冲击加速度测量不确定度的评估方法研究

发布时间：2018-03-03 00:27

本文选题：测量不确定度　切入点：冲击加速度　出处：《中北大学》2017年硕士论文　论文类型：学位论文

【摘要】：冲击加速度传感器及其测试系统是目前获取各种高冲击瞬态信号以及各种弹道参数的核心部件,它们的准确性对整个测试过程能否取得成功以及测试结果是否可靠起着决定性的作用,是以很有必要对冲击加速度传感器及其测试系统的测量不确定度进行评估。按照不确定度评定结果,可以确定冲击加速度测量的准确度。基于此,本文主要进行了如下研究:(1)研究了目前常用的几种测量不确定度评定方法,包括GUM法、蒙特卡洛法和贝叶斯评定法,并对各自的基本原理及使用方法做了详细分析,总结了测量不确定度评定的一般流程。(2)通过分析测量系统的不确定来源,以冲击加速度传感器峰值灵敏度的Hopkinson杆校准系统为例,对校准结果分别运用GUM、贝叶斯和蒙特卡洛评定法进行不确定度评定,详细分析了这三种方法各自的优缺点,并提出在动态测试中,对于不同的测试系统若用这三种方法需分别寻求各自的适用条件,不具有普遍适用性,且其无法对整个连续过程的不确定度进行估算,针对这些问题提出基于频率域的动态不确定度评定法,且其适用于在一定范围内对各种不同测试系统进行不确定度估计。(3)在频率域对动态测量不确定度进行估算法的具体流程是:针对实际测试系统,建立一个理想测试系统,求出两个测试系统的动态测量误差;分别求出两个测试系统的幅.频特性和相频特性,并根据帕斯瓦尔定理求出该动态误差的功率谱函数;根据功率谱求出实际的动态测量不确定度。最后以冲击加速度传感器的动态校准系统以及测试系统为例,将该动态测量不确定度估算法应用于实际当中。(4)对动态校准系统以及测试系统进行建模,求出系统特性,通过将对输入信号的响应曲线与实际测得的响应曲线进行比较求出测量不确定度,最后将结果与频率域的估算结果进行比较,验证提出的频率域动态测量不确定度估算法的可行性。
[Abstract]:The shock acceleration sensor and its testing system are the core components for obtaining all kinds of high impact transient signals and various ballistic parameters. Their accuracy plays a decisive role in the success of the whole test process and the reliability of the test results. It is necessary to evaluate the measurement uncertainty of the shock acceleration sensor and its measuring system. According to the evaluation result of the uncertainty, the accuracy of the impact acceleration measurement can be determined. In this paper, the following research is carried out: (1) several commonly used measurement uncertainty evaluation methods, including GUM method, Monte Carlo method and Bayesian evaluation method, are studied, and their basic principles and application methods are analyzed in detail. This paper summarizes the general flow chart of uncertainty evaluation of measurement. By analyzing the source of uncertainty in measurement system, the Hopkinson rod calibration system with peak sensitivity of shock acceleration sensor is taken as an example. The uncertainty of calibration results is evaluated by using GUM, Bayes and Monte Carlo methods respectively. The advantages and disadvantages of the three methods are analyzed in detail, and the dynamic test results are proposed. For different test systems, if the three methods need to seek their own applicable conditions, they are not universally applicable, and the uncertainty of the whole continuous process can not be estimated by the three methods. To solve these problems, a dynamic uncertainty evaluation method based on frequency domain is proposed. And it is suitable for estimating the uncertainty of various test systems in a certain range. The concrete flow of the method for estimating the uncertainty of dynamic measurement in frequency domain is to establish an ideal test system for the actual test system. The dynamic measurement error of the two test systems is obtained, the amplitude, frequency and phase frequency characteristics of the two test systems are obtained, and the power spectrum function of the dynamic error is obtained according to the Pasval theorem. According to the power spectrum, the actual uncertainty of dynamic measurement is obtained. Finally, the dynamic calibration system of impact acceleration sensor and the test system are taken as an example. The uncertainty estimation method of dynamic measurement is applied in practice. (4) the dynamic calibration system and the test system are modeled, and the characteristics of the system are obtained. By comparing the response curve of the input signal with the measured response curve, the uncertainty of the measurement is obtained. Finally, the results are compared with the estimated results in the frequency domain. The feasibility of the proposed method for estimating the uncertainty of dynamic measurement in frequency domain is verified.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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