微细孔壁缺陷检测的非对中补偿

Alignment error compensation for defect measuring system of small bores

为了满足小型化、微型化的微细管道管内测量需求,采用外部光源导入、内部图像导出的新思路,突破管道内壁检测方法中传感器内置的传统模式,解决了微细管道内部空间狭小的难题。在实验室前期研究工作的基础上,完善了系统测量方案,并针对检测系统的关键难题,即视像管与待测管轴线对中问题进行了深入研究,分析了该问题对系统测量结果的影响,建立合适的数学模型,提出了基于图像畸变矫正技术的补偿方案,以提高系统的测量精度。结果表明,搭建测量系统,对直径12mm的微细管道内壁上直径为0.6mm,0.8mm及1.0mm的微孔模拟缺陷进行了重复性测量,应用补偿方案后的测量结果均值误差小于0.02mm,标准差不超过0.03mm。所提出的图像畸变矫正方案能够解决视像管非对中造成的影响,满足微细管道内壁缺陷高精度测量的要求。

In order to satisfy the requirement of miniaturization in measuring defects inside small bores, a new approach wasproposed with external light importing and internal images exporting. This method solved the problem of the limited dimensionalaccessibility of small bores. Compared with the traditional measuring methods, the new method made the breakthrough and themethod was without built-in sensors. The key problem of alignment error that had a great influence on measurement results wasstudied deeply and the measuring system was improved. The reasonable alignment error compensation method based on imagecorrection was presented and a measuring system was built. Several tests were conducted on sample pipe with diameter of 12mm.The simulated point defects with diameter of 0. 6mm, 0. 8mm, 1. 0mm were set on the internal surface of sample pipe. Theresults showed that after image correction on the unfolding image, the mean deviation of the defect diameter was less than0.02mm, and the standard deviation was less than 0. 03mm. The alignment error compensation method is reliable and able toimprove the precision of measurement