Fault Diagnosis of Bearing Based on Integration of Nonlinear Geometric Invariables

A fault diagnosis method of bearing based on integration of non-linear geometric invariables was presented for the non-linearity exiting in bearing system but ignored in traditional fault diagnosis.The meanings of non-linear geometric invariables,such as fractal dimension,Lyapunov exponent,Kolmogorov entropy,correlation distance entropy and their calculation method were analyzed.Grey theory is applied to integrate these parameters and the correlation values as fault characteristic value was input into the support vector machines for diagnosis.The experimental results show that this method can distinguish the bearing fault effectively,it provides a new approach for the fault diagnosis of rotating machinery.     

通风机性能试验自动测试系统

介绍了一套风机性能试验用于自动检测于处理系统。该系统基于Windows环境，采用Lab Windows／CVI虚拟仪器开发工具，可实现试验数据的自动采集与处理、风机转速及运行工况的自动控制，性能曲线的自动绘制等功能。现场运行结果表明了系统的有效性和优越性。     

基于机器视觉检测技术的齿轮几何参数自动测量系统

针对齿轮几何参数传统机械式测量中存在分立仪器多,价格昂贵、操作复杂、容易产生人工误差等问题,本文将机器视觉检测技术应用于齿轮几何参数自动测量中,通过图像采集、图像预处理、系统标定、边缘检测、几何特征提取和几何参数计算等步骤,实现了齿轮几何参数的自动测量。实验结果表明该系统具有测量精度高、速度快、操作简单、成本低等特点,在齿轮的几何参数测量中具有广阔的应用前景。     

A Magnetic Disturbance Compensation Method Based on Magnetic Dipole Magnetic Field Distributing Theory

The interference of carrier magnetic field to geomagnetic field has been a difficult problem for a long time, which influences on the deviation of navigation compass and the error of geomagnetic measurement. To increase the geomagnetic measuring accuracy required for the geomagnetic matching localization, the strategy to eliminate the effect of connatural and induced magnetic fields of carrier on the geomagnetic measuring accuracy is investigated. The magnetic- dipole＇s magnetic field distributing theory is used to deduce the magnetic composition in the position of the sensor installed on the carrier. A geomagnetic measurement model is established by using the measuring data with the ideal sensor. Con- sidering the magnetic disturbance of carrier and the error of sensor, a geomagnetic measuring compensation model is built. This model can be used to compensate the errors of carrier magnetic field and magnetic sensor in any case and its parame- ters have clear or specific physical meaning. The experimented results show that the model has higher geomagnetic mea- suring accuracy than that of others.     

基于阶次小波包与粗糙集的轴承复合故障诊断

针对齿轮箱启动过程中振动信号表现为非平稳非高斯特征,传统诊断方法诊断精度不高的现状,将阶次小波包和粗糙集理论引入到轴承的复合故障诊断中,利用计算阶次跟踪算法对瞬态振动信号进行重采样,采用小波包对该信号分解-重构,并对每个频段的能量进行归一化,构成一个特征向量,通过粗糙集理论得到清晰、简明的决策规则。并通过复合故障实例验证了此方法的有效性。     

一种基于SST-MOM的改进形态成分分析算法及其应用

形态成分分析(MCA)是最新提出的一种基于稀疏表示的信号和图像分解(分离)方法,其扩展算法GMCA(Generalized MCA)可用于超定和欠定情形的盲源分离。为了降低GMCA算法中重构信号的均方差,提高分离信号的精度,将半软阈值函数和MOM阈值更新机制相结合,提出了SST-MOM(Semi-soft Thresholding MOM)阈值更新策略,仿真结果表明,新算法较原GMCA算法提高了分离信号的信噪比,将其应用于齿轮箱复合故障诊断中,有效地识别出了两路观测信号中的3种故障,表明了该算法的有效性。     

高速运动目标速度测量系统

介绍高速运动目标的速度测量系统.该系统利用激光光幕区截原理:即当运动目标通过激光光幕时,采集光通量的变化从而获得运动目标的平均速度.本文介绍激光光幕的形成,光敏元件、半导体激光器和数据采集板的选择等.系统软件在虚拟仪器开发平台LabWindows/CVI上使用灵活的C语言将数据采集,分析和显示等专业工具有机组合,实现系统的信号采集、数据处理及实验报告的打印,存储等功能.实验结果表明,该系统具有操作方便、测量精度高、稳定性好、安全可靠等特点.     

基于LabWindows/CVI的风机性能测试系统

介绍利用虚拟仪器技术进行风机性能测试的系统.该系统采用LabWindows/CVI开发平台,可实现风机性能参数的自动采集与处理、风机转速及运行工况的自动控制,风机性能曲线的自动绘制等功能,测试结果表明了系统的优越性.     

基于虚拟样机技术的行星轮系的动力学仿真研究

将行星轮系扭转振动模型与虚拟样机技术结合在一起,建立力学分析模型对行星传动进行动力学仿真,考虑了行星轮系传动过程中的时变啮合刚度和齿侧间隙等因素,可较方便、准确地获得行星轮系在传动过程中的一些动态特性,为行星轮系的优化设计、寿命预测等提供了理论依据.     

非接触式人体三维测量系统的研究

针对传统的接触式测量方法效率低,测量结果抽象、不准确,不能通过图像的方式形象表达等不足,研制了一种低成本、高效率、快速获取三维人体数据的非接触式测量系统;该系统是根据投影栅相位法基本原理,采用具有一定特性的结构光进行照射,通过分析相位值获得被测物体的高度信息;文章从理论和实践两方面进行了深入研究,研制了由计算机、投影仪、摄像头、图像采集卡、工作台等组成的三维人体测量系统,有效地提高了人体的测量精度和测量速度.