Optimal Design Of Four-channel Dynamic Signal Data Processing Logic Circuit

Dynamic signal analyzer is a high-performance mechanical,acoustic,mechanical signal processing and analysis instrument,which has many advantages such as large dynamic range,multi-mode analysis and variable bandwidth.The instrument can complete the data acquisition,storage and real-time analysis quickly and accurately,and plays an important role in signal processing,acoustic testing,fault diagnosis and other fields.Thesis proposes corresponding data processing solutions for dynamic signals such as baseband signals,acoustic signals,and rotating mechanical vibration signals.In addition,trigger storage logic is incorporated and optimized to complete the design of dynamic signal processing based on FPGA.The specific research contents are as follows:Design of baseband data processing and transmission scheme: According to the algorithm requirements of five different working modes of dynamic signal analyzer(FFT analysis,octave analysis,correlation analysis,histogram analysis,order analysis),the variable bandwidth design is completed by digital down conversion and multistage extraction structure,and the functions of band selection refining and band shifting are realized.During the baseband data processing,CIC compensation filter is used to ensure the flatness of the passband,and the requirement of 120 d B dynamic range is satisfied through the truncation design of significant bits.Thesis uses the PCIe to complete the data interaction between the host computer and the logic circuit,and uniformly plans and classifies the instructions.At the same time,a coordinated operation mechanism is designed to achieve more efficient data processing and transmission.Logic design of trigger storage function: In order to meet users’ test requirements for specific signal capture,thesis designed a variety of trigger modes,such as channel trigger,source trigger and GPIB trigger.Optimizing the trigger capture logic for baseband data,effectively capturing waveform data before and after the trigger moment by truncating the data.Combined with external DDR3 memory,a deep storage scheme is proposed in thesis.The storage module makes full use of internal addresses,further optimizes the trigger mechanism,and eliminates the pre-trigger depth limit caused by internal resource problems.In addition,the overlap frame design is also added to the memory module,which solves the problems of window effect and slow refresh rate of narrowband data,and significantly improves the performance of dynamic signal analyzer.Finally,based on the dynamic signal analyzer testing platform,functional test are performed on the instrument.The test results show that the optimized dynamic signal analyzer has a dynamic range of 120 d B,signal passband flatness less than 0.1d B after filtering,and analysis parameters such as bandwidth,center frequency,and frequency resolution can be switched according to testing requirements.At the same time,the source triggering function ensures stable display of the source signal,and the storage depth of256 Mpts can be achieved in deep storage mode.