Decoupling method for four-degree-of-freedom automatic centering and tilting worktable

Abstract

The ultra-precise measurement of aero-engine rotor geometry error is the basis of its assembly, and adjusting the rotor coaxially with the measurement rotation axis is the key to ensure the measurement accuracy. As a typical adjustment device for rotor alignment, the traditional method of applying a four-degree-of-freedom centering and tilting table for adjustment does not take into account the coupling effect caused by the position of each adjustment motor not being perfectly perpendicular to each other, this paper gives the calibration method of the angle between each adjustment motor and the starting position of the angle grating, analyzes the principle of eccentricity and tilt adjustment and deduces the coupling solution method. Subsequently, the size of the coupling between the two adjustments is analyzed and an efficient adjustment method is given for its mechanical structure characteristics. The experimental results show that the platform can effectively decouple and quickly converge to the setting values of 0.3 µm and 0.5′′ for different initial eccentric distance and tilt angle. With the same adjustment accuracy, the number of adjustments is reduced by more than 50% and more than 37.5%, respectively, compared with the non-decoupled method.