Mechanically Versatile Soft Machines through Laminar Jamming

There are two major structural paradigms in robotics: soft machines, which are conformable, durable, and safe; and traditional rigid robots, which are fast, precise, and capable of applying high forces. Here, the paradigms are bridged by enabling soft machines to behave like traditional rigid robots on command. This task is accomplished via laminar jamming, a structural phenomenon in which a laminate of compliant strips becomes strongly coupled through friction when a pressure gradient is applied, causing dramatic changes in mechanical properties. Rigorous analytical and finite element models of laminar jamming are developed, and jamming structures are experimentally characterized to show that the models are highly accurate. Then jamming structures are integrated into soft machines to enable them to selectively exhibit the stiffness, damping, and kinematics of traditional rigid robots. The models allow jamming structures to efficiently meet arbitrary performance specifications, and the physical demonstrations illustrate how to construct systems that can behave like either soft machines or traditional rigid robots at will, such as continuum manipulators that can rapidly have joints appear and disappear. This study aims to foster a new generation of mechanically versatile machines and structures that cannot simply be classified as “soft” or “rigid.”     

水面舰艇光电干扰系统建模与仿真

介绍了基于HLA平台的水面舰艇光电干扰仿真系统的组成、主要模型及工作流程,对其中的反舰导弹运动模型和红外场景三维模型进行了详细描述,并对仿真结果进行了分析。文中建立的仿真系统可用于舰艇光电干扰演练和性能评估。     

基于干扰方的干扰效果评估研究

针对目前研究干扰效果评估大都将被干扰方作为评估对象的现状,研究了被干扰方作为研究对象时存在的局限,提出基于干扰方的干扰效果评估的必要性、判定标准和具体方法。将干扰支援或保护目标受雷达方威胁等级的下降程度作为评估干扰效果的依据。研究结果对于干扰资源分配、实时监控干扰有效性具有较大的军事应用价值.     

距离指标对雷达噪声干扰效能的影响

在海上编队作战中,噪声干扰是对敌方舰载远程搜索警戒雷达进行压制的一种有效干扰手段。为了能够快速简便地对雷达干扰效能做出评估,在对雷达检测概率特性分析的基础上,通过雷达干扰的空间能量方程导出在噪声干扰条件下雷达发现概率与距离之间的关系式。将雷达发现概率的下降程度作为干扰效能的评估因子,通过MATLAB仿真对干扰效能进行定量分析,得出在某一作战态势下的最小干扰距离以及雷达最大作用距离,结果明确合理。     

基于LXI的干扰控制及信号产生设备自动测试系统设计

干扰控制及信号产生设备指标类型多样,当前的测试方式流程繁杂,人工工作量大。干扰控制及信号产生设备的自动测试系统提供了高精度的测试环境,简化了测试流程,提高了测试可靠性与效率。介绍了基于LXI的干扰控制及信号产生设备自动测试系统的实施方案。     

干扰走廊的功能与雷达体制无关

提出的新概念是干扰走廊的作用机理与雷达体制无关,干扰走廊提供掩护,它对被掩护目标是更广义上的隐身,它的主要特征是对电磁波进行衰减．叙述了飞机投放走廊的主要问题,重新提出对干扰走廊的技术要求,并分述其原理。     

对二次雷达敌我识别系统的高重频询问干扰研究

文章介绍了二次雷达IFF系统的工作原理,分析了IFF系统单站、多站工作的目标识别概率。针对IFF系统工作机理中存在的不足,建立了高重频询问干扰模型,从IFF系统的识别概率的角度,论证了高重频询问干扰能提高二次雷达IFF系统的应答占据概率,因而降低IFF系统的识别概率,从而达到干扰IFF系统的目的。     

对自适应旁瓣对消系统的闪烁干扰方案研究

现代雷达普遍采用旁瓣对消技术抗有源干扰,该技术大大降低了从雷达天线旁瓣进入的干扰信号功率,使得从雷达天线旁瓣进入的有害干扰信号不至于严重妨碍雷达工作。文中分析了雷达开环自适应旁瓣对消系统的工作原理,提出了采用对开环自适应旁瓣对消系统进行闪烁干扰的理论依据及实施方法,并对闪烁干扰的干扰效果进行仿真分析,结果证实了闪烁干扰的可行性,为干扰自适应旁瓣对消系统提出了可行的干扰方案。     

外辐射源的无源定位系统干扰压制区分析

基于外辐射源的无源定位系统是以电视或调频广播的发射机作为其辐射源的，具有反侦察、抗干扰、反隐身、抗反辐射导弹的潜在优势，有良好的发展前景。文中首先通过对基于外辐射源的无源定位系统的原理分析，指出基于外辐射源的单站无源定位系统实际相当收发分置的双基地雷达，并得出其作用距离程，然后对理想条件下的干扰有效区进行了分析，得出压制区边界方程，最后对计算机仿真计算结果进行分析总结。     

GPS电子干扰范围及效果分析

介绍了GPS导航系统的基本原理及其干扰和反干扰措施。以INS/GPS组合导航为例,研究了干扰距离对其干扰效果的影响。分析了影响干扰距离的因素并研究了各因素对干扰距离影响的大小,指出有效干扰范围不仅受干扰功率的影响,还受到干扰机和接收机天线方向增益的影响及地表曲率决定的视在距离的限制。讨论了如何对未来具有强抗干扰能力GPS接收机进行有效干扰的干扰机配置方案。     

地空导弹系统受噪声干扰时雷达参数测量影响分析

现代战争中导弹和导弹系统在战场中都将受到各种电子干扰 ,导弹系统中的雷达在受噪声等干扰后 ,可能导致各种参数测量误差的增大、发现概率的降低等。研究地空导弹系统中的雷达在受噪声干扰情况下 ,其发现概率、测角精度、测距精度等所受的影响     

噪声干扰对雷达检测概率的影响

通过对雷达检测概率特性的分析，得出噪声干扰对雷达检测概率的影响，并导出在自卫干扰条件下雷达与目标之间距离和雷达发现概率的关系。     

干扰节点个数对系统性能的影响研究

在无线电干扰的实施过程中,干扰信号的功率对干扰效果的影响至关重要。在信号电平一定的情况下,干扰是否奏效主要取决于接收机输入端干扰信号功率的大小,干扰功率越大,系统干扰效果越好。而要研制高功率的干扰机成本很高,在实际的通信干扰中很难实现。基于此,提出了通过增加干扰节点个数来降低干扰功率的方法,并通过仿真验证了该方案的可行性。     

DS-FH混合扩频系统抗多址干扰能力分析

通过对DS及DS-FH两种通信体制抗干扰能力的比较分析,研究DS—FH混合扩频通信系统的抗干扰能力,特别分析了DS-FH系统良好的抗多址干扰能力。结果表明,DS-FH混合系统集中了DS及FH系统的优点,抗干扰性能明显增强。     

干扰条件下T/R-R 型双基地系统的航迹起始

干扰条件下双基地T站可观测信息具有不稳定性,传统基于有源定位跟踪系统的航迹起始算法将不再适用于T/RR型双基地系统。为提高恶劣环境下的跟踪性能,文中提出了一种干扰条件下双基地系统航迹起始算法。该方法在传统逻辑方法基础上,利用R站观测信息起始目标航迹。针对双基地系统定位精度随目标空间位置变化较大的特点,设计了能够自适应调整的初始波门,保证了系统能以较高概率起始目标航迹;同时改进了点迹与可能航迹的互联规则,大大降低了系统的虚警概率。仿真结果验证了文中方法的有效性。     

时延伪GPS卫星干扰的定位控制原理分析

对全球定位系统GPS的干扰在电子对抗领域具有十分重要的地位。文章从GPS定位原理出发，从理论上说明了GPS定位系统与四星时差无源定位系统的一致性，通过时差定位方程论述了时延伪GPS卫星干扰的定位控制原理，分析了伪卫星数目所带来的定位误差的变化，并通过仿真验证了该原理的正确性与有效性，这对于该干扰样式的工程实现具有一定的指导意义。     

激光制导武器角度欺骗干扰半实物仿真系统设计的探讨

激光制导武器角度欺骗干扰半实物仿真系统是检验激光角度欺骗干扰设备干扰效果的重要手段.详细分析了该系统的结构组成、实现原理和设计过程中的一些关键问题,给出了半实物仿真系统的完整模型,建立了内外场等效弹目视线计算模型和二维转镜控制角度求解模型.对系统在工程实现中的关键技术进行了阐述,为如何开展激光制导武器角度欺骗干扰半实物仿真试验提供有效支持.     

一种新的部分频带噪声干扰模型下的FH/MFSK系统性能分析

部分频带噪声干扰(PBNJ)是一种主要的窄带干扰,它对通信系统性能的影响十分突出。该文针对FH/ MFSK系统中,传统的部分频带干扰模型的干扰带宽最小分辨率是一个跳频子带带宽(即MFSK信号的带宽),研究了更具有实际价值的新的部分频带干扰模型,即将干扰带宽最小分辨率精确到MFSK信号带宽的1/M。该文推导了莱斯衰落信道下的误比特率(BER)公式,给出了其闭合表达式,并通过计算机仿真验证了理论推导的正确性。理论分析与仿真结果表明,M,Nh,越小,传统与新PBNJ模型下FH/MFSK信号的BER性能差异就越大。     

Comparison of Downlink Power Allocation Mechanisms in Soft Handoff for the WCDMA System with Heterogeneous Cell Structures

Handoff in heterogeneous cellular networks is one of the hot topics for wireless networks beyond the third generation. We observe that a power exhausting issue may occur in a code division multiple access (CDMA) system with mixed-sized cells. During soft handoff in the downlink transmission, a number of base stations transmit signals to a user simultaneously. Usually, a microcell has a more stringent limitation on the total available power than a macrocell. Thus, ignoring the impact of various cell sizes, the traditional downlink power allocation techniques for soft handoff may easily consume excessive power to serve soft handoff users, while leaving insufficient power for serving other regular users.To resolve such an power exhausting issue in CDMA systems, we investigate different downlink power allocation techniques used in soft handoff subject to the impact of mixed-sized cells. For the single-site power allocation technique we consider the site selection diversity transmission (SSDT) technique, while for the multi-site power allocation we study the link proportional power allocation (LPPA), the quality balancing power allocation (QBPA), and the equal power allocation (EPA) techniques. We find that the multi-site LPPA technique can more efficiently allocate power to both handoff and non-handoff users than others. In an example with the ratio of the micrcocell radius/macrocell radius equal to 1/3, it is demonstrated that LPPA can improve the capacity over EPA, QBPA, and SSDT by 125, 30, and 5%, respectively. By taking account of measurement errors in the same case, the capacity improvements of LPPA over EPA, QBPA, and SSDT become 180, 41, and 23%, respectively.This work was supported jointly by the Lee and MTI Center for networking research, and the National Science Council, Taiwan under the contracts 90-2213-E-009-068 91-2219-E-009-016, and EX-91-E-FA06-4-4. Part of results in this paper were presented at the IEEE Globecom, Nov. 2002, and the Sixth ACM International Workshop on Modelling, Analysis and Simulation of Wireless and Mobile Systems, (MSWiM’03), Sep. 2003.Ching-Yu Liao received the B.S. and M.S. degrees in electrical engineering from Huafan Institute of Technology and National Central University (NCU), Taiwan, in 1995 and 1997, respectively. She is currently working toward the Ph.D degree in communication engineering at National Chiao Tung University (NCTU), Hsinchu, Taiwan. Also, she joins the program of Graduate Student Study Abroad (GSSA), which is sponsored by National Science Council, Taiwan, R.O.C., being a visiting graduate student in Dept. of Electrical Engineering at University of British Columbia, Vancouver, Canada, in 2004. Her research interests include handoff techniques, radio resource management, heterogeneous cellular networks, etc.Li-Chun Wang received the B.S. degree from National Chiao Tung University, Taiwan, in 1986, the M.S. degree from National Taiwan University in 1988, and the Ms. Sci. and Ph. D. degrees in electrical engineering from the Georgia Institute of Technology, Atlanta, in 1995, and 1996, respectively. From 1990 to 1992, he was with the Telecommunications Laboratories of the Ministry of Transportations and Communications in Taiwan (currently the Telecom Labs of Chunghwa Telecom Co.). In 1995, he was affiliated with Bell Northern Research of Northern Telecom, Inc., Richardson, TX. From 1996 to 2000, he was with AT&T Laboratories, New Jersey, USA, where he was a Senior Technical Staff Member in the Wireless Communications Research Department. Since August 2000, he has been an Associate Professor in the Department of Communication Engineering of National Chiao Tung University in Taiwan. His current research interests are in the areas of cellular architectures, radio network resource management, and cross-layer optimization for high speed wireless networks. Dr. Wang was a co-recipient of the Jack Neubauer Memorial Award in 1997 recognizing the best systems paper published in the IEEE Transactions on Vehicular Technology. He is holding three US patents and one more pending. Currently, he is the associate editor of the IEEE Transactions on Wireless Communications.Chung-Ju Chang was born in Taiwan, R.O.C., in August 1950. He received the B.E. and M.E. degrees in electronics engineering from National Chiao Tung University (NCTU), Hsinchu, Taiwan, in 1972 and 1976, respectively, and the Ph.D degree in electrical engineering from National Taiwan University (NTU), Taiwan, in 1985. From 1976 to 1988, he was with Telecommunication Laboratories, Directorate General of Telecommunications, Ministry of Communications, Taiwan, as a Design Engineer, Supervisor, Project Manager, and then Division Director. There, he was involved in designing digital switching system, RAX trunk tester, ISDN user-network interface, and ISDN service and technology trials in Science-Based Industrial Park. In the meantime, he also acted as a Science and Technical Advisor for the Minister of the Ministry of Communications from 1987 to 1989. In 1988, he joined the Faculty of the Department of Communication Engineering and Center for Telecommunications Research, College of Electrical Engineering and Computer Science, National Chiao Tung University, as an Associate Professor. He has been a Professor since 1993. He was Director of the Institute of Communication Engineering from August 1993 to July 1995 and Chairman of Department of Communication Engineering from August 1999 to July 2001. Now, he is the Dean of the Research and Development Office in NCTU. He was an Advisor for the Ministry of Education to promote the education of communication science and technologies for colleges and universities in Taiwan since 1995. He is also acting as a Committee Member of the Telecommunication Deliberate Body. His research interests include performance evaluation, wireless communication networks, and broadband networks. Dr. Chang is a member of the Chinese Institute of Engineers (CIE).E-mail:cjchang@cc.nctu.edu.tw     

大角度离子注入机控制系统软件设计

介绍了大角度离子注入机控制系统软件的设计和实现,重点介绍了控制系统的总体设计和系统软件的结构设计、软件的具体实施和系统软件主要模块的功能.