Elimination of Gyro Drift by Using Reversal Measurement

Abstract

We aim to realize a large-scale straightness evaluation using a gyro. It detects tangential angles to evaluate a profile without any references. However, fluctuations of angular signal, called gyro drift, are considered a major contributor of error. We adopted a reversal measurement for eliminating the drift. The reversal measurement has been widely used for eliminating stable error from ancient. Here, we periodically performed reversal measurements for eliminating drift of a commercially available fiber optic gyro (FOG) unit. As a result, an angle could be derived with a standard deviation of 0.4 mrad for 1 hour of repeated measurements with an interval of 60 s, even though the gyro has a drift of several mrad/h including the effects of the Earth’s rotation. This indicates that the reversal measurement is effective in reducing the drift.