数字闭环石英挠性加速度计量化误差分析与实验研究

Quantization error analysis and experimental research on digital closed-loop quartz flex accelerometer

数字闭环方案可以减小模拟伺服方案中A/D转换环节所引入的精度损失,而量化误差是影响数字闭环石英挠性加速度计系统精度的重要因素之一。介绍了数字闭环石英挠性加速度计检测系统的工作原理,讨论了AD,DA位数的选择依据,基于现有硬件检测电路,软件上采取AD,DA降位使用的方法分析量化误差对闭环系统精度的影响。搭建数字闭环实验系统,实验结果表明:在一定范围内,随着AD,DA位数的降低,量化误差影响增大,闭环系统精度降低,与理论分析相吻合,为数字闭环加速度计的精度改善提供必要的理论指导和实验基础。

Digital closed-loop scheme can reduce precision loss in analog to digital （A/D）conversion of analog servo scheme,and quantization error is one of the important factors which influence system precision of digital closed-loop quartz flex accelerometer （DCL-accelerometer）. Working principle of DCL-accelerometer detecting system is introduced, and digits selection criteria of AD, DA bit is discussed, i. e, based on existing hardware detection circuit, use AD, DA dropping method to analyze closed-loop system precision influenced by quantization error from software aspect. Build up digital closed-loop experimental system, experimental results show that in a certain range, as AD, DA bits dropping, effect of quantization error is increased while closed-loop system precision is reduced, which coincides with the theoretical analysis and provides necessary theoretical guidance and experimental basis for improvement of precision of the accelerometer.