An expert measurement system for photogrammetric industrial application

Abstract

As for any photogrammetric application, the accuracy of the derived object data is mostly dependent on the accuracy of the camera calibration. For many photogrammetric applications, use of a simple model for lens distortion in conjunction with co-linearity equations is sufficient. However, the combination of very close ranges and the large distortions typically associated with the lenses used on line-scan cameras requires an extended lens model to account for variation of distortion within the object space. The fidelity of the calibration model becomes particularly important where stringent tolerances are set, for example construction experiments or surface measurement. For an application in industrial photogrammetry, twin industrial cameras with IEEE 1394 standard, which are the essential part of an expert system has been calibrated with 16 mm fix focused lenses from Corsmicar Pentax on a test field. The main orientation of the photogrammetric extraction has been obtained from the first image set of the experiment steps. The configuration of the signal points have been designed which coordinates have been calculated basic surface model. Afterwards the system has been used for determining geometric properties of the slabs. The 3D surface model of the slabs has been obtained precisely and the deformations of the slabs have been documented. (C) 2006 Elsevier Ltd. All rights reserved.