Optical Autocollimation Comparing Goniometer Digital Measurement Technology Research

The traditional method to use Autocollimator is to interpret the pattern on the reticle through the eyepiece of the instrument. A long time operation is likely to cause eyestrain, increase the alignment error and reading error, and reduce efficiency. Autocollimator is frequently used in optical workshop. To reduce the difficulty of observing and improve the efficiency of processing and testing, there is an urgent need to transform Autocollimator into digitization.In this paper, the photoelectric imaging system of an Autocollimator has been designed and developed. A CCD camera has been used to collect reticle images of the Autocollimator instead of eyes, then the images are processed with two methods, using Hough transform to recognize the lines on the reticle, or using convolution operation to recognize the numbers on the reticle. The distance between the two dividing lines can be obtained automatically in order that the Autocollimator can achieve digitization.By measuring optical wedge windows, the measurement errors of traditional Autocollimator, Nikon Autocollimator and the digital Autocollimator are analyzed. After transformation, the measurement error of the digital Autocollimator is within1%, which is less than traditional Autocollimator and matches with that of Nikon Autocollimator. At the same time, the digital Autocollimator improves the measurement efficiency. After using the transformed digital Autocollimator in optical workshop, the eyestrain is greatly reduced, and the operation is more convenient. So the component testing is speeded up, thereby the efficiency of processing is enhanced. Moreover, it is more conducive to train new employees.