Underwater Acoustic Array Signal Acquisition And Transmission Technology Based On FPGA

With the development of deepening research of underwater acoustic technology and electronic technology,underwater acoustic array signal acquisition,transmission and processing has been more and more important.The underwater acoustic signal is very complex,so the practicability of array signal acquisition system,the accuracy and stability of the requirements is very important.Now the underwater acoustic array signal acquisition system gradually towards miniaturization,intelligent and low power direction.Underwater acoustic array signal acquisition and transmission technology system based on FPGA,the main function of the system is the realization of synchronous collection signal,parallel transmission and storage of data.1.Signal conditioning circuit design mainly includes the preamplifier circuit design,filter circuit design and differential circuit design four parts.Among them,the pre amplification circuit for amplifying gain index system to meet the requirement of signal,and can improve the signal detection ability of small signal.The filter circuit is composed of two parts of the high pass filter circuit and the low-pass filter circuit.Because the input signal ADS1274 is the differential form,so the differential output circuit converts the single ended signal into a differential signal.2.Signal conditioning circuit design mainly includes the preamplifier circuit design filter circuit design and differential circuit design four parts.FPGA module circuit design includes digital isolation module circuit design and A/D conversion module circuit design.The isolation circuit will digital plate isolation and analog board,the main role is to prevent the digital signal into analog board,so it can reduce the interference.The A/D conversion module circuit part has carried on the design of ADS1274 working mode and data output mode.Function of circuit module network design includes DM9000 A circuit design and NIOSII soft core hardware platform construction.Power network chip DM9000 A is relatively low,meet the low power requirement of the system.3.FPGA program design includes the programming of data acquisition and Ping Pang cache program design.Among them,the data acquisition program realizes synchronous data acquisition of four channels of nine pieces of ADS1274,Ping Pang cache program packets of data cache.NIOSII programming design includes DM9000 A program design and data sending program design based on UDP protocol.4.Finally on the performance,power consumption and output waveform of the signal conditioning circuit is tested,the software part of the data transmission function of debugging,achieves the required index.According to the test result,the design of the underwater acoustic array signal acquisition and transmission technology system meet the requirement of high gain,low power and synchronous data acquisition index.