Parameters Calculation And The Error Measurement Method Of The Hemispherical Resonator Gyro

Hemispherical Resonator Gyro is a new type of high-precision and high reliability inertial grade solid gyro. In addition to having the features of small volume, light-weight, low power dissipation, no need of temperature compensation, rapid start-up, strong anti-interference ability, it can be used for more than 15 years, which make it suitable for use in space applications. In this paper, performance parameters test method, drift caused by mass nonuniformity,error mechanism of natural frequency cracking, random error and gyro's experiment on a three-axis turntable's were researched.Firstly, the kinetic equation of hemispherical resonator in second order natural vibration type was established under the Kirchhof - Liya Fu hypothesis.The natural frequency of HRG was calculated, its basic performance parameters such as bias, threshold, resolution, scale factor and misalignment angle were measured in this paper. By means of calculating, the scale factors were measured using 1st and 2nd order model, some reasons for scale factor nonlinearity and asymmetry were given.Secondly, the dynamics equation of the resonator was established under the nonuniform massdistribution.The drift models under parameter driven mode and position driven mode were studied.Thus the formula of natural frequency cracking was given.Aiming at the previously identified problems of Allan variance, the accurate identification method of indentifying error model coefficients was given.And the influence of the random error on the accuracy of gyro north seeking was verified.After instaling and aligning the gryo, the rate turnable test method of the gyro on three-axis turntable was designed to identify the error model coefficients concerned the angular rate.The indentification accuracy was enhanced by compensating for the errors of the turntable and gyro's static error.