Automatic mode matching control loop design and its application to the mode matched MEMS gyroscope

In this paper, a mode matching control loop is suggested for the matching of the resonant frequency of the sensing mode with that of the driving mode. Matching of two modes is critical issue of the MEMS vibratory gyroscope to achieve the high sensitivity of the sensor. A new mode matching control loop using the concept of phase locked loop (PLL) is proposed and analyzed. Through the computer simulation using MATLAB and experiments using a real MEMS gyroscope, it is verified that the proposed control loop design matches those two modes and correspondingly improves the sensitivity of a gyroscope.