Ship control device, ship control method, ship control system, and computer readable medium

Abstract

The object of the present invention is to effectively suppress an overshoot of a heading during turning. A ship control device is provided with processing circuitry. The processing circuitry measure an overshoot amount of a heading of the ship during turning based on an excessive turning amount of the heading with respect to a setting direction of the ship and calculates a rudder angle offset amount based on the overshoot amount.

What is claimed is: 
     
         1 . A ship control device, comprising:
 processing circuitry configured to:
 measure an overshoot amount of a heading of the ship during turning based on an excessive turning amount of the heading with respect to a setting direction of the ship, and 
 calculates a rudder angle offset amount which suppresses an overshoot during turning based on the overshoot amount. 
   
     
     
         2 . The ship control device of  claim 1 , wherein the processing circuitry is further configured to:
 measure the overshoot amount every time an overshoot occurs in a plurality of turnings, and   calculate and update the rudder angle offset amount every time the overshoot amount is measured.   
     
     
         3 . The ship control device of  claim 1 , wherein the processing circuitry is further configured to:
 set the maximum value of the excessive turning amount measured a plurality of times in one turn as the overshoot amount.   
     
     
         4 . The ship control device of  claim 3 , wherein the processing circuitry is further configured to:
 set a command rudder angle based on the setting direction and the heading, and output the command rudder angle corrected by the rudder angle offset amount, and   correct the command rudder angle by the rudder angle offset amount when the maximum value of the overshoot amount is equal to or greater than a threshold for correction.   
     
     
         5 . The ship control device of  claim 1 , wherein the processing circuitry is further configured to:
 calculate a standard deviation of the heading, and   calculate the rudder angle offset amount based on the overshoot amount and the standard deviation of the heading.   
     
     
         6 . The ship control device of  claim 5 , wherein the processing circuitry is further configured to:
 calculate the standard deviation of the heading during course keeping of the ship.   
     
     
         7 . The ship control device of  claim 1 , wherein the processing circuitry is further configured to:
 calculate a correction value for the rudder angle offset amount based on a difference between the overshoot amount and the standard deviation of the heading, and   correct the rudder angle offset amount based on adding the rudder angle offset amount calculated during the past turning and the correction value.   
     
     
         8 . The ship control device of  claim 4 , wherein the processing circuitry is further configured to:
 calculate a normalized rudder angle offset amount based on a turning angle, and   correct the command rudder angle based on the normalized rudder angle offset amount.   
     
     
         9 . The ship control device of  claim 8 , wherein the processing circuitry is further configured to:
 generate a denormalized rudder angle offset amount based on multiplying the normalized rudder angle offset amount by the current turning angle, and   correct the command rudder angle based on the denormalized rudder angle offset amount.   
     
     
         10 . The ship control device of  claim 1 , wherein the processing circuitry is further configured to:
 determine an occurrence of an overshoot based on the heading, the setting direction, and an turn rate, and   measure the overshoot amount when the overshoot occurs.   
     
     
         11 . A ship control system comprising the ship control device of  claim 1 , further comprising:
 a sensor configured to acquire an observation value associated with a behavior of the ship including the heading.   
     
     
         12 . The ship control device of  claim 2 , wherein the processing circuitry is further configured to:
 set the maximum value of the excessive turning amount measured a plurality of times in one turn as the overshoot amount.   
     
     
         13 . The ship control device of  claim 12 , wherein the processing circuitry is further configured to:
 set a command rudder angle based on the setting direction and the heading, and output the command rudder angle corrected by the rudder angle offset amount, and   correct the command rudder angle by the rudder angle offset amount when the maximum value of the overshoot amount is equal to or greater than a threshold for correction.   
     
     
         14 . The ship control device of  claim 13 , wherein the processing circuitry is further configured to:
 calculate a standard deviation of the heading, and   calculate the rudder angle offset amount based on the overshoot amount and the standard deviation of the heading.   
     
     
         15 . The ship control device of  claim 14 , wherein the processing circuitry is further configured to:
 calculate the standard deviation of the heading during course keeping of the ship.   
     
     
         16 . The ship control device of  claim 15 , wherein the processing circuitry is further configured to:
 calculate a correction value for the rudder angle offset amount based on a difference between the overshoot amount and the standard deviation of the heading, and   correct the rudder angle offset amount based on adding the rudder angle offset amount calculated during the past turning and the correction value.   
     
     
         17 . The ship control device of  claim 13 , wherein the processing circuitry is further configured to:
 calculate a normalized rudder angle offset amount based on a turning angle, and   correct the command rudder angle based on the normalized rudder angle offset amount.   
     
     
         18 . The ship control device of  claim 17 , wherein the processing circuitry is further configured to:
 generate a denormalized rudder angle offset amount based on multiplying the normalized rudder angle offset amount by the current turning angle, and   correct the command rudder angle based on the denormalized rudder angle offset amount.   
     
     
         19 . A ship control method, comprising:
 measuring an overshoot amount of a heading of the ship during turning based on an excessive turning amount of the heading with respect to a setting direction of the ship, and   calculating a rudder angle offset amount which suppresses an overshoot during turning based on the overshoot amount.   
     
     
         20 . A non-transitory computer-readable medium having stored thereon computer-executable instructions which, when executed by a computer, cause the computer to:
 measure an overshoot amount of a heading of the ship during turning based on an excessive turning amount of the heading with respect to a setting direction of the ship, and   calculate a rudder angle offset amount which suppresses an overshoot during turning based on the overshoot amount.