Authors: C. Painter and A. Shkel
Affilation: University of California, Irvine, United States
Pages: 420 - 423
Keywords: MEMS, gyroscope, rate integrating, dynamically amplified
The paper presents the design, modeling, simulation, and initial characterization of a novel MEMS vibratory rate integrating gyroscope, which uses a dual mass architecture. In contrast to conventional micromachined vibratory gyroscopes which measure angular rate, our device outputs a signal proportional to the angular deflection. Undesirable nonlinearities due to the large amplitudes of motion limit stability of the device and complicate efforts at control algorithms for drive, sense, and error suppression. Our solution to this challenge is the implementation of a dual mass system where a driven first mass is used to amplify the deflections of a coupled secondary mass. The motion of the first mass, used exclusively for drive and control, is restricted to a small linear operating regime, while the second sense mass is passive and used exclusively for sensing. By design, the sense mass operates at higher amplitudes to facilitate higher performance of the gyroscope. The device keeps the energy of the slave mass constant through an energy compensating feedback control. This control architecture achieves an almost tenfold amplification gain in the slave mass and additionally allows the free precession of the device. Computer simulation of the device calculates the precession angle to be within 1% of the actual angular displacement.