Analysis and modification of turntable's axis calibration

A new method using the standard ball and geometrical transform technique was proposed to modify the calibration error of the turntable's axis in three dimensional laser digitizing system. The turntable's axis was counted by the center of the standard ball at 8 different rotation angles, The center of different positions was revolved to the zero degree position by geometrical transform, the deviations between the center of different positions and the center of the ball at the zero degree position was counted. Through reverse geometrical transform, the modified format of the eccentricity was deduced from the coordinate deviation caused by turning on the eccentricity. The registration accuracy was raised to 0.07 mm by self-design three dimensional laser scan measurement platform, the multiple views have been integrated automatically on line. Compared with the previous methods, the new method is simple and efficient, and can be used in other measuring system with a turntable.