Single-screw, twin-rudder vessel equipped with a controllable pitch propeller

Abstract

To carry out vessel position retaining navigation with excellent fixed point retaining property by adjusting propeller propulsion to an appropriate value when carrying out vessel position retaining navigation at low speed.SOLUTION: A vessel position retaining control unit 661 is configured to: cause a propulsion propeller 101 to rotate at constant speed in a proceeding direction in low speed range; set to be a neutral angle a blade angle of the propulsion propeller 101 with steering angles of two pieces of high lift rudders 102, 103 serving as hover angles not generating propulsion speed components; calculate an adjustment rudder angle to be imparted to the two pieces of high lift rudders 102, 103 according to position deviation in present vessel position with respect to a target vessel position; calculate rudder angle deviation of the adjustment rudder angle with respect to a hover rudder angle; and calculate an adjustment blade angle having blade angle deviation with respect to the neutral angle necessary to obtain propeller propulsion in ratio to the magnitude of the rudder angle deviation.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a single-shaft, twin-rudder ship equipped with a controllable pitch propeller, and to a technology that enables highly accurate maneuvering while maintaining a fixed position. [Background technology]

[0002] Conventionally, as a technology for applying a braking force to a ship, there is an emergency ship maneuvering method described in Patent Document 1. In this method, emergency steering means is activated in an emergency and rudder control means is controlled with priority over any normal steering mode, thereby giving two high-lift rudders a rudder angle that maximizes the propeller wake as reverse thrust, and this reverse thrust gives the ship a reverse force that resists the inertial force in the forward direction of the ship, thereby causing the ship to stop or move astern in an emergency. With the propeller operating in a single forward direction, reverse thrust can be obtained immediately, and the ship can be stopped or moved astern in a short time and over a short distance with few steps.

[0003] Furthermore, Patent Document 2 proposes a ship steering device that realizes special movements such as moving straight alongside, moving diagonally forward and backward, and turning on the spot when maneuvering to maintain ship position and heading, and that requires high maneuvering accuracy in position, speed, etc. In this ship steering device, in a maneuvering assistance mode, a command unit commands a command direction of movement, a command turning angular velocity, a command speed in the bow-stern direction, and a command speed in the width direction to a hull motion control unit to steer the ship, and a thrust distribution unit distributes the hull control force and turning hull control force to a target propeller thrust generated by a combination of the thrust of a propeller propeller rotating constantly forward and the rudder angles of two high-lift rudders, and a target thruster thrust generated by a bow thruster. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 7-52887 [Patent Document 2] Patent Publication No. 2017-052297 Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally, the Dynamic Positioning System (DPS) has been used to control the movement of ships and floating structures in deep waters with high precision to maintain a set position, direction, and course. DPS systems use propellers and side thrusters to provide control against external forces from disturbances such as wind, waves, and currents.

[0006] In addition, for a ship to navigate safely within a harbor with many surrounding obstacles such as quays and other ships, it is required to maneuver carefully, taking into account external forces that affect the ship's hull, such as rip currents, onshore currents, tidal forces, wind forces, etc., and to always be aware of the distance between the ship and obstacles.

[0007] However, in diesel-engine fixed-pitch propeller (FPP) ships, it is not common to precisely control the propeller speed over time, and it is difficult to frequently adjust maximum thrust during control in an automatic positioning system.

[0008] Furthermore, when the propeller speed at which the desired thrust is output is close to the critical speed of the main engine, there is a problem that an appropriate propeller thrust cannot be output.

[0009] The present invention is devised to solve the above-mentioned problems, and aims to provide a single-shaft, twin-rudder ship equipped with a controllable pitch propeller that can adjust the propeller thrust to an appropriate value when maneuvering to maintain position at low speeds, thereby enabling maneuvering to maintain position with high stationary position keeping performance. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the single-shaft, twin-rudder ship of the present invention equipped with a controllable pitch propeller comprises a thrust system, a steering system which controls the thrust system, and an observation system which observes the ship's hull motion state, the thrust system comprises a single controllable pitch propeller propeller disposed at the stern, a pair of left and right high-lift rudders disposed aft of the propulsion propeller, and a pair of steering gears which drive each high-lift rudders, the observation system comprises a position measuring device which measures the ship's position, the steering system comprises a positioning motion control unit and a positioning control unit, and the positioning control unit calculates the blade angle of the propulsion propeller when the propulsion propeller rotates at a constant speed in the forward direction at low speeds and the rudder angle of the two high-lift rudders is a hover rudder angle which does not produce a forward speed component. The system is characterized in that it sets the steering angle to a neutral angle, calculates adjustment rudder angles to be given to the two high-lift rudders in accordance with the position deviation of the current ship position from the target ship position, calculates the rudder angle deviation of the adjustment rudder angle from the hover rudder angle, and calculates an adjustment blade angle having a blade angle deviation from the neutral angle required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation, and the positioning motion control unit has a positioning steering control unit that controls each of the pair of steering gears and controls the direction of the ship motion by combining the rudder angles of the two high-lift rudders, and a blade angle control unit that variably controls the blade angle of the propulsion propeller, and the positioning steering control unit controls the two high-lift rudders to the adjustment rudder angle input from the positioning control unit, and the blade angle control unit controls the blade angle of the propulsion propeller to the adjustment blade angle input from the positioning control unit.

[0011] In addition, in the single-shaft, twin-rudder ship equipped with a controllable pitch propeller of the present invention, the blade angle deviation is a value obtained by multiplying the rudder angle deviation by an arbitrary proportionality coefficient. Effect of the Invention

[0012] With the above configuration, ship positioning maneuvering at low speeds, i.e., the propellers are rotated at a constant forward speed at low speeds, and the two high-lift rudders are steered near a hover rudder angle where no forward speed component is generated. If the ship deviates from the target ship position at the hover rudder angle, the rudder angles of the two high-lift rudders required to cause the ship to move toward the target ship position are calculated as adjustment rudder angles. This adjustment rudder angle increases according to the positional deviation of the current ship position from the target ship position.

[0013] The larger the propeller thrust at this adjusted rudder angle, the faster the ship can return to the target position. Therefore, the blade angle of the propulsion propeller is adjusted to increase the propeller thrust as the position deviation increases. In other words, the rudder angle deviation of the adjusted rudder angle from the hover rudder angle is calculated, and the blade angle of the propulsion propeller required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation is calculated as an adjusted blade angle having a blade angle deviation from the neutral angle.

[0014] Therefore, in a single-shaft, twin-rudder ship equipped with a controllable pitch propeller, the propeller thrust can be adjusted to an appropriate value to perform maneuvering to maintain position with high performance in keeping at a fixed position.This means that in deep water areas or in harbors with many surrounding obstacles such as quays and other ships, the movement of the ship can be safely controlled with high precision to a specified position and heading, while taking into account the external forces that affect the ship, such as rip currents, onshore currents, tidal forces, tides, and wind forces. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing a thrust system, a steering system, and an observation system of a single-shaft, twin-rudder ship equipped with a controllable pitch propeller according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a propulsion device, a high-lift rudder, and a bow thruster in the embodiment. [Diagram 3] FIG. 2 is a perspective view showing the configuration of the stern portion in the embodiment; [Figure 4] FIG. 2 is a schematic diagram showing a steering stand of a single-propeller, twin-rudder ship according to the embodiment; [Diagram 5] FIG. 2 is a block diagram showing a configuration of a ship steering stand according to the embodiment; [Figure 6] FIG. 2 is a block diagram showing the configuration of a ship positioning steering unit according to the embodiment; [Figure 7] FIG. 4 is a schematic diagram showing the operating range of a high-lift rudder in the embodiment; [Figure 8] FIG. 4 is a schematic diagram showing the combined rudder angle and turning direction of the high-lift rudder in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (Configuration of the embodiment) The single-shaft, twin-rudder ship equipped with a controllable pitch propeller in this embodiment is equipped with a thrust system 100, a steering system 200 that controls the thrust system 100, and an observation system 300 that observes the ship's hull motion state, as shown in Figures 1 to 8.

[0017] The thrust system 100 includes a single shaft propeller 101 disposed at the stern of a hull 110 and two high-lift rudders 102 and 103 disposed behind the propeller 101.

[0018] Each high-lift rudders 102, 103 is configured to be able to steer 105° outboard (outboard side) and 35° inboard (inboard side). With the single-shaft propeller 101 rotating forward, the pair of two high-lift rudders 102, 103 can be operated independently at various angles, and the combination of rudder angles of the high-lift rudders 102, 103 on both sides can be changed to distribute the propeller wake in a desired direction, and the thrust in each direction can be freely changed.

[0019] Therefore, by freely changing the thrust in each direction, the propeller wake can be controlled to control the thrust around the stern in all directions, 360°, allowing the ship to move forward or backward, stop, turn forward, turn backward, etc., and the ship's movement can be freely controlled.

[0020] Furthermore, the thrust system 100 has rotary vane steering gears 104, 105 that drive the high-lift rudders 102, 103, rudder control devices (servo amplifiers) 106, 107 that control the rotary vane steering gears 104, 105, a bow thruster 108 arranged on the bow side of the hull 110, and a thruster control device 109 that controls the bow thruster 108.

[0021] In addition, pump units 151, 152, rudder angle transmitters 153, 154 and feedback units 155, 156 are connected to the rotary vane steering gears 104, 105, respectively, and the feedback units 155, 156 are connected to the rudder control devices 106, 107.

[0022] The observation system 300 is equipped with a ship speed measuring device 312 that measures the ship's bow-stern speed, ship's width speed, and heading angular velocity, a position measuring device 313 that measures the ship's position using GPS, and a heading measuring device 314 that measures the ship's bow heading.

[0023] The ship maneuvering system 200 is housed in a ship maneuvering stand 250, to which a gyrocompass 251, a ship radar device 310, a ship speed measuring device 312, a position measuring device 313, and a direction measuring device 314 are connected.

[0024] The ship radar device 310 transmits a collision warning signal from a warning signal output unit 311 to the ship maneuvering system 200 of the ship maneuvering stand 250 when a collision with another ship is predicted.

[0025] The maneuvering system 200 includes the following components integrated into the stand housing: a gyro direction display unit 252 that displays the gyro direction of a gyrocompass 251, an auto-steering unit 253 that steers the ship in a steering mode by autopilot using a GPS compass, a joystick steering unit 255 that steers the ship in a steering mode by a joystick lever 254, a manual steering unit 257 that steers the ship in a steering mode by a manual steering wheel 256, a non-follow-up steering unit 259 that steers the ship in a steering mode by non-follow-up steering levers 258a and 258b, and a mode switching unit 261 that switches between the steering units using a mode switching switch 260.

[0026] Further, the navigation system is provided with a display device 262 having a touch panel on the screen, an image control unit 263 for controlling the image displayed on the display device 262, an emergency stop unit 265 for maneuvering in a maneuvering mode for stopping the ship urgently in priority over all maneuvering modes by operating an emergency stop button 264, a rudder angle instruction unit 280 for giving an instruction rudder angle to the rotary vane steering gears 104, 105 via the rudder control devices 106, 107, an electronic chart display unit 282 for displaying an electronic chart for navigation on the display device 262, a course line setting unit 283 for setting the planned route of the ship on the electronic chart for navigation, and a course correction unit 284 for eliminating the positional deviation of the ship from the course line. Also, the navigation system is provided with a positioning control unit 660 for controlling the motion of the ship to a set position and direction with high accuracy.

[0027] The image control unit 263 selectively displays or simultaneously displays a chart display image 266 showing an electronic navigational chart, a gyro orientation display image 267 showing the gyro orientation, an orientation display unit operation image 268 for touch-operating the gyro orientation display unit 252 on the monitor screen, and an auto-pilot operation image 269 for touch-operating the auto-pilot unit 253 on the monitor screen.

[0028] The joystick operation unit 255 is configured so that the joystick lever 254 can be operated in either the X or Y direction, and the tilt direction of the joystick lever 254 controls the commanded direction of movement of the hull, and the tilt angle in the tilt direction controls the commanded speed in the bow-stern direction and the commanded speed in the hull turning direction.

[0029] The joystick steering unit 255 controls the rudder angles of the high-lift rudders 102, 103 on both sides to 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, 103 on both sides, the thrust of the propeller wake is diverted toward the desired direction, and the rudder angles of the high-lift rudders 102, 103 on both sides are controlled by both rotary vane steering gears 104, 105 within a range of 105° to the outboard side and 35° to the inboard side.

[0030] The basic combinations of rudder angles of the high-lift rudders 102, 103, the states of the joystick lever 254, their names, propeller wake streamlines, and movement directions will be explained with reference to FIG.

[0031] In Figure 8, the rudder is shown in horizontal section, and the rudder angle of each rudder is shown to the side or below. Rudder angles are shown as positive (+) when the stern is turned to the right, and negative (-) when turned to the left, and names for combinations of these rudder angles are given. The propeller wake is shown with a thin arrow, and the resulting propulsion direction of the ship is shown with a thick hollow arrow.

[0032] By the way, "forward left turn" is port rudder -35° and starboard rudder -35°, "forward left turn" is port rudder -70° and starboard rudder -35°, "astern left" is port rudder -105° and starboard rudder +45° to +75°, "astern left turn" is port rudder -105° and starboard rudder +75° to +105°, "forward" is port rudder 0° and starboard rudder 0°, and "hover" (the ship stops in place) is port rudder -105° and starboard rudder +75° to +105°. Rudder -75°, starboard rudder +75°, ``astern'' is port rudder -105°, starboard rudder +105°, ``forward turn right'' is port rudder +35°, starboard rudder +35°, ``forward turn right'' is port rudder +35°, starboard rudder +70°, ``astern move to starboard'' is port rudder -45° to -75°, starboard rudder +105°, and ``astern turn right'' is port rudder -75° to -105°, starboard rudder +105°.

[0033] In addition, if thruster thrust of the bow thruster 108 is applied in the starboard direction during "forward port turn," thereby increasing the port turning speed, this becomes an "on-the-spot port turn," and if thruster thrust of the bow thruster 108 is applied in the port direction during "forward right turn," thereby increasing the right turning speed, this becomes an "on-the-spot starboard turn."

[0034] Similarly, if the thruster thrust of the bow thruster 108 is applied in the port direction during "astern shift to the left," thereby increasing the right turning speed, resulting in a "right turn on the spot," and if the thruster thrust of the bow thruster 108 is applied in the starboard direction during "astern shift to the right," thereby increasing the left turning speed, resulting in a "left turn on the spot."

[0035] In addition, the center of turning can be moved by increasing or decreasing the thrust of the thrusters of the bow cluster 108.

[0036] In this way, a single-shaft, twin-rudder ship equipped with two high-lift rudders 102, 103, a bow thruster 108, and a controllable pitch propeller 101 can freely vary the direction and magnitude of thrust in all directions of the ship by varying the combined rudder angle of the high-lift rudders 102, 103, and can achieve on-the-spot turning by combining this with the thruster thrust of the bow thruster 108.

[0037] The auto-steering unit 253 guides and controls the ship to a predetermined course based on the ship's current position information, guidance route information, and stationary holding position information obtained from a GPS compass and an electronic chart system.

[0038] When the emergency stop button 264 is pressed in an emergency, the emergency stopping unit 265 cancels the rudder angle related to the current maneuvering, regardless of the maneuvering state indicated by the joystick lever 254 or regardless of the maneuvering mode in which the ship is being maneuvered, and turns the port rudder 103 in the starboard direction (clockwise direction as seen from above) and the starboard rudder 102 in the starboard direction (counterclockwise direction as seen from above) until they are hard over (fully turned), thereby applying braking force to the ship to stop it.

[0039] The manual steering unit 257 steers the ship by controlling the rudder angles of the two high-lift rudders 102 and 103 through the rotation of a manual steering wheel 256.

[0040] The non-follow-up steering unit 259 steers to starboard or port depending on the time that the non-follow-up steering levers 258a, 258b are operated to the left or right.

[0041] The ship positioning steering unit 660 includes a ship positioning control unit 661 and a ship positioning motion control unit 662 .

[0042] The ship positioning control unit 661 controls the rudder angle of each of the two high-lift rudders 102, 103 within a set rudder angle range, which is a rudder angle range of several 10 degrees around the hover rudder angle of -75° port rudder and +75° starboard rudder, at which the ship stops in place.

[0043] Then, the blade angle of the propulsion propeller 101 when the propulsion propeller 101 rotates at a constant speed in the forward direction in the low speed range and the rudder angle of the two high-lift rudders 102, 103 is a hover rudder angle that does not generate a forward speed component is defined as a neutral angle, and an adjustment rudder angle to be applied to the two high-lift rudders is calculated according to the position deviation of the current ship position from the target ship position. Furthermore, the rudder angle deviation of the adjustment rudder angle from the hover rudder angle is calculated, and an adjustment blade angle having a blade angle deviation from the neutral angle required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation is calculated. Here, the blade angle deviation is a value obtained by multiplying the rudder angle deviation by an arbitrary proportionality coefficient. Also, an adjustment thruster control amount is calculated.

[0044] The positioning motion control unit 662 includes a positioning thruster control unit 663 that controls the turning angular speed by adjusting the thruster thrust of the bow thruster 108 using the thruster control device 109, a positioning steering control unit 664 that controls each of the rotary vane steering gears 104, 105 and controls the bow-stern speed and widthwise speed by combining the rudder angles of the two high-lift rudders 102, 103, and a blade angle control unit 665 that variably controls the blade angle of the propulsion propeller 101.

[0045] Then, the two high-lift rudders are controlled by the vessel positioning steering control unit 664 to the adjustment rudder angle input from the vessel positioning control unit 661, the vessel positioning thruster control unit 663 controls the adjustment thruster control amount input from the vessel positioning control unit 661, and the blade angle control unit 665 controls the blade angle of the propulsion propeller 101 to the adjustment blade angle input from the vessel positioning control unit 661. Note that the adjustment thruster control amount is controlled as necessary. The operation of the above configuration will now be described.

[0046] Joystick control mode A joystick steering mode is selected by operating the mode switch 260. The joystick steering unit 255 uses a joystick lever 254 to command the direction of hull movement, bow / stern command thrust, and width command thrust.

[0047] In this maneuvering, while the propeller 101 continues to rotate forward, the high-lift rudders 102, 103 are independently operated at various angles to control the propeller wake and control the thrust around the stern in all directions of 360°. This control allows the ship to move forward or backward, stop, turn forward, turn backward, etc., thereby improving maneuverability in maneuvering.

[0048] In other words, by changing the combination of the rudder angles of the two rudders, it is possible to change the thrust in a desired direction by directing the propeller wake in the desired direction. The combination of rudder angles given here is one example, and the combination of rudder angles can be changed arbitrarily to obtain the desired propulsion direction and thrust.

[0049] In this way, there is no need to reverse the thrust of the propeller (reverse the propeller) when maneuvering the ship, and all maneuvering control can be performed with the main engine always rotating in forward direction.By adjusting the rudder angle of both rudders, the ship speed can be controlled steplessly and precisely from the maximum forward speed corresponding to the propeller speed at that time, to the maximum astern speed, without having to adjust the main engine speed.

[0050] Maneuvering mode with emergency stop section With a single action of pressing the emergency stop button 264, the emergency stop unit 265 is activated, and the ship can be stopped urgently, taking priority over all steering modes. That is, regardless of the steering mode of the joystick lever 254 or other steering modes, the emergency stop unit 265 switches to crash astern mode (the port rudder steers 105° to the left, and the starboard rudder steers 105° to the starboard), and both rudders generate very large braking and astern forces, so that the ship can be stopped in a much shorter time and distance than by steering the ship by reversing the propeller.

[0051] Furthermore, even in crash astern mode, there is no need to stop the main engine and restart it in reverse, so the ship will not enter a so-called uncontrollable state during maneuvering, making it possible to respond quickly to emergencies during navigation.

[0052] Furthermore, if the ship needs to turn due to its characteristics or external disturbances while maneuvering using the emergency stopping unit 265, or if it is necessary to change the ship's forward direction, including its heading, by simply operating the joystick lever 254, the ship can be steered freely using the joystick lever 254 to take an avoiding maneuver, just like with a normal joystick operation.

[0053] Autopilot mode In normal ship navigation, the mode selector switch 260 is operated to select the autopilot mode.

[0054] An auto-piloting operation image 269 is displayed on the monitor screen of the display device 262, and the ship's position, the direction to proceed, the position to be reached, or the bow-stern line direction are input to the auto-pilot unit 253 by touching the monitor screen, and the ship is automatically guided and steered along the set course.

[0055] Furthermore, the electronic chart display unit 282 displays the electronic navigation chart as a chart display image 266 on the monitor screen of the display device 262, and the course line setting unit 283 sets the planned route of the ship on the electronic navigation chart.

[0056] The autopilot 253 appropriately controls the rudder angle based on the current position information of the ship, the guidance route information, and the anchorage holding position information. The autopilot holds the course indicated by the gyrocompass as the heading or bow-stern line heading set in the autopilot operation image 269.

[0057] However, since it does not keep the ship's position on the course line, while the bow heading remains parallel to the course line on the electronic navigation chart, the ship's position may deviate from the course line due to wind pressure, ocean currents, etc.

[0058] The course correction unit 284 calculates the minimum distance from the ship to the course line as the positional deviation of the ship's position relative to the course line when the ship's bow heading on the electronic navigation chart is parallel to the course line on the electronic navigation chart due to steering by autopilot.

[0059] When the minimum separation distance exceeds the set allowable range, autopilot maneuvering is temporarily stopped, and the course correction rudder angle set to orient the bow to a course that intersects the course line is output to the rudder angle indication unit 280.

[0060] The rudder angle instruction unit 280 gives a course correction rudder angle to the rotary vane steering gears 104, 105 via the rudder control devices 106, 107, and the course correction unit 284 returns to autopilot operation when the ship position reaches the course line.

[0061] Manual Pilot Mode A mode change switch 260 is operated to select a steering mode using the manual steering wheel 256. In this steering mode, the rudder angles of the two high-lift rudders 102, 103 are instructed to a manual steering unit 257 by rotating the manual steering wheel 256, and the rudder angles of the two high-lift rudders 102, 103 are controlled to steer the ship.

[0062] Non-follow-up maneuvering mode A steering mode using the non-follow-up steering levers 258a, 258b is selected by operating the mode change switch 260. In this steering mode, the non-follow-up steering unit 259 steers the rotary vane steering gears 104, 105 corresponding to the non-follow-up steering levers 258a, 258b to the starboard or port side depending on the time that the non-follow-up steering levers 258a, 258b are operated to the left or right.

[0063] Positioning mode In the joystick steering mode, when the joystick lever 254 is in a neutral position where it is not tilted, the ship positioning steering unit 660 is activated. Ship positioning steering in the low speed range, that is, the propeller 101 is rotated at a constant speed in the forward direction in the low speed range, and the two high-lift rudders 102, 103 are steered near a hover rudder angle where no forward speed component is generated. Then, when the ship deviates from the target ship position at the hover rudder angle, the rudder angles of the two high-lift rudders 102, 103 required to cause the ship to move toward the target ship position are calculated as adjustment rudder angles. This adjustment rudder angle increases according to the position deviation of the current ship position from the target ship position.

[0064] The larger the propeller thrust at this adjusted rudder angle, the faster the ship can return to the target position. Therefore, the blade angle of the propulsion propeller 101 is adjusted to increase the propeller thrust as the position deviation increases. In other words, the rudder angle deviation of the adjusted rudder angle with respect to the hover rudder angle is calculated, and the blade angle of the propulsion propeller 101 required to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation is calculated as an adjusted blade angle having a blade angle deviation with respect to the neutral angle.

[0065] The positioning movement control unit 662 controls the two high-lift rudders to the adjusted rudder angle input from the positioning control unit 661 using the positioning steering control unit 664, controls the adjustment thruster control amount input from the positioning control unit 661 as necessary using the positioning thruster control unit 663, and controls the blade angle of the propulsion propeller 101 to the adjusted blade angle input from the positioning control unit 661 using the blade angle control unit 665, thereby maintaining the ship's position and bow heading at the target position.

[0066] Therefore, in a single-shaft, twin-rudder ship equipped with a controllable pitch propeller, the propeller thrust can be adjusted to an appropriate value to perform maneuvering to maintain position with high performance in keeping at a fixed position.This means that in deep water areas or in harbors with many surrounding obstacles such as quays and other ships, the movement of the ship can be safely controlled with high precision to a specified position and heading, while taking into account the external forces that affect the ship, such as rip currents, onshore currents, tidal forces, tides, and wind forces. [Explanation of symbols]

[0067] 100 Thrust System 110 Hull 101 Propulsion Propeller 102, 103 High-lift rudders 104, 105 Rotary vane steering gear 106, 107 Rudder control device 108 Bow Thruster 109 Thruster Control Device 151, 152 Pump unit 153, 154 Rudder angle transmitter 155, 156 Feedback unit 200 Steering System 250 Steering stand 251 Gyrocompass 252 Gyro direction display unit 253 Auto steering unit 254 Joystick Lever 255 Joystick Control Unit 256 Manual steering wheel 256 257 Manual steering unit 257 258a, 258b Non-follow-up steering lever 259 Non-follow-up steering section 260 Mode Switch 261 Mode switching section 262 Display Device 263 Image Control Unit 264 Emergency stop button 265 Emergency Stopping Department 266 Nautical Chart Display Images 267 Gyro Orientation Display Image 268 Direction display section operation image 269 ​​Auto-pilot operation image 280 Rudder angle indicator 282 Electronic Chart Display Unit 283 Course Line Setting Section 284 Course correction unit 300 Observation System 310 Marine radar equipment 311 Alarm signal output unit 312 Ship speed measuring device 313 Position Measuring Device 314 Direction measuring device 660 Positioning and steering section 661 Positioning control unit 662 Positioning control unit 663 Positioning Thruster Control Unit 664 Positioning Steering Control Unit 665 Wing angle control section

Claims

1. The vessel is equipped with a thrust system, a steering system that controls the thrust system, and an observation system that observes the vessel's own hull motion state. The thrust system comprises a single controllable pitch propeller disposed at the stern, a pair of left and right high-lift rudders disposed aft of the propulsion propeller, and a pair of steering gears for driving each high-lift rudders, The observation system is provided with a position measuring device for measuring the position of the ship itself, The maneuvering system is equipped with a ship positioning motion control unit and a ship positioning control unit. The ship positioning control unit sets the blade angle of the propulsion propeller to a neutral angle when the propulsion propeller rotates at a constant speed in the forward direction in a low speed range and the rudder angle of the two high-lift rudders is a hover rudder angle that does not generate a forward speed component, Calculating adjustment rudder angles to be applied to two high-lift rudders in accordance with the position deviation of the current ship position from the target ship position, calculating the rudder angle deviation of the adjustment rudder angle from the hover rudder angle, and calculating an adjustment blade angle having a blade angle deviation from the neutral angle necessary to obtain a propeller thrust proportional to the magnitude of the rudder angle deviation, The vessel positioning motion control unit has a vessel positioning steering control unit which controls each of the pair of steering gears and controls the direction of vessel motion by combining the rudder angles of the two high-lift rudders, and a blade angle control unit which variably controls the blade angle of the propulsion propeller, A single-shaft, twin-rudder ship equipped with a controllable pitch propeller, characterized in that a positioning steering control unit controls two high-lift rudders to an adjusted rudder angle input from a positioning control unit, and a blade angle control unit controls the blade angle of a propulsion propeller to an adjusted blade angle input from the positioning control unit.

2. 2. A single-shaft, twin-rudder ship equipped with a controllable pitch propeller according to claim 1, characterized in that the blade angle deviation is a value obtained by multiplying the rudder angle deviation by an arbitrary proportionality coefficient.

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