Research On Underwater Large-scale Photoelectric Zone Interception Device

The underwater measurement on the speed and target coordinates of the bullet has significant impact to study ballistic characteristics of the projectile into the water and the development of new underwater weapons.According to the pre-research in the construction of 20-meter underwater target,we select non-contact light screen and embedded microcontroller hardware system as a scheme to design the 1000mm×1000mm underwater photoelectric zoneblock experimental system,and propose a new calculation method of target coordinates.Underwater photoclectric zone-block device is comprised of two light screens with optical axes perpendicular to each other and a set of controller hardware system,in which that underwater light screen consists of a waterproof and pressurized shelf?light module and signal transmit module.By studying the influence from water,the device chooses the red laser to light and design two kinds of experimental system like parallel and fan-shaped curtain.Signal transmit unit chooses laser receiving tube as photo electricity detector,and designed signal processing functional circuit to eliminate interference signal while measuring.In the system,the light source and detector are both modular arrays of line arrays,so the screen area can be designed to meet the requirement of large screen measurement,according to the size which user needs.With STM32F103ZET6 singlechip,we add the microcontrol system to coordinate each part's function of the device and make sure threshold triggering?timing and arithmetic logic for signals from underwater light screens.We measure the time that the projectile passes through two light screens and solve the speed with the distance between screens.While the projectile passes through the light intersection area in one light screen,the system records the time when the signal is triggered and identify the location of the corresponding signal receiver,then solve X and Y target coordinates of the projectile according the coordinate measurement model.After static debugging and improvement of the device system,we carried out several underwater simulation experiments in the laboratory tank.The idea of the underwater photoelectric zone-block system and the feasibility of the calculation algorithm are verified.Finally,we discuss and analyze the measurement data,and explain the reasons for various types of errors which may appear.