Compensation to imperfect fabrication and asymmetry of micro-gyroscopes by using disturbance estimator

Abstract

Owing to the imposed coupling accelerations such as quadrature error and cross-axis perturbation, the micro-machined gyroscope could not be unconditionally retained at resonant mode. Once the preset resonance is not sustained, the performance of the micro-gyroscope is accordingly degraded. In this paper, a direct model reference adaptive control loop which is integrated with a modified disturbance estimating observer (MDEO) is proposed to guarantee the resonant oscillations at drive mode and counterbalance the undesired disturbance caused by quadrature error and cross-axis perturbation. The parameters of controller are on-line innovated by the dynamic error between the MDEO output and expected response. In addition, Lyapunov stability theory is employed to examine the stability of the closed-loop control system. At last, the efficacy of evaluation of the exerted time-varying angular rate, which is to be detected and measured by the gyroscope, is verified by intensive simulations.