| 摘要 |
<p>An apparatus and method for providing high resolution non-contact absolute contour measurements of an object with moire interferometry. The invention utilizes a projection moire system in which the entire projection system is translated to perform a field shift. The field shift produces a phase shift that is proportional to the height of the object. A coarse three dimensional map of the surface is first obtained from the phase shift. This is combined with high resolution relative measurements of the phase to obtain an absolute Z map of the surface. The invention does not suffer from the 2 PI ambiguity problem and is suitable for prismatic discontinous structures. In addition, the present invention is applicable to industrial environments and requires a relatively inexpensive optical system. Further, the field shifting technique is applicable to fast parallel process computers thereby allowing for fast absolute contour generation of prismatic parts. <IMAGE></p> |
