Research on Closed-Loop Control Method of MEMS Disk Resonant Gyroscope Based on Dual-Modal Parametric Excitation

Among the MEMS gyroscopes, MEMS disk gyroscopes exhibit high performance potential and broad development prospects. However, due to the small mass and detection capacitance of the MEMS gyroscopes, the detection sensitivity and the signal-to-noise ratio of the gyroscope are low. Moreover, the structural coupling and errors introduced by the manufacturing processing errors of the gyroscope can interfere with the angular rate detection. Parametric excitation is proposed as a kind of excitation scheme, involving periodic modulation of stiffness, which can effectively improve the quality factor and enhance the detection sensitivity and signal-to-noise ratio of gyroscope. Therefore, this dissertation takes the independently designed MEMS disk gyroscope as the object, and proposes and establishes the dual-modal parametric excitation dynamic equations of stiffness coupling and damping coupling. Based on the above analysis, a dual-modal parametric excitation control system for the MEMS disk resonator gyroscope is established, and the influence of parametric excitation on the drive signal and the sense mode is verified. Compared with the open-loop detection and control scheme without parametric excitation, the main performance of the gyroscope has been significantly improved, including a 6.4-fold increase in the quality factor amplification gain for the drive mode, a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{4.9}$</tex> -fold improvement in open-loop detection sensitivity, and a 2.5-fold enhancement of bias instability. The bias instability is increased from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{20.18}^{\circ}/\mathbf{h}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{8.04}^{\circ}/\mathbf{h}.\mathbf{The}$</tex> angle random walk is increased from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1.65}^{\circ}/\surd\mathbf{h}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{0.59}^{\circ}/\surd\mathbf{h}$</tex>