Design Of Multi-function High-speed Wide Dynamic Range Acquisition System Based On PCIe

With the development of defense technology,the striking accuracy and destructive effect of various new weapons are being continuously improved,which has higher requirements on testing technology.In the transient flow field of gun bore and explosion shock wave,chamber pressure and shock wave pressure are critical parameters to evaluate the performance of weapon equipment,and the detection of their dynamic change process with time is beneficial to the study of the service life of the body tube and the development of new weapons.As highfrequency and fast dynamic signals,it is necessary to develop a high-precision,fast-transferring,and stable acquisition system for dynamic pressure signals,in view of the harsh testing environment,rapid changes and short duration.According to the characteristics of the measured signal and the test environment,this paper designs a multi-functional high-speed wide dynamic range acquisition system based on PCIe for fast capture and accurate measurement of the test signal.Based on the scientific problem,this paper introduces the system implementation scheme in detail,using FPGA as the control core,equipped with 18-bit high-precision A/D acquisition chip to obtain the pressure signal in real time by multi-channel synchronization;at the same time,the data is deposited into DDR3 chip by means of AXI interface to ensure data integrity.In order to meet the requirements of real-time analysis and processing of signals,PCIe bus transmission is used to transfer data to the upper computer for processing and display,and the comparison of transmission methods of PIO,bus master DMA and decentralized aggregation DMA is completed respectively,and the XDMA IP core is used to realize PCIe high data transmission design through comparison and analysis.In addition,based on the principle of DDS signal generation and analysis of the causes of spurious generation,the function of high-precision signal source generation is integrated on the basis of the acquisition system,which is used to realize the verification and channel calibration of the normal function index of the test system to ensure the accuracy and stability of the acquisition system.Based on the completion of the system hardware circuit design and FPGA internal functional logic design,this paper adopts the architecture of VS+QT to realize the design of the upper computer software display and analysis interface,and complete the PCIe bus driver of KMDF framework under Windows system.Finally,the test environment of the system is built and the FPGA logic program and the system functional index are tested experimentally.The test data shows that the single channel of the system can approach 1MHz sampling rate with synchronous sampling,the maximum allowable error is within 0.3%,and the dynamic range of the system can reach 100 d B;the spurious-free dynamic range of the signal source output is better than 60 d B,and the frequency error is within 0.05%;the transmission rate of the system based on PCIe2.0 x8 can reach up to 3 GB/s.The test results meet the design requirements and verify the validity of the solution.The test results meet the design requirements and verify the effectiveness of the solution.