Research On Error Compensation Technology Of Mechanically Dithered Ring Laser Gyro SINS

Optic gyro (including ring laser gyro and fiber optic gyro etc) is an angle rate sensor, which is on the base of Sagnac generalized relativity effect. It shows the direction of inertial instrument and inertial component, which has lots of advantages such as not sensitive to g, quick startup, long use, no motive parts, strong vibration and high acceleration, broad dynamic range, good linearity of scale factor, high output rate and high frequency bandwidth, digital output, low weight. For the advantage as above, the optic gyro is very potential to the strap-down inertia navigation system. In this paper, dithered ring laser gyro is viewed as the object of investigation and several aspects is investigated as follows.the Allan variance technique method is applied to analye the inertial sensors error elements for various and complex error sources, and analyze the additional interference and noise derived from gyros in dithered ring laser gyro SINS. It directs the advance of the dithered ring laser gyro performance.The output characteristic (static state) of dithered ring laser gyro is essentially stochastic procedure, which is described by the ARMA model. In general, ARMA(2,1) is the suitable model of output characteristic of dithered ring laser gyro. And according to the model of output characteristic of dithered ring laser gyro, the test data of output characteristic of dithered ring laser gyro is dealt with Kalman's filter and compensation, and the effect is better in this paper.In this paper, the author studies the variation of the two-frequency coning error with the dithering of the RLG's assembly, and infers the equations of the accelerometer drift and gyro two-frequency motion. On the base of theoretical analysis and calculation, the author calculates the error form and value to assure the dithering error of the present system in the permission.