基于AD7124的高精度MEMS加速度计信号处理系统  

High-precision Micro-electro-mechanical System Accelerometer Signal Processing System Based on AD7124

作　　者：唐宇莎 张伟[1] 郭子龙 TANG Yusha;ZHANG Wei;GUO Zilong(Key Laboratory of Sensor,Beijing Information and Technology University,Beijing 100101,CHN;School of Opto-electronical Engineering,Xi an Technology University,Xi an 710021,CHN)

机构地区：[1]北京信息科技大学传感器重点实验室,北京100101 [2]西安工业大学光电工程学院,西安710021

出　　处：《半导体光电》2024年第5期792-797,共6页Semiconductor Optoelectronics

基　　金：国家自然科学基金资助项目(61372016);北京市教育委员会科技计划重点项目(KZ201711232030);传感器北京市重点实验室开放课题基金资助项目(2022CGKF002).

摘　　要：为降低加速度计存在的零点漂移对测量精度的影响,满足低量程微机械(MEMS)加速度计的测量精度和漂移需求,设计了一种基于AD7124的高精度MEMS加速度计信号处理系统。以STM32F303CBT6为核心控制器,驱动高精度模/数(A/D)转换芯片AD7124进行数据采集。设计脉冲宽度调制输出方波作为加速度计的激励信号,运用加权移动平均滤波对信号进行去噪和平滑,提出一种零点漂移抑制与跟踪的算法,解决了零点漂移过大的问题。测试结果表明,加速度计在±1 g量程下的灵敏度为146 mV/g,经过数字滤波后的加速度计输出稳定度提高了5.97倍,最终零偏稳定性由45.850 mg/h改善为0.055 mg/h。To reduce the influence of the zero-drift problem on the measurement accuracy of an accelerometer and satisfy the measurement accuracy and drift requirements of a low-range micro-electro-mechanical system(MEMS)accelerometer,a high-precision MEMS accelerometer signal processing system based on AD7124 is designed.The hardware uses STM32F303CBT6 as the core controller to drive AD7124,and a high-precision analog-to-digital(A/D)conversion chip is used for data acquisition.In the software,the pulse width modulation(PWM)output square wave is designed as the excitation signal of the accelerometer,and the weighted moving average filter is used to denoise and smooth the signal.An algorithm for zero-drift suppression and tracking is proposed,which solves the problem of excessive zero-drift.After testing,the sensitivity of the accelerometer is 146 mV/g at the±1 g range,the output stability of the accelerometer after digital filtering is increased by 5.97 times,and the final bias stability is improved from 45.850 mg/h to 0.055 mg/h.

关 键 词：微机械加速度计 AD7124 脉冲宽度调制 加权移动平均滤波 零点漂移 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TN379[自动化与计算机技术—控制科学与工程]