OLF-4在线铁谱仪的采样数据及其特征提取的研究

借助齿轮试验数据进行 OL F- 4在线铁谱仪的采样数据及其特征提取的研究 ,讨论了采样时间选择和特征参数定量分析的方法 ,并指出基准参数监测的重要性。     

在线铁谱仪磁场的优化设计

提出了一种适用于在线铁谱仪磁场的优化设计方法。首先建立结合永磁体与电磁铁的混合磁铁模式,然后设计一种以磨粒所受磁力为依据的衡量磁场性能的目标函数,再采用改进遗传算法和有限元方法对混合磁铁进行了优化设计。以优化结果为依据研制了混合磁铁,并进行了实验测试。结果表明,与磁感应强度相比,所提出的目标函数更适合判断铁谱仪磁场的性能;混合磁铁满足在线铁谱仪的功能要求,体积只有电磁铁的1/3。     

在线铁谱仪性能测试分析

本文介绍了适用于监测煤矿机械设备循环润滑油中磨屑量连续读数的在线铁谱仪的工作原理,测试分析了在线铁谱仪的线性、重复性、沉积率等性能指标。     

在线铁谱仪中的磨粒沉降机理研究

为给研制在线铁谱仪提供理论依据，建立了在线铁谱仪中的磨粒沉降运动模型，采用有限元法仿真了直流电磁铁磁场的分布情况，研究了磨粒在磨粒探测器中的沉降运动机理，分析了油样粘度ηc、初始高度y0、磨粒直径D等参数对磨粒沉积位置的影响。仿真结果表明：在两个磁极之间存在一个夹角β的条件下，在线铁谱仪既具有较高的磨粒沉淀率，又避免了大磨粒的“堆积”。     

一种新型的在线铁谱仪

本文介绍了最新研制的在线铁谱仪的原理和功能。该仪器利用电磁铁产生的高强度、高梯度磁场捕获润滑油中的磨粒，利用传光光纤、传像光纤束分别传递光强信号和特征大磨粒的图像信号。通过由Tms320F240 DSP控制CMOS图像传感器，可以同时获得磨粒遮光面积百分比及铁磁性与顺磁性金属大磨粒的数据。监测数据能够通过串行接口传输到上位机做进一步分析处理。上位机处理程序采用Delphi编程，能够分析遮光面积、磨损指数等参数的发展趋势。最后，用实验结果说明设计该仪器时应注意的事项。     

分析式铁谱仪与旋转式铁谱仪的对比研究

从分析式铁谱仪与旋转式铁谱仪制谱时磨屑的沉积机理、磨屑的实际沉积过程、谱片上磨屑特征参数的统计规律、谱片重复性等方面对两种铁谱仪的特点进行了对比分析。     

砂纸在线纹理特征提取方法的研究

纹理特征作为图像的表面固有特征,在模式识别中有着重要的作用。针对提取砂纸表面缺陷纹理特征的问题,提出了灰度共生矩阵的概念,建立了砂纸的灰度共生矩阵模型,对模型进行相关的理论分析,诠释了图像预处理工作的重要性和各个参数的影响机制;同时针对砂纸图像光照不均匀的现象,采用了基于概率的数字图像不均匀校正算法,对图像质量进行改进。通过对实验的仿真分析,验证了传统的灰度统计特征的方法在提取砂纸纹理特征中的不足,得出灰度共生矩阵在纹理特征提取中具有更好的适应性结论。最终构建砂纸的特征向量,为模式识别过程中分类器的训练提供了理论依据。     

直读式旋转铁谱仪定量测试方法研究

在自行研制开发的DRF-II型直读式旋转铁谱仪的基础上,提出了利用光电传感器对包括斑点、油质、旋转谱片等进行测试的在用润滑油定量测试方法,并在机械设备的磨损状态检测中进行了试验应用研究。结果表明:提出的定量测试方法,数据可靠度高,对反映机械运行过程中的磨损状态和油质变化比较敏感;扩展了DRF铁谱仪的测试范围,为故障诊断提供了更多的依据。     

自动化便携式铁谱仪的设计与实验研究

设备油液中的磨粒携带的各种特征信息是设备进行故障诊断与维护的重要依据,铁谱仪是分析研究机械设备磨损状态的专用设备。为满足铁谱仪自动化以及制谱分析过程快捷方便的要求,设计了一套便携式铁谱仪系统。该铁谱仪采用单片机控制,运用PID速度环控制方法,实现了从制谱到清洗的全自动过程,成功制得沉积效果良好的谱片。结合自动扫描显微镜观测部分,以图像灰度方差函数为目标函数,采用变步长遍历搜索法,实现了图像的自动聚焦与采集,验证了自动化便携式铁谱仪的制谱效果。     

直读铁谱仪读数误差的分析

本文分析了铁谱仪的几种读数误差,通过作者开展的一些实验,观察到了铁谱仪中的光电传感器由于其始点电压值不同而引起的系统误差,并提出了对应的解决方法。     

Analysis of Wear Debris from Full-Scale Bearing Fatigue Tests Using the Ferrograph

The Ferrograph was used to determine the types and quantities of wear particles generated during full-scale bearing fatigue test. Deep-groove ball bearings made from AISI 52100 steel were used. A MIL-L-23699 tetraester lubricant was used in a Recirculating lubrication system containing a 49-μm absolute filter. Test conditions included a maximum Hertz stress of 2.4 GPa, a shaft speed of 15 000 rpm and a lubricant supply temperature of 74°C (165°F). four fatigue failures were detected by accelerometers in this test set. In general, the Ferrograph was more sensitive (up to 23 h) in detecting spall initiation than either accelerometers or the normal spectrographic oil analysis (SOAP). Four particle types were observed: normal rubbing wear particles, spheres, nonferrous particles, and severe wear (spall) fragments.     

A New On-Line Visual Ferrograph

An on-line visual ferrograph (OLVF) characterized by direct reading and on-line analysis was developed based on magnetic deposition and image analysis. A digital sensor was integrated with a CMOS image sensor to obtain images of deposited wear debris under illumination conditions. An electromagnetic instrument was designed to deposit the wear debris flowing through an oil flow channel. The oil flow channel, fixed on the electromagnet, was arranged parallel to the magnetic flux in the air gap between two electromagnet poles. The deposition effect on wear debris was analyzed theoretically. The result shows that the wear debris in different sizes can be deposited in the same zone by controlling the oil flow rate and magnet field intensity. Corresponding application software for image sampling and processing was developed. An index of relative wear debris concentration, IPCA (Index of Particle Coverage Area), is given as an output in addition to wear debris images. Finally, two kinds of experiments were specified to assess the effect and validity of the OLVF. The results show that the OLVF has effective deposition and identification for both relatively large and small wear debris with rational control parameters. The validity examinations with the commercial particle quantifier (PQ) and direct reading ferrograph (DR) show that the OLVF has an approaching trend to the reference instruments in both heavily and lightly contaminated oil.     

A Hybrid Method for the Segmentation of a Ferrograph Image Using Marker-Controlled Watershed and Grey Clustering

Aimed at the correct segmentation of wear particles in ferrograph images, a new method combining marker-controlled watershed and an improved grey clustering algorithm is proposed in this article. First, the marker-controlled watershed is applied to ferrograph images to efficiently obtain the initial segmentation of wear particles. Then, an improved grey clustering algorithm utilizing color characteristics and relative position information is applied to merge the oversegmented regions after the watershed segmentation. This new algorithm is tested for ferrograph images and the results are compared with those of other algorithms. The experimental results show that the proposed method is effective for the segmentation of large wear particles and fine wear debris deposited as chains on the ferrograph, and it is proven to be a practical method for segmenting wear particles quickly and accurately.     

一种旋转式铁谱仪机电一体化方案设计

润滑油铁谱分析是检测机械磨损程度的重要手段,旋转式铁谱仪由于其成谱效果良好而广受欢迎.为满足油液检测工作的要求,设计一种性能稳定、自动化程度高的旋转式铁谱仪.该铁谱仪采用STC系列单片机作为控制核心,结合机电一体化技术,实现铁谱仪制谱磁头转速控制及油样与清洗剂自动供应等功能,能同时满足分系统独立操作与整个系统的全自动操作的需要.     

Wear Condition Monitoring and Working Pattern Recognition of Piston Rings and Cylinder Liners Using On-Line Visual Ferrograph

This study applies stepped loading and stepped velocity approaches to simulate the actual working conditions of gasoline engines. Accelerated wear tests were conducted for piston rings and cylinder liners under different lubricating conditions by using a self-made pin-on-disc wear machine equipped with an on-line visual ferrograph (OLVF) for wear monitoring. The wear coefficients for oil monitoring were extracted to distinguish between constant conditions and stepped changing conditions. A similarity model for oil monitoring was constructed and the monitoring data sets of similar working conditions were grouped together. Results show that the OLVF monitoring system can be used to obtain the real-time variation in debris concentration. The index of particle coverage area (IPCA) of OLVF increases abruptly after the load or speed changes. The similarity model can evaluate the similarity of the variation trend of IPCA under different operating conditions. The relationship between IPCA and working conditions was examined in this study and provides an essential support to wear monitoring and life prediction of engines.     

图像可视在线铁谱传感器的图像数字化处理技术

为实现图像可视在线铁谱传感器的磨粒图像自动辨识,建立数字图像获取系统,探讨铁谱图像数字化处理方法。研究了铁谱图像的预处理方法,对比在RGB和YUV颜色空间对铁谱图像的灰度化处理效果,采用不同的微分模板对平滑后图像进行锐化处理;探讨减背景法和自动阈值法在铁谱图像磨粒分割中的应用效果;给出适用于在线铁谱图像的定量描述方法。研究表明,采用YUV颜色空间的明视度分量可以得到平滑的灰度图像,合理的模板选择可以使微分法在锐化磨粒边缘的同时保持整体图像的平滑;铁谱图像的磨粒分割结果表明,减背景法由于采用人工选取门限值而难以适用于在线铁谱图像的处理,而自动阈值法可以根据铁谱图像自动选取合适的阈值以达到良好的分割效果;采用磨粒百分覆盖面积作为定量指标可反应良好分割的铁谱图像中的磨粒统计质量分数。     

铁谱图像的彩色纹理特征提取与识别

纹理是铁谱图像的特征之一,但大部分的铁谱图像的纹理研究是以灰度图像为基础的,这样就丢失图像的彩色纹理信息。对铁谱图像的彩色纹理特征进行了提取,运用支持向量机的方法,对铁谱图像的磨粒颗粒进行了识别,试验结果表明,所提取的特征值,有利于磨损颗粒纹理的识别。