在线图像可视铁谱成像系统的像面照度均匀性

李博; 冯松; 毛军红

doi:doi:10.3788/ope.20162410.2347

光学精密工程, 2016, 24 (10): 2347, 网络出版: 2016-11-23

在线图像可视铁谱成像系统的像面照度均匀性

Illumination uniformity of an imaging system for on-line visual ferrograph

论文大纲

李博冯松毛军红

作者单位

西安交通大学现代设计及转子轴承系统教育部重点实验室润滑理论及轴承研究所，陕西西安 710049

摘要

为了定量评价在线图像可视铁谱( OLVF)成像系统的像面照度均匀性，建立了一种像面照度模型。以像方参数及放大倍率表征物方视场，将物方视场区域离散化，采用朗伯余弦理论建立入瞳模式的像面照度模型，实现了像面照度的计算与均匀性评价。利用Matlab进行了物面照度仿真分析，确定了OLVF成像系统环形阵列光源的发光二极管(LED)数量，基于像面照度分析确定了最佳成像焦距和放大倍率。计算了油腔通油情况下成像系统中的光能量损耗以及磨粒沉积面的照度分布，建立了油液吸光系数与CCD像面轴上像点照度的关系。结果显示: LED发光强度已知时，仿真计算的像面不均匀度约为5.60%，实际测试的像面不均匀度为8%~9%，满足不均匀度≤10%的要求。开展了磨粒铁谱图像采集实验，结果表明: 图像中磨粒清晰可辨，便于图像分割与视觉特征提取。提出的模型可定量描述OLVF成像系统的像面照度，可作为优化系统结构，提高系统成像性能的依据。

Abstract

To evaluate quantitatively the uniformity of image illumination for an On-line Visual Ferrograph (OLVF)imaging system, a new mathematical model of image illumination was presented. The view field of an object space was represented by image space parameters and optical magnification, then it was discretized into a micro area. By taking Lambert-cosine law as reference, the image illumination model based on the aperture of entrance pupil was established, the image illumination distribution was calculated reliably and the uniformity of image illumination was evaluated successfully. On the basis of Matlab simulation analysis, the number of single Light Emission Diodes(LEDs) in the circular ring array source of the OLVF imaging system was obtained and the optimized values of focal length and optical magnification were determined. The light loss of imaging system and the illumination distribution of wear debris deposition region were analyzed and calculated under the condition of the oil cavity filled with lubricant oil. The relationship between the absorptivity of lubricant oil and the peak value of CCD image illumination was investigated. The experimental results show when the luminous intensity of LED arrays is known, the imaging plane illumination non-uniformity is more than 5.60% by simulating calculation and that is from 8% to 9% by a practical test, which satisfies the demand by indicator less than 10%. Finally, this imaging system was practically used to capture the reflected ferrograph. The results show that the characteristics of wear debris has been clearly distinguished from the reflected ferrograph, and it is favorable to the ferrograph segmentation and image extraction. It concludes that the proposed model evaluates quantitatively the uniformity of image illumination, optimizes systematical structure and improves the imaging performance of the system.

参考文献

[1] WU T H, MAO J H, WANG J T, et al.. A new on-line visual ferrograph ［J］. Tribology Transactions, 2009, 52(5): 623-631.

[2] FENG S, FAN B, MAO J H, et al.. Prediction on wear of a spur gearbox by on-line wear debris concentration monitoring ［J］. Wear, 2015, 336-337: 1-8.

[3] WU J Y, MI X Y,MAO J， et al.. A wavelet-analysis-based differential method for engine wear monitoring via on-line visual ferrograph ［J］. Proc. IMechE Part J.: J. of Engineering Tribology, 2013, 227(12): 1356-1366.

[4] CAO W, CHEN W, DONG G N, et al.. Wear condition monitoring and working pattern recognition of piston rings and cylinder liners using on-line visual ferrograph ［J］. Tribology Transactions, 2014, 57(4): 690-699.

[5] 李博，冯松，毛军红．在线图像可视铁谱LED阵列反射光源设计与实现研究［J］．西安交通大学学报, 2014, 48(10): 29-34．

LI B, FENG S, MAO J H. Design and implementation of a LED array reflecting light for on-line visual ferrograph ［J］. Journal of Xi’an Jiaotong University, 2014, 48(10): 29-34．(in Chinese)

[6] KANG D K, YANG H,SHA D， et al.. Measurement of image plane illumination uniformity of photoelectric imaging system ［C］. 7th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, Harbin, SPIE, 2014，9282:92822O-92822O-8.

[7] 沈湘衡, 杨亮, 贺庚贤,等. 光电测量设备光学系统的像面照度均匀性检测［J］. 光学精密工程, 2008, 16(12): 2531-2536.

SHEN X H, YANG L, HE G X, et al.. Measurement of image plane illumination non-uniformity of optical system in photoelectric equipment ［J］. Opt. Precision Eng., 2008, 16(12): 2531-2536. (in Chinese)

[8] BROWN M S, SONG P,CHAM T J， et al.. Image pre-conditioning for out-of-focus projector blur ［C］. 2006 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, New York: IEEE, 2006: 1956-1963.

[9] LU Z Y, PENG Q，YAN X P, et al.. Method of eliminating and segmenting ferrographic images nonuniform background ［C］. International Conference on Measuring Technology and Mechatronics Automation, Changsha: IEEE, 2010: 640-643.

[10] ZHONG X, ZHANG L, JIN G. Illumination uniformity optimization of position-sensitive detector sensing optical system by circular and annular obscurations ［J］. Applied Optics, 2012,51(35): 8401-8406.

[11] 张光明, 孙胜利, 张伟, 等. 导弹助推段天基红外探测的像面照度模型及其应用［J］. 红外与毫米波学报, 2007, 26(6): 425-428.

ZHANG G M, SUN SH L, ZHANG W, et al.. Model and application of image plane illumination for the space-based infrared detecting of boost-phase missile ［J］. Infrared Millim. Waves, 2007, 26(6): 425-428. (in Chinese)

[12] CHANTLER M, PETROU M, PENIRSCHE A, et al.. Classifying surface texture while simultaneously estimating illumination direction ［J］. International Journal of Computer Vision, 2005, 62(1-2):83-96.

[13] 屈恩世, 张恒金, 曹剑中, 等. 对光学设计中照度计算公式的讨论［J］. 光学学报, 2008, 28(7): 1364-1368.

QU E SH, ZHANG H J, CAO J ZH, et al.. Discussion of illuminance formula in optical design ［J］. Acta Optica Sinica, 2008, 28(7): 1364-1368. (in Chinese)

李博, 冯松, 毛军红. 在线图像可视铁谱成像系统的像面照度均匀性[J]. 光学精密工程, 2016, 24(10): 2347. LI Bo, FENG Song, MAO Jun-hong. Illumination uniformity of an imaging system for on-line visual ferrograph[J]. Optics and Precision Engineering, 2016, 24(10): 2347.

在线图像可视铁谱成像系统的像面照度均匀性

关于本站 Cookie 的使用提示

全站搜索

在线图像可视铁谱成像系统的像面照度均匀性

相关论文

相关资讯

关于本站 Cookie 的使用提示

全站搜索