Structural Design And Optimization Of Sixth-Antinode Cylindrical Resonator Gyroscope

The Cylindrical Resonator Gyroscope(CRG)is a solid vibration gyroscope that uses the Standing Wave Feed Effect(SWFE)on the shell surface to sense the angular rate,with good impact resistance,high precision,short start-up time and low processing cost.The SixthAntinode Gyroscope(SAG)works in the bending vibration state with circumferential wave number n=3,which has higher Quality Factor(Q)compared with the classical Fourth-Antinode Gyroscope(FAG),Still,it is also more susceptible to processing errors and requires higher accuracy.Combining the advantages and shortcoming,it is analyzed that with the progress of processing level and heat treatment process,the Sixth-Antinode Cylindrical Resonator Gyroscope(SACRG)will have the potential to produce high performance with enormous production volume.1.In this thesis,based on the operating principles of SARG and CRG,a Sixth-Antinode Cylindrical Resonator(SACR)structure with a diameter of 28 mm and a Q value of 11180 was designed by modal simulation,piezoelectric sensitivity simulation,and quality factor simulation to meet the size,sensitivity,and quality factor indicators of the project.2.To suppress the frequency splitting,this thesis has firstly demonstrated that the sixth harmonic component has a substantial effect on the frequency splitting in the Fourier expansion term of the function of the uneven density of the distribution leading to the frequency splitting of the SAG by combining theory and simulation;Then the effect of defect quality on frequency splitting was analyzed qualitatively and quantitatively,and then a frequency tuning scheme was proposed for the SACR.Finally,the frequency splitting of the finished resonator was reduced from 9.535 Hz to 0.369 Hz.3.To improve the vibration stability of the SACRG in a temperature-changing environment,this thesis has first demonstrated through simulation that frequency tuning was not the last step in the gyro design process,and that it needed to continue to be optimized from a thermal stress perspective;Then this thesis has proposed a teardrop-shaped guiding structure based on the stress concentration theory,and then has proved through simulation that this structure was more effective than the classical circular guiding structure in optimizing the stability of the rigid shaft of the resonator.4.the SACR was machined precisely.The test results showed that the surface roughness Ra of the machined SACR was 0.085 μm,the roundness error was better than 0.1 μm,and the axiality error was better than 0.1 μm,which met the requirements of the project high precision machining indicators.Finally,the SACR was subjected to modal test,frequency splitting tuning,vacuum encapsulation,quality factor test and turntable test,and the scale factor of the whole SACRG was measured to be 20.37 m V/(°/s),which met the sensitivity indicator requirement of the gyro prototype.