Structural Parameter Identification of the Center Support Quadruple Mass Gyro

In this paper, a structural parameter identification method of a MEMS planar gyroscopes is reported for the first time, which is based on the multiorder dynamic modeling, reasonable linear compensations, and frequency response tests. Compared with conventional coriolis vibratory gyros, the circular quadruple masses resonator of the center supported quadruple mass gyroscope (CSQMG) has a simple structure design and sufficient measureable resonant modes. Consequently, by means of the serpentine beams simplification and the structure symmetry simplification, a multiorder system dynamics model that contains 12 degrees of freedom is carried out to reflect all of the eight in-plane modes of the CSQMG. This new model, together with two hypotheses (the “neglect of length and thickness variation” hypothesis and the “minimum Euclidian norm of the width change” hypothesis), provides sufficient conditions for the identification of the five beams’ width which directly affect the resonant frequency of the gyro. Compared to the design values, the identification results show a maximum deviation of less than 0.17 $\mu \text{m}$ after approximate liner compensation, which means that combined with the frequency response tests, each significant part of a gyro product can be nondestructive online measured efficiently, and the MEMS process error can be evaluated and improved by reasonable compensations.