水声信道模拟仪设计与实现

Design and implementation of an underwater acoustic channel simulator

水声信道是无线传输水下观测信息的重要途径。为了测试水下装备,通常需要开展水下观测和水声传输实验,周期长、成本高。在陆上模拟水声信道,基于模拟信道测试水下装备观测端至终端的水声传输性能,有望提升实验效率、降低实验成本。然而,目前水声信道模拟通常通过计算机仿真实现,无法实体连接水下装备对其测试。发展模拟水声信道的嵌入式仪器是实现水下装备陆上测试的迫切需求。为了达到此目标,该研究基于指定海域温度、盐度、地形地貌等参数,配置水声信道模型,设计并实现水声信道模拟系统软件,适配至国产嵌入式平台,形成水声信道模拟仪。水声信道模拟仪能够与水下装备实体连接,形成短周期、低成本的水下装备陆上测试新实验方案。

[Objective]Transmission of observational information through underwater acoustic channels is a critical aspect of testing underwater equipment.Traditional experimentation involving underwater observation and acoustic transmission is characterized by lengthy cycles and high costs.We aim to enhance experimental efficiency and reduce costs by simulating underwater acoustic channels on land to test the performance of underwater equipment from the observation end to the terminal.However,existing computer-based simulation methods struggle with direct physical integration with underwater equipment.To address this limitation,we aim to develop an embedded instrument to stimulate underwater acoustic channels,thereby facilitating onshore testing of underwater equipment.[Methods]To achieve this goal,we compile a database of underwater environmental parameters,including temperature,salinity,and topography.Using data from this database,we configured an underwater acoustic channel model tailored to a designated sea area.Our preferred model,Bellhop,derives from ray acoustics and can model acoustic channels in complicated underwater environments.Subsequently,we develop system software to operate the Bellhop model.In conjunction with the acoustic channel model,this software is adapted and embedded in a processing unit,specifically the chip RK3566,for our purposes.Additionally,we developed a circuit interface to establish a physical connection between the underwater equipment and the simulator.A user interface is also developed,which features configuration options,a display for the simulated channel,and an observation display.Through these innovations,we have developed an underwater acoustic channel simulator that facilitates direct physical connection to underwater equipment and offers flexible simulation of diverse sea areas.Onshore tests of the underwater equipment can be easily conducted by using an underwater acoustic channel simulator.[Results]We conducted onshore tests of an underwater camera and its accompanying underwater acoustic communication scheme using the developed underwater acoustic channel simulator.This simulator was programmed to replicate the underwater acoustic channel conditions of a designated area in the Yellow Sea.The camera captured images and transmitted them through a simulated underwater acoustic channel to stimulate the process from the observation end to the terminal,with the images ultimately displayed by the simulator.This setup allowed us to assess the underwater equipment’s performance concerning image transmission quality over underwater acoustic communication.We obtained and analyzed images transmitted under varying conditions in the designated sea area,evaluating the performance of the underwater equipment and its acoustic communication scheme based on the quality of the images.[Conclusions]The introduction of the novel underwater acoustic channel simulator represents a significant advancement in testing methodologies for underwater equipment.This novel instrument facilitates experimental tests characterized by short cycles and low costs.Polit experiments can be efficiently conducted using the simulator to evaluate the performance of underwater equipment before conducting real-world underwater trials.Therefore,the underwater acoustic channel simulator emerges as a powerful tool for improving experimental test efficiency and reducing the costs associated with underwater equipment testing.