Abstract: Focusing on a tuning fork vibratory gyroscope fabricated through silicon bulk micromachining, the matrix perturbation technology in the random finite element method is introduced to analyse the statistical characteristics of the output capacitance of tuning fork vibratory gyroscope. The influences of random material parameters and dimensional parameters on the performance of a microgyroscope are quantitatively described by a so-called impact factor based on probability. The impact factors exactly point out that the sensitivity of parameters variance to performance variance and finally bring out the five key parameters of a microgyroscope. These limited key pa-rameters not only simplify the dimensions of design space for the robust optimization design of a microgyroscope, but also provide a special quantitative reference to the accuracy control in the fabrication procedures of the microgyroscopes.

Key words: Coefficient of dispersion, Impact factor, Micromachined gyroscope, Output capacitance, Random parameters, Statistical analysis