【作者】 赵晓东；

【导师】 裴东兴； 范锦彪；

【作者基本信息】 中北大学 ， 测试计量技术及仪器， 2010， 硕士

【摘要】 本文主要研究高g值加速度计的冲击校准方法,以提高校准精度,为侵彻测试提供可靠的加速度计特性参数。在查阅大量国内外文献的基础上,采用理论分析、计算机仿真与实验研究相结合的方法进行了以下研究：(1)在多普勒信号解算方面,针对冲击加速度计的校准,编写了多普勒解算验证算法,检验了相位法和过零点法对多普勒瞬时频率的解算精度。经模拟验证得出,信噪比为30dB时相位求导法的解算误差为0.20%,优于过零点法。最后通过对988型压电式加速度计在18371g-86806g的校准实验表明了试验装置和解算方法的有效性。(2)在干扰信号去除方面,由于电网的工频干扰,频率为50Hz的周期信号叠加在加速度计输出信号中,难以分辨其中的加速度信息。本文通过分析干扰信号的频率成分提出了一种滤波算法,有效消除了工频干扰对加速度计输出信号的影响。(3)在校准数据处理方面,为了获取加速度计动态特性参数,采用时域建模方法建立加速度计动态数学模型,对8309加速度计的计算结果表明,加速度计及其安装座装配体谐振频率为76.8kHz,工作频带(即幅值误差为±5%或±10%的两种工作频带)为0-53.8kHz或0-69.2kHz。(4)在校准误差分析方面,本文在建立霍普金森杆中各力学量(应力、速度、加速度)传播、变换的力学模型的基础上,分别讨论两种理想极限情况下横向激光测速系统对激励信号的测量误差,并根据得出的结果对实际校准情况下的激励信号测量误差进行评估。本文对988型和8309压电式加速度计、SIMIT-AYZ-3压阻式加速度计的校准实验表明了试验装置和解算方法的有效性。更多还原

【Abstract】 This paper is mainly research the high-g accelerometer shock calibration methods in order to improve the calibration accuracy for the penetration testing to provide a reliable accelerometer parameters. Having been searched abroad the related documents, the paper adopts the methods such as theoretical analysis, computer simulation and experimental study to investigate the issues in question:(1) In the Doppler signal decoding, a kind of arithmetic about decoding the Doppler signals is compiled to test the precision of the zero-cross method and the phase method. The simulating result shows that the phase method is superior to the zero-cross method with the error of 0.20%, under the SNR of 30dB. A 988-type accelerometer is calibrated with the input acceleration ranging from 18371g to 86806g, which has justified the efficiency of the calibration apparatus and the method for signal processing.(2) In the aspect of removing interference signals, because of the power frequency interference, frequency of 50Hz periodic signals mixed in the output signal of the accelerometer. It is difficult to distinguish the acceleration signal. This paper presents a filtering algorithm by analyzing the frequency components of interference signal, which effectively eliminates the influence that power frequency interference on the accelerometer output signals.(3) In the calibration data processing, using time-domain modeling methods to establish accelerometer dynamic mathematical model to obtain accelerometer dynamic characteristic parameter, the 8309-type accelerometer calculation results show that the resonant frequency of accelerometer and assembly seat is 76.8kHz, and frequency band is 0-53.8kHz or 0-69.2kHz.(4) In the calibration error analysis, on the basis of the mechanical model that establishment of Hopkinson bar mechanical quantities (stress, velocity, acceleration) communication and transformation, measurement error of transverse laser velocimetry system to excitation signal are discussed under two kinds of ideal limit conditions. According to the results estimate measurement error of excitation signal in the actual situation of calibration.In this paper,988-type and 8309-type piezoelectric accelerometers and a kind of piezoresistive-type accelerometer SIMIT-AYZ-3 are used. And the result of the calibrations entitled this calibration device and the method with validity.更多还原