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1.
强跟踪滤波器在AUV执行机构故障诊断中的应用   总被引:1,自引:0,他引:1  
刘向明  边信黔  施小成 《应用科技》2004,31(11):32-34,38
建立了AUV的推力器及舵等执行机构的偏差型故障模型;引入强跟踪滤波器理论,采用SFEKF算法(一种采用时变渐消因子实现的强跟踪滤波器算法)在线估计AUV状态及执行机构故障偏差,利用贝叶斯决策方法对得到的残差进行分析,实现了AUV执行机构的故障诊断;仿真验证了强跟踪滤波器在AUV执行机构故障诊断中的有效性.  相似文献   

2.
肖文英 《科技资讯》2012,(15):112-113,115
从分析无源电力滤波器和有源电力滤波器各自滤波的特点入手,提出了一种将无源电力滤波器与有源电力滤波器相结合的混合型电力滤波器,通过对电路的分析和实验,验证了本新型混合电力滤波器用于电铁谐波治理的显著效果。  相似文献   

3.
传统CIC滤波器用作抽取和内插抗混叠滤波器时其通带偏差和混叠镜像衰减通常不能满足软件无线电系统的要求,为此提出了一种用内插二阶多项式级联锐化CIC滤波器的改进方法,它能同时使通带和阻带的性能得以提高.数值仿真结果表明,所提出的这种新型抽插抗混叠CIC滤波器能够有效补偿通带的偏差,同时又能增加旁瓣部分的衰减,更适合应用于对宽带信号处理的软件无线电数字上下变频器中.  相似文献   

4.
基于LMS自适应滤波器对噪声干扰的语音恢复研究   总被引:2,自引:0,他引:2  
从自适应滤波器的基本原理出发,利用自适应滤波器对白噪声干扰下的语音信号进行恢复处理,研究自适应算法不同步长对处理结果的影响.理论分析及实验结果表明,在合适的步长下,采用Least Mean Squarc(LMS)算法自适应滤波器,从被噪声干扰的语音信号中恢复实际信号,其偏差在工程上可以接受,而且算法实现简单,具有较好的消噪效果.  相似文献   

5.
一种新的高阶全极点TC带通滤波器   总被引:1,自引:0,他引:1  
提出五种高阶全极点跨导电容带通滤波器设计方法。该滤波器与MOS工艺兼容,便于单片集成。文中给出了带通滤波器的设计实例和PSPICE模拟分析,说明此滤波器可行。  相似文献   

6.
提出一种基于局部统计特性的新的滤波算法,可用于去除图像中混合噪音(高斯噪音和一致脉冲噪音),称之为线性局部混合噪音滤波器(简记为LLMF).该滤波器有机地结合了局部滤波算法和线性滤波算法,它采用局部邻域偏差判断像素的相似性,从而提高了对高斯成分的去噪能力.对纯高斯、纯脉冲以及它们的混合噪音都有较好的去噪效果.从实验结果可见,使用LLMF滤波器,图像的视觉效果、峰值信噪比、均方误差均优于同类混合滤波器.  相似文献   

7.
介绍交通视频检测的基本过程,分析了交通视频图像的特征,研究了三种形态滤波器——中值滤波器、普通形态滤波器、顺序滤波器对交通视频图像的处理能力.顺序滤波器的使用依赖于二值图像中噪声与目标的分布参数P.提出了选择交通视频图像分布参数P和滤波窗大小的基本方法.实验证明,选用合适参数P的顺序滤波器能够大大减少计算量,快速地处理交通视频的二值图像,基本满足在各种气象条件下的实时采集交通数据的要求。  相似文献   

8.
详细分析了高通滤波器与带通滤波器的冲击响应函数和幅频响应函数之间的关系,提出了一种新的带通滤波器的设计方法,利用带通滤波器的冲击响应(或幅频响应)等于两个不同截止频率的高通滤波器的冲击响应(或幅频响应)之差设计带通滤波器,并给出了仿真结果。与传统的设计方法相比,该方法设计简单、运算量少、灵活性强,为带通滤波器的设计提供了一种新思路。  相似文献   

9.
介绍了一种基于并联枝节线单元的超宽带滤波器.该滤波器由3种基本元件组成:短路枝节线、开路枝节线和连接线.其中,每个短路枝节线和开路枝节线组成一个枝节线对,在枝节线对间利用连接线实现强电磁耦合.在设计中,这3种基本元件的电长度是相同的.通过合理选择各元件的特征阻抗,就能实现带宽在100%左右的超宽带滤波器.此外,该超宽带滤波器还具有较宽的高端阻带.文中首先基于理想传输线模型对该滤波器进行了仿真研究;然后在全波仿真的基础上,利用微带线实现了一个三阶的超宽带滤波器;最后利用平面印制板技术对滤波器进行了实物加工.测试和仿真结果吻合良好.实验结果表明,该滤波器的中心频率为1.775 GHz,相对带宽为97.5%.通带内匹配优于-15 dB,最小插入损耗为0.25 dB(在1.3 GHz处).第一个寄生通带的频率高于6 GHz,是通带中心频率的3.4倍左右.  相似文献   

10.
联邦滤波器的最优性   总被引:6,自引:1,他引:6  
Carlson应用方差上界技术和信息分配原理论证了当主滤波器和局部滤波器的维数都相同时联邦滤波器的全局最优性,并且信息分配系数选定后是不变的。为了实现当主滤波器维数大于局部滤波器维数时的全局滤波和局部滤波的最优性,该文提出了一种解析补偿和动态最优信息分配系数确定的方法。结果表明:解析补偿方法附加计算量小,同时可作为一种性能指标用于软故障检测;信息分配系数确定的新方法由于实现了联邦滤波器局部滤波的最优性,从而提高了软故障检测灵敏度。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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