Reference coordinate calculating method, reference coordinate calculating program, recording medium thereof, reference plate and form measuring machine

摘要

Positions of a plurality of reference points arranged on a reference plate (200) having a larger area than a measurement area of a measuring machine (300) are obtained as coordinate points on a standardized reference coordinate system. First, the plurality of reference points are grouped according to the measurement area of the measuring machine (300). At this time, the reference points are grouped so that one of the groups shares a predetermined number or more of the reference points with the other one of the groups (a grouping step). The reference points are measured for each of the groups (a measuring step). A coordinate transformation function is calculated for each of the groups, the coordinate transformation function respectively transforming values of the reference points which are shared by the different groups and obtained by measuring the reference points in the different groups into the same or extremely approximate coordinate points (a reference point coordinate transformation function calculating step). The coordinates of the positions of the respective reference points measured for each of the groups are transformed with the coordinate transformation functions respectively calculated for the groups (a coordinate transformation processing step).