Study On Error Model Of The Ring Laser Gyro

As a new kind of Sagnac effect-based gyro, the ring laser gyro is used to sense the angle velocity. Its operate principle is Sagnac effect: when the resonator is rotating, the frequency difference of the two beams counter-propagating in the resonator is proportional to the rotating speed. The ring laser gyros have been used widely in the strapdown inertial navigation system for its many advantages which can not be obtained with mechanical gyros. The ring laser gyros can make a perfect performance with simple framework in theory. Because of the lock-in effect and zero bias, many techniques have to be adopted which make the ring laser gyro complicated and introduce several error source in itself. The content of this paper is:The fundamental of RLG is elucidated in detail. The input-output equation is analyzed in three theory frames and the conclusion is that whatever the theory is, the form of the input-output equation never changes.The source of the lock-in effect is analyzed with a model. The techniques used to limit the lock-in effect is discussed in detail and the influence of the mechanical dither technique which is the most widely used technique, is studied in theory and experiment.As another error source of the RLG, the zero bias is also studied. The method is discussed to compensate the influence of the change of temperature and magnetic field and the result of the experiment is positive.