In incremental sheet forming process, the bolster model usually applies guide pin to position. However, it is inefficient and rough due to the bolster model floating and fit tolerance between guide pin and aligning hole. This paper introduces a new method to position the bolster model. The image capture system captured the aligning holes images, and then processed it. The trajectory orientation system, which was based on machine vision, applied the least square principle to determine the parameters of aligning holes and obtain the coordinate system of bolster model. The camera calibration software, which was developed by Vision C++6.0, obtained the relationship between machine tool coordinate system and bolster model coordinate system. Then, CNC system transformed the machine coordinates offline, which enabled the forming trajectory coordinates to match bolster model coordinates automatically. Additionally, the forming process of automobile door is presented, which applied the new method, the result demonstrates that non-touch position method is more rapid and more accurate.
