汽车发动机润滑油清净分散性定量测定方法

Quantitative determination method on detergent-dispersant performance of automobile engine oil

针对目测法测定机油清净分散性存在耗时、费力和主观偏差大的缺点,提出了一种融合扩散环宽度和沉淀环亮度信息的机油清净分散性测定方法,基于油斑晕环在HSV颜色空间的色度、饱和度和亮度差异特性,运用最大类间自适应地确定分割阈值,并辅以数学形态学处理去除噪声、间隙等,自动地分割出沉淀环、扩散环和油环。直径比重反映了扩散环的宽度与清净分散性的关系,灰度差比重表征了沉淀环亮度与清净分散性的关系,融合扩散环宽度和沉淀环亮度信息得到清净分散性系数,依据清净分散性系数定量判定机油清净分散性能等级。试验测试结果表明:该方法能准确地提取油斑的各晕环区域,并依据清净分散性系数值定量评定油品的清净分散性等级,目测法只能给出定性的评定结果,提出的方法避免了人工测量带来的主观判断误差影响,提高了测量结果的客观可信度水平。

To overcome the shortages of time-consuming and large subjective bias in the manual visual method, a new determination method on detergent-dispersant performance of automobile engine oil fusing the width of diffusion ring and brightness of settling ring was proposed in this paper. Based on the differences in chromaticity, saturability and brightness of oil stain aureole in HSV color space, the maximal interclass adaptive threshold partition was used. Noise and gap were removed and the sedimentation ring, diffusion and oil ring were segmented automatically with the assist of mathematical morphology. The diameter ratio reflected the relationship between the width of diffusion ring and detergent-dispersant performance. The ratio of gray level difference reflected the relationship between the brightness of sedimentation ring and detergent- dispersant performance. The coefficient of detergent-dispersant performance could be obtained by the fusion of the width of diffusion ring and the brightness of sedimentation ring and the detergent-dispersant performance level of engine oil could be assessed quantitatively based on the coefficient. The results show that this method can be used to extract the aureole area of oil stain accurately and quantitatively assess the level of detergent-dispersant performance of engine oil.Compared with visual method which only provides the qualitative assessment result, this method can avoid the subjective judgment errors in manual measurement and improve the objective reliability level of the measurement result. 2 tabs, 2 figs, 16 refs.