Measurement of Spindle Tilt Error Based on Interference Fringe

The spindle rotation error is one of the important factors that affect the precision of the machined parts. The study of spindle rotation error is of great significance for finding the source of error, predicting the surface shape error of machining parts and improving the machining accuracy of ultra-precision machine tools. The structural of the aerostatic spindle this article focuses on is motorized spindle and the spindle tilt error has the maximum effect on the machining precision. A new method for measuring the rotation error of ultra-precision aerostatic spindle based on interference fringes is proposed in this paper. By using the principle of phase shifting interferometry, the mathematical model between the shape of interference fringes and the motion law of the spindle rotor is established by theoretical modeling. The interference fringes are processed with gray, smooth filtering, expansion corrosion, and edge detection and so on. The distance and direction of the interference fringes are calculated in the coordinate system, so as to get the spindle tilt error. Finally, the measurement system for the spindle rotation error of the aerostatic spindle is developed. The accuracy and effectiveness of this method are shown based on the experimental results.