A Model of the Elastic Dynamic Torsion of a Ring Laser Gyroscope Mechanical Dither and a Method for its Calibration

We present a model of the dynamic elastic torsion of the mechanical dithering devices of ring laser gyroscopes and analyze its impact on the accuracy of attitude determination in a strapdown inertial navigation system. We also describe a method for calibrating such parameters in order to compensate for this effect in attitude integration algorithm. The method is an extension to the existing calibration technique introduced in 2009 by N.A. Parusnikov of Moscow State University, applicable to tactical and navigation grade inertial systems on a turntable with horizontal rotation axis. New parameters of dynamic elastic torsion are included into the state vector of a linear state-space model subject to estimation. We examine their estimability and predicted covariance, and as present experimental results. We extend the model with three parameters, which was described in our previous work, to the one with nine parameters.