Research On The Reflective Laser Light Curtain Speed Measurement System Based On FPGA

With the continuous development of weapon technology,the initial velocity measurement method of the projectile is becoming more and more important.The light screen velocity measurement technology has gradually replaced the traditional coil target and other speed measurement methods because of its high precision and good repeatability,and has been widely used at home and abroad.However,some evidence suggests that most of the speed-measuring light curtain targets remain problems of small detection range,low sensitivity,large volume and discontinuous measurement.To address these,this thesis aims to conduct a reflective laser curtain velocity measurement research based on the FPGA.This thesis sought to make further and deeper analysis in the reflective-light screen velocity measurement technology and the signal storage measurement technology of the projectile over-target,and designed a measurement system for the light curtain velocity,mainly aimed at processing of the signal on the projectile passing through the double-light curtain target back and forth.What`s more,the detailed analysis and design were made for the detection unit of the projectile reflected light signal,and then the mechanical design and auxiliary calibration device design of the system device were introduced.As for the design of the hardware in the system,FPGA was used as the core control device.The high-speed AD conversion chip and the Flash memory chip were used to store the projectile over-target signal.The digital tube was used to display the speed measurement results.Lastly,the USB was employed for communicate with the host computer.With regards to the design of system logic control,Verilog DHL hardware description language was used to carry out modular design of AD module,Flash storage module,USB communication,timing control and digital display.Besides,the waveform simulation of the logic module was performed by ModelSim software.At the same time,the upper computer software design based on Labview was adopted.According to the entirely system design,this thesis has tested the system through simulation experiments at last,which mainly verified the signal of analog circuit,the function of signal triggering,data storage system and timing function respectively.Overall,the experimental results shed light on the reflective laser curtain measurement system designed in this study with the advantages of high timing accuracy,large light curtain target area and high data transmission speed,which has a good application prospect.