双光束差动激光多普勒测速法在高冲击校准技术中的应用

Application of Double Beam Differential Laser Doppler Velocimetry in High g Impact Calibration Technology

在以气炮为激励源的高冲击校准技术中,精确测量高速运动砧体的速度是其中关键技术之一。提出了一种双光束差动激光多普勒测速方法,一方面解决了低量程激光多普勒测速仪测量高速度的问题,另一方面解决了动态角度偏差对物体运动速度测量精度的影响问题;并结合该测速方法在量程为2×10~6m/s^2高冲击校准系统中的应用,介绍了测速系统的组成和双光束夹角测量系统组成,分析了测速系统的不确定度来源。结果表明,建立的双光束差动激光多普勒测速系统测量范围为0~124 m/s,速度测量的相对扩展不确定度小于1.4%,满足高冲击加速度校准系统的使用要求。

In the gas-gun-excited high g impact calibration, one of the key technologies is to measure precisely the velocity of the high- speed anvil. The paper presents a double beam differential laser Doppler velocimetry. This method allows low-range laser Doppler velocimeters to measure the velocity of high-speed moving objects, and solves the dynamic angle deviation effects on the speed measurement accuracy of moving objects. Taking as an example its application in the high g impact calibration system within 2×10^7m/s^2, this paper introduces the composition of the velocimeter system and the double beam angle measurement system, and analyzes the uncertainty sources of the velocimeter system. The re- sults indicate that the double beam differential laser Doppler velocimetry can measure the speed range of 0 - 124 m/s, and the related expanded uncertainty of velocity measurement is 1.4%, which satisfies the operating requirements of high g impact acceleration calibration system.