Abstract: The measurement is simplified by preinstalling measuring points, and the error from blank anamorphosis is homogenized by positioning fitting algorithm and mathematic programming optimum algorithm. The fitting characteristics of two al-gorithms are analyzed quantitatively. When measuring points have 3 pairs, the results of two algorithm have little difference, the calculating time of positioning fitting algorithm, however, is much shorter than that of mathematic programming optimum algorithm. When measuring points exceed 3 pairs, the fitting effect of mathematic programming optimum algorithm increases distinctly, but calculating time increases rapidly; in practical application of the machining of maglev guideway girder, geometric fitting algorithm is mainly adopted.

Key words: Machining and positioning Magnetically levitated vehicle (Maglev) Guideway girder, Huge workpiece