Error Analysis and Comparison of the Fiber Optic Gyroscope Scale Factor Obtained by Angular Velocity Method and Angular Increment Method

Abstract

The fiber optic gyroscope (FOG) has a broad application prospect in the field of dynamic angle measurement. The scale factor, which is an important indicator of the FOG, directly determines the angle measurement precision. In this paper, the principles of angular velocity method and angular increment method, which have been commonly used in obtaining the scale factor, are introduced, and the error sources that affect the scale factor in both methods are analyzed in detail. The theoretical analysis results show that the main error sources of the scale factor are the relative error of the angular velocity benchmark generated by the rotary table and the value of the selected angular velocity benchmark in the angular velocity method. Other error sources need to be considered only at small angular velocity benchmark. Instead, the main error of the scale factor comes from the position precision of the rotary table in the angular increment method. Finally, the experiments on the scale factors of the FOG in both methods are carried out, and they are applied to the angle measurement experiments, respectively. The angle measurement results show that the deviation of the angle can be limited in 0.002° when the scale factor obtained by the angular increment method is adopted in angle measurement. It is an order of magnitude smaller than the angular velocity method. We can get the conclusion that the scale factor obtained by the angular increment method is more suitable for angle measurement than the angular velocity method.