Metrological support of video measuring systems

Abstract

Test objects of various types are used when creating and using video measuring systems which are part of the robots` technical vision, television sights, triangulation measuring systems, as well as 3D scanners. At the same time, an individual test object is developed for each type of device. This paper considers the possibility of development and construction of test objects for calibration (verification) of 2D and 3D video measuring systems, which are used to measure the geometric parameters of twodimensional (2D) and three-dimensional (3D) objects, respectively. We propose to use a measure based on a liquid crystal monitor to calibrate 2D systems. The calibration of such measure is based on the use of a high-precision displacement measurement devices. They are a laser interferometer and subpixel image resolution algorithms. The measure corresponds to the standard of the 3rd category according to the State verification scheme for measuring instruments of length in the range of 1·10–9–100 m and wavelengths in the range of 0.2–50 microns. The measure can be used to measure the modulation transfer function (MTF) of a video system and the point spread function (PSF). We also propose to use gauge block and move it in space according to the specific program using a translator and an external linear encoder. We introduce the technical specifications of the developed measures that can be used as working standards for calibration (verification) of a wide class of video measuring systems.