全视场活塞视窗的图像矫正方法  

Image Rectification of Full-Visible Piston Crown

作　　者：梁帅[1] 蒋一洲 马骁[1] 李雁飞[1] 徐宏明[1,2] 王建昕[1] Liang Shuai Jiang Yizhou Ma Xiao Li Yanfei Xu Hongming Wang Jianxin(State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China School of Mechanical Engineering, University of Birmingham, Birmingham B 15 2 TT, United Kingdom)

机构地区：[1]清华大学汽车安全与节能国家重点实验室,北京100084 [2]伯明翰大学机械工程系

出　　处：《内燃机学报》2017年第1期75-83,共9页Transactions of Csice

基　　金：国家自然科学基金资助项目(51506111)

摘　　要：在一台汽油缸内直喷光学发动机上,设计并应用了全场可视的下置式活塞视窗,进行了高速摄影研究.为了实现燃烧室全场可视的目标,活塞视窗须采用曲面设计,曲面设计会造成图像的变形.研究了活塞视窗实现全场可视的条件,讨论了全场可视的设计准则;采用近轴平行光线计算了图像的理论畸变,并尝试优化视窗曲面型线,减轻图像的理论畸变;最后通过试验标定,采用了空间坐标变换的方法对图像进行了矫正,并将矫正前、后的图像与热力学数据进行拟合,结果表明:矫正后的图像与热力学数据的相关性有显著的提高.High speed photography was carried out on an optical gasoline direct injection （GDI） engine coupled with a new designed full-visible piston crown. To meet full visibility of the combustion chamber, a curved surface design was adopted on the piston crown. In this study, the conditions for realizing the full-visibility were investigated, and the principles of full-visible design were discussed. Theoretical distortion was calculated using the paraxial and parallel rays, and an attempt to refine the curved surface of the window was made to minimize theoretical distortions. With the calibrated data from experiments, distortion was corrected by coordinate transformation. After rectification, the correlation between images and thermal data was distinctly improved.

关 键 词：汽油机 全场可视 图像变形 图像矫正 

分 类 号：TK411.2[动力工程及工程热物理—动力机械及工程]