Dynamical analysis of an improved MEMS ring gyroscope encircled by piezoelectric film

摘要

Micro-electro-mechanical system (MEMS) gyroscope is an important sort of inertial sensor for measuring the angular velocity of spinning structures, which has been extensively applied in various engineering areas used for guidance, location and motion control. In this paper, an improved design of MEMS vibratory ring gyroscope is proposed, in which a thin layer of piezoelectric film (PZF) is introduced encircling the circumferential surface of the ring, aiming to modify the rigidity of the gyroscope. The ring and the PZF are both driven by direct in conjunction with alternating voltages. The coupled differential equations governing the drive and sense motions are established via the Lagrangian equations. The forced responses to the periodic electrostatic action are obtained and the effects of the drive bias voltage, piezoelectric voltage and spinning speed are discussed. Numerical example demonstrates that the employment of PZF can greatly enhance the gyroscope sensitivity. Parametric vibration of the gyroscope due to periodically varying rigidity induced by the periodic piezoelectric voltage is also investigated. The stability regions of the system are acquired by using the multiple scales method, and the effect of the piezoelectric voltage is analyzed. The results show that the attached PZF can also enhance the gyroscope sensitivity by the generated parametric resonance.