Design of robust controller for micromachined rate gyroscopes

This paper presents methods to design the control loops for different device layouts of rate gyroscopes by modeling the micromachined rate gyroscope structures, where the very low damping of the system and plant parameter variations due to production tolerances and variability of the environment are considered. A robust controller to rebalance the seismic mass is designed for the detection loop using the Quantitative Feedback Theory (QFT). The resulting controller design improves not only the performance of the rate gyroscopes like better linearity and larger bandwidth, it is also robust with respect to large plant parameter variations.