Study Of The Key Technology Based On The DAQ System For Submersible Buoy

In order to safeguard the national Maritime Sovereignty,our country has been committed to developing the technology of marine environment observation,which is still in the initial stage for far-sea and deep-sea.Submersible buoy is an important observation equipment which can adapt to the harsh marine environment such as far-sea and deep-sea.With the development of the advanced submersible buoy system,the anchorage depth of new-type submersible buoy is required to be 2 km,and its running time should be more than 3 years,where the demand of data storage capacity has been over 480 GB/year.The transmission and recovery speed of submersible buoy are required to be no less than 300 Mbps and 1440 Mbps,respectively,while the low power consumption should be 1.8 W in such a high performance.Meanwhile,the bit error rate of the data communication in each board is required to be less than 10-8 under such rigorous conditions of far-sea and deep-sea.Submersible buoy system is encountering various challenges such as large capacity,low power consumption,high-speed data transmission and low bit error rate.In this paper,five key technologies of submersible buoy system are proposed:lossless data compression technology,which not only improves the data storage capacity and data transmission speed of nearly 100%,but also reduces the system power consumption of nearly 50%;The driving and control technology of the dual mode of SD card,where the low speed SPI mode effectively reduces the system power consumption during the long-term operation of the submersible buoy,while the high speed UHS-I mode improves the data transmission speed up to 400Mbps significantly;SSD storage and control technology,which could control large-capacity SSD,with the data transmission speed up to 6Gbps to satisfy the recovery capacity of high-speed demand;dual Gigabit Ethernet transmission technology,which can be extended to 2km for long-distance data transmission via optical fiber,with the theoretical data transmission speed up to 2000Mbps;Data retransmission technology,which is applied to the communication between each board,can maintain the bit error rate no more than 10"10 in the poor environment of inter-board communication.In this paper,the prototype board and key technology of DAQ system of the submersible buoy are tested.The test results show that the average power consumption of submersible buoy system is about 1.11 W,which could support the read-write control of the 64-GB SD card and SSD with the large-capacity of 1 TB,where the transmission speed of SD card is about 370 Mbps,the reading speed of SSD is up to 4200 Mbps,while the transmission speed of comprehensive data in dual Gigabit Ethernet is no less than 1700 Mbps,the bit error rates in the environment of laboratory test and QianDao-Lake test are less than 4×10-12 and 10-11,separately.The test results indicate that the development of the submersible buoy system and the design of its key technologies have solved the difficulties that the new-type submersible buoy system suffered from,and the system has been approved by the 715th Institute of China Shipbuilding Industry Group.The main innovations of this paper are as follows:(1)The design and development of the submersible buoy DAQ system with independent intellectual property rights is completed.This is the first time to realize the DAQ system of submersible buoy with low power consumption,large capacity of data cache and storage,and high-speed data recovery,filling the gap in this field in China.(2)In the DAQ system of submersible buoy,five key technologies are integrated simultaneously,including the SD card control technology with high-speed data transmission of 400 Mbps,the SSD control technology with high-speed data transmission of 6 Gbps,dual Gigabit Ethernet communication,real-time lossless data compression technology and data retransmission technology.This is the best DAQ system up to now which is applied to the same type of submersible buoy in China.(3)The hardware implementation of real-time lossless data compression technology based on FPGA,reduces the operating power consumption of the submersible buoy DAQ system by 50%and increases the data transmission speed by 100%,thus effectively solves the contradiction between low-power design and high-speed data transmission in the submersible buoy system.