A new MEMS three-axial frequency-modulated (FM) gyroscope: a mechanical perspective

Micro-Electro-Mechanical Systems (MEMS) gyroscopes are inertial sensors for the measurement of angular rates. They have a variety of applications from consumer electronics to drones and the need of stability against environmental fluctuations, such as temperature, is a key factor in order to avoid expensive calibration procedures. Frequency Modulation (FM) has been recently proposed as an innovative working principle for MEMS gyroscopes and as the desired solution in terms of stability against environmental fluctuations. In this paper, the FM working principle is formalized for the three-axial case for the first time and the governing equations are derived both in the idealized case of a point-mass gyroscope and in the real case of a distributed-mass gyroscope. Moreover, the mechanical structure of the first three-axial MEMS FM gyroscope is proposed and studied. Preliminary experimental measurements prove the validity of both the model and the simulations results employed during the design process. The proposed structure overcomes lots of the constraints of the surface micromachining fabrication processes and represents an important step towards the development of a new class of MEMS gyroscopes.