数字闭环加速度计带宽测试方法的研究

Study of bandwidth measurement method of digital closed-loop accelerometer

为了消除传统电模拟法引入的激励信号对力矩器驱动模块造成的影响,提出了一种在数字闭环加速度计系统反馈回路数模转换器输入端叠加一个激励信号来测试系统带宽的方法。通过对该方法的电激励模型进行分析,表明在带宽测试时系统反馈回路D/A输入端叠加激励信号可以等效为外界输入的加速度。搭建测试平台测试系统带宽,实验表明,用该方法测得的数字闭环加速度计系统带宽与传统机械振动法的测试结果相接近。该方法未增加其它电路,降低了系统的复杂度,消除了电模拟法外加激励信号源对力矩器驱动模块的影响。此外,该方法操作快速简单、便于在线测试,可满足大多数数字闭环加速度计的带宽测试要求。

In order to eliminate the influence of the excitation signal introduced by the traditional electric simulation method on the torque driver module, a method which adds the excitation signal at the input of the digital-analog converter in feedback circuit of the digital closed-loop accelerometer to measure the bandwidth of the accelerometer is proposed. Through the analysis of the electric excitation model, it is shown that the effect of the excitation signal added at the input of the digital-analog converter in feedback circuit can be equivalent to an acceleration imported from the outside. The testing platform system for bandwidth measure is set up. The experiment shows that the bandwidth data of the digital closed-loop accelerometer system is closed to the data measured by the method of traditional mechanical vibration. Because of without increasing any other circuits, the method reduces the complexity of the system and eliminates the effects of the incentive source introduced by electricity simulation method on the torque driver module. The method is easy to operate, and convenient to test online, which can meet most of the bandwidth testing requirements of digital closed-loop accelerometer.