Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63H—MARINE PROPULSION OR STEERING
  • B63H25/00—Steering; Slowing-down otherwise than by use of propulsive elements; Dynamic anchoring, i.e. positioning vessels by means of main or auxiliary propulsive elements
  • B63H25/42—Steering or dynamic anchoring by propulsive elements; Steering or dynamic anchoring by propellers used therefor only; Steering or dynamic anchoring by rudders carrying propellers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B79/00—Monitoring properties or operating parameters of vessels in operation
  • B63B79/10—Monitoring properties or operating parameters of vessels in operation using sensors, e.g. pressure sensors, strain gauges or accelerometers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B1/00—Hydrodynamic or hydrostatic features of hulls or of hydrofoils
  • B63B1/32—Other means for varying the inherent hydrodynamic characteristics of hulls
  • B63B2001/325—Interceptors, i.e. elongate blade-like members projecting from a surface into the fluid flow substantially perpendicular to the flow direction, and by a small amount compared to its own length
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T70/00—Maritime or waterways transport
  • Y02T70/10—Measures concerning design or construction of watercraft hulls

Definitions

• the present invention relates to an arrangement for automatic control of turns of a marine vessel comprising a hull with an angular bottom portion, which marine vessel is empowered by at least two propulsion pod units being mounted onto the hull with their respective vertical axis in an angle against the horizontal plane, said arrangement comprising at least a steering angle acquiring unit, a speed acquiring unit and a control unit arranged to automatically compensate to improve comfort and/or improved fuel economy.
• An automatic stabilizing unit for watercrafts is disclosed in WO2008/110519 where an electrical controller is provided which stabilizes the water position via actuating members in the form of trim tabs. Trim tabs attached on the trailing edge of the hull are widely used on planing- or semi-planing type boats such as cruisers or sport fishing boats, and serve the purpose of adjusting the pitch attitude during traveling and to adjust unwanted list generally caused by wind or uneven loading of the vessel.
• Hydraulic driving means have been used in order to operate the trim tabs, however hydraulics is quite undesirable since it results in a slow system and a large time delay if weight and space are to be kept at acceptable levels. Such a time delay may lead to an unbalanced system where unsynchronized compensation measures may cause rolling movements of the vessel, which is of course a major drawback.
• electric driving means have been used, but here the problem is that the motors need to be big for providing the necessary transmission which is undesired since it occupies a lot of space.
• propulsion pods meaning propulsion units (e.g. propellers) positioned below the stern of a vessel, each unit being mounted in such a way rotatable around a central axis.
• propulsion pods are able to combine propulsive and steering functions which lead to an excellent propulsion efficiency and turning capacity.
• These pods are often used in combination with vessels having a deadrise other than zero degrees, that is, having a hull with an angular bottom section for instance in the shape of a "V” or a "U”.
• Use of propulsion pods has also great advantages regarding maneuvering
• At least a pair or propulsion units are used in combination for attaining best steering possibilities, for instance by connecting them to a Joystick system.
• a disadvantage is that when the propulsion units are installed perpendicular or nearly perpendicular to a hull surface inclined to an angle, as is common in the case of a V- or U-shaped hull, the hull may heel (tilt) more than desired when turning the boat. For best comfort, a ship should heel a certain amount depending on radius of turn and speed of the ship. Rotation of the propulsion units for turning also leads to that a lifting force is developed which is increased as a result of the V- or U shape of the hull.
• a related kind of problem is caused when cross winds are present.
• the driver will need to steer somewhat to compensate for the drift caused by the wind.
• the boat will heel more as a result of that the propulsion units are mounted perpendicular or nearly perpendicular to an inclined hull surface as in the case of a V- or U shaped hull.
• the object of the present invention is to eliminate or at least to minimize the problems described above. This is achieved by an arrangement for automatic control of turns of a marine vessel comprising a hull with an angular bottom portion, which marine vessel is empowered by at least two propulsion pod units being mounted onto the hull with their respective vertical axis essentially perpendicular to the hull, said arrangement comprising at least a steering angle acquiring unit, a speed acquiring unit and a control unit arranged to automatically compensate to improve comfort and/or improved fuel economy.
• the control unit is arranged to automatically and instantaneously generate a command signal to control a moment generating device arranged to provide an intercepting roll moment based on input from said steering angle acquiring unit and said speed acquiring unit respectively.
• Said moment generating device comprises at least two individually, adjustably displaceable blades of interceptor members arranged on the hull.
• the at least two interceptor members are located at the aft portion of the hull at different sides of the keel of the hull respectively.
• a so called coordinated turn can be achieved, coordinating the movement of the rotatable pod units with the moving interceptor members.
• a turn can be performed while reducing unease to the passengers that may otherwise be caused by the heeling and turning movement.
• Another benefit is that the fuel efficiency of the vessel will be significantly improved. In cross winds, the boat will heel less into the wind when the driver keeps the course by steering up against the wind. Also, the performance of sharper turns with a higher degree of control over the turning movement is enabled by the arrangement according to the invention.
• activation of an interceptor member leads to the generation of forces acting on the hull of the ship in front of the corresponding interceptor blade.
• intercepting roll moment comprising a lifting force and also, due to the angular hull bottom portion, a steering force.
• This is particularly advantageous in combination with propulsion pods since the steering force originating from the activated interceptors will contribute to a turning movement of the ship, thereby reducing the need to steer with the pod unit and consequently also reducing the risk of developing uncontrolled roll moment and undesirably large heel angle during turning.
• the acquired steering angle of the vessel (meaning the direction of movement of the vessel) is used for controlling and activating the interceptor members.
• interceptor members are exceptionally quick and can be displaced into the water virtually without any delay.
• displacement of the interceptor blades may be performed very quickly, for instance the moving of an interceptor blade from a fully retracted position up and away from the water to a position of maximum projection into the water can be performed in a very short time, typically around 3 s, depending on the motor used for the operation.
• the speed of the interceptors will contribute to that the counteracting force required to control the heel angle of the ship can be achieved essentially simultaneously with the pod rotation to balance the unwanted part of the heel and act on the ship already at the beginning of the turn, before the undesirable conditions of the turn arise.
• the time (At) between upcome of roll moment MPOD and generation of the desired intercepting roll moment Mi can be essentially eliminated, meaning the movements of the propulsion pods and the interceptor blades are essentially completely synchronised.
• At is between 0 s and +/- 1 s, more preferably between 0 s and +/- 0.5 s, even more preferably between 0 s and +/- 0. 1 s.
• the steering angle of the vessel is acquired in immediate connection to the steering device (e.g. the steering wheel) of the ship, meaning the steering command (the steering angle and the rate of turn) of the steering wheel is registered and directly used for further control of the interceptor members.
• the steering command of the steering wheel is interpreted within a preprogrammed system, for instance a MAP system, so that a certain turning rate/steering angle leads to a predetermined activation of the interceptors. This leads to that the steering wheel will maneuver both the pod units and the moment generating device (i.e. the interceptors) simultaneously, and steering movements with the pod units is therefore compensated by adjustments of the interceptors in a completely
• control system becomes extremely reactive and compensates for any undesired roll moment (M POD ) in such a fast way that
• the steering angle of the vessel is acquired by a sensor able to register real-time turns and the real-time turning angle.
• a sensor able to register real-time turns and the real-time turning angle.
• the data in the form of registered real-time turning angle is transferred to the control system (control unit) along with the speed of the ship and is used for controlling and/or adjusting the moment generating device in the form of said interceptors.
• Fig. 1 shows a planar side view of a ship with a preferred embodiment of the invention
• Fig. 2 shows a planar view of the ship of Fig. 1, seen from behind, and
• Fig. 3 shows a schematic view of the control system according to the invention.
• Fig. 1 shows a side view of a ship with an angular hull 1, beneath which at least one pod unit 2 is mounted for propulsion of the ship.
• Said pod unit 2 is a propulsion unit comprising a rotatable thruster that is arranged to be rotated around a first axis 21 that extends essentially perpendicularly from a bottom surface 41 of the hull 1 of the ship.
• the thruster is mounted in a casing 22.
• the at least one pod unit 2 can be rotated in such a way that a driving force exerted by the pod unit 2 on the surrounding water can be directed in a suitable direction.
• This rotation of said pod unit 2 can be effected by being coupled to a steering device (not shown), in such a way that manoeuvring said steering device, such as a steering wheel or other, also means a rotation of the pod unit 2.
• a pod unit 2 generally comprises a suitable propulsor, such as for instance one or several propellers 20 or a jet device (not shown).
• the ship further comprises a stem 3 and a stern 4.
• At the stern 4 is mounted at least two interceptors 11 each comprising an adjustably displaceable blade 10, as is known prior art.
• the interceptors may be arrangements according to application No. W099/55577, which is hereby incorporated into the present application by way of reference.
• the blades 10, 10' of the corresponding interceptors 11, 11 ' are individually displaceable.
• the interceptor 11 is attached to the substantially vertical surface of the stern 4 of the vessel.
• interceptors are aligned with the angular hull so that the respective blade 10, 10' are mounted in an angle a against the horizontal plane (see Fig. 2), however it is to be understood that other alignments of said blades are also possible.
• Said interceptor 11 comprises a fastening section that is mounted onto the ship, for instance by bolts (screws), and a drive unit such as an electric motor or an hydraulic driving means that is connected to the blade 10 and can move the blade upwards or downwards in a direction that is essentially perpendicular to the hull bottom, depending on command signals. The generation of such command signals is further described below.
• interceptor blades 10, 10' Thanks to the use of interceptor blades 10, 10' the forces required to counteract the imperfect heel of the ship can be achieved through only a relatively small force provided by an electrical motor or the like for operating the blade 10, 10'.
• the forces generated by the water coming into contact with the interceptor blade 10, 10' will for the most part be transferred to the bottom surface 41 of the ship, where they are most needed for lifting the ship in the counteracting movement.
• Fig. 2 the ship of Fig. 1 is shown from the stern 4, i.e. in a view taken from the left of Fig. 1.
• the hull 1 has an angular bottom with a V-shape, the bottom surface 41 extending downwards to a keel 42 in such a way that an angle a is created between the bottom surface 41 and a horizontal line.
• the hull may equally have a U-shaped bottom.
• a pod unit 2, 2' is mounted along the bottom surface 41 with the respective vertical axis 21, 21 ' in an angle ⁇ against the horizontal plane.
• Each pod unit 2, 2' is mounted at a distance A from the chine 8 and at a distance B from the keel 42, said chine 8 being at an outer limit of the bottom area 41, where said bottom 41 is in contact with an adjacent side 6 of the hull 1.
• an interceptor member 11 , 11 ' is mounted so that it is positioned at least partly at the area of the hull 1 along said distance A.
• the interceptor 11, 11 ' is mounted completely within the area A preferably also covering an essential portion of the area A, however it is equally possible positioning an interceptor 1 1 , 1 1 ' at the area behind a pod unit 2, 2' and/or partly also covering area B. An interceptor will become more effective the closer it is to the chine 8, since such a positioning will generate a more efficient intercepting roll moment Mi.
• the pod unit 2, 2' and the interceptor members 1 1, 1 1 ' may be mounted to the hull 1 individually, but it is also possible to provide modular units leading to that a propulsion pod 2, 2' may be mounted onto the hull 1 together with a an interceptor 1 1 , 1 1 ' as one entity.
• One or more interceptor members may be mounted onto each side of the keel 42.
• each of the port and starboard side of said stern portion 4 of the hull 1 may comprise large interceptor members 1 1 , 1 1 ' or a plurality of smaller ones, although in the example of Fig. 2 only one interceptor 11 , 1 1 ' per side is shown.
• the port side interceptor 1 1 ' is activated and has been displaced to a position where the respective interceptor blade 10' is protruding downwards from the lowermost portion of the stern part 4 of the hull 41.
• the port side interceptor 1 1 ' is activated as seen in Fig. 2 for compensating a heel angle caused by a port turn.
• the present invention relates to an
• Said arrangement for automatic control of turns of a marine vessel empowered by at least two propulsion pod units 2, 2' being mounted onto the hull 1.
• Said arrangement comprises at least a steering angle acquiring unit 5, a speed acquiring unit and a control unit 12 arranged to automatically compensate to improve comfort and/or improved fuel economy.
• the control unit 12 is arranged to control a moment generating device (i.e. the interceptors 1 1, 1 1 ') automatically and instantaneously generating a control action/signal to provide an intercepting moment Mi based on input from said steering angle acquiring unit 5 and the speed acquiring unit respectively.
• Said moment generating device comprises at least two individually, adjustably displaceable interceptor members 1 1 , 1 1 ' arranged on the hull 1.
• the direction of movement of the vessel can be controlled by a driver operating a steering device (for instance in the form of a steering wheel). Turning is performed by turning the steering device thus directing the pod units 2, 2' which is done by rotating each unit 2, 2' around the respective central axis 21 , 21 ' .
• a steering device for instance in the form of a steering wheel
• Known propulsion pods are for instance rotatable around approximately +/- 25° from a straight forward position.
• the interceptors 1 1 , 1 1 ' are used for keeping the ship in a desired position with regards to the surface of the surrounding water.
• FIG. 2 schematically shows a hull 1 during a port turn, said pod units 2, 2' being positioned accordingly, giving rise to forces F L pi, F S pi, F L p 2 and F S p 2 respectively which in their turn result in roll moment MPOD causing the hull to heel.
• the port side interceptor 1 1 ' is activated and the blade 10' lowered so that it projects below the hull 1 of the vessel.
• the lowered blade 10' will give rise to force F L i and due to the hull bottom angle a also to force Fsi.
• Forces Fn and Fsi will act on the hull portion in front of the interceptor 1 1 ' resulting in an intercepting roll moment Mi.
• an activated interceptor unit 1 1 , 1 1 ' will give rise to a lifting force FLI as well as to a steering force Fsi acting on the hull bottom, leading to that not only the pod units 2, 2' but also the interceptors 1 1 , 1 1 ' will contribute to a turning movement of a vessel.
• the need to steer the ship with the pod units is reduced and thereby also the risk of too large heeling caused by rotation of propulsion units when turning the ship.
• Interceptor blades 10, 10' mounted onto an angular hull will thus contribute to achieving an optimal heel angle during a turn (also called a coordinated turn) in two ways: firstly for cancelling undesired part of said roll moment M PO D, and secondly for generating a steering force Fsi contributing to a turning movement so that the need for using pod units is reduced.
• the theoretical ideal heel angle corresponds to the inclination when all the side forces acting on an object on board during turning are cancelled. This is achieved by tilting the vessel during turning so that a certain optimal heel angle arises which, according to the invention, is performed by controlling the intercepting roll moment Mi by adjusting the interceptor blades 10, 10' .
• the undesired part of said roll moment MPOD is cancelled by intercepting roll moment Mi SO that a perfect heel is achieved and comfort, safety and operation of the ship are optimised.
• the interceptor blades 10, 10' are controlled in a continuous manner so that movements of the vessel during turns are compensated for
• Fig. 3 is a schematic illustration of a control system 7 and a principle example of arrangement propulsion pod and interceptor coordinated turn system according to the invention.
• the POD control unit 14 and the control unit 12 are shown as separate units it is possible that both may be integrated into one common control unit, as will also be described later.
• the control system 7 is provided in the ship and serves to continuously monitor the steering angle of the ship along with its speed by using a steering angle acquiring unit 5 and a speed acquiring unit 9 respectively.
• the vessel may be provided with a rate-of-turn sensor 5 and/or a GPS antenna 9 for registering input data for the system in form of steering/turning angle and speed of the ship.
• any kind of sensing device such as a Gyro or a GPS sensor, may be used for acquiring the turning degree of the vessel.
• the number of revolutions of the engine or a driveshaft can be used as input instead of the speed of the ship.
• the steering angle is registered by acquiring the steering command of the steering device 5, which steering device 5 may for instance, but not necessarily, be in the form of a steering wheel.
• the steering command may comprise information both in form of the angle of the steering device 5 (e.g. to what extent the steering wheel is turned) and the rate of turn (e.g. how fast the steering wheel is turned).
• the registered command of the steering device 5 may be automatically interpreted for instance by a conventional MAP system provided in the ship prior to transfer to the control unit 12 along with the speed of the vessel for further control of the moment generating device 1 1 , 1 1 ' .
• the control unit 12 is preferably arranged to automatically and instantaneously generate a command signal to control the moment generating device 1 1 , 1 1 ' arranged to provide an intercepting roll moment Mi based on input in the form of turning angle and speed of the vessel.
• the moment generating device comprises said interceptor members 1 1, 1 1 ' which, via control by the control unit 12, are displaced accordingly in order to generate an intercepting roll moment Mi thus compensating for any undesired roll moment MPOD during turning.
• the control system 7 can determine when a turn is made and how sharp the turn is, so that a blade 10, 10' of the right interceptor 1 1 , 1 1 ' can be lowered into the water in order to generate an intercepting roll moment Mi for controlling the turn of the ship.
• the control system 7 When a turn is made, the control system 7 is activated to analyze the movement and determine what response should be given by the interceptors 1 1 , 11 ' in order to counteract any unwanted roll moment MPOD a counteracting force Mi is required, which can be achieved thanks to the use of interceptors 1 1 , 1 1 '. After determining the desired magnitude of this counteracting force/roll moment Mi the control system 7 determines what action needs to be taken by the interceptor 1 1 , 1 1 ' in order to create this force.
• a registered speed of 20 knots and turning rate of 100% may correspond to an ideal difference between the port side and starboard side interceptors of 70%. If, for instance, both interceptor blades 10, 10' are fully retracted at this point one of them is simply moved out 70% of maximum projection. If, on the other hand, both blades 10, 10' projects 60%> of maximum projection, both blades could be moved but in opposite directions, one is withdrawn and the other is projected, until the difference between the two equals 70%>.
• the ideal difference between the interceptor blades 10, 10' may be another percentage.
• the adjustments of the interceptors are decided and monitored by the control system 7, which according to one example of the invention may be preprogrammed, for instance comprising a MAP system. Displacement of the interceptor blades 10, 10' may be performed virtually without any delay. For instance, the time from that to that an interceptor blade 10, 10' has moved from a fully retracted position to maximum projection is between 0.1 - 5 s, preferably 0.1 - 3 s, even more preferably 0.1 - 2 s.
• the time from that a command signal is generated to the moment when an intercepting roll moment Mi is started to get generated may be between 0.1 - 1 s, preferably 0.1 - 0.5 s.
• the steering device 5 may maneuver the pod units 2, 2' via an engine/pod control unit 14. This means the steering wheel 5 maneuvers both the pod units 2, 2' and the moment generating device (i.e. the interceptors 1 1 , 1 1 ')
• control unit 12 and the engine/pod control unit 14 are integrated into one single control unit which receives input data from the steering device 5 and the speed acquiring unit 9
• command signals both to the interceptors 1 1 , 1 1 ' and to the pod units 2, 2'.
• Such a system is advantageous in case the interceptors 1 1 , 1 1 ' and the propulsion units 2, 2' respectively are powered by the same kind of driving unit, for instance an electrical motor.
• one type of command signal may control both parts of the system (e.g. interceptors and propulsion units), meaning the interceptors 1 1 , 1 1 ' and the pod units 2, 2' will receive command signals simultaneously and will therefore become extremely well synchronised during operation of the vessel.
• the time (At) between upcome of roll moment MPOD and generation of the desired intercepting roll moment Mi is essentially zero.
• At is between 0 s and +/- 1 s, more preferably between 0 s and +/- 0.5 s, even more preferably between 0 s and +/- 0.1 s.
• generation of intercepting roll moment Mi may precede upcome of roll moment MPOD as well as the other way around depending on the inherent delay in the propulsion system and the interceptor system respectively.
• the overall aim of the arrangement according to the invention is that At shall equal zero which is achievable thanks to the inherent speed of the interceptor blades 10, 10'.
• the movement of the interceptor blade 10, 10' can be monitored during turn to correspond at any given time to the movement and the speed of the ship, and the whole of the turning movement can thereby be adapted to achieve a coordinated turn where the best possible conditions for the operation of the ship and the well being of the passengers can be achieved.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)

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Cited By (5)

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• 2011
  • 2011-02-15 EP EP11742558A patent/EP2536622A1/de not_active Withdrawn
  • 2011-02-15 WO PCT/SE2011/050163 patent/WO2011099931A1/en not_active Ceased

Non-Patent Citations (1)

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