Information Processing Technique Of The Projectile Passing Through The Trapezoidal Light-screen

The flight parameters such as the flight velocity and the impacting coordinates of the projectile launched by the weapon are the basic indexes to measure the performance of this kind of weapons,are the essential parameters of the range test.Six light-screen array sky screens vertical target is a widely used measuring equipment which can form six detection light-screen in space according to a certain position and angle.When the projectile passes through the detection light-screen instantaneous,the projectile signal corresponding to each light-screen can be output,and the acquisition of six signals synchronously collected by the data acquisition instrument and the calculation of the time when the projectile passes through the light-screen,combined with the position parameter of the light-screen,the projectile flight parameters can be calculated.The spatial thickness distribution of the mirror light-screen is trapezoidal.When the projectile passes through the trapezoidal light-screen at a certain angle,there is a certain time measurement error in the traditional method of feature extraction.In this paper,a correction algorithm for extracting characteristic time information of the trapezoidal light-screen is proposed.By analyzing the spatial distribution of the thickness of the light-screen and combining the flight process of the projectile,the accurate time value of the projectile reaching the center of the inclined trapezoidal light-screen is calculated accurately.At the same time,the recognition algorithm of screen signal in complex environment is studied to improve the accuracy of the measurement system.The main contents of this paper are as follows:Firstly,according to the principle of lens imaging,the spatial distribution of the thickness of light-screen formed by the slit aperture passing through is analyzed,and the calculation formula of the thickness of the light-screen at different positions of the lens is deduced.The test platform is built and verified by the experiment.Secondly,according to the angle of spatial tilt of the light-screen,the pitch angle of the projectile flight direction and the thickness of the light-screen,the relationship between the time when the projectile tail reaches the center of the thickness of the screen and the amplitude of the signal is studied,and the corresponding calculation formula is derived.The time when the projectile tail reaches the center of the light-screen in different states is accurately calculated,and the error caused by the traditional half-peak characteristic point algorithm is corrected.Then,the frequency characteristics of the projectile passing through the screen are analyzed,and the generation principle and the characteristics of the interference signal are studied.Then an effective recognition algorithm of the projectile signal based on lifting wavelet algorithm is proposed.So the projectile signal can be effectively identified from the complex interference signal,and the applicability of the light-screen array under the condition of near-sonic projectile and continuous firing can be improved.Finally,the method of coordinate alignment is used to verify the algorithm of extracting the feature moment of inclined trapezoidal light-screen.The accuracy of measurement is improved by 7.9% compared with the traditional method.The method of speed comparison is used to validate the signal recognition algorithm,which can effectively identify the projectile signal passing through the light-screen from the interference signal.