油膜厚度测量的双色光干涉光强调制方法

发布时间：2018-04-27 14:41

本文选题：润滑油膜测量 + 激光　；参考：《青岛理工大学》2012年硕士论文

【摘要】：在轴承或齿轮等机械结构中，相对运动的诸元间存在极薄的油膜从而避免严重的磨损，这种润滑形式称之为弹性流体动压润滑（elastohydrodynamiclubrication/EHL）。光干涉方法是EHL润滑油膜测量的主要手段，依照入射光源的不同，光干涉测量方法可分为单色光干涉、双色光干涉及彩色光干涉。对于单色光干涉，研究人员对其技术应用和光学原理都进行了较为详细的研究，而对于双色光干涉和彩色光干涉，现有的研究大多围绕技术应用进行。针对这一研究现状，本文根据薄膜光学理论，对油膜测量中的双色光干涉和彩色光干涉的测量理论进行了研究，揭示了干涉条纹的强度和色彩的形成机制。在此基础上首次提出了一种基于干涉光强调制的油膜厚度测量技术，并实验验证了技术的可行性。完成的主要工作包括： 1使用彩色光干涉色度学模型对彩色光干涉、伪双色光干涉及激光双色光干涉的光学特性进行了研究，确定了各光学参数对光干涉测量的影响，为光干涉系统的设计和参数设定提供了参考数据。 2利用旋转滤波法成功消除了激光散斑对油膜厚度干涉测量系统的干扰，成功将激光光源引入油膜测量系统中，增大了可测膜厚，提高了测量精度。使用激光取代普通光源加滤光片的结构，使用双色激光光源取代普通光源加双色滤光片的机构，能够有效降低光源的半高全宽。 3首次提出双色光干涉光强调制油膜膜厚测量技术。常化双色光干涉图像的RG色彩强度，再将其线性叠加（相加或相减），便可得到光强调制曲线，发现在较大范围内光强调制的极值与膜厚存在唯一对应的关系。以此发现为基础，提出了基于光强调制的新的双色光干涉油膜厚度测量技术，避免了原有膜厚测量方法的弊端。 4使用VisualBasic6.0编程语言编写了光强调制膜厚测量技术的测量程序，并成功对稳态纯滚动条件下的球-盘伪双色光干涉图像进行了膜厚测量，充分证明了光强调制膜厚测量方法的可行性。 5对光强调制的测量原理进行了详细的研究，使用双光束干涉理论及多光束干涉理论对光强调制的特性进行分析，确定了波长选择、初相位、带宽等对光强调制的极值点、变化周期等的影响，为测量方法的实际应用建立了理论基础。 6使用设计的双色激光干涉系统，采集双色激光干涉图像，使用光强调制膜厚测量程序，处理双色激光干涉图像。利用光强调制膜厚测量技术，成功测量获得真实条件下不同载荷下静态球-盘接触的膜厚。已有的双色光或彩色光干涉测量技术多利用干涉图像的颜色刺激值测量油膜厚度，，测量精度依赖于严格的标定，微小的实验条件变化会导致测量结果产生极大的误差。本研究提出的双色光干涉光强调制膜厚测量技术，能够有效的避免测量过程中的膜厚误判，消除单色光干涉法及彩色光干涉法弊端的同时，最大限度的保留了两种方法的优势，能够直接确定干涉图像中某些特殊位置的膜厚。
[Abstract]:In mechanical structures such as bearings or gears, there is a thin oil film between the elements of relative motion to avoid serious wear and tear. This form of lubrication is called elastic fluid dynamic lubrication (elastohydrodynamiclubrication/EHL). The optical interference method is the main measure of the measurement of EHL lubricating oil film. According to the difference of the incident light source, the optical interferometer is measured. The method can be divided into monochromatic light interference, double color light interference and color light interference. For monochromatic light interference, the researchers have made a more detailed study of its technical application and optical principle. For the two color light interference and color light interference, most of the existing researches are carried out around the technology applications. The theory of the measurement of double color light interference and color light interference in oil film measurement is studied. The intensity of interference fringe and the formation mechanism of color are revealed. On the basis of this, an oil film thickness measurement technology based on interference intensity modulation is first proposed, and the feasibility of the technology is verified by experiments. Including:
1 the color light interference chromaticity model is used to study the color interference, the pseudo double color interference and the optical characteristics of the laser double color light interference. The influence of the optical parameters on the optical interference measurement is determined, and the reference data for the design and parameter setting of the optical interference system are provided.
2 the interference of laser speckle to the oil film thickness interferometry system is successfully eliminated by rotating filter method. The laser light source is introduced into the oil film measurement system successfully. The thickness of the measurable film is increased and the measurement precision is improved. The structure of the ordinary light source and the filter is replaced by the laser. The double color laser light source is used instead of the ordinary light source and the double color filter. The mechanism can effectively reduce the half full width of the light source.
3 for the first time, the technique of measuring the film thickness of a double color light interference light intensity modulation oil film thickness is first proposed. The RG color intensity of the normalized double color light interference image, and then the linear superposition (adding or subtracting) the intensity modulation curve can be obtained. It is found that the extreme value of the light stress system in a larger range has the only relation to the film thickness. Light intensity modulated new two-color light interference film thickness measurement technology avoids the disadvantages of the original film thickness measurement method.
4 using the VisualBasic6.0 programming language to write the measurement program of the optical emphasis film thickness measurement technology, and successfully measured the thickness of the ball disk pseudo double color interference image under the steady state rolling condition, and fully proved the feasibility of the light emphasis film thickness measurement method.
5 the principle of light intensity modulation is studied in detail. Using the theory of double beam interference and multi beam interference theory, the characteristics of light intensity modulation are analyzed. The influence of wavelength selection, initial phase, bandwidth and so on on the extremum of intensity modulation and the change period are determined, and the theoretical basis for the practical application of the measurement method is established.
6 using the designed dual color laser interference system, the two color laser interferometric images are collected, and the two color laser interferometric images are processed with light emphasis on film thickness measurement program. The film thickness of the static ball disk contact under different loads under real conditions is successfully measured by using light emphasis film thickness measurement technology.
The existing dual color light or color optical interference measurement techniques use the color stimulus value of the interferometric image to measure the thickness of the oil film, and the measurement precision depends on the strict calibration. The change of the small experimental conditions will lead to the great error of the measurement results. When the thickness of the film is misjudged in the measurement process, the disadvantages of the monochromatic light interference method and the color light interference method are eliminated, and the advantages of the two methods are retained to the maximum limit, and the film thickness of some special positions in the interfered image can be directly determined.

【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH744.3;TH117.2

【参考文献】