摘要
由于存在测量误差,测量结果就带有不确定性,测量不确定度是评估测量结果质量高低的重要指标。将采样长度与信号周期比值分为整数和小数部分,推导出离散傅里叶变换(DFT)算法频率和相位差的测量误差;运用B类不确定度评估方法,分别分析由频谱泄漏、加窗和栅栏效应造成的频率测量不确定度,得到频率测量合成不确定度表达式;通过相位差测量误差与频率测量误差的关系,推导出相位差不确定度表达式;最后通过计算分析,验证了频率和相位差测量误差、测量不确定度与采样长度的关系,分析结果表明了评估过程的可行性和有效性。
Because of the measurement error,the measurement result is uncertain.Measurement uncertainty is an important indicator for evaluating the quality of measurement results.The ratio of the sampling length to the signal period is divided into integer and decimal parts,and the measurement errors of the DFT frequency and phase difference are deduced.The Class B uncertainty evaluation method is adopted to analyze the frequency measurement uncertainty caused by spectrum leakage,windowing,and fence effect,and the synthetic uncertainty of frequency measurement is obtained.Then the phase difference uncertainty is determined through the relationship between phase difference measurement error and frequency measurement error.Finally,through calculation and analysis,the relationship between the sampling length and measurement error as well as uncertainty of frequency and phase difference is verified.The analysis results show that the evaluation process is feasible and effective.
作者
彭钰钦
涂亚庆
杨辉跃
Peng Yuqin;Tu Yaqing;Yang Huiyue(Army Logistics University of PLA,Chongqing 401311,China)
出处
《电子测量与仪器学报》
CSCD
北大核心
2020年第9期17-22,共6页
Journal of Electronic Measurement and Instrumentation
基金
国家重点研发计划(2018YFB2003900)
国家自然科学基金(61871402)
重庆市自然科学基金(cstc2019jcyj-msxmX0245)资助项目。
关键词
DFT
频率测量
相位差测量
不确定度评估
DFT
frequency measurement
phase difference measurement
uncertainty evaluation
