No abstract

Este documento tiene el objetivo de describir el potencial de una interfaz visual básica en un Autocolimador del tipo Nikon 6B/6D, para reemplazar al operario en una medición de calidad metrológica. La interfaz visual implementada consta de una cámara con sensor CMOS adosada al ocular del autocolimador, partes posicionales, y un sistema de procesamiento digital de imágenes propio, escrito en lenguaje Matlab R , que analiza la imagen de la retícula para detectar la escala y la cruz de medición a nivel sub-píxel. Mediante un experimento controlado, realizado con un nivel electrónico trazable internacionalmente, se obtuvieron, con este sistema,ángulos de cabeceo (α y) con una resolución tres veces mejor que la del instrumento sin interfaz. Este ejemplo sugiere que el valor de 0.06 píxeles para la incertidumbre asociada con la posición sub-píxel de las diferentes líneas que conforman la retícula de medición es realista, y permite seguir trabajando en una interfaz robusta para todos los parámetros angulares posibles de ser medidos por el autocolimador.

The goal of this paper is to describe the potential of a visual interface applied to a Nikon 6B/6D autocollimator in order to replace human operator within a "laboratory grade" measurement. The optical interface implemented consists of a Basler HD camera attached to the autocollimator's eyepiece, camera positioning devices, and a proprietary digital image processing package, built around Matlab environment. The whole system is used to analyze the reticle image to detect both the scale and the measuring crosshair lines at sub-pixel level. The system performance was compared in a controlled experiment against an electronic level with internationally traceable certification. The resolution of the pitch angles obtained was 10 times better than that originally obtained with the instrument. This example shows that the value of 0.02 pixels for the uncertainty associated with sub-pixel position of reticle lines is realistic, allowing for continue working on a robust interface for all angle parameters that can be measured using autocollimators.

No abstract

In this paper, we present an electronic interface created for the Nikon 6B/6D visual autocollimator that allows for an increase in the final resolution of measurements and a reduction in the vignetting and distortion effects produced by this optical instrument's lenses. The electronic interface consists of a Basler ACE high-definition camera and its positioning devices and a computer with a subpixel digital image processing package. The latter includes two main procedures: one for scale calibration and the other for determining the position of crosshair lines. Both procedures work at subpixel level. The feasibility of the measurement method was verified. The resolution obtained for the measurement of angular displacements is about 0.019 s of arc, 25 times better than the one registered by the original visual system. Its overall performance was compared against an electronic level with internationally traceable certification.Index Terms-Autocollimator, Hough transform, subpixel line detection, vignetting effect, visual interface.