Design And Implementation Of Underwater Acoustic Signal Acquisition System

The ocean is an emerging field of strategic development related to national defense security and revitalization.As an essential acoustic feature in the marine environment,the research and exploration of the ocean hydroacoustic signal are of great significance to ocean development.At present,most of the hydroacoustic signal acquisition systems are high-frequency,non-self-capacitating devices,but the study of low-frequency hydroacoustic signals is equally essential.As the research on low-frequency hydroacoustic signals becomes increasingly urgent,this paper will realize a self-capacitating device that operates underwater to acquire low-frequency hydroacoustic signals.The main contents include the following.(1)The paper first determines the technical indexes and overall design scheme of the hydroacoustic signal acquisition based on the technical importance of low-frequency hydroacoustic signal acquisition in the variable environment of the ocean.(2)The system is designed in hardware with high sensitivity hydrophone to collect hydroacoustic signals.The amplifier circuit is designed to amplify the collected signal;the filter circuit is designed to filter out the interference signal;the voltage conversion circuit is designed to realize the conversion of the voltage signal;and the Simulink simulation circuit verifies the correctness of the designed circuit.In order to realize the low-power operation of the system,STM32F407 is selected as the main control chip;in order to collect the high-resolution hydroacoustic signal,ADS1256 is selected as the analog-to-digital conversion chip;finally,an SD card is selected as the storage medium to complete the real-time and high-speed storage of data.(3)The software design of the system mainly includes the development of the lower computer and the upper computer,and the lower computer mainly completes the development of the system’s peripheral driver.In addition,this paper upgrades the traditional ping-pong caching method to process the data based on the characteristics of this design system for water acoustic signal acquisition and storage.The upgraded ping-pong cache method further reduces the program’s memory consumption and dramatically improves the system’s efficiency by ensuring no data loss.The upper computer software is designed to provide human-computer interaction services to ensure the convenience of setting system parameters and data reading.(4)The mechanical structure design of the system mainly includes a hydrophone protection frame and a pressure-resistant bin.Firstly,to address the problem that the hydrophone is easily damaged in the complex marine environment,this paper innovatively designs a hydrophone protection bracket with a spring mechanism to increase the reliability and extend the service life of the hydrophone to ensure the smooth performance of the testing task.Secondly,we design a pressure-resistant chamber and perform strength calculations to verify the rationality of the structure;and carry out sealing treatment to ensure the stable operation of electronic components under a high-pressure environment.(5)Finally,the modules of the underwater acoustic signal acquisition system are tested,and the power consumption test,vibration test,Qiandao Lake test,and pressure test of the system are completed.The test shows that the hardware circuit system design,software development,and mechanical structure design of this paper all meet the technical requirements,and can work in a complex marine environment.