Digital signal processing algorithm for velocity measurement light screen

Abstract

In order to solve the technical problem of the light screen disturbed incorrect signals due to external environmental interference, a digital signal processing algorithm is put forward in this paper. The band-pass filter is used to filter out signals of mosquitoes, shock wave and random noise in order to improve the reliability of the test system by analyzing the difference of frequency between the interference signal and the projectile signal. The triggering moment of the light screen center can be selected correctively by means of the 4 power Gaussian curve-fitting for the sampling data to achieve high-precision measurement with the lower sampling rate. The testing result of the computer simulation and the firing show that the algorithm is eligible to measure the flight velocity of various projectiles, and it can broaden the application field of the light screen target. The result proved the algorithm measurement relative error is not more than 0.1%.