Research On High Speed Signal Acquisition And Processing Of Lidar Wind Measurement System Based On FPGA

In recent years,lidar wind measurement system has been rapidly developed and widely used in aviation safety,atmospheric science,wind power generation,weather forecasting and other important fields.As a new type of wind speed measuring instrument,lidar wind measurement system has the characteristics of high precision and high resolution,which makes it have a certain demand in the field of real-time wind measurement.At the same time,the wind measurement system has higher and higher requirements for the amount of echo signal data and transmission rate,so the high-speed acquisition and processing of echo signal is an important part of the lidar wind measurement system.Firstly,this thesis describes background and significance of the research,and discusses the research status of lidar wind measurement system at domestic and foreign.Aiming at the existing problems of lidar wind measurement system,the high-speed signal acquisition and processing module,data transmission module and upper computer application module based on FPGA has been designed.Secondly,based on the principle of lidar wind measurement technology,this thesis clearly proposes to use continuous coherent lidar wind measurement technology to detect short-range clear air wind speed information in real-time,and focuses on the high-speed acquisition technology,FPGA application design technology and lidar echo signal processing algorithm used in the design of the system.Thirdly,in this thesis,the overall design architecture of continuous coherent lidar wind measurement system,the hardware module design architecture and hardware implementation function of data acquisition and processing device are described in detail.At the same time,the details of 1024 point flow mode,block floating point FFT algorithm,1024 cumulative average filtering algorithm,SPI bus protocol and SOC FPGA system on FPGA are given.Fourthly,based on the application interface programming of Qt host computer,this thesis expounds the design scheme of the software system,gives the overall software architecture and software realization functions according to the actual wind measurement requirements,and describes in detail the realization process of data communication,human-computer interaction,data processing,data warning,data display and data storage software functions.Finally,embedded logic analyzer(Signal Tap II)and Modelsim simulation software are used to test the correctness of the main functions of software and hardware modules.In addition,a prototype of continuous coherent lidar wind measuring system with a working wavelength of 1550 nm has been built for system joint adjustment,and the designed software and hardware modules were tested,echo signal algorithm verification and FPGA resource utilization analysis.The experiment results show that the acquisition and processing module can meet the real-time acquisition and processing of echo signal under the 100 MHz clock,and the spectrum resolution reaches 97.66 k Hz,and the accuracy of wind speed measurement is improved to 7.57 cm/s,which optimizes the requirements of wind field for wind speed measurement accuracy,and has high engineering application value.