| Hemispherical Resonator Gyro(HRG)is a typical high-precision vibratory gyroscope based on the principle of Coriolis Effect.Fully solid state Force to Rebalance Hemispherical Resonator Gyro(FTRHRG)has the advantages of high reliability and long life by its very nature,and has been used in the aerospace field.With the development of industrial technology,the vibration performance of hemispherical resonator is continuously improved,and the performance of Rate Integrating Hemispherical Resonator Gyro(RIHRG),which has the characteristics of large dynamic range and high reliability,is increasing day by day.Because RIHRG is significantly superior to other types of gyroscopes in volume,power consumption,cost and reliability under the same accuracy conditions,it has attracted extensive attention in the fields of land,ocean,aviation and space.In this dissertation,by taking the Flat-Electrode RIHRG as research target,problems like the modeling of HRG sensing head synthesis model,vibration performance test and mass balancing of hemispherical resonator,Rate Integrating mode standing wave control and its drift compensation are focused on solving,and it can provide a reference for the development of HRG.Research contents of this dissertation are as follows:1.The motion model of nonideal hemispherical resonator with various axes misalignment errors is derived based on the elastic thin shell theory and Lagrange Equation.The assembly model of hemispherical resonator with multiple parameters,such as assembly inclination angle,assembly direction angle of inclination and average assembly gap,is established.The electrostatic exciting model and vibration detecting model of hemispherical resonator are established respectively based on Lagrange Equation and linear impedance voltage division principle.The above models are combined to form a synthesis model of two-piece flat-electrode HRG sensing head,and the accuracy of the synthesis model is verified with experiments.2.The factors affecting the vibration performance of hemispherical resonator are analyzed,and the vibration characteristics of fused quartz hemispherical resonator are discussed based on the typical data.The frequency split signal model of resonator is deduced,the synchronous identification scheme of core vibration performance parameters such as resonator quality factor,frequency split and rigid axis angle is designed based on the nonlinear optimization method,and the identification accuracy of parameters are analyzed systematically.The vibration performance test system for hemispherical resonator is designed and implemented,and the test system and the proposed test scheme are verified by experiments in kind.3.The motion model of nonideal resonator with circumferential variable density parameters is derived,and the influence mechanism of the first four order harmonic components of the circumferential mass distribution on the resonator frequency split is revealed.The spherical mass removing function of ion beam is established,the resonator circumferential harmonic mass removing method and corresponding evaluation method are proposed,and the mass balancing technology of hemispherical resonator is further formed.After optimizing the key parameters of circumferential harmonic mass removing process,the hemispherical resonator balancing experiments in kind are carried out with ion beam etching system.4.The vibration excitation and detection problems of HRG with flat-electrode structure are solved based on time-division scheme of standing wave excitation and detection.The demodulation method and multi-loop control scheme of standing wave in Rate Integrating mode are improved to reduce control loop computation and improve its dynamic performance.An initiative driving control scheme of standing wave azimuth based on vector control is proposed to solve the high-precision precession control problem of standing wave.The standing wave precession rate model of resonator under the action of excitation and detecting misalignment error is established,the mechanism of standing wave drift caused by control loop gain difference is revealed,and the gain difference identification and compensation technology of vibration detection channel are implemented.The proposed control and compensation schemes are systematically verified by experiments in kind.The sensing head synthesis model formed in this dissertation accurately describes the response characteristics of the HRG under the action of multiple error parameters,which can provide theoretical support and simulation verification means for the gyroscope development.The implemented synchronous identification technology of the hemispherical resonator vibration performance parameters eliminates the influence of the resonator inherent frequency drift on the test,and significantly improves the identification accuracy and efficiency of the frequency split and rigid axis angle.It is the necessary condition for high-precision mass balancing.The implemented ion beam mass balancing technology of resonator based on circumferential harmonic mass removing achieves sub-millihertz mass balancing accuracy,and it’s the core link in the development of high-precision HRG sensing head.The improved standing wave multi-loop control scheme improves the standing wave dynamic performance in Rate Integrating mode,the proposed initiative driving control scheme of standing wave azimuth solves the high-precision precession control problem of standing wave.At the same time,the implemented gain difference identification and compensation technology of detection channel can effectively eliminate the measurement error of standing wave precession rate and significantly improve gyro bias stability. |
