Measurement of the velocity vector of a flying projectile with infrared light screens

摘要

A conventional velocity measuring system of flying projectile consists of two light screens and a chronometer. The flying trajectory is vertical to the sensing plane of light screens. Otherwise the system might produce more measurement errors. In the terminal of trajectory, it is very difficult to ensure that the trajectory of the flying projectile is vertical to the sensing plane because of the scattering of the projectiles. Especially, there is a quite big angle between the flying trajectory and the sensing plane in measuring the velocity of terminal of the fragments. More errors may occur if using two light screens to measure velocity. The new method for measuring velocity at any direction with six infrared light screens is presented. The six infrared light screens are composed of light screen arrays in some special geometric structure. The chronometer records the times of the projectile going through each screen. The flying velocity and special angle of the projectile, that is flying velocity vector, can be calculated according to six times and the geometric structure parameters.