• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2024, Vol. 60 ›› Issue (4): 82-91.doi: 10.3901/JME.2024.04.082

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Study on Automatic Gain Control and Phase Compensation Control for MEMS Resonant Pressure Sensors

WANG Songli1,2, FANG Xudong1,2,3, GAO Bonan1,2, ZHAO Libo1,2,3, TIAN Bian1,2,3, LIN Qijing1,2,3, ZHANG Zhongkai1,2,3, RAO Hao4, LI Yu4, JIANG Zhuangde1,2,3   

  1. 1. School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049;
    2. State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710056;
    3. Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing, Yantai 265503;
    4. AECC Aero Engine Control System Institute, Wuxi 214026
  • Received:2023-04-06 Revised:2023-10-11 Online:2024-02-20 Published:2024-05-25

Abstract: The amplitude stability and frequency tracking of the detection signal of the silicon micro resonant pressure sensor are very important to its performance, but the nonlinear characteristics of the current amplitude control and frequency tracking methods will cause nonlinear changes in the vibration frequency of the resonator, which limits comprehensive accuracy further improvement of the sensor. In order to reduce the influence of the nonlinear change of the resonator vibration frequency, based on the linearization analysis theory of automatic gain control(AGC), the AGC and phase compensation model is established for the high-Q silicon micro-resonant pressure sensor. With the model, the control characteristics of AGC amplitude control and frequency tracking linearization, and the effect of phase compensation on closed-loop control performance are analyzed. The self-excited drive based on AGC has been proved to make the resonator work stably at the resonant frequency and keep the amplitude stable. Simulink/PSpice simulation verifies the accuracy of the linearization analysis of the nonlinear system. Afterwards, a control circuit is designed and fabricated based on the AGC and phase compensation model for the silicon resonant pressure sensor, which can make the frequency stability of the whole meter better than ±0.05 Hz@sampling period 5 ms, and the comprehensive accuracy is better than ±0.02%. The engineering application of AGC in resonant pressure sensors solves the problem of sensor performance degradation caused by the nonlinear frequency tracking of resonators. The study in this work demonstrates AGC and phase compensation control can be widely used in closed-loop control of high-Q resonators.

Key words: silicon micro resonator, pressure sensor, AGC, phase compensation, nonlinearity

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