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801.
802.
基于DSP的全数字闭环光纤陀螺 总被引:14,自引:2,他引:12
张春熹 《北京航空航天大学学报》1998,24(6):695-698
介绍了一种采用DSP(Digital Signal Processor)技术实现的全数字闭环光纤陀螺.该闭环光纤陀螺采用以多功能集成光学器件为核心的全保偏结构,以方波为偏置调制,数字阶梯波反馈.文中对该闭环光纤陀螺的前置放大、信号检测、数字解调、数字滤波等部分进行了设计和实现,对采用DSP技术解决系统精度和实时性矛盾的方案进行了讨论,并对闭环光纤陀螺的性能和参数进行了理论分析和实验测试.测试结果表明系统达到了小于0.3/h的零漂和100×10-6的非线性度指标. 相似文献
803.
With the increase of complexity of electromagnetic environment and continuous appearance of advanced system radars, signals received by radar reconnaissance receivers become even more intensive and complex. There- fore, traditional radar sorting methods based on neural network algorithms and support vector machine (SVM) cannot process them effectively. Aiming at solving this problem, a novel radar signal sorting method based on the cloud model theory and the geometric covering algorithm is proposed. By applying the geometric covering algo- rithm to divide input signals into different covering domains based on their distribution characteristics, the method can overcome a typical problem that it is easy for traditional sorting algorithms to fall into the local extrema due to the use of complex nonlinear equation to describe input signals. The method uses the cloud model to describe the membership degree between signals to be sorted and their covering domains, thus it avoids the disadvantage that traditional sorting methods based on hard clustering cannot deinterleave the signal samples with overlapped param- eters. Experimental results show that the presented method can effectively sort advanced system radar signals with overlapped parameters in complex electromagnetic environment. 相似文献
804.
For maritime radiation source target tracking in particular electronic counter measures(ECM)environment,there exists two main problems which can deteriorate the tracking performance of traditional approaches.The frst problem is the poor observability of the radiation source.The second one is the measurement uncertainty which includes the uncertainty of the target appearing/disappearing and the detection uncertainty(false and missed detections).A novel approach is proposed in this paper for tracking maritime radiation source in the presence of measurement uncertainty.To solve the poor observability of maritime radiation source target,using the radiation source motion restriction,the observer altitude information is incorporated into the bearings-only tracking(BOT)method to obtain the unique target localization.Then the two uncertainties in the ECM environment are modeled by the random fnite set(RFS)theory and the Bernoulli fltering method with the observer altitude is adopted to solve the tracking problem of maritime radiation source in such context.Simulation experiments verify the validity of the proposed approach for tracking maritime radiation source,and also demonstrate the superiority of the method compared with the traditional integrated probabilistic data association(IPDA)method.The tracking performance under different conditions,particularly those involving different duration of radiation source opening and switching-off,indicates that the method to solve our problem is robust and effective. 相似文献
805.
V.M.Vasyliūnas 《空间科学学报》2010,30(4)
Magnetospheric global modeling is a method to link observations from distant regions via physical laws and has long played a unique and crucial role in space physics. It, different from computer simulations, represents the highest level of abstraction of the physical understanding of the processes that cause observed phenomena. It results in various specific models. While it appears in the form of cartoons, it is based on and has to be qualitatively consistent with physical laws. With the advancement of computer simulations, clues to the connection between physical laws and observation can be perceived much more easily than as ever before. However, computer simulation results are highly dependent on the used boundary conditions and numerical methods which may or may not represent the reality, even if the initial conditions are properly set. Therefore, simulations can easily mislead the investigations. Furthermore, a simulation result needs to be examined using diagnostic tools, such as field line tracing and streamline tracing programs. There are uncertainties in these diagnostic methods. The errors can be very large in certain areas under certain conditions. For example, a small error may link two different field lines or stream lines. The interpretations of the simulation results can be misled by these errors. The knowledge of global modeling can be useful in identifying the inconsistencies in the simulations and the flaws in the theoretical interpretation from the simulations. This review-tutorial article outlines the principles of the global modeling and discusses the successes and flaws of several global models. 相似文献
806.
数控加工在当今的冷加工中应用越来越多,其切削用量与普通机床有很大不同。本文对数控加工中切削用量的确定做了简要的分析,提供了一些选取原则和方法,并对应该注意的问题进行了分析,以供数控操作人员参考。 相似文献
807.
808.
介绍了“大工程观”教育理念的实质及特点,结合中国民航大学与华北空管局实施管制学员雷达管制实践能力联合培养的教学试点改革案例,指出应积极推进雷达管制实践教学模式改革,以应对行业快速发展对空管人才综合素质的更高要求. 相似文献
809.
为更好地发挥军事需求的牵引作用,将武器装备符合性质量观念提升到适用性质量观念,提高通用弹药质量水平,科学地评价通用弹药质量非常重要.分析了外军武器装备需求实现和现代质量观念,提出了面向需求的武器装备质量评价理念,论述了面向需求的武器装备质量评价的作用,研究并建立了面向需求的武器装备质量评价模型,评价模型贯彻了需求牵引的思想.通过对通用弹药的特点和基本需求分析,建立了科学的、系统的通用弹药质量评价指标体系. 相似文献
810.
文章以武器装备体系(Weapon System-of-Systems,WSoS)发展论证需求为牵引,结合现代战争复杂电磁环境下武器装备体系特点,综合考虑武器装备体系效能评估方法,采用我国原创的可拓学理论,从定性与定量两个角度对武器装备体系效能进行评估,结合层次分析法、Delphi法,建立武器装备体系效能评估模型,利用Matlab进行实例仿真实验,表明该方法能够根据隶属等级对武器装备体系效能进行评估,并可分析得出二级指标的弱项,对各指标的优化具有指导作用。 相似文献