润滑油膜厚度的光学相干层析成像测量

Thickness measurement of lubricant film by optical coherence tomography

为了对滑动轴承的润滑油膜厚度进行精确测量,搭建了光纤结构的谱域光学相干层析成像(OCT)检测系统。该检测系统通过谱域OCT对油膜进行高分辨率成像,根据一维深度图像和二维层析图像中油膜和轴承表面的相对位置得到油膜厚度。分析了SD-OCT的检测原理,并对油膜厚度进行了测量,通过干涉光谱解耦法减小噪声对测量结果的影响。实验结果表明,该系统的测量误差小于2μm,具有良好的重复性和可靠性。该测量方法能够对油膜进行快速准确测量,有望应用于机械设备轴承运行状况的在线监测。

In order to measure lubricant film thickness of sliding bearing accurately, a fiber-based spectral-domain optical coherence tomography （SD-OCT） detection system was constructed. The detection system could perform high-resolution imaging to lubricant film with SD-OCT, and the lubricant film thickness was determined according to the relative location of lubricant film and bearing surface in one-dimensional depth image and two-dimensional tomography image. The measuring principle of the SD-OCT was detailed and performed in a film thickness measuring experiment, in which the interference spectrum decouple method was used to reduce the effect of noise on measurement results. Experimental result shows that the system with the measuring error lower than 2 /,m exhibits good repeatability and reliability, thus realizing rapid and accurate measurement of lubricant film. The system is expected to be applied in on-line monitoring of bearing operation of mechanical equipment.