Abstract: For the HRG’s technology fabrication deviation, effect of the resonator’s thickness nonuniformity on the gyro accuracy is studied. The error model is established and the error mechanism is analyzed. First, the strains of an arbitrary point on the resonator is analyzed, then a thin shell element is chosen to make a force analysis, the dynamics equation is established according to the force and torque equilibrium equation. According to the dynamics equation, the HRG error caused by the resonator’s thickness nonuniformity is obtained. The results show that the first to third order harmonic terms of the nonuniformity have no impact on the error of angular rate, while the fourth order harmonic terms has impact on the error of angular rate .In order to improve HRG accuracy , some methods are adopted to balance the thinckness nonuniformity.

Key words: hemispherical resonator gyro, thickness nonuniformity, angular rate, resonator, dynamics