Title page for etd-0021117-152704


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URN etd-0021117-152704
Author Hsi-He Chen
Author's Email Address jszxc123@gmail.com
Statistics This thesis had been viewed 5573 times. Download 15 times.
Department Institute of Undersea Technology
Year 2016
Semester 1
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Evaluation of Surface Localization and Underwater Communication Systems for the IUT AUV
Date of Defense 2017-01-16
Page Count 138
Keyword
  • Surface localization
  • IUT AUV
  • Tauchi method
  • Acoustic modem
  • Underwater communication
  • Abstract Since 2010, the Institute of Undersea Technology (IUT) of the National Sun
    Yat-sen University has been devoted to the research on autonomous underwater ve
    hicle (AUV). The IUT AUV prototype equipped with a main controller, an interface
    for mission planning, and the Seaflor Laser Scanner (SLS) was developed in 2012,
    which is able to maintain a stable altitude to the sea flor for measuring fie-scale
    bottom roughness. Based on the knowledge and experience gained from the IUT
    AUV prototype development, a new IUT AUV is currently under development for
    reliable operation purposes. The objective of this work is to develop a surface local
    ization system and evaluate the performance of an underwater acoustic modem for
    the new IUT AUV. To ensure safety in deployment and recovery stages of the AUV,
    a global positioning system (GPS) receiver integrated with a radio frequency (RF)
    communication module is developed and will be installed with the AUV for remotely
    tracking and monitoring the vehicle while it is on surface. The GPS with RF com
    munication module before waterproof has been tested and demonstrated to have a
    operation range up to 7 km. A waterproof housing was designed and manufactured
    for the GPS with RF communication module, which has been successfully pressure
    tested at a water depth of 1100 m. The operation range of the GPS/RF module,
    however, is reduced to 1 km only when it is installed in the waterproof housing.
    In addition to the GPS/RF module, an acoustic modem will be integrated into the
    IUT AUV to provide a wireless digital communication link between the surface ves
    sel and the underwater vehicle. A waterproof housing that is 3000 m depth rated
    was designed and fabricated for the electronics of the subsea acoustic modem. In
    order to identify signifiant factors affcting the performance of the acoustic modem,
    experiments were conducted in the Kaohsiung harbor and open ocean environments.
    The testing result demonstrates that, in the Kaohsiung harbor, the acoustic modem
    can deliver excellent performance in horizontal communication at a short range of 50
    m. However, at a 450 m long range test, the performance of the acoustic modem in
    horizontal communication is signifiantly worse and is severely affcted by unknown
    time-varying factors. Based on the 450 m long range communication experiments
    conducted in the Kaohsiung harbor, the optimum combination of variables was de-
    termined, with the Taguchi method, as the transmit rate of 600 bps, the transmit
    power of 20 W and the transmit data of 45 bytes. Also, experiments for evaluating
    performance of the acoustic modem in vertical communication were carried out of
    southwestern Taiwan, and the best combination of variables was identifid by the
    Taguchi method. The experimental results demonstrate that, in the open ocean en-
    vironment, the acoustic modem can perform the best vertical communication with
    the transmit power of 20 W at the distance of 45 m. Still, in the open ocean environ-
    ment, the performance of the acoustic modem in vertical communication is severely
    inflenced by unidentifid noises.
    Advisory Committee
  • Chi-Cheng Cheng - chair
  • Yu-Cheng Chou - co-chair
  • Chau-Chang Wang - co-chair
  • Hsin-Hung Chen - advisor
  • Files
  • etd-0021117-152704.pdf
  • indicate access worldwide
    Date of Submission 2017-01-23

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