Unified discrete time optimal control for MEMS gyroscopes

This paper presents a novel control strategy, unified discrete time optimal control (UDTOC), for controlling the sense axis of a vibrational MEMS gyroscope and estimating the rotation rate. The total disturbance, which includes both the internal dynamics and external disturbances, is estimated by a current discrete extended state observer and cancelled by the discrete time optimal controller in real time. It is assumed that the drive axis outputs an ideal sinusoidal signal. A force-to-rebalance mode of operation is applied to the sense axis of the gyroscope and the sense axis output is continuously monitored and driven to zero by UDTOC. The demodulation technique is employed to estimate the rotation rate. Simulation results demonstrate the effectiveness and robustness of the UDTOC against parameter variations and noises.