A virtual parallel two-point roundness error measurement system

Abstract

As a typical artifact in machining, the roundness of shaft artifacts is an important tolerance standard. How to measure with high precision in ultra-precision machining is a difficult point. At present, the three-probe method is the most widely used method to measure spindle rotation error and artifact roundness error, which has the advantage of on-machine measurement, but the three-probe method has the critical problem of harmonic suppression. To completely separate the spindle error when measuring the roundness of the artifact, a new virtual parallel two-point measurement system is proposed in this paper. The probe is fixed on the flexible hinge stage, which is driven by a voice coil motor so that the measurement function of two probes can be realized only by using a single probe. Detailed numerical analysis and simulation analysis have been carried out to verify that the method can completely separate the spindle error in theory. Finally, the accuracy of the measurement system is tested through experiments. The new method results are compared with the single-point scanning method without error separation and the high-precision roundness instrument Talyrond 585LT. The comparison results show that the new method can separate the rotation error of the spindle and can improve the roundness measurement accuracy.