Research On Data Acquisition Technology Of Laser Scanning Array

The power and damage efficiency of warhead are directly related to the combat effectiveness of weapon system.The distribution of fragment velocity and fragment group velocity is one of the core parameters for evaluating the combat effectiveness of the warhead.The comb-shaped differential laser light screen technology has the advantages of strong anti-interference ability,high testing accuracy and simultaneous identification of multiple fragment targets.The fragment velocity test has shown that the general data acquisition equipment has the problem of low applicability in simultaneously collecting the passing-screen signals of multi-channel fragments as well as the signals' passing-screen time.Therefore,a special data acquisition system needs to be developed.In this paper,the data acquisition requirements of comb-shaped differential laser target in fragment test are analyzed.With the use of embedded acquisition method and GPS timing technology,a multi-channel hybrid data acquisition system is designed to solve the problems of large number of output channels,high sampling rate,and high resolution of passing screen time.The system with multiple triggering modes can realize continuous or intermittent acquisition functions and support the cascade operation of multi equipment.This data acquisition system uses ARM and FPGA as the core controllers to acquire signals of the 16-channel crossing-screen wave.In regard to high resolution of crossing-screen time,the system measures the local and external time deviations based on GPS timing technology to correct the output frequency of local crystal oscillator,producing a system synchronized clock which is used to mark the time for fragment crossing-screen wave.Fragment crossing-screen wave and the corresponding time scale information constitute a mixed data package,with DDR2 chip as the main buffer and USB2.0 bus for data transmission.At the same time,the buffer capacity,communication rate and time scale accuracy of the system are demonstrated and analyzed in detail.The test results show that the designed mixed-data-acquisition card can acquire the16-channel waveform,and the maximum sampling rate of single channel can reach 1msps without packet loss.Multiple devices can be used in cascade mode and the time scale accuracy is at microsecond level,which meets the requirements of practical application and technical requirements.