Research On Shock Wave Overpressure Test System Based On Ethernet Transmission

Shockwave is one of the important reference indicators for evaluating the power of weapons and ammunition.When a light gas gun loads an energetic projectile with a high-velocity impact target box,the shockwave is generated in the target box.In order to study the effectiveness of energetic explosives,shock waves can be used to calculate the relationship between energy and density of explosives.The ratio of energy to density is called specific energy.The research content of this thesis comes from the “Specific Energy Test Recorder” project of the National University of Defense Technology.Firstly,the paper introduces the development status of the shock wave test system and FPGA and Ethernet.Secondly,it analyzes the dynamic characteristics of the test system.Then it focuses on the process of the software and hardware design of the shock wave test system and the design of the Ethernet interface.Its contents include:1.A scalable multi-channel cascading acquisition unit designed.Multiple collection units form a bus-type cascade structure.It realized the parameter-setting and reading operations of the collection unit through the mode of hierarchical transmission.This satisfies the need for a device that can perform multiple shock wave testing points on the target wall.2.In order to improve the reliability of the system,implemented internal and external trigger stored separately design ideas.The collection and storage circuit is based on the XILINX FPGA as the control logic of the sequential logic.The internal and external trigger data are stored separately in Mram and Flash.It has realized the design ideas of small and key data stored in Mram and long data stored in Flash as a back-up.3.In order to read data quickly,designed and implemented an Ethernet transmission interface.The data in the memory chip is sent out in serial communication mode.Then data is received by a reading box which is controlled by ALTERA FPGA.The serial communication protocol is transferred to UDP,IP,MAC Ethernet frame protocol,then data is sent to the computer via Ethernet transmission mode.We also designed a kind of upper-computer software for decapsulation of the Ethernet frame header,then the software helps to realize data processing and waveform display.Finally,the paper introduces the system’s verification experiment and actual explosion test,and verifies the reliability and effectiveness of the designed system.