测量系统相频特性对动态测量误差影响研究

Study on Effects of Phase Frequency Characteristicsof Measurement System on Dynamic Measurement Errors

随着动态测量在测试领域中的比重日益增加,动态测量不确定度的评定与应用问题已经成为现代不确定度理论的核心。当前,学界对于静态不确定度的研究趋于成熟,但关于动态不确定度的评定与应用仍有待研究。针对常规不确定度评定方法不适用于在线测量应用、动态测量不确定度评定方法尚未达成统一的现状,研究了测量系统相频特性对动态测量不确定度的影响。对测量系统的模型进行了阐述。从二阶系统入手,通过仿真分析,比较了不同频率信号和混合信号作为激励的情况下,线性相位与非线性相位测量系统的响应。对比结果表明,非线性相位是动态测量不确定度的一个重要来源,也是导致测量系统延时发生变化的主要原因。该研究结果对于降低测量系统动态测量误差、提高动态测量可信度具有一定的指导意义。

The evaluation and application of uncertainty in dynamic measurement have become the core issue of modern uncertainty theory as we used the dynamic measurement more frequently.The problem that the common uncertainty evaluation approach doesn’t fit for evaluating the uncertainty of dynamical measurement is addressed,and researchers have not accepted methods presented for evaluating the uncertainty of dynamical measurement.The attribute of phase-frequency of a measurement system to dynamical measurement has been studied.The model of the measurement system was described firstly.Started from two-order system,responses of the linear phase system,and that of the non-linear phase system to single-frequency input and mixed input with different frequencies were compared respectively by simulation analysis.The results show that the non-linear phase is a principal source of dynamic measurement uncertainty and the main reason for the alteration of the measurement system’s lag.The results of this study have a certain guiding significance for reducing the dynamic measurement error of the measurement system and improving the reliability of the dynamic measurement.