Compensation of position-independent and position-dependent geometric errors in the rotary axes of five-axis machine tools with a tilting rotary table

Abstract

We describe a method to separate, measure, and compensate for position-independent and position-dependent geometric errors in the rotary axes of a five-axis machine tool with a tilting rotary table using double ball-bar measurements. The measurement paths require control of a single rotary axis, and they are not affected by the accuracy of the linear axes. The positions of the balls of the double ball-bar are modeled as the nominal positions, with geometric errors considered via a kinematic analysis to represent the measurement configuration. The method is applied to measure both position-independent and position-dependent geometric errors, and the results are verified via measurements with compensation for the geometric errors. Furthermore, the possible range of the measured geometric errors is determined by analyzing the contributors.