High-accuracy automatic machine vision based calibration of micrometers

Abstract

The calibration of simple handheld instruments is often more expensive than the price of a new device. Therefore, the amount of manual labour is kept at a minimum in order to keep the price of calibration at a tolerable level. This also means that only a few points of e.g. a length scale can be checked. By using automatic machine vision based systems, the calibration of measurement instruments can be done faster and more thoroughly. In order to study the possibilities of machine vision automation for volume calibration tasks a set-up for micrometer calibration was constructed at Centre for Metrology and Accreditation (MIKES). With the developed automated machine vision system it is possible to check hundreds of points on the scale of a micrometer, giving new insight into error sources of the micrometer screw. The attained uncertainty is at the same level as calibration with gauge blocks according to ISO 3611.

A robust and automatic recognition system of analog instruments in power system by using computer vision

“…Mostly, the automatic recognition systems are used to calibrate analog measuring instruments [1][2][3][4][5].…”

“…This equipment focuses on the calculation of measurement uncertainty [4]. They also proposed an updating of developed equipment to calibrate micrometers [5].…”

Automatic Calibration System for Digital-Display Vibrometers Based on Machine Vision

“…Most of the digital-display vibrometers could not be calibrated by the ordinary automatic calibration system directly because of no output or interface except the display on the vibrometers for cost considerations. In the recent years, machine vision technology has widely been applied in automatic systems [8][9][10][11][12][13][14][15][16][17]. A digital camera can be applied to replace human eyes to capture the images of digital or analog displays, and then the captured images are transmitted to a computer, in which the displays are recognized by some image recognition algorithms.…”

Segmentation-free approaches of computer vision for automatic calibration of digital and analog instruments

“…In the last years, many authors have proposed automatic calibration approaches using computer vision techniques [1][2][3][4][5][6][7].…”

“…They also presented an updating of developed equipment into a calibration device for micrometers [6].…”