基于超短基线的深水网箱网衣监测系统设计

Design of net monitor system of sea cage based on USBL

海水网箱养殖已经发展成为中国海水养殖的支柱产业之一,网衣的状态对深水网箱的养殖过程至关重要。为掌握网衣的实时状态,设计了一种基于超短基线水声定位技术的深水网箱养殖网衣监测系统。系统由固定于网箱监测平台上的基阵和安装在网衣节点上的水下信标组成,基阵与信标之间收发声信号,对信标进行定位。系统多个信标的水声定位采用m序列伪随机信号,利用码分多址技术以区分网衣上的多个信标。信标信号的收发由单片机控制,当接收到基阵的定位指令信号时,即发送本机地址码,根据传播时间及相位计算每个信标的空间坐标。监测系统利用该空间坐标计算网衣的容积,还原网衣状态,实现对养殖过程的实时监测。此系统可有效解决网衣水下光学监测存在的问题,如可视范围小、水质要求高、难以长期监测等,可用于浑浊海区的网箱网衣监测。

Marine cage aquaculture has developed into one of the pillar industries in China, the real time status acquisition of net is essential for deep-sea cage aquaculture, this paper proposed a net monitor system of the deep-sea cage based on ultra short baseline acoustic positioning technique. The system is composed of acoustic transducer array which is fixed to cage platform and underwater nodes which are attached to the net, the acoustic signals are transmitted and received between array and the nodes, so the position of the nodes can be located. The positioning signal of multiple nodes is m sequence of pseudo random signal, using CDMA technology to distinguish the individual node on the net. Node acoustic transducer is controlled by microcontroller, when a node received the positioning signals transmitted by the array, it will send the address code. Monitoring system determines the coordinates of each node, according to it, the net volume can be calculated and the real-time status of the net can be displayed, so real-time monitoring of the aquaculture process of deep-sea cage is achieved. This system can effectively solve the problem existed in underwater net optical monitoring system, such as small visual range, demanding for high water quality, hard for long-term monitoring and so on, and it can be used for muddy sea water.