Autonomous ships equipped with anti-hijacking measures

Abstract

In the event of a hacking incident, an autonomous vessel can autonomously and quickly stop sailing and remain stationary. [Solution] The interlock device 180 includes a safety confirmation signal receiving unit 181 that determines the presence or absence of a safety confirmation signal, and a rudder control signal blocking unit 182 that blocks the signal path from the ship steering control device 210 to the rudder control devices 106 and 107 when the safety confirmation signal is interrupted. The rudder control devices 106 and 107 include a home position setting unit 110 that sets the hover rudder angle as the home position of the high-lift rudder, a signal detection unit 111 that detects the interruption of the rudder control signal by the interlock device 180, and a home position holding unit 112 that steers and holds the high-lift rudder 102 and 103 to the home position when the signal detection unit 111 detects the interruption of the signal.

Description

Technical Field

[0001] The present invention relates to an automatically navigating ship provided with anti-hijacking countermeasures, and relates to a technology for preventing theft, runaway and collision of an automatically navigating ship caused by hijacking.

Background Art

[0002] Conventionally, there is an automatically navigating single-shaft double-rudder ship described in Patent Document 1. This is a ship in which a pair of left and right high-lift rudders are arranged behind one propulsion propeller disposed at the stern, and an automatic control device controls a pair of rotary vane steering gears that drive each high-lift rudder, and controls the direction of hull motion by combining the rudder angles of the two high-lift rudders.

[0003] An emergency control device independent of the automatic control device, when receiving an emergency command via satellite communication, performs hovering maneuvering that keeps the hull in place by combining the rudder angles of the two high-lift rudders.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0005] However, when a ship navigates automatically and autonomously without crew, information necessary for navigation such as destination, route, weather information and the like is obtained from the outside via satellite communication, so the possibility that an external third party intrudes into the automatic control device via satellite communication cannot be eliminated.

[0006] When the ship deviates from the route it should originally navigate and heads for a port different from the original destination for theft due to hacking by this external third party, so-called hacker, or when an abnormal maneuvering state with an abnormally increased ship speed occurs and a collision risk arises, it is required to stop the ship and keep it in place.

[0007] In the aforementioned prior art, a ground station monitors the navigation status of a vessel, and when an abnormality is detected in its navigation, the ground station instructs the vessel to hover via satellite communication.

[0008] However, even with monitoring the ship's navigation status, there is no guarantee that a hacking incident will be detected promptly, and there may be delays in taking action to stop the autonomous vessel.

[0009] The present invention aims to solve the above problems and to provide an autonomous navigation vessel equipped with anti-hijacking measures that, in the event of a hacking incident, can autonomously and quickly stop its navigation and remain in place, thereby avoiding theft of the vessel and its cargo, runaway movement of the vessel, and collision. [Means for solving the problem]

[0010] To solve the above-mentioned problems, the autonomous ship equipped with the hijacking countermeasures of the present invention comprises a single propulsion propeller located at the stern, a pair of left and right high-lift rudders located behind the propulsion propeller, a pair of steering gears that drive each high-lift rudder, a pair of rudder control devices that control each steering gear, and a steering control device that controls the direction of the ship's movement by combining the rudder angles of the two high-lift rudders and controls the operation of the ship for autonomous navigation. An interlock device interposed in the signal path between the ship's steering control system and the rudder control system, A satellite communication device that inputs commands received via satellite communication into the ship's control system, A security satellite communication device that inputs commands received via satellite communication into an interlock device. The interlock device is equipped with, The system comprises a safety confirmation signal receiving unit, a decoding key registration unit, a security code inspection unit, and a rudder control signal blocking unit. The safety confirmation signal receiving unit receives a safety confirmation signal from the ship's control device and determines whether or not the safety confirmation signal, which is a security code indicating the reliability of satellite communication received by the satellite communication device, is present. The rudder control signal blocking unit blocks the signal path from the ship's control device to the rudder control device when the safety confirmation signal is interrupted. The decoding key registration unit stores the decoding key received by the security satellite communication device via satellite communication. The security code inspection unit verifies the authenticity of the security code using the decoding key and, if the security code is a false code, instructs the rudder control signal blocking unit to block the signal path to the rudder control device. The rudder control device is characterized by having a home position setting unit that sets the hover rudder angle, which is the rudder angle for hovering maneuvering that keeps the hull in place, as the home position of the high-lift rudder; a signal detection unit that detects signal interruption of the rudder control signal by an interlock device; and a home position holding unit that, when the signal detection unit detects signal interruption, steers and holds the high-lift rudder to the home position regardless of the maneuvering instruction.

[0012] In an autonomous ship equipped with the hijacking countermeasures of the present invention, the satellite communication device communicates via a first communication satellite, and the security satellite communication device communicates via a second communication satellite.

[0013] In an autonomous ship equipped with the hijacking countermeasures of the present invention, moreover, The interlock device includes a power supply circuit that supplies power to each steering gear, and a power switch interposed between the power supply circuit and the main power supply. The interlock device has a timer unit that measures the elapsed time since the signal path to the steering control device was cut off, and when the elapsed time reaches a predetermined set time, it instructs the power switch intercept unit to cut off the power supply to each steering gear.

[0014] In an autonomous ship equipped with the hijacking countermeasures of the present invention, moreover, The ship steering control device comprises a first communications satellite antenna device connected to a satellite communication device, a communications blocking device interposed in the signal path between the first communications satellite antenna device and the satellite communication device, and a second communications satellite antenna device connected to a security satellite communication device. The satellite communication device communicates via the first communications satellite, and the security satellite communication device communicates via the second communications satellite. The ship steering control device has a restore restart device and a remote manual control device. The interlock device has a release signal receiving unit that receives a lock release signal from the security satellite communication device and instructs the communications blocking device to block satellite communication. The restore restart device, while blocking satellite communication between the ship steering control device and the first communications satellite, receives a restart signal from the security satellite communication device and restores and restarts the control program of the ship steering control device. The remote manual control device remotely controls the rudder control device based on instructions input from the security satellite communication device after the control program of the ship steering control device has been restored and restarted.

[0015] In an autonomous ship equipped with the hijacking countermeasures of the present invention, Interlock device It is characterized by having an emergency shutoff signal receiving unit that receives an emergency shutoff signal from a security satellite communication device and instructs the rudder control signal shutoff unit to shut off the signal path.

[0016] In the autonomous ship equipped with the hijacking countermeasures of the present invention, the home position setting unit is characterized by setting the initial value of the home position on the ship by adjusting the adjustment rudder angle to the reference hover rudder angle. [Effects of the Invention]

[0017] In the above configuration, an interlock device interposed in the signal path between the steering control device and the rudder control device determines whether or not the steering control device receives a safety confirmation signal via satellite communication. If the safety confirmation signal is lost, the rudder control device turns and holds the high-lift rudder to the home position, regardless of any steering instructions, keeping the ship in place.

[0018] Therefore, if a hacking incident occurs while a ground station is transmitting a safety confirmation signal to an autonomously navigating vessel via satellite communication, and satellite communication with the ground station is disrupted, the safety confirmation signal will not reach the interlock device. As a result, the rudder control system will steer the high-lift rudder to its home position and hold it there, causing the vessel to remain in place.

[0019] Therefore, autonomous ships can quickly and autonomously stop sailing and remain in place, enabling the rapid implementation of anti-hijacking measures that can prevent theft of the ship and its cargo, runaway movement, and collisions.

[0020] Furthermore, by using a security code that indicates the reliability of satellite communication as the security confirmation signal, and by using an interlock device to verify the authenticity of the security code using a decoding key received via a separate satellite communication, advanced anti-hijacking measures can be implemented.

[0021] Furthermore, when the time elapsed since the rudder control system turned and held the high-lift rudder in the home position reaches a predetermined time, the power switch will cut off the power supply to each steering gear according to the instructions of the interlock device, thus making hijacking physically impossible.

[0022] Further, since the communication blocking device blocks satellite communication between the ship steering control device and the first communication satellite in accordance with an instruction from the interlock device, restoration and restarting of the control program of the ship steering control device by the restoration / restart device can be performed in a state where hacking is blocked, and the rudder control device can be remotely manually controlled based on an instruction input from the security satellite communication device in a state where hacking is blocked. [Brief Description of the Drawings]

[0023] [Figure 1] Schematic diagram showing a thrust system and an automatic control device of an automatically navigating ship provided with anti-hijacking measures according to an embodiment of the present invention [Figure 2] Block diagram showing the interlock device in the same embodiment [Figure 3] Block diagram showing the rudder control device in the same embodiment [Figure 4] Schematic diagram showing a ship handling console in the same embodiment [Figure 5] Block diagram showing the configuration of the ship handling console in the same embodiment [Figure 6] Plan view showing the movable range of a high-lift rudder in the same embodiment [Figure 7] Perspective view showing a propeller and a high-lift rudder in the same embodiment, and showing the configuration of the stern part of the thrust system [Figure 8] Schematic diagram showing combined rudder angles of rudders and turning directions [Mode for Carrying Out the Invention]

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0025] As shown in Figs. 1 to 8, the automatically navigating ship provided with anti-hijacking measures according to the present embodiment includes a thrust system 100 and a ship steering system 200 that controls the thrust system 100.

[0026] As shown in Figure 7, the thrust system 100 consists of a propeller thruster 101 with one propeller and one shaft located at the stern of the hull 110, and two high-lift rudders 102 and 103 located behind the propeller.

[0027] The high-lift rudders 102 and 103 are rudders having rudder blades with a cross-sectional shape that provides high lift along the axis direction of the propeller. Although high-lift rudder blades come in various shapes, the rudder blades of the high-lift rudders 102 and 103 in this embodiment have the following shapes.

[0028] In other words, as shown in Figure 6, the shape consists of a front edge portion 102a, 103a that protrudes forward in a semicircular shape in the horizontal cross-sectional contour, an intermediate portion 102c, 103c that increases in width in a streamlined manner continuous with the front edge portion 102a, 103a and then gradually decreases in width toward the minimum width portion 102b, 103b, and a fishtail rear edge portion 102e, 103e that increases in width continuously with the intermediate portion 102c, 103c toward the rear end 102d, 103d of a predetermined width.

[0029] Each of the high-lift rudders 102 and 103 is configured to be steerable 105° outboard and 35° inboard. With the single propeller rotating forward, the pair of high-lift rudders 102 and 103 can be operated independently at various angles. By changing the combination of rudder angles of the high-lift rudders 102 and 103 on both sides, the propeller wake can be distributed in the desired direction, and the thrust in each direction can be freely changed. Therefore, the combined thrust of the thrust in each direction can be freely changed, and by controlling the propeller wake and controlling the thrust around the stern in all 360° directions, the ship's movement can be freely controlled, allowing for forward and backward movement, stopping, forward turns, and reverse turns.

[0030] Furthermore, as shown in Figure 1, the thrust system 100 includes rotary vane steering gears 104 and 105 that drive high-lift rudders 102 and 103, rudder control devices (servo amplifiers) 106 and 107 that control the rotary vane steering gears 104 and 105, and a bow thruster 108 located on the bow side of the hull 110 and a thruster control device 109 that controls the bow thruster 108.

[0031] Furthermore, the rotary vane steering gears 104 and 105 are connected to pump units 151 and 152, rudder angle transmitters 153 and 154, and feedback units 155 and 156, respectively, and the feedback units 155 and 156 are connected to rudder control devices 106 and 107.

[0032] Interlock devices 180 are connected to the rudder control devices 106 and 107, and power supply circuits 157 that supply power to the pump units 151 and 152 of each rotary vane steering gear 104 and 105 are connected to the main power supply 158, with a power switch 159 interposed in the power path between the power supply circuits 157 and the main power supply 158. In this configuration, the power switch 159 cuts off the power to the power supply circuits 157 that supply power to the pump units 151 and 152, but if the steering gear is electric, it is also possible to configure it to cut off the power to the power supply circuit that supplies power to the motor of the steering gear.

[0033] The ship handling system 200 includes a ship handling control device 210, a ship radar device 271, a satellite communication device 272, and a security satellite communication device 273.

[0034] The ship handling control device 210 includes an automatic control device 201 for controlling the direction of ship movement by combining the rudder angles of two high-lift rudders 102 and 103 in an unmanned, autonomous, automatic navigation control mode; a manned control device 202 for manned operation by combining the rudder angles of the two high-lift rudders 102 and 103 in an automated navigation control mode; a remote manual control device 203 for remotely controlling the direction of ship movement by combining the rudder angles of the two high-lift rudders 102 and 103 independently of the automatic control device 201 in an automated navigation control mode; and a restore / restart device 204 for restoring and restarting the control program of the ship handling control device 210.

[0035] The ship handling control device 210 is housed in the ship handling stand 250 and is connected to a gyrocompass 251, a ship radar device 271, a satellite communication device 272, and a security satellite communication device 273.

[0036] The satellite communication device 272 is connected to the antenna device 274 for the first communication satellite, and a communication blocker 275 is interposed in the signal path between the antenna device 274 and the satellite communication device 272. The security satellite communication device 273 is connected to the antenna device 276 for the second communication satellite. The satellite communication device 272 communicates via the first communication satellite, and the security satellite communication device 273 communicates via the second communication satellite, and the communication path of the security satellite communication device 273 is separate and independent from the communication path of the satellite communication device 272.

[0037] As shown in Figure 2, the interlock device 180 includes a safety confirmation signal receiving unit 181, a rudder control signal blocking unit 182, a decoding key registration unit 183, a safety code inspection unit 184, a timer unit 185, a release signal receiving unit 186, and an emergency shutoff signal receiving unit 187.

[0038] The safety confirmation signal receiving unit 181 receives a safety confirmation signal from the ship steering control device 210 and determines whether or not a safety confirmation signal is present. The rudder control signal blocking unit 182 blocks the signal path from the ship steering control device 210 to the rudder control devices 106 and 107 when the safety confirmation signal is interrupted.

[0039] The decoding key registration unit 183 stores the decoding key received by the security satellite communication device 273 via satellite communication through the second communication satellite, and the security code inspection unit 184 uses the decoding key to verify the authenticity of the security code. If the security code is a false code, the rudder control signal blocking unit 182 blocks the signal path to the rudder control devices 106 and 107.

[0040] The timer unit 185 measures the elapsed time since the signal path to the rudder control devices 106 and 107 was cut off. When the elapsed time reaches a set time set by the user, it instructs the power switch 159 to cut off the power supply to the pump units 151 and 152 of each rotary vane steering gear 104 and 105.

[0041] The release signal receiving unit 186 receives a lock release signal from the security satellite communication device 273 and instructs the communication blocking device 275 to block satellite communication with the first communication satellite.

[0042] The emergency shutoff signal receiving unit 187 receives an emergency shutoff signal from the security satellite communication device 273 and instructs the rudder control signal shutoff unit 182 to shut off the signal path.

[0043] As shown in Figure 5, the automatic control device 201 is operated by an autopilot using a gyrocompass 251 and a GPS compass (not shown). It has an automatic navigation and maneuvering unit 253 that autonomously steers the ship while detecting surrounding ships and obstacles with a ship radar device 271, and a ship command receiving unit 265 that receives ship command instructions via satellite communication.

[0044] The manned control device 202 includes a gyro direction display unit 252 that displays the gyro direction of the gyrocompass 251, a joystick steering unit 255 for steering the vessel using a joystick lever 254, a steering handle 256, a mode switching unit 261 for switching between the automatic control device 201 and the manned control device 202 using a mode switching switch 260, a display device 262 with a touch panel on its screen, and an image control unit 263 for controlling the images displayed on the display device 262.

[0045] The image control unit 263 selectively displays, or simultaneously displays, a gyro direction display image 267 showing the gyro direction, a direction display unit operation image 268 for touch operation of the gyro direction display unit 252 on the monitor screen, and an auto steering operation image 269 for touch operation of the automatic navigation steering unit 253 on the monitor screen.

[0046] The joystick control unit 255 is configured such that the joystick lever 254 can be operated in either the X or Y direction, and the direction of the ship's commanded movement is controlled by the tilt direction of the joystick lever 254.

[0047] The joystick steering unit 255 controls the rudder angles of the high-lift rudders 102 and 103 on both sides to the rudder angles set according to the tilt direction of the joystick lever 254, and by combining the rudder angles of the high-lift rudders 102 and 103 on both sides, it redirects the thrust of the propeller wake in the desired direction, and the rotary vane steering gears 104 and 105 on both sides control the rudder angles of the high-lift rudders 102 and 103 on both sides within a range of 105° outward and 35° inward. Further details will be described later.

[0048] The automatic navigation and steering unit 253 uses a gyrocompass 251, GPS compass, and electronic chart system to guide and control the ship to a set course received via satellite communication, based on the ship's current position information, guidance path information, and stationary position information.

[0049] The restore and restart device 204, with satellite communication between the ship steering control device 210 and the first communication satellite interrupted, receives a restart signal from the second communication satellite via the security satellite communication device 273 and restores and restarts the control program of the ship steering control device 210.

[0050] The remote manual control device 203 remotely controls the rudder control devices 106 and 107 based on instructions input from the second communication satellite via the security satellite communication device 273, after the control program of the ship steering control device 210 has been restored and restarted. Remote manual control is performed by placing a device with the same configuration as the manned control device 202 at a ground station. The joystick lever at the ground station is used to instruct the remote manual control device 203 to control the rudder control devices 106 and 107. As shown in Figure 3, the rudder control devices 106 and 107 include a home position setting unit 110, a signal detection unit 111, and a home position holding unit 112.

[0051] The home position setting unit 110 sets the hover rudder angle, which is the rudder angle for hovering maneuvers that keep the hull in place, as the home position for the high-lift rudders 102 and 103. The home position is adjustable, and the initial value of the home position for this vessel is set by adding or subtracting the adjustment rudder angle to the reference hover rudder angle.

[0052] The signal detection unit 111 detects the interruption of the rudder control signal by the interlock device 180.

[0053] The home position holding unit 112 steers and holds the high-lift rudders 102 and 103 to the home position regardless of the steering instructions, when the signal detection unit 111 detects a signal interruption.

[0054] Figure 8 illustrates the basic combinations of rudder angles for the high-lift rudders 102 and 103, as well as the state of the joystick lever 254, its designation, and the propeller wake and direction of motion.

[0055] In Figure 8, the rudder is shown in a horizontal cross-section, with the rudder angle of each rudder indicated to the side or below it. A rudder angle to the right is indicated as positive (+) and a rudder angle to the left is indicated as negative (-), and the names for these combinations of rudder angles are listed. The propeller wake is shown with a thin arrow line, and the resulting direction of the ship's propulsion is shown with a thick, hollow arrow line.

[0056] Incidentally, "TURN TO PORT" (turning left forward) is -35° on the port rudder and -35° on the starboard rudder, "ROTATE TO PORT" (turning left bow) is -70° on the port rudder and -35° on the starboard rudder, "STERN TO PORT" (turning left stern) is -105° on the port rudder and +45° to +75° on the starboard rudder, "ASTERN TO PORT" (turning left backward) is -105° on the port rudder and +75° to +105° on the starboard rudder, and "AHEAD" (forward) is 0° on the port rudder and 0° on the starboard rudder.

[0057] The standard "HOVERING" (stopping in place) is a port rudder of -75° and a starboard rudder of +75°. However, the appropriate hover rudder angle varies depending on the size and structure of the hull, so it is adjusted by adding or subtracting the adjustment rudder angle from the standard hover rudder angle (port rudder -75°, starboard rudder +75°). Here, the port rudder angle is adjusted within the range of -70° to -80°, and the starboard rudder angle is adjusted within the range of +70° to +80°.

[0058] "ASTERN" (reverse) is -105° port rudder and +105° starboard rudder, "TURN TO STARD" (forward right turn) is +35° port rudder and +35° starboard rudder, "ROTATE TO STARD" (bow right turn) is +35° port rudder and +70° starboard rudder, "STERN TO STARD" (stern right turn) is -45° to -75° port rudder and +105° starboard rudder, and "ASTERN TO STARD" (reverse right turn) is -75° to -105° port rudder and +105° starboard rudder.

[0059] The following explains the operation of the above configuration. 1. Manned control mode 202 The mode selector switch 260 is operated to select the joystick control mode of the manned control device 202. The joystick control unit 255 commands the direction of the ship's movement using the joystick lever 254.

[0060] In this maneuver, the propeller thruster 101 is kept rotating forward, while each high-lift rudder, 103 is operated independently at various angles to control the propeller wake, thereby controlling the thrust around the stern in all 360 degrees. This control allows the ship to move forward and backward, stop, turn forward, turn backward, etc., thereby improving the maneuverability during operation.

[0061] In other words, by changing the combination of rudder angles on both sides, the thrust can be directed in the desired direction of the propeller wake. The rudder angle combinations listed here are just examples, and the combination of rudder angles can be arbitrarily changed to obtain the desired propulsion direction and thrust.

[0062] Thus, in ship handling, reversing the propeller thrust (reversing the propeller rotation) is unnecessary, and all ship handling controls can be performed while the main engine is always rotating forward. Without adjusting the rotation speed of the main engine, the ship's speed can be precisely controlled steplessly from the maximum forward speed corresponding to the current propeller rotation speed to the maximum reverse speed by adjusting the rudder angles of both rudders. 2. Operation modes by the automatic control device 201 The mode selection switch 260 is operated to select the control mode by the automatic control device 201.

[0063] The automatic control device 201 operates autonomously and unmanned. Specifically, the automatic control device 201 receives navigation information such as destination, route, and ship speed from a remote location via satellite communication as navigation command receiving unit 265. Based on the received command, it operates using an autopilot with a GPS compass, and guides and controls the ship to the set course received via the navigation command from satellite communication, based on the ship's current position information, guidance route information, and stationary position information from the GPS compass and electronic chart system.

[0064] In ship operation using this automatic control device 201, similar to ship operation using the manned control device 202, the propeller thruster 101 is kept in forward rotation, and the high-lift rudders 102 and 103 are operated independently at various angles to control the propeller wake, thereby controlling the thrust around the stern in all 360 degrees. This control allows the ship to move forward and backward, stop, turn forward, turn backward, etc.

[0065] When the vessel is operating automatically in the control mode operated by the automatic control device 201, a safety confirmation signal is transmitted from the ground station to the first communications satellite at regular intervals or periodically.

[0066] The ship handling control device 210 receives ship handling commands from the satellite communication device 272 and sends a safety confirmation signal to the interlock device 180.

[0067] The interlock device 180 uses a safety confirmation signal receiving unit 181 to determine whether or not a safety confirmation signal is received through the ship steering control device 210. If the safety confirmation signal is interrupted, the rudder control signal blocking unit 182 blocks the signal path from the ship steering control device 210 to the rudder control devices 106 and 107.

[0068] When the signal detection unit 111 of the rudder control devices 106 and 107 detects a signal interruption of the rudder control signal by the interlock device 180, the home position holding unit 112 steers and holds the high-lift rudders 102 and 103 to the home position, regardless of the steering instruction.

[0069] Therefore, if a hacking incident occurs while a ground station is transmitting a safety confirmation signal to an automatically navigating vessel via the first satellite communication, and communication between the ground station and the satellite via the first satellite communication is disrupted, the safety confirmation signal will not reach the interlock device 180. As a result, the rudder control devices 106 and 107 will steer and hold the high-lift rudders 102 and 103 in their home positions, causing the vessel to remain in place.

[0070] Therefore, autonomous ships can quickly and autonomously stop sailing and remain in place, enabling the rapid implementation of anti-hijacking measures that can prevent theft of the ship and its cargo, runaway movement, and collisions.

[0071] Furthermore, by using a security confirmation signal as a security code indicating the reliability of satellite communication, and by having the interlock device 180 register a decoding key received from a separate second communication satellite in the decoding key registration unit 183, and by having the security code inspection unit 184 verify the authenticity of the security code using the decoding key, and by instructing the rudder control signal blocking unit to block the signal path to the rudder control device if the security code is a fake code, an advanced anti-hijacking measure can be implemented.

[0072] Furthermore, in the timer unit 185 of the interlock device 180, when the elapsed time since the rudder control devices 106 and 107 turned and held the high-lift rudder 102 and 103 in the home position reaches a predetermined time, the power switch 159 cuts off the power supply to the pump units 151 and 152 of the rotary vane steering gears 104 and 105 at the instruction of the timer unit 185, thus providing a countermeasure against hijacking that makes it physically impossible to hijack the ship by hacking.

[0073] Furthermore, when the interlock device 180 instructs the communication blocking device 275 to block satellite communication between the ship steering control device 210 and the first communication satellite, the hacking activity is blocked, and the restore / restart device 204 can restore and restart the control program of the ship steering control device 210. With the hacking activity blocked, the rudder control devices 106 and 107 can be remotely controlled manually based on instructions input from the second communication satellite via the security satellite communication device 273. [Explanation of Symbols]

[0074] 100 Thrust System 110 hull 101 Propeller thruster 102, 103 High-lift rudder 104, 105 Rotary vane steering gear 106, 107 Rudder control device 108 Bow thruster 109 Thruster control device 110 Home position setting section 111 Signal detection unit 112 Home position holding section 151, 152 Pump Units 153, 154 Rudder angle transmitters 155, 156 Feedback Unit 157 Power supply circuit 158 Main power supply 159 Power switch 180 Interlock device 181 Safety Confirmation Signal Receiver 182 Rudder control signal cutoff unit 183 Decryption Key Registration Section 184 Security Code Inspection Department 185 Timer section 186 Release signal receiving unit 187 Emergency shutdown signal receiving unit 200 ship handling systems 201 Automatic control system 202 Manned control equipment 203 Remote Manual Control Device 204 Restore and Restart Device 210 Ship steering control system 250 Steering Stand 251 Gyrocompass 252 Gyro Direction Display Unit 253 Automated Navigation and Maneuvering Unit 254 Joystick Lever 255 Joystick Control Unit 256 Steering wheel 260 Mode Selector Switch 261 Mode switching section 262 Display devices 263 Image Control Unit 271 Ship radar equipment 272 Satellite communication equipment 273 Security satellite communication equipment 274 Transceiver and receiver antenna equipment for the first communications satellite 275 Communication Blocking Device 276 Transceiver and receiver antenna equipment for the second communications satellite

Claims

1. The ship is equipped with a single propulsion propeller located at the stern, a pair of high-lift rudders positioned behind the propulsion propeller, a pair of steering gears that drive each of the high-lift rudders, a pair of rudder control devices that control each of the rudder gears, a ship handling control device that controls the direction of the ship's movement by combining the rudder angles of the two high-lift rudders and controls the automatic navigation maneuvering, an interlock device interposed in the signal path between the ship handling control device and the rudder control device, a satellite communication device that inputs commands received via satellite communication to the ship handling control device, and a security satellite communication device that inputs commands received via satellite communication to the interlock device. The interlock device includes a safety confirmation signal receiving unit, a decoding key registration unit, a safety code inspection unit, and a rudder control signal blocking unit. The safety confirmation signal receiving unit receives a safety confirmation signal from the ship's control device and determines whether or not the safety confirmation signal, which is a security code indicating the reliability of satellite communications received by the satellite communication device, is present. The rudder control signal cutoff unit cuts off the signal path from the ship steering control device to the rudder control device when the safety confirmation signal is interrupted. The decoding key registration unit stores the decoding keys received by the security satellite communication device via satellite communication. The security code inspection unit uses a decoding key to verify the authenticity of the security code, and if the security code is found to be a false code, it instructs the rudder control signal blocking unit to block the signal path to the rudder control device. An autonomous ship equipped with anti-hijacking measures, characterized in that the rudder control system includes a home position setting unit that sets the hover rudder angle, which is the rudder angle for hovering maneuvering that keeps the ship in place, as the home position of the high-lift rudder; a signal detection unit that detects signal interruption of the rudder control signal by an interlock device; and a home position holding unit that, when the signal detection unit detects signal interruption, steers and holds the high-lift rudder to the home position regardless of any maneuvering instructions.

2. An autonomous ship equipped with anti-hijacking measures according to claim 1, characterized in that the satellite communication device communicates via a first communication satellite, and the security satellite communication device communicates via a second communication satellite.

3. Furthermore, the system includes a power supply circuit that supplies power to each steering gear, and a power switch interposed between the power supply circuit and the main power supply, The autonomous ship equipped with hijacking countermeasures according to claim 1, characterized in that the interlock device has a timer unit that measures the elapsed time since the signal path to the rudder control device was cut off, and when the elapsed time reaches a set time, it instructs the power switch to cut off the power supply to each steering gear.

4. The present invention further comprises a first communications satellite antenna device connected to a satellite communication device, a communications blocking device interposed in the signal path between the first communications satellite antenna device and the satellite communication device, and a second communications satellite antenna device connected to a security satellite communication device. The satellite communication device communicates via the first communication satellite, and the security satellite communication device communicates via the second communication satellite. The ship's control system includes a restore and restart device and a remote manual control device. The interlock device has a release signal receiving unit that receives a lock release signal from the security satellite communication device and instructs the communication blocking device to block satellite communications. The restoration and restart device, with satellite communication between the ship's control system and the first communications satellite interrupted, receives a restart signal from the security satellite communications device and restores and restarts the control program of the ship's control system. The autonomous ship equipped with hijacking countermeasures according to claim 1, characterized in that the remote manual control device remotely controls the rudder control device based on instructions input from the security satellite communication device after the control program of the ship steering control device has been restored and restarted.

5. The autonomous ship equipped with hijacking countermeasures according to Claim 1, characterized in that the interlock device has an emergency cutoff signal receiving unit that receives an emergency cutoff signal from a security satellite communication device and instructs the rudder control signal cutoff unit to cut off the signal path.

6. The autonomous ship equipped with hijacking countermeasures according to claim 1 is characterized in that the home position setting unit sets the initial value of the home position on the ship by adjusting the adjustment rudder angle to the reference hover rudder angle.

Images