In order to expand the target area

and to suit for the velocity measurement of large-caliber and high-speed flying objects

this system uses light curtain without refective devise as the target.The influence factors of detective distance are analyzed

and the actual detective performance of the system is verified through experiment.The system forms a circle field of view

an area of 0.502 mm2

with a radius of 400 mm generally at a distance of 1 300 mm from the lens.In this field of view

object of diameter greater than or equal to 40 mm can be detected when it pass through the light curtain.The related solution on index improvement is brought forward depending on the impact parameters.This system can not only detect the target

but also optimizes of the mechanical structure

easy to regulate and greatly reduces the volume.So it is more convenient to use in the wild environment.