Azier Alexandre, Kacem Najib, Chaumet Bernard, Bouhaddi Noureddine
Department of Applied Mechanics, FEMTO-ST Institute, CNRS/UFC/ENSMM/UTBM, University Bourgogne Franche-Comté, 25000 Besançon, France.
Thales Avionics, 26027 Valence, France.
Micromachines (Basel). 2022 Apr 20;13(5):655. doi: 10.3390/mi13050655.
In this paper, we develop a new approach in order to understand the origin of the quadrature error in MEMS gyroscopes. As the width of the flexure springs is a critical parameter in the MEMS design, it is necessary to investigate the impact of the width variations on the stiffness coupling, which can generate a quadrature signal. To do so, we developed a method to determine the evolution of the stiffness matrix of the gyroscope springs with respect to the variation of the bending beams width of the springs through finite element analysis (FEA). Then, a statistical analysis permits the computation of the first two statistical moments of the quadrature error for a given beam width defect. It turns out that even small silicon etching defects can generate high quadrature level with up to a root mean square (RMS) value of 1220°/s for a bending beam width defect of 0.9%. Moreover, the quadrature error obtained through simulations has the same order of magnitude as the ones measured on the gyroscopes. This result constitutes a great help for designing MEMS gyroscopes, as the consideration of the bending beams width defects is needed in order to avoid high quadrature error.
在本文中，我们开发了一种新方法，以了解MEMS陀螺仪中正交误差的来源。由于挠性弹簧的宽度是MEMS设计中的一个关键参数，因此有必要研究宽度变化对刚度耦合的影响，刚度耦合会产生正交信号。为此，我们开发了一种方法，通过有限元分析（FEA）来确定陀螺仪弹簧刚度矩阵相对于弹簧弯曲梁宽度变化的演变。然后，通过统计分析可以计算给定梁宽度缺陷下正交误差的前两个统计矩。结果表明，即使是很小的硅蚀刻缺陷也会产生高正交水平，对于0.9%的弯曲梁宽度缺陷，均方根（RMS）值高达1220°/s。此外，通过模拟获得的正交误差与在陀螺仪上测量的误差具有相同的数量级。这一结果对设计MEMS陀螺仪有很大帮助，因为需要考虑弯曲梁宽度缺陷以避免高正交误差。
