Analysis of Assembly Errors and Design of Precise Micro-regulator for Micro-hemispherical Resonator Gyroscope (mHRG)

The forming mechanism of assembly error of micro-hemispherical resonator gyroscope(mHRG) is analyzed, and the requirement of assembly accuracy is calculated. In case that the anchor diameter of m HRG structure is 1 mm, if the uniformity of assembly clearance is less than 10%, the height deviation of the anchor surface needs to be less than 0.1 μm. By using numerical calculation and finite element model, the effects of assembly errors on electrode driving ability, static capacitance, stiffness regulation and first-order mode shape are respectively studied. The results show that the uneven gap between electrodes influences detecting, driving and stiffness regulation as a function of 1 st, 2 nd, 3 rd power, and at the same time it can cause a slight structural swing. In order to improve the uniformity of electrode assembly, a micro-regulator based on flexible reduction unit is designed. By using the adjusting screw and flexible cushion, the quartz glass substrate can generate a 2-DOF micro-swing, thus achieving high precise assembly. Test results show that the average capacitance error of the m HRG is about 30%～40% after assembly, but parasitic capacitances are introduced. After eliminating parasitic influence, the average capacitance error is 12%.