System and method for monitoring safety status of ship using roll motion data

Abstract

Proposed are a system and a method for monitoring a safety status of a ship using roll motion data. The system and the method may be configured as follows. Rolling period data, average list angle data, and significant rolling angle data may be received from a rolling period computation part, an average list angle computation part, and a significant rolling angle computation part. It may be determined whether the rolling period data is equal to or less than a maximum unique rolling period. On the basis of the maximum unique rolling period, a controller may determine whether a rolling period is in a normal, caution, or danger state.

What is claimed is: 
     
         1 . A system for monitoring a safety status of a ship using roll motion data, the system comprising:
 a rolling period computation processor configured to compute rolling period data by performing fast Fourier transform (FFT) analysis on rolling angle data over time shown by an electronic inclinometer;   an average list angle computation processor configured to compute average list angle data by performing FFT analysis on the rolling angle data;   a significant rolling angle computation processor configured to compute significant rolling angle data by performing FFT analysis on the rolling angle data;   a controller configured to:
 receive the computed rolling period data, the computed average list angle data, and the computed significant rolling angle data, 
 perform comparative analysis on the rolling period data with a maximum unique rolling period and the maximum unique rolling period+40% of the maximum unique rolling period to determine a normal, caution, or danger state of a rolling period, 
 perform comparative analysis on the average list angle data with 50% of a grade criterion and the grade criterion to determine a normal, caution, or danger state of an average list angle, 
 perform comparative analysis on the significant rolling angle data with 50% of the grade criterion and the grade criterion to determine a normal, caution, or danger state of an average significant rolling angle, and 
 output a display control signal corresponding to each of the determined states; and 
   a display configured to receive the display control signal from the controller and display the display control signal.   
     
     
         2 . The system of  claim 1 , wherein as the grade criterion, the lesser of a limit inclination angle of the ship and 10 [deg] is selected. 
     
     
         3 . A method for monitoring a safety status of a ship by using a system for monitoring the safety status of the ship using roll motion data, the method comprising:
 receiving, by a controller, rolling period data, average list angle data, and significant rolling angle data from a rolling period computation processor, an average list angle computation processor, and a significant rolling angle computation processor;   determining, by the controller, whether the rolling period data is equal to or less than a maximum unique rolling period;   determining, by the controller, that a rolling period is in a normal state and displaying a rolling period normal state through a display in response to the rolling period data being equal to or less than the maximum unique rolling period;   determining, by the controller, that the rolling period is in a caution state and displaying a rolling period caution state through the display in response to the rolling period data is greater than the maximum unique rolling period and is equal to or less than the maximum unique rolling period+40% of the maximum unique rolling period; and   determining, by the controller, that the rolling period is in a danger state and displaying a rolling period danger state through the display when the rolling period data is greater than the maximum unique rolling period+40% of the maximum unique rolling period.   
     
     
         4 . The method of  claim 3 , after the receiving, further comprising:
 determining, by the controller, whether the average list angle data is equal to or less than 50% of a grade criterion;   determining, by the controller, that an average list angle is in a normal state and displaying a list angle normal state through the display in response to the average list angle data being equal to or less than 50% of the grade criterion;   determining, by the controller, that the average list angle is in a caution state and displaying an average list angle caution state through the display in response to the average list angle data being greater than 50% of the grade criterion and being equal to or less than the grade criterion; and   determining, by the controller, that the average list angle is in a danger state and displaying an average list angle danger state through the display in response to the average list angle data being greater than the grade criterion.   
     
     
         5 . The method of  claim 3 , after the receiving, further comprising:
 determining, by the controller, whether the significant rolling angle data is equal to or less than 50% of a grade criterion;   determining, by the controller, that a significant rolling angle is in a normal state and displaying a significant rolling angle normal state through the display when the significant rolling angle data is equal to or less than 50% of the grade criterion;   determining, by the controller, that the significant rolling angle is in a caution state and displaying a significant rolling angle caution state through the display in response to the significant rolling angle data being greater than 50% of the grade criterion and being equal to or less than the grade criterion; and   determining, by the controller, that the significant rolling angle is in a danger state and displaying a significant rolling angle danger state through the display in response to the significant rolling angle data being greater than the grade criterion.