Control method and control unit for a marine vessel

Abstract

A method to control a marine vessel comprising two or more drive units. The method involves registering an operating command indicating a requested sideways or bow bollard push function; detecting a current vessel position; registering the current vessel position as a desired vessel position; executing the requested bollard push function; and monitoring the current vessel position in order to detect a deviation relative to the desired vessel position. If it is detected that a deviation between the desired vessel position has exceeded a predetermined value, then the requested bollard push function is deactivated. The disclosure further relates to a control unit arranged to control a marine vessel and a marine vessel comprising such a control unit.

Claims

1. A method to control a marine vessel comprising two or more drive units; the method involving the steps of: registering an operating command indicating a requested bollard push function; detecting a current vessel position; registering the current vessel position as a desired vessel position; executing the requested bollard push function by controlling thrust and direction of the drive units in order to push the vessel against a fixed structure at a requested heading with a predetermined force; during execution of the requested bollard push function, monitoring the current vessel position in order to detect a deviation relative to the desired vessel position; if the detected deviation relative to the desired vessel position has exceeded a predetermined value, deactivating the requested bollard push function, wherein deactivation of the bollard push function will at least involve an inhibition of the thrust from the drive units.

2. The method according to claim 1, comprising monitoring if the deviation of a current vessel position relative to the desired vessel position has exceeded a predetermined distance.

3. The method according to claim 1, comprising monitoring if the deviation of a current vessel heading relative to the desired vessel heading has exceeded a predetermined angle.

4. The method according to claim 1, comprising monitoring if the rate of change of the deviation for a current vessel position relative to the desired vessel position has exceeded a predetermined value.

5. The method according to claim 1, comprising registering the bollard push function in response to an input signal from a joystick.

6. The method according to claim 1, comprising registering the bollard push function in response to an input signal from a graphical user interface.

7. The method according to claim 1, comprising registering the bollard push function in response to input signals from at least one throttle controller and a helm controller.

8. The method according to claim 1, comprising disengaging the drive units when deactivating the requested bollard push function.

9. The method according to claim 1, comprising the further steps of: registering an updated current vessel position; and executing a position hold function in order to maintain the updated current vessel position.

10. The method according to claim 1, wherein the vessel position is determined by a Global Navigation Satellite System.

11. A non-transitory computer program product comprising program code stored on a computer readable medium for performing the method according to claim 1 when said program code is run on a computer.

12. A control unit arranged to control a marine vessel comprising two or more propulsion units, the control unit comprising processing circuitry, the processing circuitry being configured to receive an input indicating a requested vessel function, wherein the processing circuitry is configured to: register an operating command indicating a requested bollard push function; detect a current vessel position; register the current vessel position as a desired vessel position; execute the requested bollard push function by controlling thrust and direction of the drive units in order to push the vessel against a fixed structure at a requested heading with a predetermined force; during execution of the requested bollard push function, monitor the current vessel position in order to detect a deviation relative to the desired vessel position; if the detected deviation relative to the desired vessel position has exceeded a predetermined value, the processing circuitry is configured to: deactivate the requested bollard push function, wherein deactivation of the bollard push function will at least involve an inhibition of the thrust from the drive units; register an updated current vessel position; and execute a station keeping function in order to maintain the updated current vessel position.

13. Marine vessel, wherein the marine vessel comprises a control unit according to claim 12.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following text, the invention will be described in detail with reference to the attached drawings. These schematic drawings are used for illustration only and do not in any way limit the scope of the invention. In the drawings:

(2) FIG. 1 shows a schematically indicated vessel

(3) FIG. 2 shows the marine vessel maneuvered according to a first control strategy;

(4) FIG. 3 shows the marine vessel maneuvered according to a second control strategy;

(5) FIG. 4 shows a flow chart illustrating a first alternative method for controlling the vessel;

(6) FIG. 5 shows a flow chart illustrating a second alternative method for controlling the vessel; and

(7) FIG. 6 shows the method applied on a computer arrangement.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

(8) FIG. 1 shows a side view of a schematically illustrated marine vessel 100 comprising a hull 101 and a pair of drive units 102, 103 mounted to a transom on the vessel 100. The drive units 102, 103 are each powered by a driveline comprising a corresponding engine 104 and a transmission 105 (one shown). The example in FIG. 1 shows two drive units driven by inboard engines. A non-exclusive list of alternative arrangements includes, for instance, two or more outboard engines, a single propulsion unit combined with a bow thruster 106 (indicated in dashed lines), or two or more azimuthing pods arranged under the hull of the vessel. The engines can of course be replaced by electric motors using battery packs or fuel cells, or engines operated on alternative fuels. According to the disclosure, at least two drive units are required for manoeuvring the vessel.

(9) The marine propulsion units 102, 103 are controllable by a control means such as a joystick 110 located at an operating position. The joystick 110 is connected to an electronic control unit (ECU) 111 via suitable wiring 112, which ECU 111 is connected to the driveline 104, 105 via additional wiring 113. Alternative control means includes a graphical user interface (GUI), such as a touch sensitive display, or manual controls comprising throttle levers and a steering wheel.

(10) FIG. 2 shows the marine vessel being maneuvered according to a first control strategy. In this first example a vessel 200 is placed alongside a dock 201, with the side of the vessel arranged parallel to the side of the dock. The operator will then operate the vessel propulsion system, which comprises two or more drive units, requesting a transverse thrust sufficient to hold the vessel 200 against the dock 201, where after the operator issues an operating command to a control unit (see FIG. 1) indicating that a sideways bollard push function is requested. The operating command is registered in response to an input signal from a joystick, a graphical user interface (GUI) or to input signals from at least one throttle controller and a helm controller, optionally in combination with a switch. When the sideways bollard push function is activated, the drive units will maintain the requested transverse thrust in the direction of the arrow F to maintain the side of the vessel in contact with the dock in a desired vessel position P.sub.1.

(11) The control unit will then continuously monitor if a deviation has occurred between the current vessel position P.sub.2 and the desired vessel position P.sub.1. During the manoeuvre, a displacement in the transverse and/or the longitudinal direction of the vessel is constantly monitored. If the ambient conditions are unfavourable, the vessel can be suddenly displaced away from or along the dock, by a gust of wind, indicated by an arrow W, and/or a sudden water current, indicated by an arrow C. If a deviation of the current vessel position P.sub.2 relative to the desired vessel position P.sub.1 has exceeded a predetermined distance, then the requested sideways bollard push function is deactivated. The predetermined distance can be measured as a transverse distance X at right angles to the dock, a longitudinal distance Y parallel to the dock, or as a distance D between the desired vessel position P.sub.1 and the current vessel position P.sub.2. When the selected distance has exceeded the predetermined distance, the sideways bollard push function is deactivated and the thrust from the drive units is inhibited. Suitable values for the predetermined distances X, Y, D described above can be one or more pre-set values selected by the manufacturer or can be selected by the operator. The distance can be selected up to, for instance, 1 m.

(12) The thrust from the drive units is inhibited in order to avoid further unexpected displacement of the vessel caused by the requested thrust and to give the operator time to resume control over the vessel. Optionally, the control unit can automatically activate a position hold function in response to a deactivation of the sideways bollard push function. In this way, the vessel can be prevented from drifting further away from the vessel position P.sub.2 where the deactivation of the sideways bollard push function occurred. This will provide additional time to resume control over the vessel, should the operator not be in the immediate vicinity of the controllers at the operating position (see FIG. 1).

(13) FIG. 3 shows the marine vessel being maneuvered according to a second control strategy. In this second example a vessel 200 is placed at an angle relative to a dock 201, with the bow of the vessel arranged against the dock. Here, the longitudinal direction, or heading of the vessel is arranged at right angles to the side of the dock. The operator then operates the vessel propulsion system, which comprises two or more drive units, requesting a forward thrust sufficient to hold the vessel 200 against the dock 201, where after the operator issues an operating command to a control unit (see FIG. 1) indicating that a bow bollard push function is requested. The operating command is registered in response to an input signal from a joystick, a graphical user interface (GUI) or to input signals from at least one throttle controller and a helm controller, optionally in combination with a switch. When the bow bollard push function is actuated, the drive units will maintain the requested forward thrust in the direction of the arrow F to maintain the bow of the vessel in contact with the dock in a desired vessel position P.sub.1.

(14) The control unit will then continuously monitor if a deviation has occurred between a current heading H.sub.2 at a current vessel positions P.sub.2 and the desired heading H.sub.1 at the desired vessel position P.sub.1. During the manoeuvre, at least an angular displacement of the vessel, where the bow is at least initially a pivot point, is constantly monitored. If the ambient conditions are unfavourable, the vessel can be suddenly displaced away from or along the dock, by a gust of wind, indicated by an arrow W, and/or a sudden water current, indicated by an arrow C. If the current vessel heading H.sub.2 is suddenly displaced a predetermined angle away from the initial desired vessel heading H.sub.1 relative to the dock, then the requested bow bollard push function is deactivated. The predetermined angle is measured as an angular displacement representing a change in the vessel heading to either side of the desired vessel heading H.sub.1. In FIG. 3, this would entail that the vessel would remain with the bow in the initial, desired position while the current heading H.sub.2 changes relative to the desired heading H.sub.1.

(15) Optionally, a displacement in the transverse and/or the longitudinal direction of the vessel is simultaneously monitored (see FIG. 2). If a deviation of the current vessel position P.sub.2 P.sub.2 relative to the desired vessel position P.sub.1 has exceeded a predetermined distance before the angle is exceeded, then the requested bow bollard push function is deactivated. The predetermined distance can be measured as a transverse distance X at right angles to the dock, a longitudinal distance Y parallel to the dock, or as a distance D between the desired vessel position P.sub.1 and the current vessel position P.sub.2. By monitoring both parameters, any undesired displacement whether angular or linear can be detected. When either one of the predetermined angle or the predetermined distance X, Y, D has exceeded its predetermined value, the bollard push function is deactivated and the requested thrust from the drive units is inhibited. FIG. 3 shows the latter example, where simultaneous angular and linear displacement has occurred to move the vessel to a new heading H.sub.2 and a new position P.sub.2. Suitable values for the predetermined angle can be one or more pre-set values selected by the manufacturer or can be selected by the operator. The angle can be set at angles up to 20.

(16) The thrust from the drive units is inhibited in order to avoid further unexpected displacement of the vessel caused by the requested thrust and to give the operator time to resume control over the vessel. Optionally, the control unit can automatically activate a position hold function in response to a deactivation of the bow bollard push function. In this way, the vessel can be prevented from drifting further away from the vessel position P.sub.2, P.sub.2 where the deactivation of the bow bollard push function occurred. This will provide additional time to resume control over the vessel, should the operator not be in the immediate vicinity of the controllers at the operating position (see FIG. 1).

(17) According to a further example, the method involves monitoring if the rate of change of the deviation for a current vessel position relative to the desired vessel position has exceeded a predetermined value. For instance, if the vessel in FIG. 2 or 3 is placed with its side or bow, respectively, against a dock when the bollard push manoeuvre is being performed, then the drive units will provide a suitable thrust to maintain the side or the bow of the vessel in contact with the dock. During the manoeuvre, any angular or linear displacement of the vessel is constantly monitored. If the vessel is displaced linearly or angularly away from the initial vessel position against the dock at a rate that exceeds a predetermined rate of change, then the requested bollard push function is deactivated.

(18) FIG. 4 shows a flow chart illustrating a first alternative method for controlling the vessel. The method involves performing a first step 401 where an operating command indicating a requested bollard push function is registered. In a second step 402 a current vessel position is detect using a suitable GNSS means, such as a Differential Global Positioning System (DGPS). In a third step 403 the current vessel position is registering as a desired vessel position in a control unit. In a fourth step 404 the control unit executes the requested bollard push function, using currently requested throttle and helm settings to hold the vessel in a desired position. In a fifth step 405 the control unit monitors the current vessel position in order to detect a deviation relative to the desired vessel position.

(19) In a sixth step 406 the control unit compares a detected deviation parameter to a predetermined deviation value. The detected deviation can be that the vessel has been displaced a predetermined distance from the desired vessel position to the current vessel position. Alternatively, or in combination, the detected deviation can be that the vessel heading has been displaced a predetermined angle from the desired vessel heading to the current vessel heading. Further, the detected deviation can be that the rate of change of the linear or angular deviation for a current vessel position relative to the desired vessel position has exceeded a predetermined value. If a deviation is not detected, then the process returns to the fifth step 405, where the control unit continues to monitor any deviation from the current vessel position. If a detected deviation relative to the desired vessel position has exceeded a predetermined value, then the process proceeds to a seventh step 407, where the requested bollard push function is deactivated. In this example, deactivation of the bollard push function will also involve an inhibition of the thrust from the drive units. The operator will then take over and control the vessel manually.

(20) FIG. 5 shows a flow chart illustrating a second alternative method for controlling the vessel. In the same way as described for the first alternative method, the second alternative method involves performing a first step 501 where an operating command indicating a requested bollard push function is registered. In a second step 502 a current vessel position is detect using a suitable GNSS means, such as a Differential Global Positioning System (DGPS). In a third step 503 the current vessel position is registered as a desired vessel position in a control unit. In a fourth step 504 the control unit executes the requested bollard push function, using currently requested throttle and helm settings to hold the vessel in a desired position. In a fifth step 505 the control unit monitors the current vessel position in order to detect a deviation relative to the desired vessel position.

(21) In a sixth step 506 the control unit compares a detected deviation parameter to a predetermined deviation value. The detected deviation can be that the vessel has been displaced a predetermined distance from the desired vessel position to the current vessel position. Alternatively, or in combination, the detected deviation can be that the vessel heading has been displaced a predetermined angle from the desired vessel heading to the current vessel heading. Further, the detected deviation can be that the rate of change of the linear or angular deviation for a current vessel position relative to the desired vessel position has exceeded a predetermined value. If a deviation is not detected, then the process returns to the fifth step 505, where the control unit continues to monitor any deviation from the current vessel position. If a detected deviation relative to the desired vessel position has exceeded a predetermined value, then the process proceeds to a seventh step 507, where the requested bollard push function is deactivated. Deactivation of the bollard push function also involves a temporary inhibition of the thrust from the drive units.

(22) Following the deactivation of the bollard push function the process proceeds to an eight step 508 where an updated current vessel position is registered in the control unit, Subsequently, the control unit will execute a position hold function in a ninth step 509. The position hold function is performed in order to maintain the vessel in the updated current vessel position. The updated current vessel position can be the position of the vessel at the time when the requested bollard push function is deactivated and/or the thrust from the drive units is inhibited. This operation will prevent the vessel from drifting further away from the dock or towards the dock under the influence of external factors, such as wind or water currents. The vessel position is preferably determined by a Global Navigation Satellite System (GNSS) with a suitable accuracy, such as a Differential Global Positioning System (DGPS). The operator can then take over and control the vessel manually when desired.

(23) The methods described in connection with FIGS. 4 and 5 are applicable to both sideways and bow bollard push manoeuvres.

(24) According to a second aspect the disclosure relates to a control unit 111, 600 arranged to control a marine vessel comprising two or more propulsion units. The control unit is indicated in FIGS. 1 & 6 and comprises processing circuitry which is configured to receive an input indicating a requested vessel function. In particular, the processing circuitry is configured to: register an operating command indicating a requested bollard push function; detect a current vessel position; register the current vessel position as a desired vessel position; execute the requested bollard push function; monitor the current vessel position in order to detect a deviation relative to the desired vessel position;
and if a detected deviation relative to the desired vessel position has exceeded a predetermined value, the processing circuitry is configured to: deactivate the requested bollard push function.

(25) Optionally, the processing circuitry is further configured to: register an updated current vessel position; and execute a station keeping function in order to maintain the vessel in the updated current vessel position.

(26) The present disclosure also relates to a computer program, and a computer program product to be used with a computer for executing the method as described in any one of the above examples. FIG. 6 shows the method described in connection with FIG. 4 or 5 applied on a computer arrangement.

(27) FIG. 6 shows an apparatus 600 according to the present disclosure, comprising a non-volatile memory 620, a processor 610 and a read-write memory 660. The memory 620 has a first memory part 630, in which a computer program for controlling the apparatus 600 is stored. The computer program in the memory part 630 for controlling the apparatus 600 can be an operating system. The apparatus 600 can be enclosed in, for example, a control unit, such as the control unit 111 in FIG. 1. The data-processing unit 610 can comprise, for example, a microcomputer. The memory 620 also has a second memory part 640, in which a program for controlling the docking manoeuvre according to the invention is stored. In an alternative embodiment, the program for controlling the docking manoeuvre is stored in a separate non-volatile storage medium 650 for data, such as, for example, a CD or an exchangeable semiconductor memory. The program can be stored in an executable form or in a compressed state.

(28) When it is stated below that the data-processing unit 610 runs a specific function, it should be clear that the data-processing unit 610 is running a specific part of the program stored in the memory 640 or a specific part of the program stored in the non-volatile storage medium 650. The data-processing unit 610 is tailored for communication with the storage memory 650 through a data bus 614. The data-processing unit 610 is also tailored for communication with the memory 620 through a data bus 612. In addition, the data-processing unit 610 is tailored for communication with the memory 660 through a data bus 611. The data-processing unit 610 is also tailored for communication with a data port 690 by the use of a data bus 615.

(29) The method according to the present disclosure can be executed by the data-processing unit 610, by the data-processing unit 610 running the program stored in the memory 640 or the program stored in the non-volatile storage medium 650.

(30) The present disclosure should not be deemed to be limited to the embodiments described above, but rather a number of further variants and modifications are conceivable within the scope of the following patent claims.