External visual interface for a Nikon 6D autocollimator

GUILLERMO BERGUES; GUILLERMO AMES; LUIS CANALI; CLEMAR SCHURRER; ANA GEORGINA FLESIA

Montevideo

Conferencia; I2MTC 2014 - IEEE I&M INTERNATIONAL INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE 12?15 May 2014 MONTEVIDEO, Uruguay; 2014

IEEE Instrumentation & Measurement Society

The goal of this paper is to describe the potentialof a visual interface applied to a Nikon 6B/6D autocollimator inorder to replace human operator within a ?laboratory grade?measurement. The optical interface implemented consists of aBasler HD camera attached to the autocollimator?s eyepiece,camera positioning devices, and a proprietary digital imageprocessing package, built around Matlab environment. The wholesystem is used to analyze the reticle image to detect both the scaleand the measuring crosshair lines at sub-pixel level. The systemperformance was compared in a controlled experiment againstan electronic level with internationally traceable certification. Theresolution of the pitch angles obtained was 10 times better thanthat originally obtained with the instrument. This example showsthat the value of 0.02 pixels for the uncertainty associated withsub-pixel position of reticle lines is realistic, allowing for continueworking on a robust interface for all angle parameters that canbe measured using autocollimators.