Facing the problems in forming process

such as difficult springback prediction

low accuracy of CAE simulation software

and difficulty in estimating fact error entirely

a non-contact 3D optical measuring method with digital close-range industrial photogrammetry technology and surface scanner technology is proposed

where un-coded point and coded-point fixed on the surface of parts may be figured out and the whole marked-points is exported via photogrammetry system. The surface scanner system makes use of the global marked points

hence every pieces of point data may be assembled automatically. Then 3D data of the object surface and CAD model of workpieces are acquired precisely. Contrasted with CAD model of die

the errors between workpiece and CAD model can be obtained with the present method as the springback values of workpiece to provide a geometric compensation for finishing die. An automobile door is taken as an example

and the experiment verifies the accuracy of the proposed springback measurement method.