基于改进等周期法的振梁加速度计测频方法  

Frequency Measurement Method of Vibrating Beam Accelerometer Based on Improved Isoperiodic Method

作　　者：张雅宁 王晓东 袁文辉 华旭 张博学 ZHANG Ya-ning;WANG Xiao-dong;YUAN Wen-hui;HUA Xu;ZHANG Bo-xue(Beijing Aerospace Xinghua Technology Co.,Ltd,Beijing 100039)

机构地区：[1]北京航天兴华科技有限公司,北京100039

出　　处：《导航与控制》2023年第4期59-66,58,共9页Navigation and Control

基　　金：国家重点计划研发课题(编号:2021YFB3201505)。

摘　　要：振梁加速度计的输出量频率需要被连续、准确地测量,而现有应用于小型化电路板上的测频方法相比于频率计存在较大的原理性误差,针对运用等周期法的测频方法精度不高的问题,提出了一种改进等周期法来测量加速度计输出的频率值。本实验采用Altera max10型的FPGA芯片来实现测频和数据处理及运算,实验中使用测频电路和标准频率计53220A分别测量标准信号源、振梁加速度计的频率输出。实验结果显示,对比改进前后的算法,输入信号为标准信号源时,测频电路的输出精度有效提升,数值由原来的3.513μg变为1.078μg;输入信号为振梁加速度计的输出时,经过指数平滑滤波之后的输出精度由原来的22μg变为9.2464μg。对比频率计对振梁加速度计输出的测频结果,分析了影响加速度计测频精度的主要影响因素。经过测量后的结果表明,所提的基于改进算法的测频电路相比于等周期法可以有效地提升精度,并且拥有小型化、精度高的特点,在未来具有很好的应用价值。The output frequency of the vibrating beam accelerometer needs to be measured continuously and accurately,but the existing frequency measurement method applied to the miniaturised circuit board has a principle error compared to the frequency meter.Aiming at the problem that low accuracy in frequency measurement method utilizing the isoperiodic method,an improved isoperiodic method is proposed to measure the frequency value of the accelerometer output.The experiment uses an Altera max10 FPGA chip to implement the frequency measurement,data processing and operation.In the experiment,a frequency measurement circuit and a standard frequency meter 53220A are used to measure the frequency output of the standard signal source and the vibration beam accelerometer respectively.The experiment results show that the output accuracy of the frequency measurement circuit is effectively improved,and the value is changed from 3.513μg to 1.078μg compared with the improved algorithm before and after when the input signal is a standard signal source.The output accuracy is changed from 22μg to 9.2464μg after exponential smoothing filtering when the input signal is the output of the vibrating beam accelerometer.By comparing the frequency measurement results of a frequency meter on the output of a vibrating beam accelerometer,the main influencing factors affecting the frequency measurement accuracy of the accelerometer are analyzed.The measured results show that the proposed frequency measurement circuit based on the improved algorithm can effectively improve the accuracy compared to the isoperiodic method,and has the characteristics of miniaturisation and high accuracy,which is of good value for future applications.

关 键 词：振梁加速度计 测频电路 等周期法 

分 类 号：V19[航空宇航科学与技术—人机与环境工程]