全视场在线图像可视铁谱磨粒显微成像特性分析

为了评估全视场在线图像可视铁谱磨粒显微成像特性，提出了一种反射光显微成像模型。首先，基于朗伯余弦与小角度散射理论建立了全视场(OLVF)的反射光辐照度模型，实现了磨粒显微成像清晰度定量评价。然后，仿真计算磨粒显微成像的反差透视比，确定了最优光学倍率和适用于全视场OLVF探测的油液衰减系数范围，明确了光学参数对磨粒显微成像质量的影响规律。结果显示：光学倍率为2.0×且油液衰减系数≤2.0条件下，磨粒沉积于物方视场的主光轴附近，全视场OLVF可获得最佳磨粒显微成像清晰度。最后，开展了磨粒显微成像实验测试，结果表明：全视场OLVF能够从油液衰减系数小于2.0的在用液压油和齿轮油中获取反射光谱片图像，并提取磨粒视觉信息进行磨损在线监测。

Evaluation and analysis of microscopic imaging characteristics of wear debris for full field-of-view online visual ferrograph

To analyze the microscopic imaging characteristics of wear debris for full field-of-view online visual ferrograph (OLVF), a new reflected light microscopic imaging model is proposed. First, by taking the lambert-cosine law and the small-angle scattering theory as references, a reflected light irradiance model based on the wear debris microscopic imaging is formulated. The microscopic imaging sharpness of wear debris is evaluated quantitatively. Then, according to Matlab simulation calculation of contrast transmittance, the optimized value of optical magnification and the numerical ranges of oil attenuation coefficient detected by full field-of-view OLVF are determined. The changing rules of microscopic imaging sharpness of wear debris are investigated and determined successfully by analyzing the effectiveness of the numerical increasing of oil attenuation coefficient on contrast transmittance. Simulation results show that, under 2. 0× optical magnification and less than 2. 0 oil attenuation coefficient, wear debris deposites near the optical axis of object field of view. And the high-quality microscopic imaging of full field-of-view OLVF for detecting wear debris can be achieved. Finally, the experimental measurement of wear debris microscopic imaging is implemented by using the current full field-of-view OLVF. Results show that the full field-of-view reflected ferrograms of wear debris can be reliably obtained from different in-use lube oils with less than 2. 0 oil attenuation coefficient. It has potential for online wear monitoring by extracting the visual feature information of wear debris.