单轴加速度计信息采集系统设计

为了实现对惯导系统中加速度计信号的采集,本文提出了一种新的单轴加速度计信息采集方案。该方案是将加速度计输出的电流信号通过采样电阻转化成电压信号,再由高精度A/D芯片进行模/数转换,在小电流情况下,运用切换采样电阻值的方式将小电流信号转换成大电压信号,从而充分利用了A/D芯片的量程,提高了加速度计信息采集精度。实验证明,该方法可以提高信号的采集精度,使得在小电流情况下加速度精度达到±1×10^-5g以内,满足了惯性导航系统的要求。

Design of Single-axis Accelerometer Signal Acquisition System

This paper presents a new single-axis accelerometer signal acquisition program.In the program we can transform current signal to voltage signal through precision sampling resistor,then convert the analog voltage signal into digital by the high precision 24 bit A/D chip AD7732.In the case of small current value,the system will also get the large voltage signal in the method of switching the high-value resistors.This method makes full use of the A/D chip measurement range and enhances the precision of the system digital collection properly.The experimental results show that the method of switching range can improve the precision signal acquisition.This method enhances the precision of the accelerometer signal acquisition system to ±1×10^-5 g or less in the small current value,which can satisfy the requirement of inertial navigation system.