Design Of Encoding Type Phototransistor Array Based On Laser Projection

The measurement of projectile's flying velocity and firing accuracy is the important contents during the range test.The light screen target is commonly used,which consists of light source and receiving unit.Phototransistors are usually putted in array to expand the signal's reception range.The design of phototransistor array can directly influence measuring accuracy of the system.At present,the output signal of phototransistor array is put by several phototransistor in parallel.The phototransistor array can't collect the signal from single photo-sensor,and have poor anti-jamming capability.To avoid the interference caused by the flare and air disturbance around the tube,a new design of laser projection encoding type phototransistor array is putted up,which can collect data from each single phototransistor.In this thesis,laser detection screen is set up by using semiconductor laser as light source,and phototransistor array as light sensitive component.Coordinated with related circuit and algorithm,the encoding phototransistors' output is realized by collecting the signal of bullet through the screen.This new-type phototransistor array can measure projectile's flying velocity and on-target coordinate,and improve performance of the anti-jamming capacity to flare,vibration,and smog.The main contents in the thesis as follow.Firstly,by analysis to the existing light sensitive array,the structural model of phototransistor array is optimized.The circuit model and integrated system including selection of detector is designed.Its sensitivity and frequency response characteristics are verified by experiment.Secondly,the system can measure projectile's flying velocity and target coordinate,in range test.The formulation relationship between projectile's target coordinate and output coding is deduced,when bullet through the screen of the systemThirdly,for the arrangement of light activated triode,the corresponding circuit is designed,which can collect the output signal of triode.The signal is converted,latched,and serial outputted by logic design in the environment of Quartus? to match the signal processing of upper computer.Finally,error of the system is analyzed.Experiment in the lab and the shooting range,respectively,the results show that the design of the system is correct.