Hardware Design And Implementation Of Small Underwater Acoustic Positioning Buoy

Based on the background of the long-baseline cooperative target underwater positioning system,this paper analyzes the functional requirements of the buoy positioning system according to the actual working principle and process of the buoy positioning system,and analyzes the shortcomings of the traditional positioning buoy.on this basis,the relevant design scheme of small underwater acoustic positioning buoy is proposed.Then the processors So C,FPGA and other related functional modules in the system are selected.Finally,the specific software and hardware design process and methods in the scheme are described in detail.The underwater acoustic positioning buoy designed in this paper can be divided into analog receiver unit and signal processing and data communication unit.In the analog receiver unit of the system,the differential signal generated by the hydrophone is converted into a single-ended signal,and the converted signal is processed by preamplification,bandpass filtering,post-amplification and Optocoupler isolation.Finally,the analog original signal with low noise and appropriate amplitude is obtained for signal processing and data communication module to sample and follow-up processing operation.The signal processing and data communication unit is responsible for the signal processing,the storage of the original data and the data / instruction communication with the display and control platform.This module uses Xilinx’s Spartan-6 series FPGA to collect and cache the original signal of the three-channel hydrophone,and sends it to So C for processing through the u PP interface.And the synchronization function of the system is realized by the synchronous pulse calibrated by GPS second pulse.The So C used in this paper is OMAP-L138 of TI Company,which combines ARM processor with DSP to form a dual-core architecture.The ARM processor runs the Linux operating system.Through the multi-process scheduling function of the Linux system,it realizes the functions of data communication with FPGA,network instruction data exchange with display and control,and buoy GPS position coordinate recording and data storage.The DSP core is mainly responsible for signal detection and time delay estimation of the original signal,and achieves the function of inter-core communication with the ARM core by means of asynchronous interrupt notification and shared memory.Finally,the results of DSP and GSP positioning data are packaged by ARM core and uploaded to the display and control platform through the radio,which realizes the basic functions of buoy primitives in the positioning system.At the end of this paper,the software and hardware functions of the analog signal conditioning module and the signal processing and data communication module are tested,and the test results and analysis are given.Finally,the stability and reliability of the software and hardware design scheme of the buoy system are verified to meet the design requirements.