基于交点法的高精度指针式仪表自动检定系统设计

Automatic calibration for high precision pointer instrument based on intersection method

利用机器视觉的办法对高精度指针式仪表进行自动检定,存在相机与指针所在平面和仪表平面不垂直而产生的视差的问题。针对这一问题,查表法必须要求相机和仪表表盘位置相对固定,但不同仪表的表壳尺寸总有差异,查表法无法消除因仪表尺寸差异所带来的误差而造成的读数不准确;模板匹配结合查表法准确度又有所下降。本文提出一种"交点法"实现相机和仪表指针旋转中心对准。实验表明,采用的方法显著提高读数的准确性。

Automatic calibration of high precision pointer instrument by machine vision method has the problem of parallar caused by the plane of camera and pointer and the plane of instrument not perrendicular to each other. For this problem,the table searching method must be relatively fixed position of the camera and instrument dial,while the shell size of different instruments are always different,the table searching method can not eliminate the error caused by inaccurate readings result of the instrument size differences. The accuracy of template matching combined with table searching decreases again. This paper presents a "cross point method"to make the alignment of the camera and the pointer rotation center. Experiments demonstrate that the accuracy of readings is significantly improved by the proposed method.