Projectile flight parameters measurement method based on the spatial distribution of light-screen thickness

Abstract

The light-screen is widely used as a sensor in the measurement of projectile flight parameters of rapid-fire weapons due to the high sensitivity and the fast response. The current measurement theory regards the light-screen as an ideal plane. therefore, it is necessary to arrange at least four light-screens in space to form a detection array to measure the flight velocity and coordinates of the projectile. However, the actual light-screen is not an ideal plane but has a certain thickness, and the spatial shape distribution of light-screen thickness should follow a certain law. Based on the formation principle of light-screen, the spatial shape distribution of light-screen thickness is analyzed in this paper. According to the corresponding relationship between the trajectory position and the thickness distribution of the light-screen the characteristic difference of the LSPTS (Light-screen Passing Through Signal) is studied, then the measurement model is built and the measurement formula is deduced. Finally, the live firing experiment is carried out, and the results show that the proposed measurement method can realize the simultaneous measurement of the flight velocity and impact coordinates with only two light-screens, which reduces the number of light-screens by half compared with the current measurement methods. And the experiment result shows that the relative error of the impact coordinate measurement results is 8.1% on the abscissa axis and 8.2% on the ordinate axis, and the relative error of flight velocity measurement error is 3.1%. The research in this paper can provide a new idea for measuring the flight parameters of projectile by photoelectric principle.