Multivariable quantitative feedback theory approach to robust control of vibrational micro-electromechanical systems gyroscope
Abstract
Recent advances in micro-electromechanical systems (MEMS) have led to the creation of small low-cost gyroscopes that have low power consumption levels. This paper presents a novel design methodology for a robust controller that can improve the performance of a vibratory MEMS gyroscopes despite the existence of coupling between vibratory gyroscope modes and inherent model uncertainties. The drive-mode of the gyroscope is able to track a desired sinusoidal trajectory while the sensing mode is bounded against uncertainties. In other words, while the sensing mode of the gyroscope operates under a bounded unknown disturbance and measurement noise, the multivariable robust quantitative feedback theory (QFT)-based controller compensates undesirable mechanical spring coupling between two vibrating directions, regulates both modes, and most significantly compels the output of the sensing mode to be bounded and the output of the drive mode to track a desired sinusoidal reference signal at a given amplitude and frequency. The robust performance of the closed-loop system is verified through a series of frequency-domain analyses. Finally, the effectiveness of the proposed QFT-based controller is demonstrated through simulations. © Author 2011.