Study on Dynamic Characteristics of Shock Wave Pressure Sensor Assembly Based on Differential Method

摘要

Under damage condition, the sensor system which measures the shock wave ground-reflected pressure must be affected by parasitic effects, like thermal shock and mechanical vibration. To measure the ground-reflected pressure accurately, appropriate measures need to be taken to the sensor to reduce the influence of parasitic effects. These measures make the sensors dynamic characteristics change, so it is necessary to calibrate the sensor assembly. In this paper, shock tube was chosen to calibrate the sensor assembly and get the step response signals. According to the characteristics of the response signals, this article investigated the calculating methods of the dynamic characteristics of sensor assembly. By differential method, the digital differentiator with low-pass filtering function was designed and used to differentiate the step response signals. By chirp-z transform spectrum zoom, the dynamic characteristics of the sensor assembly could be calculated. Dynamic characteristics analysis showed that the dynamic characteristics of the sensor assembly could reflect the structural characteristics of the sensor assembly.