Design On The Digital Signal Processing For High Speed Verlocity Log Based On FPGA And DSP

Speed sonar(including the DVL,ADCP,etc.)is an autonomous acoustic navigation system,with the characteristic of independent working.Without auxiliary equipment,speed sonar can provide the ship with a high accuracy of the bottom speed,convection speed and range and other parameters.Speed sonar system generally includes underwater transducer array,transmitter system,receiver system,digital signal processing system and host computer display control software.Among them,digital signal processing platform is the key part of the whole system to achieve real-time echo signal processing,to achieve function controlling and interact with the host computer.Based on the needs of high-frequency speed measurement sonar system,this paper designs a digital signal processing platform to accomplish the acquisition,transmission and real-time processing of sonar echo signals,and resolves some problems in practical use of high-frequency speed measurement sonar.Based on the analysis of the working frequency of the whole machine,the number of echo signal channels,the requirements of sampling,the requirements of real-time processing capability,and the requirements of echo signal transmission,the paper determines the DSP + FPGA as the core devices and designs the digital signal processing platform hardware parts.The paper mainly describes the design and implementation of the key parts such as analogdigital conversion circuit,FPGA on-chip module and Nios II processor soft core.Through analyzing data receiving and transmitting throughput,transmission stability requirements,host computer control requirements and signal real-time processing requirements,the system software engineering was completed and a Nios II on-chip real-time system for network data transmission was set up,allowing users to control Nios II processor for signal transmission function control,and on the DSP to achieve a rough estimate of the echo signal frequency parameters to verify the real-time solution of digital signal processing platform.Finally,this article has carried on the comprehensive test to the design digital signal processing platform.The use of signal generator to meet the needs of the test signal,with the host computer and control software,completed the system signal acquisition,signal transmission network,PC control,echo signal frequency solution and other functions of the test.The stability of the system operation and the correctness of data transmission are evaluated.The results show that the design can meet the needs of the function,in line with the design requirements.