冲击波测试系统低频特性与补偿方法研究

为提高冲击波超压峰值的测量精度，多数学者把重点集中在系统高频特性研究上，以拓宽带宽的方式提高峰值测试的准确性。冲击波另外两个主要参数正压作用时间、比冲量却和测试系统的低频特性息息相关。针对实爆中出现的不同传感器正压作用时间差异较大的问题，对冲击波信号进行了边际谱分析，获得了信号的低频特性。建立了一阶参数模型来表征低频特性，通过激波管试验数据获取了7种系统的低频模型参数。采用零极点配置法设计了低频补偿模型。结果表明:冲击波测试系统低频特性严重影响冲击波信号正压作用时间测试准确性，基于低频特性补偿的数据处理方法可以有效的提高冲击波信号正压作用时间、比冲量地测试精度。

Research on low frequency characteristics and compensation method of a shock wave test system

In order to improve the measurement accuracy of shock wave overpressure peak, most scholars focus on the study of high-frequency characteristics of the system for improving the accuracy of peak value measurement by broadening the bandwidth. The other two main parameters of the shock wave, positive pressure action time and specific impulse, are closely related to the low frequency characteristics of the test system. Aimed at the problem that the positive pressure action time of different sensors varies greatly in real explosion, the marginal spectrum analysis of the shock wave signal was carried out, and the low frequency characteristics of the signals were obtained. A first-order parametric model was established to characterize the low-frequency characteristics, and the low-frequency model parameters of seven systems were obtained from the experimental data of shock tube. The low-frequency compensation model was designed by the zero pole configuration method. The results show that the low-frequency characteristics of shock wave testing systems seriously affect the accuracy of positive pressure action time measurement of shock wave signals. The data processing method based on the low-frequency characteristic compensation can effectively improve the measurement accuracy of positive pressure action time and specific impulse of shock wave signals.