Development of a guidance system for safe navigation in rough seas

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The main objective of this research work is development of a guidance system for safe navigation in rough seas. The research work was continued for three years and following five major results were obtained. According to the results, it can be conclude that the system developed here will contribute to safe navigation of ships.1.Making up the hardware : The weather condition, ship motions in waves and wave loads must be monitored by the system in order to support the safe navigation in rough weather. The requirements of the system are to be cost-effective and durable. The system developed here can satisfy those requirements by reducing the sensors.2.Development of system application program : The system application program was developed based on two kinds of prediction technique. The first one is the stochastic prediction technique called "short term prediction method" in the field of naval architecture and the second one is Baysian estimation method. Furthermore, introducing a suitable … More graphical user interface and a function of data storage as a data base, usefulness in the actual operation was improved.3.Feasibility tests : On board tests were carried out using the training ship Shioji-maru and the system application program was revised. According to the results, it was revealed mat the ship motions can not be analyzed as a non-stationary stochastic process in the actual ship operation. Therefore, the "short term prediction method should not be applied directly.4.Improvement of the estimation algorithm for directional wave spectra : For the reasons mentioned above, the estimation algorithm was modified. Introducing the TVVAR modeling and extending the Baysian estimation, it was shown mat non-stationary ship motions and time-varying wave spectrum can be analyzed.5.Maritime Broadband system : A new concept was proposed for merchant fleet management. The real-time remote monitoring system was developed using the Maritime Broadband system, which is a developing system of T.S.Shiojimaru using a communications satellite. Time consuming calculations for estimating wave spectra can be shifted to the shore side. Less