Patent Publication Number: US-2018046190-A1

Title: Ship

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is the U.S. national stage of application No. PCT/JP2016/055631, filed on Feb. 25, 2016. Priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) is claimed from Japanese Application No. 2015-041337, filed on Mar. 3, 2015, the disclosures of which are also incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     At least an embodiment of the present invention relates to an art of recognition of a position of a ship. 
     BACKGROUND 
     Conventionally, as a position recognition means for a position a ship on the sea, a Global Positioning System (GPS) is known (for example, see the Patent Literature 1). Conventionally, based on GPS information, operation of a ship such as fixed point holding or automatic docking on the sea is performed. 
     However, a precision error of GPS information or precision error of map information stored previously may make it difficult to determine an accurate position of the ship itself on the sea. 
     Patent Literature 1: the Japanese Patent Laid Open Gazette 2013-28296 
     SUMMARY 
     A problem to be solved by at least an embodiment of the present invention is to provide a ship in which an accurate position of the ship itself on the sea can be determined. 
     A ship of at least an embodiment of the present invention has a recognition means for a position of the ship itself on sea, the recognition means has a first camera provided in a front part of a hull and a second camera provided in a rear part of the hull, each of the first camera and the second camera specifies a land-based target among land-based structures, the recognition means photo images of the land-based targets respectively by the first camera and the second camera, and by operating the ship so as to maintain sizes of the plurality of the images of the land-based targets, fixed point holding on the sea is performed. 
     According to the ship of at least an embodiment of the present invention, the accurate position of the ship itself on the sea can be recognized. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which: 
         FIG. 1  is a  FIG. 1  is a block diagram of an apparatus configuration of a ship of a first embodiment. 
         FIG. 2  is a flow chart of fixed point holding control. 
         FIG. 3  is a schematic drawing of a function of the fixed point holding control. 
         FIG. 4  is a block diagram of an apparatus configuration of a ship of a second embodiment. 
         FIG. 5  is a flow chart of another embodiment of fixed point holding control. 
         FIG. 6  is a schematic drawing of a function of the fixed point holding control. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , an apparatus configuration of a ship  100  is explained. 
     In  FIG. 1 , the apparatus configuration of the ship  100  is shown schematically by a block diagram. 
     The ship  100  is an example of at least one embodiment of the present invention. The ship  100  of this embodiment is not limited especially and may be a leisure boat, a fishing boat or the like. The ship  100  has a ship operation controller  150  and a recognition controller  160  as a recognition means. 
     The ship operation controller  150  operates or steers the ship  100 . The ship operation controller  150  is connected to an Engine Control Unit (hereinafter, referred to as ECU)  151  controlling rotation speed of an engine driving a screw propeller, a thruster controller  152  controlling rotation speed of a motor driving a thruster, and a hydraulic circuit  153  controlling a position of a hydraulic cylinder driving a rudder. 
     The thruster of this embodiment is a bow thruster or a stern thruster. The ship  100  of at least an embodiment of the present invention may have a propulsion device of stern drive type, POD type, or an outboard motor or the like. 
     The recognition controller  160  recognizes a position of the ship  100  on the sea. The recognition controller  160  is connected to a first camera  161 , a second camera  162  and the ship operation controller  150 . The first camera  161  is provided in a front part of a hull. The second camera  162  is provided in a rear part of the hull (see  FIG. 3 ). 
     Referring to  FIG. 2 , a flow of a fixed point holding control S 100  is explained. 
     In  FIG. 2 , the flow of the fixed point holding control S 100  is shown by a flow chart. 
     In the fixed point holding control S 100 , an image of a structure S 1  is photographed by the first camera  161 , an image of a structure S 2  is photographed by the second camera  162 , and the ship is operated so as to maintain sizes of the photographed images of the structure S 1  and the structure S 2 , whereby the fixed point holding of the ship  100  is performed on the sea. 
     In a step S 110 , the recognition controller  160  photographs an image P of the structure S 1  as a land-based target by the first camera  161  and stores as an image P 1 . 
     In a step S 120 , the recognition controller  160  photographs the image P of the structure S 2  as another land-based target by the second camera  162  and stores as an image P 2 . 
     In a step S 131 , the recognition controller  160  photographs the image P of the structure S 1  by the first camera  161  again, and transmits a command to the ship operation controller  150  and operates the ship  100  so as to make a size of the photographed image P the same as that of the stored image P 1 . 
     In a step S 132 , the recognition controller  160  photographs the image P of the structure S 2  by the second camera  162  again, and transmits the command to the ship operation controller  150  and operates the ship  100  so as to make the size of the photographed image P the same as that of the stored image P 2 . 
     Hereinafter, the recognition controller  160  performs the fixed point holding of the ship  100  while repeating a step S 130  (step S 131  and step S 132 ) for every predetermined time. 
     Referring to  FIG. 3 , a function of the fixed point holding control S 100  is explained. 
     In  FIG. 3 , the function of the fixed point holding control S 100  is shown schematically. 
     In the step S 110 , the image P of the structure S 1  is photographed by the first camera  161  and stored as the image P 1 . In the step S 120 , the image P of the structure S 2  is photographed by the second camera  162  and stored as the image P 2 . 
     In the step S 131 , he image P of the structure S 1  is photographed by the first camera  161  again, and a command is transmitted to the ship operation controller  150  and the ship  100  is operated so as to make the size of the photographed image P the same as that of the stored image P 1 . 
     In this case, the ship  100  is operated so as to make a relative distance to the structure  51  the same as that to a point at which the image P 1  is photographed (step S 110 ). 
     In the step S 132 , he image P of the structure S 2  is photographed by the second camera  162  again, and a command is transmitted to the ship operation controller  150  and the ship  100  is operated so as to make the size of the photographed image P the same as that of the stored image P 2 . 
     In this case, the ship  100  is operated so as to make a relative distance to the structure S 2  the same as that to a point at which the image P 2  is photographed (step S 120 ). Namely, the ship  100  is held at the position at which the image P 1  and the image P 2  are photographed (step S 110  and step S 120 ). 
     An effect of the ship  100  is explained. 
     According to the ship  100 , an accurate position of the ship  100  on the sea can be recognized so as to perform the fixed point holding. 
     In this embodiment, the position of the ship  100  on the sea is recognized by the recognition controller  160 , the first camera  161  and the second camera  162  so as to perform the fixed point holding. However, the configuration is not limited thereto, and for example, it may alternatively be configured that the position of the ship  100  on the sea is recognized and automatic docking is performed. 
     Referring to  FIG. 4 , an apparatus configuration of a ship  200  is explained. 
     In  FIG. 4 , the apparatus configuration of the ship  200  is shown schematically by a block diagram. 
     The ship  200  is at least another embodiment of the present invention. The ship  200  of this embodiment is not limited especially and may be a leisure boat, a fishing boat or the like. The ship  200  has a ship operation controller  250  and a recognition controller  260  as the recognition means. 
     The ship operation controller  250  operates or steers the ship  200 . The ship operation controller  250  is connected to an ECU  251  controlling rotation speed of an engine driving a screw propeller, a thruster controller  252  controlling rotation speed of a motor driving a thruster, and a hydraulic circuit  253  controlling a position of a hydraulic cylinder driving a rudder. 
     The recognition controller  260  recognizes a position of the ship  200  on the sea. The recognition controller  260  is connected to a first distance sensor  261 , a second distance sensor  262  and the ship operation controller  250 . The first distance sensor  261  is provided in a front part of a hull. The second distance sensor  262  is provided in a rear part of the hull. 
     The first distance sensor  261  and the second distance sensor  262  may be provided in any position which is not interrupted by an obstacle, such as a cabin of the hull. 
     The first distance sensor  261  and the second distance sensor  262  emit infrared light to a subject, detect the light reflected by the subject, and calculate a distance to the subject based on arrival time of the reflected light. The first distance sensor  261  and the second distance sensor  262  can be rotated for 360° so as to confirm subjects of all directions. 
     Referring to  FIG. 5 , a flow of a fixed point holding control S 200  is explained. 
     In  FIG. 5 , the flow of the fixed point holding control S 200  is shown by a flow chart. 
     In the fixed point holding control S 200 , a distance L 1  to the structure S 1  is measured by the first distance sensor  261 , a distance L 2  to the structure S 2  is measured by the second distance sensor  262 , and the ship is operated so as to maintain the distance L 1  and the distance L 2 , whereby the fixed point holding of the ship  200  is performed on the sea. 
     In a step S 210 , the recognition controller  260  measures a distance L to the structure S 1  as the land-based target by the first distance sensor  261 , and stores the distance Las the distance L 1 . 
     In a step S 220 , the recognition controller  260  measures the distance L to the structure S 2  as the land-based target by the second distance sensor  262 , and stores the distance L as the distance L 2 . 
     In a step S 231 , the recognition controller  260  measures the distance L to the structure S 1  by the first distance sensor  261  again, and transmits a command to the ship operation controller  250  and operates the ship  200  so as to make the measured distance L the same as the stored distance L 1 . 
     In a step S 232 , the recognition controller  260  measures the distance L to the structure S 2  by the second distance sensor  262  again, and transmits a command to the ship operation controller  250  and operates the ship  200  so as to make the measured distance L the same as the stored distance L 2 . 
     Hereinafter, the recognition controller  260  performs the fixed point holding of the ship  200  while repeating a step S 230  (step S 231  and step S 232 ) for every predetermined time. 
     Referring to  FIG. 6 , a function of the fixed point holding control S 200  is explained. 
     In  FIG. 6 , the function of the fixed point holding control S 200  is shown schematically. 
     In the step S 210 , the distance L to the structure S 1  is measured by the first distance sensor  261  and stored as the distance L 1 . In the step S 220 , the distance L to the structure S 2  is measured by the second distance sensor  262  and stored as the distance L 2 . 
     In the step S 231 , the distance L to the structure S 1  is measured by the first distance sensor  261  again, and the command is transmitted to the ship operation controller  250  and the ship  200  is operated so as to make the measured distance L the same as the stored distance L 1 . 
     In the step S 232 , the distance L to the structure S 2  is measured by the second distance sensor  262  again, and the command is transmitted to the ship operation controller  250  and the ship  200  is operated so as to make the measured distance L the same as the stored distance L 2 . 
     In this case, the ship  200  is held at the position at which the distance L 1  and the distance L 2  are measured (step S 210  and step S 220 ). 
     An effect of the ship  200  is explained. 
     According to the ship  200 , an accurate position of the ship  200  on the sea can be recognized so as to perform the fixed point holding. 
     In this embodiment, the position of the ship  200  on the sea is recognized by the recognition controller  260 , the first distance sensor  261  and the second distance sensor  262  so as to perform the fixed point holding. However, the configuration is not limited thereto, and for example, it may alternatively be configured that the position of the ship  200  on the sea is recognized and automatic docking is performed. 
     INDUSTRIAL APPLICABILITY 
     At least an embodiment of the present invention can be used for a ship. 
     While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. 
     The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.