3D Measurement System Based On Stereo Vision

Traditional 3D measurement almost relies on mechanism to orientate the contact measurement head in space, which is not convenient in practical measurement. With the rapid development of machine vision in recent years, photogrammetry technology has make greatly advances and been employed in industrial measurement widely.In this paper,in order to overcome the shortcomings of mechanism, A novel method is proposed to orientate the measurement head indirectly via the stereo vision 3D tracking of the mark points in the head. The main achievements of this thesis are as follow:Firstly, via the procession of the digital image and the epipolar geometry, the edges of mark point is extracted accurately and employed to fit the centers of the mark points and these centers match to each other in the two images of dual-camera. Morewhile, the sub-pixel image centers are used to calculate its actual 3D position in space through the photography geometry.Secondly, via the fixed space position relationship of mark points in the measurement head, mark points correspond to the serial number of itself and the probe position in space is calculated indirectly.Finally, the convenient coordinate system special designed transform the coordinate from the camera coordinate system to the subject coordinate system and is applyed to the integration of the measurement in different position and of large-size object.