• CN:11-2187/TH
  • ISSN:0577-6686

›› 2006, Vol. 42 ›› Issue (12): 128-131.

• 论文 • 上一篇    下一篇

梳齿式微机械加速度计闭环系统的线性度

吴天准;董景新;赵长德;冯宇翔   

  1. 清华大学精密仪器与机械学系
  • 发布日期:2006-12-15

CLOSED-LOOP SYSTEM LINEARITY OF A COMB-FINGER MICRO-ACCELEROMETER

WU Tianzhun;DONG Jingxin;ZHAO Changde;FENG Yuxiang   

  1. Department of Precision Instruments and Mechanology, Tsinghua University
  • Published:2006-12-15

摘要: 为研究离心试验中微机械加速度计的线性度和输入加速度的关系,分析闭环系统的位置误差,然后根据微机械加速度计闭环系统的输出公式,对离心试验的加速度输入和电压输出之间的关系进行最小二乘分析,提出单程线性度和全程线性度的公式,证明线性度为输入的二次曲线函数,且与开环系统低频环路增益有关。线性度公式表明增大低频环路增益,增大悬臂梁机械刚度以提高线性度的方法。利用电测法估算机械参数,并利用离心试验的数据进行验证。结果表明,可以利用±1 g静态翻滚试验的数学模型和电气参数来估计高g输入下的线性度,理论值与实测值符合得较好,因此可以用简单廉价的±1 g线性度测试来粗略替代复杂且昂贵的离心试验进行满量程线性度的估算。

关键词: 离心试验, 梳齿式微机械加速度计, 数学模型, 微机电系统, 位置误差, 线性度

Abstract: To clarify the relation between linearity of a micro- accelerometer and the input acceleration in a centrifugal test, a cubic mathematic model is built and the least squared criterion is applied in the analysis of closed-loop system output. Linear-ity formulae are put forward and proved that the linearity is a quadric function of input, and relates to open-loop gain of low frequency band. The formulae indicate theoretical means to improve linearity by altering electrical and structural parameters. Electrometric method is used to measure mechanical parameters, and the formulae are verified by centrifugal testing data. The result shows that linearity can be estimated according to the mathematic model obtained in the static rolling test, and calcu-lated values are close to corresponding measured values.

Key words: Centrifugal experiment, Linearity, Mathematic model, Micro-accelerometer, Micro-electro-mechanical system (MEMS), Positional error

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