Approach of simultaneous localization and mapping based on local maps for robot

An extended Kalman filter approach of simultaneous localization and mapping（SLAM） was proposed based on local maps A local frame of reference was established periodically at the position of the robot, and then the observations of the robot and landmarks were fused into the global frame of reference. Because of the independence of the local map, the approach does not cumulate the estimate and calculation errors which are produced by SLAM using Kalman filter directly. At the same time, it reduces the computational complexity. This method is proven correct and feasible in simulation experiments.     

Adaptive de-noising method based on wavelet and adaptive learning algorithm in on-line PD monitoring

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System failure analysis based on DEMATEL–ISM and FMECA

A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory（DEMATEL） method was used to calculate the degree of correlation between the failure subsystems, analyze the combined effect of related failures, and obtain the degree of correlation by using the directed graph and matrix operations. Then, the interpretative structural modeling（ISM） method was combined to intuitively show the logical relationship of many failure subsystems and their influences on each other by using multilevel hierarchical structure model and obtaining the critical subsystems. Finally, failure mode effects and criticality analysis（FMECA） was used to perform a qualitative hazard analysis of critical subsystems, determine the critical failure mode, and clarify the direction of reliability improvement.Through an example, the result demonstrates that the proposed method can be efficiently applied to system failure analysis problems.     

基于数据挖掘的入侵检测系统研究

提出了一种基于数据挖掘技术的入侵检测系统模型,该模型是一个核模型,具有很好的扩展能力和适应能力.结合异常检测和误用检测方法,提出了一种改进型的基于数据挖掘的入侵检测系统.论述了数据挖掘技术在入侵检测系统中的应用,讨论了数据预处理和特征提取问题.     

Deforming analysis of sheet metal based on stereo vision and coordinate grid

A new approach based on stereo vision technology is introduced to analyze sheet metal deformation. By measuring the deformed circle grids that are printed on the sheet surface before forming, the strain distribution of the workpiece is obtained. The measurement and analysis results can be used to verify numerical simulation results and guide production. To get good accuracy,some new techniques are employed: camera calibration based on genetic algorithm, feature abstraction based on self-adaptive technology, image matching based on structure feature and camera modeling pre-constrains, and parameter calculation based on curve and surface optimization. The experimental values show that the approach proposed is rational and practical, which can provide better measurement accuracy with less time than the conventional method.     

Identification and analysis based on genetic algorithm for proton exchange membrane fuel cell stack

The temperature of proton exchange membrane fuel cell stack and the stoichiometric oxygen in cathode have relationship with the performance and life span of fuel cells closely. The thermal coefficients were taken as important factors affecting the temperature distribution of fuel cells and components. According to the experimental analysis, when the stoichiometric oxygen in cathode is greater than or equal to 1.8, the stack voltage loss is the least. A novel genetic algorithm was developed to identify and optimize the variables in dynamic thermal model of proton exchange membrane fuel cell stack, making the outputs of temperature model approximate to the actual temperature, and ensuring that the maximal error is less than 1℃. At the same time, the optimum region of stoichiometric oxygen is obtained, which is in the range of 1.8 -2.2 and accords with the experimental analysis results. The simulation and experimental results show the effectiveness of the proposed algorithm.     

Dynamic analysis and modal test of long-span cable-stayed bridge based on ambient excitation

To study the stiffness distribution of girder and the method to identify modal parameters of cable-stayed bridge, a simplified dynamical finite element method model named three beams model was established for the girder with double ribs. Based on the simplified model four stiffness formulae were deduced according to Hamilton principle. These formulae reflect well the contribution of the flexural, shearing, free torsion and restricted torsion deformation, respectively. An identification method about modal parameters was put forward by combining method of peak value and power spectral density according to modal test under ambient excitation. The dynamic finite element method analysis and modal test were carried out in a long-span concrete cable-stayed bridge. The results show that the errors of frequencies between theoretical analysis and test results are less than 10% mostly, and the most important modal parameters for cable-stayed bridge are determined to be the longitudinal floating mode, the first vertical flexural mode and the first torsional mode, which demonstrate that the method of stiffness distribution for three beams model is accurate and method to identify modal parameters is effective under ambient excitation modal test.     

Relationship between texture and residual macro-strain in CVD diamond films based on phenomenological analysis

The relationship between texture and elastic properties of chemical vapor deposition （CVD） diamond films was analyzed based on the phenomenological theory, which reveals the influence of crystalline orientation and texture on the residual macro-strain and macro-stress. The phenomenological calculations indicated that the difference in Young＇s modulus could be 15% in single diamond crystals and 5% in diamond films with homogeneously distributed strong fiber texture. The experimentally measured residual strains of free-standing CVD diamond films were in good agreement with the correspondingly calculated Young＇s modulus in connection with the multi-fiber textures in the films, though the difference in Young＇s modulus induced by texture was only around 1%. It is believed that texture should be one of the important factors influencing the residual stress and strain of CVD diamond films.     

Multistatic radar analysis based on ambiguity function and Cramér-Rao lower bounds

The primary goal of this work is to characterize the impact of weighting selection strategy and multistatic geometry on the multistatic radar performance. With the relationship between the multistatic ambiguity function （AF） and the multistatie Cram6r-Rao lower bound （CRLB）, the problem of calculating the multistatic AF and the multistatic CRLB as a performance metric for multistatic radar system is studied. Exactly, based on the proper selection of the system parameters, the multistatic radar performance can be significantly improved. The simulation results illustrate that the multistatic AF and the multistatic CRLB can serve as guidelines for future multistatic fusion rule development and multistatic radars deployment.     

Exploring harmonious development between urbanization and eco-environment based on climate analysis—A study in Changsha,China

The process of urbanization affects the urban warming. The change of urban warming was investigated by several urbanization factors in Changsha, China. The data of surface temperature (minimum, maximum and mean) of Changsha were analyzed to understand the possible effects of urbanization on the climate of this region owing to the population growth, built-up area expansion and energy consumption increases. The weights of these three factors were calculated by the analytical hierarchy process (AHP). Then, three weights were simulated with nonlinear method to obtain the urbanization development rate which was utilized to reveal the influence of the urbanization factors on the surface temperature. The result shows that there is a significant upward trend in the urban temperatures of Changsha. The temperature increase seems to be closely related to the rate of urbanization between 1993 and 2008, and there is an evidential increase trend of the influence on urban temperature by urbanization during 16 years. It is a quantifiable approach measuring the relationship between urbanization and urban eco-environment, and can be applied for the urban sustainability.     

基于小波分析的大坝变形观测数据的趋势分量提取

利用多分辨分析,提出了大坝变形观测数据趋势分量提取的小波分析方法,给出了该方法的计算思路,并通过工程实例验证了该方法的有效性.经实例验证表明,趋势分量可用于判断大坝变形是否趋于稳定,其作用与时效分量相同,趋势分量比时效分量更能反映大坝的工作性态.     

地质雷达信号分析的双正交小波预测反褶积法

为了降低电磁波衰减、噪声干扰等因素对地质雷达检测效果的影响,提出一种双正交小波预测反褶积法（PDBW法）。在PDBW法中,针对地质雷达检测信号选取具有最小重构误差的双正交小波基,运用该小波基将地质雷达检测信号分解成不同频段的时域子信号,对各频段的时域子信号进行预测反褶积等滤波处理,再对处理后的子信号进行重构变换,得到PDBW法的处理结果。将PDBW法用于实验检测信号处理,并将处理结果与预测反褶积法的处理结果进行比较,结果表明：PDBW法能有效压制多次回波干扰,准确识别深部信号,显著提高深部信号信噪比,从而进一步改善地质雷达探测分辨率和图像分析的准确性。     

小波包变换的图像融合技术的研究

图像融合技术是把同一目标的多幅图像融合成一幅高质量的图像.给出了一种基于小波包变换的图像融合方法.对两幅图像分别进行小波包分解,得到两幅图像的小波包分解系数,进一步对小波包系数进行分析和处理.对两幅图像低频波段的逼近系数取均值,对高频段选取绝对值大的小波包系数,得到融合系数矩阵.对融合数据进行小波包反变换,得到两幅图像的融合图像.使用该方法对两幅图像进行了融合,得到的融合图像汲取了两幅图像的优势,视觉效果较好.     

基于小波分析的边缘检测

中主要讲述了小波分析和边缘检测的基本理论，以及小波分析在边缘检测中的应用，力图反映出小波理论在边缘检测中的特点。     

基于小波变换的视觉工件检测技术

在小波变换的基础上,研制了视觉工件检测系统,并做了详细阐述和试验。结果证明该系统检测速度快,结构简单,精度高,便于实时化处理,具有广泛的应用前景。     

基于小波分析的风机故障诊断

根据故障信号特征和小波变换多尺度分解性质选取小波分解层次，得到能正确地反映风机运行状态的特征向量；参照特征向量的组成方法，提出并构建基于小波分析的韶钢4号风机典型故障特征表。对待检信号选用db10波进行6层小波分解，利用待检状态的特征向量与典型故障特征表，通过模糊模式识别方法进行风机故障诊断。结合傅里叶分析方法进一步找出风机存在的倍频微弱信号。实际诊断结果表明：振动信号与故障特征表中典型不平衡故障的模糊贴近度达到0．958，从而诊断出实例中风机存在不平衡故障；风机存在0.5倍频微弱信号，据此有利于发现风机与该频率相关的早期微弱故障征兆。     

基于小波包分析的水轮发电机组振动的故障诊断

针对水轮发电机组振动的频谱特点 ,提出了基于小波包分析的水轮发电机组振动的故障诊断方法 .运用小波包分析对振动信号进行分解与重构 ,可以获得振动信号的突变信息 ,即可以获得机组振动的故障状况 ,从而为诊断机组振动的故障状况提供决策支持 .理论计算表明 ,应用小波包分析技术不仅可以确定信号的突变点 ,而且可以在全频范围内确定信号的突变发生的时间及程度 .计算机仿真表明这种信号分析方法对水轮发电机组振动的故障诊断是十分有效的     

一种基于小波多尺度分析的水天线检测方法

提出一种基于小波多尺度分析的水天线检测方法．该方法针对海面背景图像的特点，利用小波变换的多尺度分析特性，依据小波变换模极大值在多尺度上的变化规律，综合了各尺度信息，对水天线进行检测，仿真实验验证了其有效性。     

基于小波分析的医学彩色内窥镜图像增强

根据人眼对颜色的心理感觉，提出在HSI颜色空间上基于小波分析的医学彩色内窥镜图像增强方法．在增强亮度分量的同时，也对饱和度分量也进行了调节．实验结果表明，该方法抑制了噪声，且使细节得到增强，处理后的图像更加清晰且色泽鲜明．     

基于小波分析的数字电路动态电流测试技术

针对数字电路中常见的晶体管桥接故障,研究了数字电路动态电流测试及定位方法。利用小波包分析技术,提取小波系数中所包含的丰富的时频信息作为故障特征,建立故障字典。实验结果表明,该方法准确、高效,用于数字电路电流检测效果良好。