基于激光和CCD组合的小孔转轮重复定位精度测量方法

小孔转轮是某试验装置光路自动校准系统的关键器件,重复定位精度是其重要指标之一.为了有效测量运行于真空环境下的小孔转轮重复定位精度,提出了一种基于激光和CCD组合的测量方法,并以转轮滤波小孔光斑中心的位置重复性作为其重复定位精度的评价指标,搭建了一套完整的测量系统.利用CCD采集通过转轮滤波小孔的激光光斑,通过图像处理的...

Measurement method of repeated positioning accuracy of pinhole runnerbased on combination of laser and CCD

The pinhole runner is the key component of the optical-path automatic calibration system of an experimental device, and the repeated positioning accuracy is one of its important indexes. In order to effectively measure the repeated positioning accuracy of the pinhole runner in vacuum environment, a measurement method based on the combination of laser and charge coupled device (CCD) was proposed, and the position repeatability of laser spot center of runner filtering pinhole was taken as the evaluation index of its repeated positioning accuracy. A complete set of measurement system was built, the laser spot filtered through the runner filtering pinhole was collected by CCD, and the laser spot image was preprocessed by the image processing methods, such as filtering and noise reduction, threshold segmentation, binarization and edge detection. The least square method was used for circle fitting of the laser spot, and the center coordinates of laser spot were obtained. Compared with laser interferometer in non- vacuum environment, the angular deviation between them was only 11″, which showed that the measurement method had high accuracy and met the measurement requirements. Finally, the repeatability measurement of the pinhole runner in vacuum environment was carried out for about 60 times forward and backward reciprocation in about 6 hours. The results show that the method can effectively measure the repeated positioning accuracy of the pinhole runner in vacuum environment.