The Design And Implementation Of Digital Multi-Function Front In The Towed Linear Array Base On FPGA

Towed linear array technology is widely used in scientific research, resource development, construction and other aspects of military around ocean. This article, aiming at the related application of towed linear array technology in underwater acoustic engineering, carries out research work. In underwater acoustic working field, a mother ship or Underwater Vehicle is the carrier of towed linear array which is towed to navigate. Towed linear array can detect the underwater acoustic environment by various underwater acoustic sensors that are integrated in its cable. This article introduces a linear array towed by underwater vehicle. In the underwater navigation of vehicle, the linear array can receive underwater acoustic signal and transmit it to underwater vehicle via cable. Meanwhile, the underwater vehicle can also emit acoustic signal through towed linear array. This, the towed linear array on its carrier has a specific fitness for the environment and the requirements of using environment. Therefore some problems need to be considered in the towed linear array of technical design work, such as convenient use, reliability, environmental adaptability, Maintainability, electromagnetic compatibility and joint commissioning and inspection methods between the carrier, etc. The front end of towed linear array is the only circuit components and it is necessary to solve these problems with the towed linear array on the front-end technology design and engineering to achieve combined.In general, the primary function of the front end installed in the towed linear array is to amplify the receiving underwater acoustic signal, anti-aliasing and digital transmission. And this front end of towed linear array in this article is for the purpose of solving some engineering application problems and an innovative design based on the traditional technology of towed linear array. It is an FPGA-based digital multifunction towed array front end, compared with the traditional front end of towed linear array, except with the above basic functions, but also has the following characteristics:a) Carry out online technical condition monitoring for the transducer integrated on the cable;b) No external commissioning inspection equipment, to achieve joint commissioning checks between towed linear array and carrier;e) Match adaptively the channel characteristics of receiving and transmitting for underwater acoustic signals of towed linear array;d) Conduct the power on self test on the towed linear array;e) Adaptive matching between the line array and carrier, without the use of one one paired.As we all know, it is vulnerable and consumable in storage, transport and use for towed linear array. The above innovative design for the front end of towed linear array makes technical preparing time in the processing of towed linear array greatly shortened and the working reliability greatly improved also can make the work efficiency of daily maintenance and repair greatly improvedThe design and implementation of FPGA-based digital multifunction towed array front end described by this article is based on research and analysis of the following technology.a) Based on the digital signal transmission technology of towed linear array;b) Intelligent instrument detection technology;c) Long distance point to point communication interface technology;d) Underwater acoustic transducer technology;e) Underwater acoustic digital signal processing technology;f) FPGA design and application technology.On this basic, according to the specific functional requirements of the front end of towed linear array, design specific solutions, carry out related design work, and achieve final realization in engineering application.