Study the effects of camera misalignment on 3D measurements for efficient design of vision-based inspection systems

Abstract

Vision based inspection systems for 3D measurements using single camera, are extensively used in several industries, today. Due to transportation and/or servicing of these systems, the camera in this system is prone to misalignment from its original position. In such situations, although a high quality calibration exists, the accuracy of 3D measurement is affected. In this paper, we propose a statistical tool or methodology which involves: a) Studying the significance of the effects of 3D measurements errors due to camera misalignment; b) Modelling the error data using regression models; and c) Deducing expressions to determine tolerances of camera misalignment for an acceptable inaccuracy of the system. This tool can be used by any 3D measuring system using a single camera. Resulting tolerances can be directly used for mechanical design of camera placement in the vision based inspection systems. © 2014 Springer International Publishing.