Vertical Target Coordinates And Velocity Measurement Based On Hotodiode Arrays

Bullet impact point coordinates and velocities mainly measured by the photoelectricvertical target measurement system, the current domestic system have shortcomings ofcomplex structure, low measurement accuracy and so on. According to this situation, thispaper presents a vertical target coordinates and velocities measurement system based onphotodiode arrays. The system overcomes these drawbacks, and has characteristics of lowcost, simple structure, high measurement accuracy. The development of this system has animportant significance for the present target system.The core of the system is the photoelectric target, system emission light source uses90°fan-shaped semiconductor laser emission, and receiver uses photodiode array, four90°laserthrough a cylindrical lens form a fan-shaped light curtains, these fan-shaped light curtaincross each other into a rectangular light curtains, photodiode array can measure light intensityof rectangular light curtain. When the bullet are flying through the laser screen, they willblock part of the laser light, and the photodiode can receive the corresponding signal,processing circuit collect signal and analysis to get the point of impact coordinates,chronograph records the time of the bullet through the light curtain target, according to screentarget distance to calculate the speed of the bullet.The paper gives the photoelectric target hardware design circuit and the bulletcoordinates and velocities calculation scheme. Hardware circuit consisted of photoelectricconversion circuit, comparison circuit and the digital signal circuit, calculation schemeconsists of coordinate calculation method and speed calculation method. Effective target of1m optical target simulation experimentexperiments show that Photoelectric targetmeasurement deviation in2mm.Design an improved photoelectric target system at the end of the paper, the system is based on two LED lights as the light source, main features is simple structure, better shockresistance. Papers to effectively target the photoelectric target of0.5m three differentsimulation, simulation experiments were from the light source away from the target surface0mm,50mm,100mm of places,50mm from the target surface, the light source photoelectrictarget minimum measurement error derived by simulation experiments. Finally, thephotoelectric target of0.5m×0.5m prototype7.62mm live ammunition test results show thatthe vertical target system has the characteristics of high precision and high sensitivity.