Software And Hardware Design And Implementation Of Transceiver Unit Of Underwater Acoustic Navigation System

Whether it is the development and exploration of the ocean or the defense of maritime territories and the prevention of foreign military forces,underwater acoustic positioning and navigation technology is inseparable.Providing high-precision and stable navigation information for underwater cooperative targets has always been the key points and difficulties of underwater acoustic navigation technology.It has important research significance.Based on the long-baseline positioning and navigation system and the principle of GPS satellite navigation,this paper designs a set of underwater acoustic navigation platform suitable for underwater GPS navigation system,completes the hardware circuit design and software program design of the platform,and verifies the stability of the platform through experiments And reliability.The long baseline underwater acoustic navigation platform designed in this paper is based on the ZYNQ-7020 core board.It modulates the position coordinates of the unmanned ship on the surface into an underwater acoustic navigation signal and sends it to the underwater cooperative target through the transmitting transducer.After the underwater target collects the signal,it demodulates the transmitted coordinate information according to the time delay and forwards the result to the DSP solution platform to calculate its own position coordinates,and then real-time adjustment of navigation parameters such as its own course or speed based on the positioning results to achieve underwater target navigation.The design of the underwater acoustic navigation platform can be divided into hardware design and software design.According to the functional requirements and design indicators of the platform,the hardware design is designed with the platform’s processing core ZYNQ-7020 core board,combined with the circuit design of various modules and interfaces,to complete serial data transmission and reception,network data transmission and reception,data storage and forwarding,signal acquisition,etc.The software design of the platform is mainly divided into three parts,the centimeter-level differential positioning module,the signal modulation transmitting module and the signal receiving preprocessing module.The centimeter-level differential positioning module obtains the original differential data by accessing the Qianxun Zhicun service of the cloud-based Qianxun location server,and completes the acquisition of centimeter-level differential positioning information and the conversion of relative Gaussian coordinates.The signal modulation transmitter module completes the periodic modulation of the Pattern time delay shift coding,and generates two complementary symmetrical square wave signals with adjustable duty cycle by reading the signal modulation netlist generated by the ARM and the coordinates of the unmanned ship.The signal reception preprocessing module completes the functions of signal acquisition,delay estimation and decoding,data storage and forwarding,etc.By copying and correlating the received signal,the transmission delay of the signal and the delay difference between adjacent signals are obtained.The difference is decoded and judged to obtain the sent coordinate information of the unmanned ship on the surface,which is forwarded to the DSP solution platform for solution along with the transmission delay.This paper has completed the hardware circuit schematic design of the underwater acoustic navigation platform,realized the data transmission of the serial port,network port and other interfaces,improved the positioning accuracy of the device to the centimeter level,and completed the periodic modulation of the time delay difference coded signal and the signal reception Pretreatment and other functions,and finally verified the overall feasibility and reliability of the platform through pond experiment and lake experiment.