Synchronous Data Acquisition System For Distributed Hydrophone Array Design And Implementation

As the sensor part of the underwater acoustic measurement system,the hydrophone array plays an important role in the performance of the system.The original centralized signal acquisition system is no longer suitable for large-scale distributed hydrophone arrays.Aiming at this problem,this paper designs and implements a synchronous data acquisition system for distributed hydrophone arrays placed on the seabed.The system adopts a cascade method to realize the data communication and time synchronization of each acquisition node in the distributed system,and can complete the synchronous acquisition of large-scale,multi-channel,and multi-sampling rate underwater signals,providing high precision and high precision for the underwater acoustic measurement system.Quality measurement data.First,the paper analyzes the requirements of the acquisition system according to the working scene of the underwater acoustic measurement system,and puts forward the corresponding design indicators.According to the index requirements,the acquisition system has been designed for the topology,data transmission,power supply,synchronization and other aspects.According to the structure of the hydrophone array,a cascaded distributed hydrophone array data is designed.The overall plan of the acquisition system.Subsequently,according to the overall plan,the hardware design of the collection and transmission node in the system was carried out.It focuses on the detailed design of the preamp conditioning circuit,acquisition and transmission circuit,water leakage alarm and pressure acquisition module,and power supply module.The ZYNQ 7020 processor is selected as the data acquisition and transmission core of the system,and the corresponding interface design is carried out.Then,based on the hardware circuit of the acquisition and transmission node,the corresponding embedded software was designed,and the FPGA and ARM software on the ZYNQ processor were programmed and debugged respectively.On the FPGA side,detailed design and implementation of the inter-core communication,ADC acquisition,self-check signal transmission and synchronization pulse modules;on the ARM side,detailed design and implementation of the inter-core communication,data package preprocessing and network data communication modules accomplish.Finally,the function and performance tests of the pre-amplifier conditioning circuit,FPGA acquisition,inter-core communication,and network transmission in the acquisition and transmission node are carried out.And connected multiple acquisition and transmission nodes into a system,and carried out synchronization deviation,signal acquisition and field testing and verification.The test results show that the various indicators of the system meet the design requirements,the hardware modules are coordinated in an orderly manner,the software program is stable and reliable,and it has the outstanding characteristics of long transmission distance,high synchronization accuracy,and strong compatibility,which can meet the needs of the underwater acoustic measurement system.