Study On 3D Surface Mosaic Technology Without Surface Interference

3D surface mosaic technology as the core technology of the 3D surface measurement directly influences the precision and use effect of 3D surface measurement system. There have a lot of techniques of 3D surface measurement. The methods that ask for help of auxiliary precise equipments have simple algorithms, but the systems based on these methods have lower adaptabilities and higher cost. The mosaic methods that extract information from overlapping part of adjacent regions to realize mosaic is flexible but easily create accumulative error. And affixing artificial marking points on the measured object would interfere with the characteristic of measured surface. A 3D surface mosaic technology based on a mosaic target is studied. With the high-resolution camera and several control points, a global coordinate system with high precision is set up. Then, by introducing the mosaic target, the translation between the global coordinate and the measuring coordinate can be established. The 3D data obtained from different viewpoints thus can be translated into a unique frame of reference. So the final results can be obtained. This method avoids creating mosaic accumulative error. Using the mosaic target avoids interfering with the characteristic of measured surface.The main contents of the thesis are as follows.1. The study on the 3D mosaic technology without surface interference—the 3D mosaic technology based the mosaic target. With several control points, a global coordinate system with high precision is set up. And by introducing the mosaic target, the translation between the global coordinate and the measuring coordinate can be established.2. An orientation method for global control points based on ray intersecting from the close-range photogrammetry is studied. The design and identification of global control points and the mosaic target is also studied.3. A method using single image to gain the transition matrix is studied aiming at raising the mosaic speed. Precision analysis is given by the experiment.4. The 3D mosaic experiment based the mosaic target is given. The method that uses single image to gain the transition and the method based on ray intersecting are used to complete the mosaic.