Systematic Modeling of a MEMS Resonant Accelerometer Based on Displacement Coordination
Jinyang Huang, Yang Zhao, Guo Ming Xia, Qin Shi, An Ping Qiu
Abstract
Microelectromechanical system (MEMS)-based resonant accelerometers have great application potential in navigation guidance. In the present work, a systematic theoretical model of a MEMS resonant accelerometer was proposed. The coupling effect of microleverage mechanisms on the proof mass and the resonator was analyzed by the displacement coordination method for the first time. The resonant frequency of the proof mass, the natural frequency of the resonator, and the sensitivity of the accelerometer were united into one model for the structural cooperative design. The analytical model was approved by finite element simulations and verification experiments, and the relative error of key parameters was less than 13%. The analysis of the accelerometer architecture revealed that 1) joints between beams and the microleverage arm should be on the same level, 2) the geometric dimensions of the input beam and pivot beam of the microleverage should be the same, and 3) the microleverage arm width should be sufficient to ensure the rigidity. The performance of the accelerometer was also tested. The bias instability of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1 \mu \text{g}$ </tex-math></inline-formula> (Allan variance), the stability of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2.12 \mu \text{g}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1\sigma $ </tex-math></inline-formula> , 1 Hz date rate, one-hour length), and the nonlinearity of 16.3 ppm with the full range of ±20 g were achieved at room temperature.