal, several receiver techniques for BOC modulation signal are introduced in order to design the satellite signal and optimize the satellite system.

  12. 天地一体化信息网络安全保障技术研究进展及发展趋势%Research status and development trends of security assurance for space-ground integration information network

    Institute of Scientific and Technical Information of China (English)

    李凤华; 殷丽华; 吴巍; 张林杰; 史国振

    2016-01-01

    天地一体化信息网络由天基骨干网、天基接入网、地基节点网、地面互联网、移动通信网等多种异构网络互联融合而成,对实现国家安全战略目标具有重要意义。首先,介绍了天地一体化信息网络架构,以及卫星节点暴露、信道开放、异构网络互连等特征,并从物理层、运行层、数据层3个层面分析了天地一体化信息网络面临的威胁;其次,从物理安全、运行安全、数据安全3个层面对抗损毁、抗干扰、安全接入、安全路由、安全切换、安全传输、密钥管理等安全保障技术的研究现状进行了阐述;最后,针对天地一体化信息网络特点和安全保障需求,指出了天地一体化信息网络安全保障技术发展趋势和研究方向。%Space-ground integration information network consists of space-based backbone network, space-based access network, the node net of foundation, Internet, mobile communication network, which has important significance for the realization of the target of national security strategy. Firstly, the characteristics of space-ground integration network, such as exposed channel, heterogeneous network integration, etc, were analyzed. Also, the corresponding threats from the physical layer, operation layer, data layer were introduced. Secondly, a comprehensive study on current status of surviv-ability, anti-jamming, secure access, secure routing, secure handoff, secure transmission and key management were made. Finally, combined with research status, the important trends were proposed.

  13. 柴油机自适应遗传非线性PID调速控制仿真%Simulation of Diesel Speed Control System Based on Genetic Algorithm- Nonlinear PID

    Institute of Scientific and Technical Information of China (English)

    石为人; 肖华; 刘晶宇; 李曼

    2012-01-01

    研究船用柴油机控制优化问题,柴油机调速要求快、稳、准.针对船用柴油机调速系统的时变、非线性及外界干扰等特点,传统PID调速稳定时间长,控制效果不佳.为提高喷油量达到控制准确度,改善调速系统性能,提出了一种柴油机自适应遗传非线性PID调速控制策略.采用Matlab对柴油机调速系统模型进行辨识并验证其准确性.利用非线性PID控制实现各参数增益的实时调整,提高了抗干扰能力,通过自适应遗传算法对系统的动态偏差进行监控,优化非线性PID控制器参数,减少了超调量,提高控制精度.仿真结果表明,采用自适应遗传非线性PID控制器稳定时间更短,鲁棒性强,控制精度更高,优化了柴油机调速系统性能.%Aiming at the features of time - varying, non - linearity and different sea conditions of ship diesel engines, the paper presented a new control method which combined nonlinear PID control with adaptive genetic algorithm , and also put it into use in the diesel speed. The system model of marine diesel speed system were identificated based on system identification toolbox in MATLAB. The nonlinear PID controller adjusted the gain parameter following the changing errors and enhanced anti - jamming capability. A new adaptive genetic algorithm was used to monitor the dynamic deviation and optimize the controller parameters of nonlinear PID in the speed control system, which reduced the overshoots and strengthened control accuracy. Compared PID controller with genetic algorithm - nonlinear PID, the simulation shows that the improved control method can achieve better control effects in both dynamic and steady state characteristics, and is more adapted to the non - linearity and time - varying environment such as ship diesel system.

  14. A computational method of touch point coordinate%一种触摸坐标计算方法

    Institute of Scientific and Technical Information of China (English)

    胡跃辉; 刘志民; 吕国强; 李小哲; 于芳芳; 丁小宇

    2015-01-01

    近年来,随着多点触摸发展的日益多元化,触摸屏的结构日趋复杂,触摸算法日渐新颖。提出了一种触摸坐标点计算的新方法,将其称为“投壶”算法,意为将满足条件的物体准确投入壶中,此时壶里的权重增加,最后将权重最大的壶视为“真实”即为有触摸点的。实验证明,此算法能够在硬件资源有限的条件下,准确的计算触摸点的坐标,尤其在多点触摸的情况下,能够有效的避免伪触摸点的出现,具备一定的抗干扰能力,具有响应速度快、计算精度高等特点,实现触摸屏的无驱安装。%In recent years, with the development of multi-touch diverse, the structure of the touch screen is more and more complex, the touch algorithm is increasingly fashionable.This paper proposes a new method of calculating the touch point, which is called “pitch pot” algorithm.It means that we will put the object which meets the condi-tions into the pot, by this time the pot’s weight is adding.At last, the heaviest pot is looked as the real pot which means it has the touch point right now .The experimental results show that , under the circumstance of limited hard-ware resources, this algorithm can accurately calculate the coordinates of the touch point, especially in the case of multi-touch.It could effectively eliminate the false touch point, has a certain anti-jamming capability fast response and high accuracy, and achieves no driver installation.

  15. Automation Reconstruction of Shenbao Coal Surface Production System%神宝煤矿地面生产系统的自动化设计

    Institute of Scientific and Technical Information of China (English)

    张国军; 苏珂嘉; 付衍斌; 饶熊舟

    2013-01-01

    The design of technical research of the automation of centralized control system of Shenbao coal 10 million tons of ground production system includes a variety of equipments for the initiation, parking, protection, adopt the automatic and manual and on-site three control methods. This design program uses Siemens S7- 414H PLC modular design thought, through the Profibus-DP connect S7-414H and each branch. Makes full use of the touch screen control, the relative centralization system control of all focused on the touch screen, it is easy to operate, and can also display the main equipment status. Fully considering the anti - jamming ability of the system, and take various measures to improve the system stability. The design scheme realized the high automation system, enhanced the production efficiency.%神宝煤矿地面1 000万t生产系统全自动化集中控制系统的技术研发设计包括多种设备的启动、停车、保护,采用自动、手动和就地3种控制方式.该设计方案运用西门子S7-414H PLC的模块化设计思想,通过Profibus-DP总线将S7-414H与各分站连接起来.充分利用触摸屏控制,将系统的相对集中控制全部集中于触摸屏,便于操作,同时还可显示主要设备的运行状况.充分考虑系统的抗干扰性能,采取多种方式提高系统稳定性.该设计方案实现了系统的高度自动化,大大提高了生产效率.

  16. 压制干扰对GPS接收机码跟踪环的性能影响分析%Analysis of the performance of the code tracking loop of GPS receiver under blanket jamming

    Institute of Scientific and Technical Information of China (English)

    汤俊杰; 薛磊; 林航; 李得申

    2011-01-01

    压制干扰是GPS接收机面临的重要的人为威胁之一,对伪码跟踪的跟踪测距精度产生影响,甚至导致伪码跟踪环失锁.干扰对伪码跟踪环的影响模型涉及许多因素,建模比较困难.以常用的非相干超前减滞后功率延迟锁定环为例,建立了码跟踪环在宽带噪声干扰、窄带干扰和点频干扰下的跟踪误差模型,比较了压制干扰对C/A码和P(Y)码跟踪环性能的不同影响.通过对不同干扰方式下C/A码和P(Y)码跟踪误差的仿真,得出了对C/A码和P(Y)码跟踪环性能影响较大的干扰方式和干扰频率,为GPS接收机干扰方法和抗干扰措施的选择提供了理论依据.%As a vital kind of man-made threat faced with GPS receiver , blanket jamming influences measurement error of code tracking , even leads to lose lock of code tracking loop. The foundation of the mode of the impact of jamming is very difficult because of complication. Taking example for the familiar DLL of noncoherent early-late processing, the mode of tracking error based on broadband noise jamming,narrowband jamming and CW jamming is founded and the performance of the code tracking loop of C/A code and P(Y) code under blanket jamming are compared. The simulation results indicated a given jamming mode and jamming frequency exert more influence on the performance of the code tracking loop of C/A code and P( Y) code receiver. It is propitious to the choice of jamming means and anti-jamming measure of GPS receiver.

  17. Performance analysis of QC-LDPC Codes in the chaotic DSSS for NBJ suppression%QC-LDPC码在混沌DSSS-NBJ抑制中的性能分析

    Institute of Scientific and Technical Information of China (English)

    李思佳; 毛玉泉; 李波; 裴鑫; 吴崇虎

    2013-01-01

    以低信噪比窄带干扰条件下混沌DSSS系统信息传输的可靠性提高为目的,在混沌DSSS系统的基础上,结合QC-LDPC码提出了一种基于QC-LDPC-CDSSS的协同窄带干扰(Narrowband Jamming,NBJ)抑制方案.该方案在直积构造方法生成校验矩阵的过程中,完成了校验矩阵4、6短环的检验与消除,采用近似下三角算法实现了QC-LDPC编码;对于混沌直序扩频系统,分析了组合混沌映射序列的性能和优选方法,采用优选的组合混沌扩频序列增强低截获能力;最后通过不同干扰条件下的仿真验证了该方案的有效性,仿真结果表明,该方案对于单音干扰的抑制效果优于多音干扰的抑制效果,在10-5的误码要求条件下,信噪比小于4dB.%In order to improve the bit-error-rate (BER) at the low SNR,a novel cooperative anti-jamming scheme for narrow-band jamming suppression is proposed based on the QC-LDPC codes and-integrated Map chaotic direct sequence spread spectrum.The QC-LDPC codes are designed through approximate lower triangular form algorithm based on the parity check matrix.The direct product is used for constructing the parity check matrix.The performance of chaotic spread spectrum sequences,produced from the integrated Chaotic MAP,is analyzed and their optimized selection algorithm is proposed.Finally,the strategy is verified through simulations with different jamming.The results show that the scheme performs better with single tone jamming than multi-tone jamming and the SNR is smaller than 4dB when the BER is 10-5.

  18. Imitation modeling of ice dams (case study of Tom’ River, Western Siberia

    Directory of Open Access Journals (Sweden)

    V. A. Zemtsov

    2014-01-01

    Full Text Available The factors of ice jam formations in the lower flow of the Tom River (Siberia are investigated. A length of the main channel under investigation is about 120 km. Approaches to solution of the problem of the jam formation control and, as a consequence, the jam induced floods are considered on the basis of the imitative computer modeling of stream dynamics and ice jams. The simulation makes it possible to analyze different scenarios of initial forcing and to predict reactions of the river bed system to the effects. On the basis of 1D models developed in the HEC-RAS 4.0 modeling system for the Tom River at the city of Tomsk we investigated a possibility of the ice jam localization, probability of which at different parts of river flow varies in time according to change of the river water discharge, stream hydraulics, and ice cover thickness. The 2D hydrodynamic model of the Tom River channel system in the SMS 9.2 modeling system has been developed. It allows simulating effects of ice jams located in different sections of the river flow on the run-off redistribution between the main channel and other river branches. It makes possible to estimate hazards and risks of ice jam floods and probable effects of ice jams on formation of the river channel system. As a result it becomes possible to regulate the safe spring ice transit through populated areas.Analysis of factors of the ice jam formations has demonstrated that due to increasing anthropogenic influence changes of hydro-meteorological and geomorphologic conditions lead to more frequent occurrence of jam floods for the last 25 years as compared to previous 40-year period. The imitative computer models are proposed to be used for planning anti-jam measures since they make possible to create a whole system of the channel structure, a relief of channel and floodplain, a flow velocity field including dangerous hydrologic processes. Similar system would allow predicting both consequences of local

  19. 基于单片机实现的油井油位测控系统设计%A Design Based-on MCS for Measuring and Controlling Oil Level of Wells

    Institute of Scientific and Technical Information of China (English)

    吴宏岐; 李超; 吕晓峰

    2013-01-01

    A system based-on single-chip is designed to measure and control oil level accurately to improve the efficiency of pumping unit.The system uses AT89C2051 as main controller,uses a new type vibratory ultrasonic detector and receiver to form an oil level detecting circuit and a LED digital display to control the states of oil pump.A single-line digital temperature sensor is used as the core of compensator to correct the errors caused by the changes of surroundings temperature,As a result,the system anti-jamming ability is improved.The system software is written in C language.Interrupt modes are used to record and deal with the time from ultrasonic emission to receiving reflection wave from oil level to get the accurate height of oil level.The system has the merits of running reliably and measuring truly through debugging,so it is worthy of extending.%为准确测量油井中的油位,以便提高抽油机工作效率,研究设计了基于单片机实现的测控系统.系统以AT89 C2051单片机为主控制器,用新型振动模式超声波探头和超声波接收器构成油液位检测电路及LED数字显示器,从而对油井油位检测、显示和对抽油机工作状态进行控制.采用单线数字温度传感器为核心的温度补偿电路,以校正由于检测电路工作环境温度变化引起的测量误差,提高了系统抗干扰性.系统软件由C语言实现,采用中断方式,完成超声波发射到接收从石油液面反射回波的时间记录和处理,以得到准确的油位高度.系统通过实验调试,运行可靠、测量准确,具有一定的推广价值.

  20. 基于低压电力载波通信的单相智能电表的设计%Design of Single-phase Smart Meter Based on low Voltage Power Line Carrier-Current Communication

    Institute of Scientific and Technical Information of China (English)

    宋树祥; 韦正丛; 梁承福; 何婷婷

    2012-01-01

    In order to remote real-time monitoring and management of single-phase smart meters, a single-phase smart meters has been designed based on carrier chip PL3201 and metering chip 90E24. This design used the low-voltage power line carrier communication, by the direct sequence spread spectrum communication technology, making the system's anti - jamming capability improved significantly. Meanwhile, the design uses the IDT's latest high - precision chip 90E24, the measurement accuracy is better than current industry standards, in a considerable time, the power sector to meet national requirements for measurement accuracy. Practical results show that the design is not only Low-cost, simple, and the measurement of high precision, strong anti -interference, for low carrier concentration meter reading system.%为了对单相智能电表进行远程实时监控管理,设计了一种基于载波芯片PL3201和计量芯片90E24的单相智能电表;该设计把直接序列扩频通信技术应用于低压电力线载波通信,使得系统的抗干扰能力得到显著提升;同时,该设计采用了IDT公司最新推出的高精度计量芯片90E24进行计量,其计量精度优于目前业内水平,能在相当时间内满足国家电力部门对计量精度的要求;实践结果表明,该设计不仅成本低廉、方法简单,且计量精度高、扰干扰能力强,适用于低压载波集中抄表系统.

  1. Technology of high density resistivity method for bedrock investigation%高密度电阻率法在基岩勘察中的应用

    Institute of Scientific and Technical Information of China (English)

    邓帅奇; 岳建华; 刘志新; 于业斌

    2012-01-01

    Based on the fundamental theory of tripotential sonde, the paper explained the principle, working method, the process of data processing of high density measurement method of electrical resistivity, and applied it to actual engineering. Through examples of analysis, Wenner array has obvious effect for detecting the up and down situation of bedrock surface due to its high vertical resolution. In addition, Wenner array has advantage of strong signal acquisition and high signal-to-noise ratio. Instead, dipole array has high sensitivity for detecting the internal structure of the bedrock due to its high transverse resolution. While dipole devise also has weak capability on signal acquisition and low ability of anti-jamming. To sum up, the paper concluded that it should get an ideal detecting results by combination. The actual application indicated that this method can get good result of detecting bedrock. It is proved by practice that the application of high density resistivity method in bedrock investigation can get great result. Furthermore: it would do great help to improve the exploration results and accuracy by combining different arrays for comprehensive measurement.%从三电位电极系基本理论出发,对高密度电阻率法常用温纳、偶极及微分装置的分辨率、信号强度等进行了比较研究.实例分析表明,温纳装置测量获得的数据纵向分辨率较高,采集信号的强度大,信噪比高,采用该装置探测基岩面的起伏状况效果明显;偶极装置采集的数据横向分辨率较高,在探测基岩内部构造方面有较好的灵敏度,但该装置采集的信号强度小,抗干扰能力差.在实际应用时,建议运用多种装置形式进行综合测量和对比解释,以进一步提高勘探效果和精度.

  2. Application and Estimation of LS Code in Underwater Acoustic Spread-spectrum Communication%LS码在水声扩频中的应用及估计

    Institute of Scientific and Technical Information of China (English)

    张帅; 高勇

    2013-01-01

    The further application of underwater acoustic spread-spectrum communication system is limited by multipath interference, so the choice of spread spectrum sequences with better performances can im-prove the anti-jamming performances of underwater acoustic spread spectrum system. Based on discussion of LS code properties, LS codes is proposed for underwater acoustic spread-spectrum communication ,and the superiority of its application also analyzed in this paper. Simulation on rayleigh channel model of un-derwater acoustic indicates good performances of the spread-spectrum communication based on LS code. With power- spectrum processing and singular value decomposition, the spread spectrum sequence of un-derwater acoustic spread-spectrum signal based on LS code is estimated. The simulation results shows that with this method,the LS code can be estimated correctly in the condition of SNR=-11 dB.%水声多径干扰限制了水声直接扩频通信系统的进一步应用,选取性能更好的扩频序列可以提高水声扩频系统的抗干扰性能。在讨论了LS码特性的基础上,提出了将LS码应用于水声直接扩频通信中,并分析了LS码应用的优势。通过多径瑞利水声信道模型仿真,验证了LS码水声扩频通信的良好性能。利用了二次谱和奇异值分解的方法对LS码水声直扩信号的扩频序列进行了估计。仿真结果表明,该方法在信噪比为-11 dB 时还能准确的估计出LS码。

  3. 一种新型的全光固体分幅相机分幅方式的研究%Research on a Novel All-optical Solid Framing Camera Framing Mode

    Institute of Scientific and Technical Information of China (English)

    袁芬芳; 刘希顺; 陈绍荣; 梁玲亮; 高贵龙

    2015-01-01

    全光固体分幅相机技术是目前超快诊断技术领域最有前途的发展方向之一.因其在实现皮秒、亚皮秒量级时间分辨率、超高空间分辨率、拓宽探测信号波段范围、可靠性、稳定性、抗辐射抗干扰等方面拥有独特的优势,引起了人们的广泛关注.文中将波分复用以及偏振复用技术应用到全光固体分幅相机系统中,进行多分幅的方案研究,在保证皮秒量级时间分辨率的前提下,探索获得几幅到十几分幅数的分幅方案.最终,在实验上获得了空间分辨达到60 lp/mm的四分幅图像.实验结果显示,对于波分分幅的时间分辨率为1.414 ps,偏振分幅的时间分辨率为15 ps.%All-optical solid framing camera technology is one of the most promising areas with the best develop?ing future in ultrafast diagnosis technology. The technology is widely paid attention due to the unique advantages of time resolution realization at picosecond and sub-picosecond level, ultra-high spatial resolution, broadening the waveband range of detection signals, reliability, stability, anti-jamming and anti-radiation. Wavelength division mul?tiplexing and polarization multiplexing technologies are applied to the all-optical solid framing camera system to the multi-framing schemeresearch. Under ensuring picosecond level time resolution, the framing schemes of acquiring several to tens of pieces of frames are explored. Four pieces of framing images with 60 lp/mm spatial resolutions are obtained through experiments. Experimental results show that time resolution of wave division framing is 1.414 ps and time resolution of polarization framing is 15 ps.

  4. A New One-cycle Control Strategy of Capacitor Current on Grid-connected Inverter%一种并网逆变器的电容电流单周期控制技术

    Institute of Scientific and Technical Information of China (English)

    吴静; 刘晓东; 方炜; 刘宿城

    2016-01-01

    On the basis of double-loops control structure of capacitive current being inner loop and net current being outer loop, a new current control strategy is proposed combining one-cycle digital control strategy with QPR controller. One-cycle controller is applied in the system inner loop in αβ stationary reference frame, and then, the duty function of one-cycle control bipolar algorithm of capacitor current is obtained to improve the anti-jamming performance of the system and to simplify the tuning process. The quasi proportional resonant(QPR) controller of the outer loop is adopted to control the grid-connected currents directly without complicated coordinates transform. Finally, Experimental results indicate that the proposed control scheme allows three-phase gird-tied inverter to meet the grid-connected demands, and the system has a good dynamic performance.%在LCL型并网逆变器传统双环结构(电容电流内环、并网电流外环)基础上,提出一种结合数字单周期控制和准比例谐振控制的新型电流控制策略。在αβ静止坐标系下,将单周期控制应用于系统内环,推导出了电容电流单周期数字控制占空比函数,提高了系统抗干扰能力并简化调节过程;外环采用准比例谐振控制器直接控制并网电流,省去了复杂的坐标变换,计算简单。最后,实验结果表明所提出控制策略能够实现逆变器有效并网,且动态性能良好。

  5. The Design of Portable Heart Sound Gathering and Processing System%便携式心音采集与处理系统的设计

    Institute of Scientific and Technical Information of China (English)

    侯海良; 罗良才; 成运; 陈洁

    2011-01-01

    目的:在心脏辅助泵血装置的研制过程中,需要一款携带方便、抗干扰能力强的心音采集与处理系统实现对心音的准确采集,同时能够将采集到的信号进行分析.方法:本文以单片机和Visual C++6.0为基础设计了一款便携式心音采集与处理系统;该系统通过随身携带的部件采集心音信号并利用蓝牙技术无线传输到PC机,实现信号的保存和和处理.结果:该系统能实现心音信号的采集、保存、波形的实时显示、采样频率设置、心音包络提取等.结论:采用该系统采集了二尖瓣区的心音信号并提取了其包络,通过与专业设备采集的数据和处理结果对比,证明该心音采集和处理系统采集的信号准确性高、可靠性强,提取的包络效果良好.%Objective: A portable and anti-jamming heart sound acquiring system is needed to gather and process heart sound signal during the design of the Heart Assistant Pumping Blood Device. Methods: This paper introduces the design of Portable Heart Sound Gathering and Processing System using Single Chip Micyoco (SCM)and Visual C++6.0. Then, using this system acquires heart sound signal by a portable component and transmits it to PC by wireless Bluetooth, realizes saving and disposing the signal. Results: This systems realizes gathering, saving and displaying the heart sound signals on real-time, sets sampling frequency and extracts envelope of the heart sound. Conclusions: It adopts this system to gather the heart sound at the mitral valve and extracts envelop. It is demonstrated to validate the efficiency, reliability and good envelop of this proposed system through comparing to the processing outcome of professional equipment.

  6. Research on remote control of motor unit based on CAN Bus%CAN总线的电机组远程控制

    Institute of Scientific and Technical Information of China (English)

    李海凤

    2013-01-01

      Focusing on distributed motor running characteristics, this study specified testing requirements and control objectives of the remote monitoring and control system,utilized PC with CAN bus functionality to test the state of motors and control them, and designed hardware control circuit. The results show that motor status of the remote site can be displayed on the monitor by using the computer as the host machine, at the same time, forming control commands and driving alarm circuit;Signal transmission uses the CAN bus so that communication has a strong error correction and anti-jamming capacity; Guest machine uses single-chip microcomputer as site monitoring, it can flexibly control motor running;Sensors use Hall components. They can effectively send the running station of the motors to the SCM; The driver circuits of DC motors use PWM and the AC motors’ use SPWM circuits to achieve stable speed. The system has some reference value on the research of remote control.%  针对现场分布式电机的运行特征,设定远程监控系统的检测要求和控制目标,采用具有CAN总线功能的上位机对电机状态进行检测和控制,设计相应的硬件控制电路。结果表明:上位机采用计算机能将远程现场的电机状态显示在监控器上,并发出控制命令和驱动报警电路;信令传输采用CAN总线结构,使通信具有很强的纠错功能和抗干扰能力;下位机采用单片机作为现场监控,能灵活控制电机的运行状态;传感器采用霍尔元件能有效地将电机的运行情况传送给单片机;直流电机驱动采用PWM电路,交流电机驱动采用SPWM电路,能够实现对电机的稳定调速。该系统对远程控制研究具有一定的参考价值。

  7. A Square Grid Structure for Target Detection of Solar Activities%基于方形网格结构的太阳活动目标检测方法∗

    Institute of Scientific and Technical Information of China (English)

    李卫疆; 亓鑫; 王锋

    2016-01-01

    Astronomical image background is complicated and contains a lot of noise. To identify and segment astronomical activities effectively and automatically from an astronomical image is difficult and a research hot-spot. This paper proposes a target detection method for solar activity based on the structure of square grid ( GBTD) . For this method, the solar image is divided into a square grid structure with the same size. Based on multiply-thresholds selection strategy and GBTD strategy, it segments the target area and background area. The experimental results show that this method delivers satisfactory performance in accuracy and time-cost;it also produces an obvious anti-jamming performance for image noise. GBTD method provides a general image segmentation method for investigations of various types of solar images;it also provides a feasible method for solving the problem of mass astronomical data storage.%天文图像背景复杂且包含噪声,从图像中自动识别和分割出有效的天文现象是一个热点和难点。提出了一种基于方形网格结构的太阳图像的目标检测方法。此方法将太阳图像划分成等大小的方形网格结构,基于多阈值选取策略和基于方形网格结构的太阳活动目标检测方法分离目标区域和背景区域。实验结果表明,该方法在切割准确度及时间开销方面取得满意的效果,对图像噪声具有良好的抗干扰性。基于方形网格结构的太阳活动目标检测方法为多种类型的太阳活动的研究提供一种通用的图像分割方法,也为解决海量天文数据存储的问题提供了一种可行的方案。

  8. 百米距离坐标的视觉检测方法%Visual Measurement Methods on 100 Meters Distance Coordinates

    Institute of Scientific and Technical Information of China (English)

    李晓峰; 赵雨; 李为民; 金兢; 张瑜

    2011-01-01

    为了实现对大型射电天文望远镜的百米远目标进行测量,建立视觉测量系统对目标检测算法、测量系统的稳定性等进行研究.首先,CCD相机获取百米远处反射靶标的图像信息,采用样条函数对靶标图像进行插值,然后用Canny算法检测靶标图像的边缘信息;接着,采用椭圆拟合算法检测靶标的位置,从而确定靶标在CCD像面上坐标.采用一个平面标准靶,对检测算法的有效性进行评价.最后,在室外条件下,研究了白天和晚上的时候对靶标进行检测的稳定性.实验结果表明:靶标检测算法可以达到亚像素的测量精度,百米距离靶标测量的稳定性达到0.08 pixels,基本满足大型射电天文望远镜百米距离坐标测量的需要,具有较强的抗干扰能力.%In order to achieve the 100 meters far away object measurement of large radio astronomical telescope, visual measurement system has been established. The arithmetic of object detection and stability of the measurement system has been researched. First, the CCD camera obtains the image information of the reflected target 100 meters far away. The target image is interpolated by using spline function and the edge information of the target is detected with Canny algorithm. Then, the position of target is measured by adopting ellipse fitting algorithm. Consequently, the image plane coordinates of the target is acquired. The validity of the detection algorithm is appraised by adopting a plane calibration jig. Finally, in the outdoor conditions, the stability of the target measurement is researched at day and night. Experiment results show that the target detection algorithm has the measurement precision of sub-pixel and the stability precision of 100 meters distance target measurement is 0.08 pixels. It can satisfy the 100 meters distance coordinates measurement of large radio astronomical telescope and has better anti-jamming capability.

  9. 基于改进Otsu的室外道路实时检测与跟踪算法%Real-time Detection and Tracking of Road Information for Outdoor Vision-based Robot Based on Improved Otsu

    Institute of Scientific and Technical Information of China (English)

    陆培源; 王建中; 罗涛

    2011-01-01

    The detection and tracking of road infornmtion, are the basis and prerequisite of environmental exploration anti autonomous navigation ],y mobile robot. In view of the complexity of the ouldoor working environment of the robot and the variety of the outdoor illumination conditions, a suitable and novel way of real-time detection and tracking for outdoor robot is presented. First, the video images obtained from CCD camera are preprocessed. Then the Region of Interest (ROI) is extracted and transformed into the HSV color space. The edge information of the road image is obtained from the ROI by using the improved Otsu algorithm. With the anti-jamming ability of the Hough transform, the regiom where robot can pass through is shown. Finally the weighted Mahalanobis distance discrimination method is used to track the passing area. Experiment results show that this algorithm enjoys a good performance in the detection and tracking of road information in outdoor environment in real-lime.%室外道路检测与跟踪是移动机器人完成室外环境探索和自主导航的基础和前提.针对室外机器人工作环境复杂、光照多变等特点,提出了一种适用于室外道路实时检测与跟踪的算法.首先将CCD摄像头获得的画面通过预处理,提取视频画面的感兴趣区域(ROI)并转化为HSV颜色空间下的图像,然后通过改进的自适应阈值分割法(Otsu)获得道路图像的边缘信息,采用抗干扰能力较强的霍夫(Hough)变换得出画面中的可通行区域,最后采用加权马氏距离判别法跟踪可通行区域.实验表明,该算法在室外环境下具有较好的道路识别跟踪能力和实时性.

  10. 光纤网络在通讯工程技术中的应用%Application of Optical Fiber Network in Telecommunications Engineering Technology

    Institute of Scientific and Technical Information of China (English)

    王林

    2015-01-01

    光纤网络的诞生和发展是电信史上的一次重要革命,因其具有抗干扰、速率快、容量大的特点,利用光纤的信息传递优势可以最大限度的提高资源利用效率,因此光纤通信改变了传统的通信方式。随着光纤网络在通讯工程技术中的广泛应用,与之配合的网络基础技术也随之发展起来,其已经渗入到有线通信的多个领域,成为现代通信的主力军,对社会生活的影响日益深刻。展望将来的通信行业,光纤网络技术具有不可限量的潜力。因此,研究光纤网络在通讯工程技术中的应用具有十分重要的现实意义。%The birth and development of optical network is an important revolution in the history of telecommunications, because of its advantages of anti-jamming, speed and large capacity optical ifber characteristics, using the advantage of information transmission can improve efifciency and maximum utilization of resources, so the optical ifber communication has changed the traditional way of communication. With the wide application of optical ifber network in telecommunications engineering technology in the basic technology and network matching has been developed, which has penetrated into many ifelds of wire communication, become the main force of modern communication, more profound inlfuence on social life. The prospect of the communications industry in the future, optical ifber network technology has limitless potential. Therefore, has the extremely important practical signiifcance in the application research of optical ifber network communication technology in engineering.

  11. An Onset Detection Method for Action Surface EIectromyography Based on SampIe Entropy%基于样本熵的肌电信号起始点检测研究

    Institute of Scientific and Technical Information of China (English)

    成娟; 陈勋; 彭虎

    2016-01-01

    该文提出了一种基于样本熵的动作肌电信号起始点检测方法,为肌电信号应用于智能假肢控制、人机交互,以及临床疾病诊断和评估等领域提供重要前提。首先利用固定长度的滑动窗对动作肌电信号分帧,然后计算每帧信号的样本熵值,之后设定自适应阈值确定动作肌电信号的起始点。实验结果表明,样本熵能够有效表征动作肌电信号的开启模式,对较短时间的肌肉收缩松弛有很好的连续性,较之于其他常见的几类检测算法具有更好的抗噪声性能,特别是对肌肉不自主收缩产生的尖锐毛刺信号具有优异的抑制性能。%Onset detection of action surface electromyography (sEMG)signals is important since it has great impact on the accuracy of subsequent sEMG analysis such as in prosthetic control,human computer interaction and clinical diagnosis and assessment,etc.This study presents a segment onset detection method based on sample entropy.Firstly,sEMG signals are framed by a fixed-length sliding window and the sample entropy of each frame is calculated.Afterwards,adaptive thresh-old is set to determine the starting point.Experimental results demonstrate the feasibility of sample entropy to characterize the switching property of action sEMG signals.Meanwhile,compared to moving average and Teager-Kaiser energy operator,the proposed method has advantages in better anti-jamming ability,not only in suppressing short muscular contraction relaxation intervals,but also in suppressing involuntary background spikes.

  12. Study of Fuzzy Adaptive PID Control of Brushless DC Motor%无刷直流电机模糊自适应PID控制的研究

    Institute of Scientific and Technical Information of China (English)

    潘晓磊; 赵川; 吕海立

    2016-01-01

    为了提高无刷直流电机控制系统的动、静态性能,将模糊控制结合PID控制算法应用到无刷直流电机速度控制系统中。在分析了无刷直流电机速度控制系统的基础上,利用PSIM与MATLAB/Simulink共同建立了无刷直流电动机模糊自适应PID控制的仿真模型,充分发挥了PSIM和MATLAB/Simulink各自在仿真方面的优势,简化了建立仿真模型的过程。仿真结果表明,采用模糊PID集成控制算法能够使无刷直流电机速度控制系统具有更快的响应速度和更强的抗干扰能力,对无刷直流电机控制系统的设计具有一定的指导意义。%In order to improve the static and dynamic performance of brushless DC motor control system, fuzzy control combined with PID control algorithm is applied to the brushless DC motor speed control system, the integration of fuzzy PID control algorithm. On the analysis of the brushless dc motor speed control system, using the MATLAB/Simulink to establish brushless DC motor speed control system simulation model. Among them, the control system of brushless DC motor drive model and control algorithm were established in PSIM and MATLAB/Simulink environment, give full play to their advantages, the PSIM and MATLAB simplifies the process of establishing simulation model. The simulation results show that the integration of fuzzy PID control algorithm can make the brushless DC motor speed control system has better dynamic and static performance and strong anti-jamming capability, the design of brushless DC motor control system has a certain guiding significance.

  13. 带扩张观测器的新型滑模导引律%A new sliding mode guidance law based on extended state observer

    Institute of Scientific and Technical Information of China (English)

    王华吉; 简金蕾; 雷虎民; 李解; 马卫东

    2015-01-01

    在精确制导问题中,为克服目标机动和弹体动态特性对制导精度的影响,建立了平面内的弹目相对运动模型,在此基础上建立考虑导弹动态特性的制导模型;为提高末制导精度,设计了考虑导弹动态特性和目标机动的自适应滑模导引律;为了实现该导引律,利用带有滤波器的扩张观测器估计视线角速率、视线角加速度、目标机动加速度及其变化率等制导信息. 仿真结果表明,扩张观测器收敛速度快、估计精度高,且具有较强的抗干扰能力;在不同机动条件下,所设计的考虑导弹动态特性的含扩张观测器的改进滑模控制律相比于比例导引律、增广比例导引律和滑模导引律具有较好的导引性能.%To overcome the effect of target maneuvering and dynamic characteristics as guidance accuracy in guidance process, a guidance model with dynamic characteristics considered was firstly established. Based on the model, an adaptive sliding mode guidance law consideriny dynamic characteristics and target maneuvering was designed. Then, an extended observer was used to es-timate the guidance message such as the rate of line-of-sight ( LOS) , acceleration of LOS, maneuvering acceleration and accelera-tion rate of target. The result of simulation shows that the extended observer has fast speed of convergence, high accuracy of estima-tion and good ability of anti-jamming. The guidance law designed has better guidance performance than that of proportional naviga-tion guidance ( PNG) , augmented proportional navigation guidance ( APNG) and sliding mode guidance ( SMG) in different condi-tions of target maneuvering.

  14. SAVSTMV波束形成算法研究%Research on SAVSTMV beamforming algorithm

    Institute of Scientific and Technical Information of China (English)

    卢中新; 周胜增; 高源

    2014-01-01

    Conventional vector array beamforming (VCBF) is able to solve the notorious port-starboard (PS) ambiguity problem of the ordinary single linear array. But, the beamwidth of VCBF is restricted by Rayleigh limit, VCBF can not distinguish the multi-targets in the same beam. Vector array steered minimum variance (VSTMV) beamforming is a wideband adaptive beamforming method with high-resolution and anti-jamming capability. However, the VSTMV beamforming implemented in the element-domain causes heavy computational load and low robustness, so it is not suitable for real-time implementation and application in sonar engineering. In this paper, an algorithm of VSTMV beamforming implemented in the sub-array domain (called SAVSTMV beamforming) is proposed, with which the computational load can be reduced and the robustness improved. The better performance of SAVSTMV beamforming over VCBF is proved through theoretical analysis and simulation calculation, which makes the proposed algorithm suitable for practical applications.%矢量阵常规波束形成(Vector array Conventional BeamForming, VCBF)能够消除普通单线阵左右舷模糊现象,但VCBF波束宽度受到“瑞利限”的限制,不能分辨同一波束内的多个目标。矢量阵导向最小方差(Vector array STeered Minimum Variance, VSTMV)波束形成算法是一种宽带自适应波束形成算法,具有高分辨力和抗干扰性能。VSTMV波束形成直接在阵元域进行,计算量较大且稳健性差,不利于实时实现和应用。提出一种分子阵 VSTMV 波束形成算法(Sub-Array Vector array Steered Minimum Variance, SAVSTMV),可有效降低计算量,算法稳健性更强。通过理论研究和仿真计算,证明该算法比矢量阵常规波束形成算法具有更好的性能,有利于实际应用。

  15. A Study on the Integrated Electronic Control System of G asoline Engine%汽油机集中式电子控制系统的研究

    Institute of Scientific and Technical Information of China (English)

    段晖辉; 姜卓; 卓斌

    2001-01-01

    介绍了基于上海大众 M3.8.2系统研制出的新型汽油机集中式电子控制系统。该电子控制系统通过运用80C196单 片机和可编程系统器件PSD402A1实现了对汽油机的多点燃油顺序喷射控制、无分电盘电子点 火控制、怠速转速控制及空燃比闭环控制。试验结果表明,该电控系统不仅在硬件接口上与 原系统完全兼容,而且通过现场可编程系统器件的运用使得系统具有体积更小、可靠性和抗 干扰能力更强的特点。通过在上海大众AJR发动机上的标定试验表明,应用了本电控系统的 汽油机,其动力性、经济性和排放指标基本达到了原系统的水平。%This paper introduced a new integrated electroinic control system of gasolin e engine based on Shanghai Volkswagen (SVW) M3.8.2 control system.With the appli cation of a new electronic control unit (ECU) based on Intel's 80C196 microcont roller & WSI Co.'s field programmable system device PSD402A1,multi-ports sequen tial fuel injection (SFI) system,distributorless electronic ignition system,idle speed control system and A/F close-loop control system were developed.The expe riments show that the new system is not only compatible with M3.8.2 system,but a lso is smaller and has better anti-jamming ability with the help of field progr ammable system device.Through the calibration experiment on SVW 2VQS AJR gasolin e engine,the results show that under the control of the new Control System,the G asoline Engine's power performance,fuel economy and exhaust emissions recover to the former.This paper will discuss the control principle & strategy of every su b-control system and the experiment result with also be illustrated.

  16. 周期性冲击对大型超导核聚变低温系统氦透平膨胀机影响研究%Study of periodicity impact of helium turbine of superconducting Tokamak device

    Institute of Scientific and Technical Information of China (English)

    付豹; 张启勇; 庄明; 朱平; 成安义

    2013-01-01

    超导核聚变装置磁体会因“交流损耗”而产生大量的热,迫使磁体内通道压力升高,导致与之直接相连的氦透平膨胀机的运行稳定性与运行效率受到严重影响,从而影响超导核聚变实验.详细分析超导核聚变装置用低温氦透平膨胀机受周期性冲击的机理与不可回避性,并用提高氦透平膨胀机本身性能、改善制动调节与氦透平膨胀机出口压力调节的反馈控制思想,得出一些提高氦透平膨胀机稳定性、降低冲击的方法.高效气体轴承与优化的转子结构可以有效提高氦透平膨胀机本身的抗干扰能力;快速响应制动功率,使之与负载匹配,可有效改善外界干扰程度;氦透平膨胀机出口压力快速调节,可降低氦透平膨胀机进出口参数,降低影响.%At the end of the experiment of the superconducting Tokamak the oils could produce lots of heat,because of the AC loss,this can induce the pressure of the coil channels raise up for the liquid helium vaporized.The isentropic fficiency and running stability of the helium turbine are severity effected,which directly supplys the liuqid helium to the coils of the superconducting Tokamak.The reasons of the periodicity impact on helium turbines were analysed,the improvement of gas bearing of helium turbine,the improvement of the braking of the helium turbine and the feed back control thought was used to increase the staility of the turbine and decrease the influence of the periodicty impact.The high efficiency gas bearing and the optimized structure of rotors can improve the anti-jamming ability of the helium turbine itself.The braking power being rapidly responded,matched with the load of the turbine can efficiently reduce the external disturbance.Moreover,the fast adjustment for the outlet pressure of the helium turbine can also decrease its inlet and outlet parameters and the impacts.

  17. 无线电/激光高度表复合测高技术研究%Research into Composite Altimetry Technology Based on Radio/Laser Altimeter

    Institute of Scientific and Technical Information of China (English)

    毕开波; 姚申茂; 谢春思

    2016-01-01

    无线电高度表和激光高度表是巡航导弹上用于探测地形高度的2种主要传感器,激光高度表具有探测精度高、抗电磁干扰能力强的优点;而无线电高度表不受天气和环境的影响,可全天候使用。因而,将无线电高度表与激光高度表进行复合探测,有利于提高地形探测精度,并增强系统抗干扰能力。在高度表测量方程的基础上,基于卡尔曼滤波公式和简单融合算法,给出了无线电/激光多传感器的滤波及融合模型;并利用M atlab对多传感器融合效果进行了仿真。仿真结果表明:基于多传感器融合的高度测量系统的精度比单个传感器的测量精度要高,且系统的稳定性和可靠性更强,所设计的基于无线电/激光高度表多传感器数据融合的高度测量算法是有效的。%Radio altimeter and laser altimeter are two main sensors which is applied to detect terrain altitude of the cruise missiles .Laser altimeter has high detection precision ,strong anti-electromag-netism-jamming ability .However radio altimeter can work under the condition of all-weather , which is immune for weather and environment .Detection system combining radio altimeter with la-ser altimeter can improve terrain detection precision and anti-jamming ability .On the basis of altim-eter measuring equation ,this paper presents radio/laser multi-sensor filtering model and fusion model based on Kalman filtering formula and simple fusion arithmetic ;simulates the fusion effect of multi-sensor by means of Matlab .The simulation results show that the altimetry system based on multi-sensor fusion has higher detection precision than single sensor ,and has good stability and re-liability ,the multi-sensor data fusion altimetry arithmetic based on radio altimeter/laser is effec-tive .

  18. 宽带电力线载波点对点通信性能测试平台设计%Design of point to point communication performance testing platform for broadband power line carrier

    Institute of Scientific and Technical Information of China (English)

    邹航; 何威; 陈瑜; 刘斌; 赵俊红; 张欢欢

    2016-01-01

    In order to test the performances of working frequency , signal power spectral density , anti-jamming capa-bility, noise immunity and anti-impedance changes for low voltage broadband power line carrier communication unit under the requirements of Q/GDW 1379.4-2013 technical specification and offer data reference , scheme basis to grid company to construct remote metering system for broadband power line carrier , a point to point communication per-formance testing platform is formed according to the characteristics of broadband power-line carrier .Three level cas-cade power filter with double SMA terminals are adopted which can insulate the influence on the communication per -formance for broadband carrier communication unit caused by harmonic , pulse signal and power-line background noise .As a consequence , the testing platform mentioned above can fully simulate the low voltage power line channel , restitute the operational state of site metering pilot and assess the actual usage of carrier communication unit .Experi-mental data certifies that the experiment environment of the testing platform constructed is pure , which can attenuate signal within the bandwidth of 2MHz~30MHz up to 93dB so as to ensure that the tested performance data of broad-band carrier communication unit is stable and reliable .%在Q/GDW 1379.4-2013通信单元检验技术规范的要求下,为测试低压宽带电力线载波通信单元的工作频段、载波信号发射功率谱密度、抗衰减能力、抗噪声干扰和抗阻抗变化等基本通信性能,给电网公司建设宽带电力载波远程集抄系统提供数据参考和方案依据。根据宽带电力线载波技术的特点搭建了点对点通信性能测试平台。该平台采用三级级联双SMA电源滤波组合,可有效隔离电网谐波、脉冲信号及电力线背景噪声对宽带载波通信单元性能的影响,使测试平台能够充分模拟低压电力线通道,还原现场集抄台区的

  19. THREE-DIMENSIONAL GLOBAL POSITIONING FOR UNDERGROUND PERSONNEL BASED ON MIMU/Wi-Fi%基于MIMU/WI-FI的井下人员三维全局定位

    Institute of Scientific and Technical Information of China (English)

    罗宇锋; 刘勇; 王红旗; 李芳; 刘志凤

    2015-01-01

    In order to further improve the positioning accuracy of coal mine personnel positioning system and overcome its current disadvantages of only for regional positioning and weak anti-jamming capability,we propose a novel MIMU/Wi-Fi combination-based three-dimensional global positioning system for underground personnel in coal mine.On the basis of analysing the positioning principle of MIMU and Wi-Fi their own,we present the system solution graph which is based on MIMU/Wi-Fi integrated positioning.By analysing the error source of MIMU and Wi-Fi respectively,we build the error model of combination system,and then further use the indirect application of Kalman filtering as well as exert the location combination means to obtain the positioning information of combination system.Finally,we simulate the error model of combination positioning.Simulation results show that the combination positioning method based on MIMU/Wi-Fi has the advantages of high positioning accuracy,strong real-time property,high reliability,and being capable of three-dimensional global positioning. It provides a better way for improving the management level of coal mine safety production,so has higher value in engineering application.%为进一步提高煤矿井下人员定位系统的定位精度,克服目前只能区域定位,抗干扰能力差等缺点,提出一种新型的基于MIMU/WI-FI组合的煤矿井下人员三维全局定位方法。在对MIMU和WI-FI各自定位原理分析的基础上,给出基于MIMU/WI-FI组合定位的系统解算图。通过对MIMU和WI-FI各自的误差源分析,建立组合系统误差模型,进而采用间接法卡尔曼滤波并运用位置组合方式获得组合系统的定位信息。最后,对组合定位误差模型进行仿真。仿真结果表明,基于MIMU/WI-FI的组合定位方法具有定位精度高,实时性强,可靠性好,能够进行三维全局定位等优点,为提高煤矿安全生产管理水平提供了一种更

  20. Algorithm Design of Trust Aware Recommender Based on Network Dynamic Interference Monitoring%网络动态干扰监控的信任感知推荐算法设计

    Institute of Scientific and Technical Information of China (English)

    张远红; 苗放

    2014-01-01

    The accuracy design of network user trust aware recommender is key to improve social network auxiliary informa-tion between the user trust degree. The network user perceived trust traditional recommendation algorithm is used in the recommendation system, social network services and user ratings based on subjectivity, collaborative filtering effect is not good. A new method of algorithm design of recommendation trust is propsoed based on aware network dynamic interference monitoring and adaptive neural fuzzy dynamic interference, the design of monitoring system network construction algorithm, vector space model of trust evaluation index system based on trust, set the periodic response variable weighted adaptive function to adjust the network topology by weight, reduce the iterative algorithm cost, it avoids the adaptive neural fuzzy net-work dynamic interference monitoring weight into curing condition, the anti jamming capability is improved. The experi-mental results show that it can reduce the prediction error, and make social network aware recommendation model is superi-or to the traditional method, the recommended reliability is better.%网络用户信任感知推荐的准确性设计是提高用户间的社交网络辅助信息信任度的重要依据。传统的网络用户信任感知推荐算法采用的是基于社交网络服务和用户评分的推荐系统,主观性较大,协同过滤效果不好。提出一种基于网络动态干扰监控的信任感知推荐算法设计新方法,设计自适应神经模糊系统网络动态干扰监测算法,构建基于向量空间模型的信任度评价指标体系结构,通过调整网络拓扑权重向量设置信任度周期响应加权变量自适应函数,有效降低迭代算法的运算成本,避免了自适应神经模糊系统网络动态干扰监测加权权重成固化状态,提高抗干扰性能。实验结果表明,算法能使社交网络感知推荐模型的预测误差减少,推

  1. Research on Channel Estimation of Filter Bank UMTS System%滤波器组UMTS系统的信道估计研究

    Institute of Scientific and Technical Information of China (English)

    何信旺; 芮赟; 王宗杰; 宋荣方

    2015-01-01

    3G UMTS system,compared with 4G LTE system,has the main disadvantage of the presence in the bandwidth and data rates, but better than the latter in the voice services and system coverage. In order to maintain the continued competitiveness of the evolution of UMTS systems,3GPP-LTE International Standardization Organization recently launches the S-UMTS research projects for 2G spectrum scattered over the age of migration. In the spectrum polymerization conditions,the wireless communication system using multiple access technology must be flexible to allocate resources to support non-contiguous occupied spectrum,and also maintain a good anti-jamming capability. The use of filtered multitone ( FMT) modulation to achieve polymeric transmission for narrow band UMTS signal becomes one of candidates in 3GPP. In the proposed CDMA-FMT system,the channel estimation scheme in the traditional WCDMA system can’ t be applied directly. Therefore,according to the transmission characteristics of the UMTS system and FMT system,propose a channel es-timation of narrow band CDMA multicarrier system based on the transmission of filter bank. Theoretical analysis and simulation results show it has a low computational complexity of the program and a good channel estimation performance.%3G的UMTS系统相比4G LTE系统,主要在系统带宽和数据速率上存在劣势,而在语音业务和系统覆盖上优于后者。为了保持UMTS演进系统的持续竞争力,3GPP-LTE国际标准化组织针对2G时代迁移过来的零散频谱,近期启动了S-UMTS的研究项目。在频谱聚合条件下,无线通信系统采用的多址技术必须能灵活支持非连续占用的频谱资源分配,同时保持较好的抗干扰能力。而采用滤波多音调制技术(FMT)实现窄带UMTS信号的聚合传输成为3GPP中的候选方案之一。在所提出CDMA-FMT系统中,传统WCDMA系统中的信道估计方案无法直接适用。因此,文中根据UMTS系统和FMT系统各自的传输

  2. 基于KVM虚拟桌面的透明消息通道设计%Design of Transparent Message Channel Based on KVM Virtual Desktop

    Institute of Scientific and Technical Information of China (English)

    崔竞松; 何松; 郭迟; 贺汇林

    2014-01-01

    Cloud management platform and end-users of virtual machine generally use proxy software or plug-ins to communicate with each other,but the convenience and anti-jamming capabilities of this method is poor. Aiming at this problem ,this paper proposes a design scheme for transparent message channel between the node provided by cloud service ( the physical host that virtual machine lies in) and the end-user of virtual machine based on virtual desktop on Kernel-based Virtual Machine( KVM) . It builds message control terminal in cloud management platform to receive and process messages that service node sends to end-users of virtual machine, and transforms the messages into images, reads the content of images into specified file in the form of bitmap pixel data as the source of message sending module. It adds message sending module and feedback receiving module into source codes by modifying the source code of Virtual Network Computing ( VNC ) server-side integrated by Qemu-KVM of KVM virtualization platform, integrates the messages into desktop image of the virtual machine,and processes the feedback from the remote terminal of VCN client. Then it builds a two-way interactive message channel between the cloud platform and the end-users which is transparent for virtual machine itself. Experimental result verifies that this scheme is feasible.%云管理平台和虚拟机终端用户间的通信一般采用代理软件或插件,便捷性和抗干扰能力较低。针对该问题,利用基于内核的虚拟机( KVM)虚拟桌面,提出一种云服务提供节点(虚拟机所在物理主机)和虚拟机终端用户之间双向交互的透明消息通道设计方案。在云管理平台中建立消息控制端,用于接收和处理服务节点发往虚拟机终端用户的消息,并将消息转换为图像,使图像内容以位图像素数据格式的方式读出到特定文件中,作为消息发送模块的消息来源。通过修改KVM虚

  3. GPS M码信号压制干扰样式效能分析%Effectiveness Analysis of the Blanket Jamming Mode to GPS M Code Signal

    Institute of Scientific and Technical Information of China (English)

    毛虎; 吴德伟; 卢虎; 白盟亮

    2015-01-01

    Aiming at the feature and superiority on anti-jamming of global position system (GPS) M code signal, in order to find an effective jamming mode for M code signal, the jamming efficiency of three types of typical blanket jamming, single frequency, band-limited Gaussian noise, and pseudo code with the same rate, are analyzed. In the analysis, the power spectral density change of GPS receiver cross-correlation filtering output is taken as the qualitative evaluation bases;the code tracking error and the ephemeris bit error rate (BER) are taken as the quantitative evaluation indexes. The influence process of jamming to evaluation factor and the oneness of each evaluation factor are derived theoretically by modeling M code signal receiving system. The simulation results show that single frequency jamming exhibits the best jamming effect while band-limited Gaussian noise jamming is the worst, the second comes pseudo code with the same rate jamming when the influence of sub-carrier modulation was eliminated. Considering the complexity of smart jamming implementation, it is suggested to choose the pseudo code with the same rate as M code signal jamming since single frequency jamming needs strict frequency setting and it is easily eliminated by frequency domain filtering.%针对GPS M码信号的特点和在抗干扰方面的优越性,为实现对其有效干扰,以接收机相关滤波输出功率谱变化情况作为定性评估依据,以码跟踪误差和星历误码率作为定量评估指标,对单频、带限高斯噪声和同速率伪码3种典型压制干扰样式的干扰效能进行分析。通过建立M码信号的接收系统模型,从理论上推导了干扰对各具体评估要素的影响过程以及各要素之间的统一性。仿真结果表明,单频干扰效果最好,消除副载波调制影响的同速率伪码干扰次之,带限高斯噪声干扰效果较差。考虑到单频干扰对干扰频偏设置的较高要求以及容易被接收

  4. Measurement Method for Leakage Current of Insulator String Applying LED Optical Fiber Sensor%采用LED光纤传感器的绝缘子串泄漏电流测量方法

    Institute of Scientific and Technical Information of China (English)

    姚陈果; 王建; 冉启华; 李成祥; 米彦

    2012-01-01

    Measuring the leakage current of insulator strings is currently one of the principal means to monitor the contamination level of transmission lines insulator surface;however,due to the complex environment of transmission lines,a large amount of electromagnetic interference will produce much noise at the time of collecting leakage current.Therefore,in order to improve the anti-jamming and accuracy when sensors were used to measure insulator leakage current,an optical fiber sensor was employed to measure leakage current of the insulator strings,in which light emitting diode(LED) was used to detect the current signal as the photoelectric conversion and light signal stability.Taking three-piece XP-160 insulator strings as examples when ρESDD was 0.05~0.2 mg/cm2 and humidity was 85%,we increased the voltage gradually to obtain the leakage current.Results reveal that the optical fiber sensor can achieve selective measurement of leakage current,the positive half cycle or negative half cycle,and the full cycle current can be monitored after differential circuit is improved.Its zero-extinct period is less than 1 ms and response time is limited in 0.1 ms,and its sensitivity reaches 40 V/A.The pertinence coefficients of linear fitting are all higher than 99.94%,and its frequency response is 1~10 kHz,which can meet the basic requirements of the leakage current measurement.%测量绝缘子串的泄漏电流是目前监测输电线路绝缘子串表面污秽状态的主要手段之一,然而由于输电线路环境的复杂性,常常会伴生出大量的电磁干扰,会在泄漏电流的采集源头产生噪声从而导致采集失真。为提高传感器测量绝缘子泄漏电流的抗干扰能力和准确度,采用廉价稳定的光学器件—发光二极管(light emitting diode,LED)设计并制作了1套光纤传感器装置,利用光电转换和光信号的稳定性,以3片XP-160绝缘子串为试验对象,取盐密为0.05~0.2mg/cm2,

  5. Design of TFT-LCD panels optical detection auto-focus system%TFT-LCD面板光学检测自动对焦系统设计

    Institute of Scientific and Technical Information of China (English)

    肖磊; 程良伦; 范富明

    2011-01-01

    -focusing was introduced. Experimental results indicate that with less than the 100 μm of auto-focusing and the 5 times objective lens the auto-focusing time is 0.36 s, the repetitive positioning accuracy is ±1.98 fun. Under the conditions of 50 times objective lens, the auto-focusing time is 0.41 s, the repetitive positioning accuracy is ±0.26 μm. It can satisfy the system requirements of non-contact, online, real time, higher precision and rapid speed, as well as strong anti-jamming and stabilization.

  6. Simulation of improved active jam method against laser imaging guidance%改进的激光成像制导有源干扰仿真研究

    Institute of Scientific and Technical Information of China (English)

    王昊鹏; 刘泽乾

    2012-01-01

    At present, the laser imaging guidance as a new type of precision way, on the battlefield is playing the more and more major role. Its good detection performance, strong anti-jamming ability, and can work day and night, etc, make its development space more and more wide, threat on military targets are getting more and more serious. However, in view of the laser imaging guidance of interference methods is not ideal but the results, the specific performance: way passive, low success, interference effect is not obvious and so on. Therefore, it is necessary to improve the existing interference measures of laser imaging guidance of interference ability. For laser imaging guidance system of the input signal is active laser interference technology is put forward new way of interference in recent years. In this paper the research foundation, on the optical simulation, especially laser optical simulation for a more in-depth research, and puts forward an improved active laser jamming methods: use the intercept enemy laser detection signal related information, copy the laser signals as interference signals, laser imaging guidance system on enemy for interference, cover important military targets, with lower cost and advantages of active way, so as to improve the laser imaging guidance to the input signal interference ability.%目前,激光成像制导作为一种新型的精确制导方式,在战场上发挥着越来越大的作用。然而,针对激光成像制导的干扰方法效果却并不理想,具体表现为:方式被动、成功率低、干扰效果不明显等。针对激光成像制导系统输入信号的激光有源干扰技术是近几年提出的新型干扰方式。在其研究基础上,对光学仿真,特别是激光光学仿真进行了较为深入的研究,并提出了一种改进的激光有源干扰方式:利用截获的敌方激光探测信号相关信息,复制其激光信号作为干扰信号,对敌方激光成像制导系统进

  7. Soil Fanua' s Distribution and Ecological Functions of Rocky Desertification Management Areas%喀斯特石漠化治理区土壤动物的时空格局与生态功能研究

    Institute of Scientific and Technical Information of China (English)

    熊康宁; 陈浒; 王仙攀; 樊云龙; 赵志成

    2012-01-01

    为了研究石漠化治理区土壤动物的动态变化.对毕节鸭池、清镇红枫湖和贞丰-关岭花江石漠化区的土壤动物的空间格局进行了调查,并对土壤动物在石漠化生态环境恢复中的功能研究作了总结.结果发现:喀斯特石漠化治理区以杂食性和植食性功能类群为主,捕食性和腐蚀性功能类群分布较小.随着纬度的增加,Shannon-wiener多样性指数和Margulef数有增加趋势,而Pielou指数和Simpon指数不存在这种趋势;随着石漠化程度的加深,物种数和个体数有减少趋势;随着土层的加深,各研究区的土壤动物的物种和个体数有减少趋势,土壤动物表聚现象显著.受气候干旱的严重影响,土壤动物的年度变化波动较大.蜱螨目和弹尾目的抗干扰性、抗旱性较强,在凋落物的分解中充当重要的角色,因此,可把这两类物种作为改良土壤的主要动物.%In order to study the dynamic change of soil animal in desertification control rock.The writer has surveyed the rocky desertification area' s soil fauna' s distribution of Yachi of Bijie, Hongfeng Lake of Qingzhen and Huanjiang Area of Zhenfeng-Guanling, and function study of soil animals on the ecological environment restoration in rocky desertification were summarized. The results found that the main functional groups of soil fauna were omnivorous and phytogyagous in the three rocky desertification areas. And predatory and corrosive functional groups were limited. As the latitude increase, the Shannon-wiener diversity index and Margulef index increase as well. But the Pielou and Simpon indexes did not have this response; the numbers of species and individual decrease as the deepen of rocky desertification degree or soil depth. Soil fanua' s surface aggregation phenomenon was obvious; Been effected by severe drought, the quantity of soil fanua changed a lot annually; With strong anti-jamming ability and drought resistance, Acarina and Collembola

  8. Thrustor Control of Autonomous Underwater Vehichle Based on Artificial Immune Feedback%基于人工免疫反馈的自治水下机器人推力器控制

    Institute of Scientific and Technical Information of China (English)

    吴乃龙; 刘贵杰; 李思乐; 徐萌

    2011-01-01

    The thruster is the crucial factor of an underwater vehicle system, because its thrust modeling and control is the core of underwater vehicle control and simulation. With a view to the drawbacks of thrust real-time response and anti-jamming capability of simplified thruster control model of Autonomous underwater vehicle, an artificial immune feedback based thrust control method of thruster is presented. This method has a good real-time performance and robustness without the difficulty of carrying out hydro-dynamic experiment and theory calculation. It can provide methods for motion control, state response and control exploitation of AUV. Aimed at a streamlined AUV prototype named Cranger-2, the immune feedback mechanism is used to control the thrust of thrusters based on the analysis of the simplified thrust model by the creation of thrust real-time debugging system. Then the thrust output response curve is obtained according to different thrust input and interference signals through simulation analysis of thrust control. By the control and verification test of brushless DC motor, the result demonstrates that the method can control the thruster's thrust effectively and can provide a reference for engineering practice.%推力器是水下机器人系统的关键要素,其推力建模和控制是进行水下机器人控制和仿真的核心.针对简化的自治水下机器人(Autonomous underwater vehicle,AUV)推力器控制系统的推力响应实时性不高和抗干扰能力不强的缺点,提出一种基于人工免疫反馈的AUV推力控制方法,该方法不受推力器水动力试验和理论计算的困难性的缺点影响,具有较好的实时性和鲁棒性,可为AUV运动控制、状态响应、控制系统开发等提供控制方法.针对流线型AUV原型样机CRanger-2,在简化推力模型的分析基础上,利用该控制策略,建立推力实时调试系统,在不同大小推力和不同干扰情况下进行推力控制仿真分析,得到推力

  9. 变参数反冲洗控制程序的研发%Research and Developmentof Variable Parameter Backwashing Control Program

    Institute of Scientific and Technical Information of China (English)

    刘喜文

    2011-01-01

    根据开发部关于核桃壳过滤器反冲洗参数调整规定,针对目前的问题,自主研发反冲洗PLC控制程序.由目前的单一强度改为参数可调的变强度反洗模式,根据优化后反洗效果的化验数据对比,确定反洗强度和时间等设定参数.在控制方面,重点开发了下位机(PLC)的控制程序,运用PID闭环控制算法,以流量为控制对象,变频输出控制反洗排量,达到设定强度的反洗.着重解决了上位机与下位机的通信问题,以及如何进行误差修正、数据交换和报警联锁保护等问题.系统投入使用后,结果表明:控制精度高,抗干扰能力强,反洗强度、时间等参数根据实际情况任意可调;自主研发,提高了自动化水平,摆脱对厂家的依赖;为其他水质站的参数优化工作提供了技术支持.%According to the adjustment regulation of walnut Glter reverse wash parameters by development department,to solve the problem of the single backwashing mode and the parameters can not be adjustable, this paper researched on the control program of backwashing PLC. It changed the single intensity into changes in intensity can be adjusted parameters backwash mode. According to the effect of washing after optimization laboratory data contrast,it set down the backwashing intensity and time set parameters, etc. In the control aspect,the key research was the control program of PLC. It used PID closed-loop control algorithm,took flow as the object of control,backwash frequency output control emissions,to set the intensity of the backwash. The paper mainly solved the problems of the PC and the next crew communication issues, and error correction, data exchange and alarm interlock protection. The system advantage is high control accuracy,strong anti-jamming capability,and the strength,the parameters such as washing time is adjustable according to the actual situation. And it is an independent research, increasing the automation level, getting

  10. 高速动车组速度传感器的电磁干扰测试与分析%Electromagnetic interference measurement and analysis of high-speed electric multiple units speed sensor

    Institute of Scientific and Technical Information of China (English)

    严加斌; 朱峰; 李军; 沙淼; 袁德强

    2015-01-01

    Combining with field measurement, the electromagnetic interference issues of CRH380BL speed sensor is studied.Firstly we analyze Hall switch sensor has good anti-jamming capability itself, and point out that car body overvoltage produced by the arc discharge during the bow down will interfere with it .Then the electric dipole theory is used to analyze the characteristics of the electromagnetic field excited during the bow down .From the point that the tangential component of magnetic field is not continuous in the surface of the medium , the reason of car body over-voltage generate is analyzed.From the perspective of the sensor transmission cable shield grounding method , the coupling mechanism of car body over-voltage interference with sensor is also analyzed.The results show that the maximum value of magnetic field is 54.07 dBμA/m and its frequency is mainly distributed around 5 MHz, the over-voltage of No.2 car body is more than 600V.Car body harassment voltage will couple to core wire by the para-sitic capacitance between cable shield and core wire , then coursing interference to speed signal transmitted in the core wire.Through adding protective grounding on No.1 car, the electromagnetic interference of speed sensor from arc discharge effectively is reduced .%结合现场实测,对CRH380BL型动车组速度传感器的电磁干扰问题进行了研究。首先分析了开关型霍尔传感器自身具有良好的抗干扰能力,指出当降弓时产生的电弧放电在车体上产生过电压时将会对其产生干扰。然后采用电偶极子理论分析了降弓时激发的电磁场的特性,从磁场在介质表面切向分量不连续的角度分析了车体过电压产生的原因,最后从传感器传输电缆屏蔽层接地方式的角度分析了车体过电压对传感器的干扰耦合机理。结果表明:降弓时产生的磁场强度最大值为54.07 dBμA/m,且频率主要分布在5 MHz附近,2号车厢车体过电压达600

  11. 一步合成硫、氮共掺杂的碳量子点及其在Fe3+检测中的应用%One-step Synthesis of Sulfur-and Nitrogen-co-doped Carbon Quantum Dots for Fe(Ⅲ) Detection

    Institute of Scientific and Technical Information of China (English)

    张文宇; 常青; 周雨锋; 魏志佳; 李凯凯; 胡胜亮

    2016-01-01

    碳量子点的光致发光性质不仅决定于尺寸还依赖于它的表面态,因此通过在碳量子点表面掺杂或嫁接不同元素与基团有望调节它的荧光发射行为。为了研究多种元素掺杂对碳量子点发光性质的影响,本文以对氨基苯磺酸为原料,通过水热法一步合成了氮、硫共掺杂的碳量子点。实验结果表明:制备的碳量子点尺寸分布均匀,氮、硫分别以氨基和磺酸基团的形式存在于碳量子点的表面。与已有的报道不同,碳量子点展现出了非激发波长依赖的蓝光发射行为,三价铁离子可有效猝灭其荧光,铁离子浓度在0~10-3 mol·L-1范围内与碳量子点的荧光猝灭程度呈现良好的线性关系,检出限约为10-7 mol·L-1。制备的碳量子点对三价铁离子具有高选择性、高灵敏性以及较好的抗干扰能力,能作为三价铁离子检测的传感器。%Not only do the photoluminescence ( PL) properties of carbon quantum dots ( CQDs) de-pend on their sizes, but also rely on their surface states. Accordingly, the PL behaviors of CQDs could be tuned by doping and/or grafting heteroatoms and groups. In this work, sulfur-and nitrogen-co-doped carbon quantum dots ( SN-CQDs) were firstly synthesized by one-step hydrothermal meth-od using p-aminobenzenesulfonicacid as carbon source. Experimental results indicate that the ob-tained SN-CQDs have a uniform size and are modified by amine and sulphonic acid groups at their surface. Unlike previous reports, the SN-CQDs show the excitation-wavelength-independent photolu-minescence behavior and their fluorescence can be quenched by Fe3+ ions. There is a good linear relationship between the Fe3+ concentrations within 0-10 -3 mol·L-1 and the fluorescence quench-ing rates of SN-CQDs. The detecting limit for Fe3+ ions is about 10 -7 mol·L-1 . The obtained SN-CQDs have the ability of high selectivity, high sensitivity and good anti-jamming capability to ferric

  12. Design of the Logging While Drilling Caliper Tool Based on Ultrasonic Distance Measurement%基于超声测距的随钻井径测量系统设计

    Institute of Scientific and Technical Information of China (English)

    倪卫宁; 李三国; 李继博; 张卫; 李胜

    2013-01-01

    Caliper measurement by using the traditional wireline multi -finger caliper tools is very difficult under the condition of while drilling. The Logging While Drilling (LWD) caliper tool based on ultrasonic distance measurement possesses the advantages of non-contact, high speed, easy process, and strong anti-jamming. By using three ultrasonic transducers which are equidistantly mounted on the surface, the caliper and the eccentricity are effectively measured. The modular design is utilized for the entire system with the MCU as the core, by drawing lessons from the domestic and international research results of the LWD caliper tool based on ultrasonic distance measurement. In order to design a high precise and eccentricity correcting caliper measurement system, the characteristics of ultrasonic transducer, hardware circuit, and program control are together considered and the collaborative design is used. According to the result of calculation and the parameter characteristics of the real ultrasonic transducers, 1MHz ultrasonic transducers are chosen. Since the variable gain detection circuit and the several gain calibrations are utilized, the first echo signal frontier is captured by the comparator, and the time precision of ultrasonic flight is improved to one period of the ultrasonic transducer oscillation. Finally the measurement precision is effectively improved and the measurement deviation is reached at lmm.%传统电缆测并的机械多臂并径仪在高速旋转的随钻条件下难以完成测量,而基于超声测距的随钻井径测量系统,具有利用超声测距的非接触、速度快、信息处理简单、抗干扰能力强等优点,通过采用3个换能器等角距圆周分布,在存在“偏心”时可有效测量井径以及井筒轴心到仪器轴心的距离矢量.本文借鉴国内外现有超声波随钻井径测量系统及技术经验,设计了以单片机为核心的模块化超声随钻井径测量系统.从超声换能器特性、

  13. Realization of high-speed real-time optical fiber image transmission system%高速实时光纤图像传输系统的实现

    Institute of Scientific and Technical Information of China (English)

    孙科林; 周维超; 吴钦章

    2011-01-01

    To improve the performance of image transmission systems on optical electronic theodolites, the Rocket 10 IP core based on a Field Programming Gate Array(FPGA) is designed to accomplish the interfaces conversion between parallel camera link and serial optical module. It uses a custom image transmission protocol to build a platform to interconnects the image transmission system with various subsystems. Using this optical fiber transmission channel,the system realizes high-speed real-time image transmmision down to a machine for processing, displaying and recording. It can also compound and transmit commands and synchronization timing up to the camera. This paper describes the system architecture, the software and hardware design for the sender, and receiver, and the key technologies for the system, and introduces attributes of Rocket 10, transceiver state machines for data-packetsand the image transmission protocol. The experimental results indicate that the system will operate at a rate up 2. 5 Gb/s, the transmission link is stable, reliable with no error codes. As the protocol is open-source, users can use the serial data directly. This design breaks through the limitations of traditional optical fiber transmission protocol, and reduces the amount of wiring. The advantages of this system is high bandwidth, high quality images and high anti-jamming level. After a validation test, the system has been applied to various projects.%为提高光电经纬仪上图像传输系统的性能,设计了利用现场可编程门阵列(FPGA)的Rocket IO IP核,完成了Camera link并行接口与光模块串行接口的相互转换.通过自定义的图像传输协议,搭建了图像传输系统与各个分系统的互联平台,实现了高速图像实时传输至机下进行处理、显示和记录,同时在该光纤通道上复合传输相机控制命令和外同步时序.阐述了系统总体结构思想,发送端和接收端的软、硬件设计,介绍了Rocket IO关键属性

  14. A New Multi-Frequency Random Phase Code Radar Signal Designing Method%多载频类随机相位编码雷达信号设计与特性分析

    Institute of Scientific and Technical Information of China (English)

    黄琼丹; 李勇; 付银娟

    2013-01-01

    We propose what we believe to be a new multi-frequency random phase code ( MRPC) radar signal de-signing method .Its core consists of:( 1) we use the chaotic biphased code based on the improved Logistic mapping and the piecewise Logistic mapping to modulate the phase of the multi-carrier phase code ( MCPC) radar signal;(2) we introduce the quasi-random properties of a chaotic signal into the MCPC radar signal and design the MRPC radar signal, whose ambiguity function , interception factor and peak-to-mean envelope power ratio ( PMEPR) is then analyzed;(3) to select the initial value of the chaotic sequence of the MRPC radar signal , the number of its frequency carriers and the number of its phase-modulated bits, we present their influence on the PMEPR .The sim-ulation results, given in Figs.2 through 6, and their analysis show preliminarily that:(1) the new MRPC radar sig-nal we thus designed keeps the strong points of the MCPC radar signal , has the thumbtack function of the quasi-noise radar signal and the excellent anti-jamming and LPI performances;( 2) the piecewise Logistic MRPC radar signal has a better performance of these kinds than the improved one .%基于OFDM技术的多频多相编码(multifrequency complementary phase coded ,简称MCPC)宽带雷达信号具有控制简单、生成便利和良好的频谱利用率等优点,己成为雷达信号研究领域的重要发展方向和研究热点。用基于改进型Logistic及分段Logistic映射的混沌二相码调制MCPC信号各载频的相位,把混沌信号类随机的性质引入到 MCP C 信号中,设计出多载频类随机相位编码(multifrequency random-like phase coded,简称MRPC)雷达信号,并对MRPC信号的模糊函数、截获因子、峰均包络功率比( PMEPR)等进行了分析。给出了混沌序列的初值、MRPC信号的载频数及码元个数对P MEP R的影响关系,以便于选择合适的初值、载频数和码元数。仿真结果表明,设

  15. Numerical simulation of seawater temperature rising and the ecological evaluation of the effect of thermal discharged from a power plant in Zhanjiang Bay%电厂温排水对湛江湾海水温升的数值模拟及生态影响评价

    Institute of Scientific and Technical Information of China (English)

    陈春亮; 梁春林; 卢仕严; 李斌

    2012-01-01

    为了清晰了解温排水入海后的时空输移路径和温升范围,及其对海洋环境的影响,以湛江湾内的某电厂为例,应用ECOMSED海洋模式计算其温排水的时空输移路径及温升范围,并结合野外生态调查结果评价其对湛江湾内海洋生态环境的影响.结果表明:某电厂温排水导致湛江湾水体温升大于4℃、2℃、1℃的面积分别为0.110、0.480、1.629 km2,相对于约190 km2的湛江湾海域,影响面积很小;夏季浮游植物丰度随温度升高的变化率分别为-8.534%、-3.573%、-1.613%,浮游动物丰度随温度升高的变化率分别为- 4.964%、-1.896%、-0.802%,温排水对浮游动、植物的影响夏季较冬季显著.某电厂温排水对湛江湾内海洋生态环境的影响即使在高温季节也不明显.%To deeply understand the thermal transfer route, the region of temperature rising and the environmental influence of thermal discharged into the sea, a numerical simulation with ECOMSED mode applied was carried out to find out the space-time distribution and temperature rise region of thermal discharged from a power plant in Zhanjiang Bay. Meanwhile, an ecological evaluation of the effect of the thermal on the marine environment in Zhanjiang Bay was carried out, based on the results of field sampling. The results of field sampling showed that plankton has a great variety of species in the sea area under research and the species of phytoplankton and zooplankton were 307 and 223 respectively. As for phytoplankton, the Bacilla-riophyceae including 54 genera, accounted for 66% , secondly the Pyrrophyta including 21 genera, occupied 25% ; the numbers of species was highest in spring, and then was in summer, and the dominance was not evident annually. The community structure of phytoplankton was stable and complex, and has a relatively high anti-jamming capability. As for the 223 species of zooplankton, the species of copepod were highest, then was the

  16. 3D numerical simulation of the flow field with push-pull hoods containing barriers between them%罩间存在障碍物的吹吸罩流场三维数值模拟

    Institute of Scientific and Technical Information of China (English)

    胡鸿; 易灿南; 廖可兵

    2013-01-01

    为了使吹吸罩达到对污染物的最佳控制,以某企业电镀生产线上行车行进过程中由于镀件表面黏附高浓度槽液而造成室内环境污染为实物模型,建立吹吸罩口间存在障碍物的三维数学模型,利用Fluent计算动力学软件对不同吹风口风速和吸风口风速下的排风罩流场进行数值模拟,经比较确定最佳联合速度,并将模拟结果与经典吹吸速度分布图及试验条件下所测得的污染气体质量分数进行对比分析.结果表明,所建立数学模型是合理的,所确定的最佳效果时的相关参数与经典理论基本一致,可用于工程实际.%This paper attempts to proposo a 3D numerical simulation model of the flow field with push-pull hoods containing barriers between them in hoping to solve the problem of the dispersion of contaminants.As is known,the dispersion of contaminants in different sections of an apparatus can be controlled effectively via a pull-push hood powered by a jet flow.Actually,such device has already been widely used in places where contaminants are serious but can not be eliminated.The said push-pullhoods are usually armed with the following features:minute air volume,perfect pollution control,powerful anti-jam behavior,free from the impact of the process operations.Although no barriers were considered in the former design between the push hood and pull hood in the regular production process according to the processing demands,we still feel it necessary to stress the demand for them,for it is necessary to choose the best velocity of push hood and pull hood to control the containments.Based on the above starting point,we have chosen the computational fluid dynamics (CFD) model to solve the problem.First of all,we have taken the contaminants accumulated in the painted work-pieces with very harmful content adhered in them as a physical model,while assuming that geometrical models are set by the GAMBIT code.Along with it,let the appropriate