The invention discloses a four-shaft
machine tool calibration method based on the multi-
station measurement of a
laser tracker, and belongs to the technical field of precise testing. The method comprises the steps: firstly determining the coordinates of measurement points in a movement space range of a four-shaft
machine tool, moving a target lens to each
measurement point during measurement, enabling the
laser tracker to carry out transfer measurement on a rotating shaft platform along with a rotating shaft, and obtaining the relative interference
length measurement value of each
measurement point to an initial
measurement point at different
station; secondly solving the coordinates of each
station and the distance between the corresponding station to the initial measurement point through employing a formula for the distance between two points, the principle of
least squares and a
laser tracker station solving optimization
algorithm; thirdly enabling the coordinates of the measurement points, the coordinates of the stations and the distances from the corresponding stations to the initial measurement point as the initial values, and solving and obtaining the correction value of each measurement point in the directions of three moving shafts of the four-shaft
machine tool through the expansion of the first-order Taylor series of an interference
length measurement error equation; finally building the mapping relation between the coordinate information of the stations of the
laser tracker and the angle of the rotating shaft through
circle fitting, and achieving the high-precision measurement of an rotating angle error of the rotating shaft.