MEMS gyroscope control systems for direct angle measurements

This paper presents a control algorithm for vibrating gyroscopes so that they can directly measure the rotation angle without integrating the angular rate. In most gyroscope systems, the rotation angles were obtained by integrating the angular rate, thus suffer from the error accumulation problem. Only a few papers reported that they could compensate the imperfect dynamics in gyroscopes and obtain the rotation angle directly. However, they either required a calibration phase prior to the normal operation or their stability was not theoretically proven. This paper proposes a one-step control algorithm so that imperfection compensation and angle measurement can be done simultaneously. In a demonstrating case, the mechanical structure uncertainties caused 10%~20% parameter variations in a gyroscope system; the signal are contaminated by zero-mean white noise with the PSD of 2.3×10^-15(ms^-1)²/Hz; the angular rate to be measured is 4sin(2¿ × 40t) rad/sec. The proposed algorithm can obtain the rotation angle with an accuracy less than 0.5 degree.