基于激波管校准的冲击波压力传感器动态特性研究

Dynamic characteristic of shock wave pressure sensor based on shock tube calibration

为对冲击波压力传感器进行校准,研究传感器动态特性非参数模型。基于双膜激波管对传感器实施动态校准试验,获得了阶跃响应输出。仿真模拟四阶串联系统,并构造阶跃响应信号。分别使用理想阶跃分解法、低阶模型分解法和微分法得到传感器动态特性非参数模型。微分法计算精度更高且简单易行。为抑制寄生效应,采用机械结构对冲击波压力传感器进行改造。采用微分法对改造前后的典型冲击波压力传感器动态特性进行了研究。仿真结果表明,改造措施虽然可以减小机械振动与冲击和热效应,但使得冲击波压力传感器工作频带变窄,无法满足工程测试无失真条件。

Dynamic characteristic non-parameter models are researched to calibrate shock wave pressure sensors. Outputs of step responses are obtained through dynamic calibration experiments using a double film shock tube. A four-step series system is simulated, and step response signals are constructed. Three dynamic characteristic non-parameter models are obtained using the ideal step de-composition method, the low-order model decomposition method and the differential method distinguishly. The differential method is more accurate and simpler. A shock wave pressure sensor is transformed using a machine to restrain parasitic effects. The dynamic characteristics of the shock wave pressure sensor before and after the transformation are calculated and compared using the differential method. The simulation results show that although the transformation can decrease thermal effects and mechanical vibration and shock, but the sensor bandwidth is narrowed, and the sensor cannot meet the without distortion conditions of engineering test.