Patent ID: 12246810

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

FIG.1shows a schematically illustrated vessel100comprising a marine hybrid installation according to the invention. The hybrid installation in this figure comprises a first and a second parallel hybrid driveline101,102arranged to drive the vessel100via a first and second drives103,104mounted on the vessel transom105. Each driveline101,102comprises a first propulsion unit111,112in the form of an internal combustion engine (ICE) operatively connected with a second propulsion unit121,122in the form of an electric motor (EM) to drive a propeller shaft107,108and produce a thrust force for propelling the vessel. Each second propulsion unit121,122is connected to an individual source of electric power (not shown), such as an electric storage unit or battery.

A request indicative of a vessel speed can be received from an operating station130by means of a controller131operated by a user. In this example, multiple levers are used for controlling the driveline speeds. The controller can also be a joystick. The operating station130also comprises a steering wheel132for controlling the steered direction, a joystick133for operating the vessel during docking, and a display134. The display134can be used for providing the operator with vessel and driveline related operating parameters, and/or for showing navigational information. The display can be a graphical user interface (GUI) and can be touch-sensitive. Control signals relating to propulsion and steering are transmitted from the operating station130to a corresponding propulsion control unit (seeFIG.3) and a steering control unit (not shown) via a CAN bus135. As indicated inFIG.1, more than one operating station can be provided.

FIG.2A-2Cshow schematically illustrated vessels with alternative driveline installations.FIG.1shows a vessel comprising two stern drives driven by parallel hybrid drivelines. However, the invention is applicable to other drives as indicated inFIGS.2A-2C, showing multiple azimuthing drives.

FIG.2Ashows a vessel comprising two parallel hybrid drivelines201,202, wherein each driveline201,202is provided with a first propulsion unit211,212in the form of an internal combustion engine (ICE) operatively connected with a second propulsion unit221,222in the form of an electric motor (EM).

FIG.2Bshows a vessel comprising three parallel hybrid drivelines201,202,203, wherein each driveline201,202,203is provided with a first propulsion unit211,212,213in the form of an internal combustion engine (ICE) operatively connected with a second propulsion unit221,222,223in the form of an electric motor (EM).

FIG.2Cshows a vessel comprising four parallel hybrid drivelines201,202,203,204, wherein each driveline201,202,203,204is provided with a first propulsion unit211,212,213,214in the form of an internal combustion engine (ICE) operatively connected with a second propulsion unit221,222,223,224in the form of an electric motor (EM).

The invention is not limited to the examples shown inFIGS.2A-2C, but is applicable to any suitable driveline installation comprising multiple hybrid drivelines. The number of drivelines used is commonly decided by the size and speed requirements for each vessel. Consequently, relatively small vessels can use two hybrid drivelines as shown inFIG.1, while relatively large vessels can use up to seven or eight drivelines.

FIG.3shows a schematic illustration of a parallel hybrid driveline installation comprising three drivelines. The installation comprises a first, a second and a third parallel hybrid driveline310,320,330arranged to drive a marine vessel. Each driveline comprises a first propulsion unit311,321,331in the form of an internal combustion engine (ICE) operatively connected with a second propulsion unit312,322,332in the form of an electric motor (EM) to drive a propeller shaft313,323,333and produce a thrust force for propelling the vessel. Each first propulsion unit311,321,331is operatively connected to a respective second propulsion unit312,322,332via a driveshaft314,324,334, which driveshaft can comprise an optional controllable clutch315,325,335. A suitable reduction gearing or transmission (not shown) is provided adjacent the output shaft of each second propulsion unit. The reduction gearing is arranged to reduce the rotational speed of the propulsion units to a lower rotational output speed for the propeller shaft. Each second propulsion unit312,322,332is connected to an individual source of electric power (not shown), such as an electric storage unit or battery. Control units316,326,336;317,327,337is arranged for individual control of each first and second propulsion unit311,321,331;312,322,332, respectively, in all the parallel hybrid drivelines. All parallel hybrid drivelines310,320,330are controlled by a central driveline control unit340communicating with and controlling each first and second propulsion unit in the respective drivelines. Each driveline310,320,330further comprises a controllable clutch318,328,338on their respective propeller shaft313,323,333, allowing the central driveline control unit340to control the thrust force from each driveline310,320,330.

An operating station350comprises a driveline speed controller351operated by a user. In this example, multiple levers are used for controlling the driveline speeds. The operating station350also comprises a steering wheel352for controlling the steered direction, a joystick353for operating the vessel during docking, and a display354. The display354can be used for providing the operator with vessel and driveline related operating parameters, and/or for showing navigational information. The display can be a graphical user interface (GUI)354and can be touch-sensitive. Signals from the speed controller351, the steering wheel352, joystick353and the graphical user interface354are processed by a helm control unit355, which in turn generates control signals to a steering controller (not shown) and the central driveline control unit340. Control signals are transmitted from the operating station350to the central driveline control unit340and the steering control unit (not shown) via a CAN bus356. The CAN bus356also connects the central driveline control unit340and the individual control units316,326,336;317,327,337for the first and second propulsion units. Alternatively, transmission and exchange of data between the control units can be made using a Local Area Network (LAN) or a similar wired connection, or by using a suitable Wireless Local Area Network (WLAN) or other wireless technology such as WiFi or Bluetooth.

FIG.4shows an example of an efficiency map for an internal combustion engine. The efficiency map is a diagram indicating engine torque (Nm) plotted on the y-axis over engine speed (rpm) plotted on the x-axis. The contour lines show the specific fuel consumption (g/kWh), indicating the areas of the speed/load regime where the engine is more or less efficient. In the diagram, it is desirable to operate an engine within contour lines having lower values for specific fuel consumption. An upper line delimiting the plotted contour lines indicates the maximum engine torque that the engine can achieve for different engine speeds.

FIG.5shows an example of an efficiency map for an electric motor. The efficiency map is a diagram indicating motor torque (Nm) plotted on the y-axis over motor speed (rpm) plotted on the x-axis. The contour lines show the motor efficiency (dimensionless), indicating the areas of the speed/load regime where the motor is more or less efficient in converting electrical power to mechanical power. In the diagram, it is desirable to operate an electric motor within a contour line having higher values for efficiency.

The following example is described with reference to a marine vessel with an installation comprising a first and a second hybrid driveline. Each hybrid driveline comprises a first propulsion unit in the form of an internal combustion engine, and a second propulsion unit in the form of an electric motor. Efficiency maps for the engine and the motor are stored in a central control unit or in individual control unit for the respective propulsion unit.

In operation, the internal combustion engines in both drivelines are initially operated at a requested engine speed no, indicated at the point P0inFIG.4. In order to improve the efficiency of the installation, the rotational speed of the first propulsion unit in the first hybrid driveline is adjusted towards a first efficiency point P1, which point is determined from a stored engine efficiency map for the first propulsion unit. The direction of the adjustment is indicated by an arrow A1. This adjustment involves a reduction of the engine speed of the first propulsion unit from the requested engine speed n0to a lower, first engine speed n1. To achieve this, the second propulsion unit in the first hybrid driveline is adjusted by increasing the load from the second propulsion unit onto the first propulsion unit in response to the required lowering of the rotational speed of the first propulsion unit. This is shown inFIG.5, where the second propulsion unit is adjusted from an initial motor speed n0at an initial operating point E0, where no torque is generated, to a first motor speed n1at a first operating point E1, where a negative, braking torque is generated. The initial motor speed n0is equal to the initial engine speed n0of the first propulsion unit. The direction of the adjustment is indicated by an arrow B1. This negative torque increases the load from the second propulsion unit onto the first propulsion unit, which second propulsion unit is now being operated at a motor speed n1equal to the rotational speed of the first propulsion unit.

Simultaneously, the rotational speed of the first propulsion unit in the second hybrid driveline is adjusted towards a second efficiency point P2, which point is determined from a stored efficiency map for this first propulsion unit. The direction of the adjustment is indicated by an arrow A2. The adjustment involves an increase of the engine speed of the first propulsion unit from the requested engine speed n0to a higher, second engine speed n2. At the same time, the second propulsion unit in the second hybrid driveline is adjusted by increasing the load from the second propulsion unit onto the first propulsion unit in response to the required increase of the rotational speed of the first propulsion unit. This is shown inFIG.5, where the second propulsion unit is adjusted from an initial motor speed n0at the initial operating point E0, where no torque is generated, to a second motor speed n2at a second operating point E2, where a negative, braking torque is generated. The direction of the adjustment is indicated by an arrow B2. This negative torque increases the load from the second propulsion unit on the first propulsion unit which is now being operated at a motor speed n2corresponding to the rotational speed of the first propulsion unit. The operation of the second propulsion units to provide a braking, negative driving torque can be achieved by controlling the second propulsion units to charge their respective electrical storage units, such as a battery or a supercapacitor.

When adjusting the rotational speed of the first propulsion units of the respective drivelines, the propulsion units are allowed to be operated at a different rotational speeds n1, n2. The rotational speed n1, n2of the respective first propulsion unit is controlled so that the combined, or average rotational speed from all first propulsion unit corresponds to the initially requested rotational speed n0for all first propulsion units. This will provide a combined rotational output speed from all drivelines required for maintaining the requested vessel speed.

FIGS.6A-6Cshow examples of thrust force distribution for a number of alternative driveline installations. According to the invention, it is possible to control the drivelines so that they are operated at different rotational output speeds after adjustment of the rotational speed of each first propulsion unit towards a desired efficiency point.

FIG.6Ashows an example of thrust force distribution for installations comprising two drivelines.FIG.6Ashows a vessel600comprising two parallel hybrid drivelines601,602. According to this example, a first propulsion unit in a first driveline601has been adjusted towards a desired efficiency point, which adjustment has required a reduction of the rotational speed for the first propulsion unit and an increase of the load from the second propulsion unit (seeFIG.4, ref. “P1”). This increase of the load from the second propulsion unit provides a braking, negative driving torque applied to the first propulsion unit of the first driveline601. The speed reduction has resulted in a reduced first thrust force F1, indicated by an arrow inFIG.6A. Simultaneously, a first propulsion unit in a second driveline602has also been adjusted towards the desired efficiency point, which adjustment has required an increase of the rotational speed for the first propulsion unit and an increase of the load from the second propulsion unit (seeFIG.4, ref. “P2”). This increase of the load from the second propulsion unit provides a braking, negative driving torque applied to the first propulsion unit of the second driveline602. The speed increase has resulted in an increased second thrust force F2, indicated by an arrow inFIG.6A. FromFIG.6Ait can be seen that the magnitude of the thrust force F2from the second driveline602is greater than that of the thrust force F1from the first driveline601. This will cause a turning moment about the center of gravity CG of the vessel600, which must be compensated for in order to prevent a deviation from the steered direction requested by the operator. The turning moment can be eliminated by a correction of the steering angle α1and/or α2of the first driveline601and the second driveline602, respectively. Such a correction can be performed by a steering control unit (not shown) in the same way as such a unit performs a correction for sideways drift caused by wind or currents. Steering control units of this type will not be described in further detail here. In this way the direction of the combined thrust force comprising the first thrust force F1and the second thrust force can be adjusted by the steering control unit in order to maintain a total thrust force F0in a desired direction. In addition, as the thrust forces are proportional to the rotational output speed of the respective first and second driveline, the individual drivelines are controlled so that the average rotational output speed from all drivelines is sufficient for maintaining the requested vessel speed. If the steering angle of one or more drivelines is corrected as indicated above, then an increase of rotational output speed can be required for one or both drivelines for maintaining the requested vessel speed.

Alternatively, if the vessel is provided with a steerable rudder and fixed drive units, then the rudder can be used to compensate for the deviation from the steered direction.

FIG.6Bshows an example of thrust force distribution for installations comprising three drivelines.FIG.6Bshows a vessel610comprising three parallel hybrid drivelines611,612,613. According to this example, a first propulsion unit in a first driveline611and a third driveline613have been adjusted towards a desired efficiency point, which adjustment has required an increase of the rotational speed for the first propulsion unit and an increase of the load from the second propulsion unit (seeFIG.4, ref. “P2”). This increase of the load from the second propulsion unit provides a braking, negative driving torque applied to the first propulsion unit of the first driveline611and the third driveline613. The speed increase has resulted in increased first and third thrust forces F1, F3, indicated by arrows inFIG.6B, which forces are equal in magnitude.

Simultaneously, a first propulsion unit in a second driveline612has also been adjusted towards the desired efficiency point, which adjustment has required a reduction of the rotational speed for the first propulsion unit and an increase of the load from the second propulsion unit (seeFIG.4, ref. “P1”). This increase of the load from the second propulsion unit provides a braking, negative driving torque applied to the first propulsion unit of the second driveline612. The speed reduction has resulted in a reduced second thrust force F2, indicated by an arrow inFIG.6B. The rotational output speeds of the individual drivelines611,612,613are controlled so that the average rotational output speed from all drivelines is sufficient for maintaining the requested vessel speed.

FromFIG.6Bit can be seen that the magnitude of the thrust forces F1, F3from the first and third drivelines611,612are greater than that of the thrust force F2from the second driveline612. As the installation inFIG.6Bcomprises three drivelines, it is possible to operate the first and third drivelines as a pair. According to this example, the first and third drivelines611,613are located with equal spacing from the centerline CLof the vessel on either side of the second driveline612located on the centerline CL. The first and third drivelines611,613are operated at the same rotational output speed, which is higher than the rotational output speed of the central second driveline612. In this way it is possible to operate the drivelines to produce a combined thrust force F0that is equal to the sum of the individual thrust forces F1, F2, F3, and which coincides with the currently requested steered direction. Dependent on the determined efficiency points for each individual driveline, it is possible to achieve a combined thrust force having a neutral direction by selective adjustment of the drivelines making up the installation.

FIG.6Cshows an example of thrust force distribution for installations comprising four drivelines.FIG.6Cshows a vessel620comprising four parallel hybrid drivelines621,622,623,624. According to this example, a first propulsion unit in a first driveline621and a fourth driveline624have been adjusted towards a desired efficiency point, which adjustment has required an increase of the rotational speed for the first propulsion unit and an increase of the load from the respective second propulsion unit (seeFIG.4, ref. “P2”). This increase of the load from the second propulsion unit provides a braking, negative driving torque applied to the first propulsion unit of the first driveline621and the fourth driveline624. The speed increase has resulted in increased first and fourth thrust forces F1, F4, indicated by arrows inFIG.6C, which forces are equal in magnitude.

Simultaneously, a first propulsion unit in a second driveline612and a third driveline613have also been adjusted towards the desired efficiency point, which adjustment has required a reduction of the rotational speed for the first propulsion unit and an increase of the load from the respective second propulsion unit (seeFIG.4, ref. “P1”). This increase of the load from the second propulsion unit provides a braking, negative driving torque applied to the first propulsion unit of the second driveline612. The speed reduction has resulted in reduced second and third thrust forces F2, F3, indicated by arrows inFIG.6C. The rotational output speeds of the individual drivelines621,622,623,624are controlled so that the average rotational output speed from all drivelines is sufficient for maintaining the requested vessel speed.

FromFIG.6Cit can be seen that the magnitude of the outermost thrust forces F1, F4from the first and fourth drivelines621,624are greater than that of the innermost thrust forces F2, F3from the second and third drivelines622,623. As the installation inFIG.6Ccomprises four drivelines, it is possible to operate the outermost first and fourth drivelines, as well as the innermost second and third drivelines622,623as pairs. According to this example, the first and fourth drivelines621,624are located with equal spacing from the centerline CLof the vessel on either side of the second and third driveline622,623, which in turn are located with equal spacing from the centerline CLinside the first and fourth drivelines621,624. The first and fourth drivelines621,624are operated at the same rotational output speed, which is higher than the rotational output speed of the innermost second drivelines622,623. In this way it is possible to operate the drivelines to produce a combined thrust force F0that is equal to the sum of the individual thrust forces F1, F2, F3, F4, and which coincides with the currently requested steered direction. Dependent on the determined efficiency points for each individual driveline, it is possible to achieve a combined thrust force having a neutral direction by selective adjustment of the drivelines making up the installation.

According to the invention, a vessel can comprise three or more parallel hybrid drivelines, wherein the drivelines located equidistantly on either side of the centerline of the vessel can be operated in pairs. This principle of selecting pairs of symmetrically located drivelines operated at the same rotational output speed will balance the combined thrust force can be applied to installations comprising any number of drivelines. However, the invention is not limited to this principle. Within the scope of the invention it is also possible to operate all drivelines in the installation at different rotational output speeds, as long as the average rotational output speed from all drivelines is sufficient for maintaining the requested vessel speed.

According to a further example, if the vessel comprises two or more parallel hybrid drivelines, at least one driveline can be stopped if the rotational output speed of the remaining driveline or drivelines is sufficient for maintaining the requested vessel speed.

FIG.7shows a schematic diagram illustrating the operation of a driveline. In operation, the method is triggered in an initial step700when the vessel is being operated. In a first step701a control unit receives a request indicative of a vessel speed. In a second step702, the control unit determines a rotational speed for each first propulsion unit for achieving the requested vessel speed, based on the received request. In a third step703, efficiency points are determined for each of the first propulsion units and the second propulsion units from stored efficiency maps for each propulsion unit, based on the determined rotational speeds for the first propulsion unit in the respective drivelines. In a fourth step704, the rotational speed of the first propulsion unit in each powertrain is individually adjusted to improve the efficiency of this first propulsion unit while maintaining the requested vessel speed. Simultaneously, a fifth step705involves adjusting the load on the corresponding second propulsion unit in each powertrain to improve the efficiency of each powertrain and the complete powertrain installation. In a sixth step706, the individual powertrains are controlled so that the combined, average rotational output speed from all drivelines is sufficient for maintaining the requested vessel speed. In a final step707, the process returns to the first step if a request for a new rotational speed for the first propulsion units is received. The method is ended if an engine off signal is received.

The present disclosure also relates to a computer program, computer program product and a storage medium for a computer all to be used with a computer for executing said method.FIG.8shows an apparatus840according to one embodiment of the invention, comprising a nonvolatile memory842, a processor841and a read and write memory846. The memory842has a first memory part843, in which a computer program for controlling the apparatus840is stored. The computer program in the memory part843for controlling the apparatus840can be an operating system. The apparatus840can be enclosed in, for example, a control unit, such as the control unit340shown inFIG.3. The data-processing unit841can comprise, for example, a microcomputer.

The memory842also has a second memory part844, in which a program for controlling the target gear selection function according to the invention is stored. In an alternative embodiment, the program for controlling the transmission is stored in a separate nonvolatile storage medium845for 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. When it is stated below that the data-processing unit841runs a specific function, it should be clear that the data-processing unit841is running a specific part of the program stored in the memory844or a specific part of the program stored in the non-volatile storage medium845.

The data-processing unit841is tailored for communication with the storage memory845through a data bus851. The data-processing unit841is also tailored for communication with the memory842through a data bus852. In addition, the data-processing unit841is tailored for communication with the memory846through a data bus853. unit841is also tailored for communication with a data port859by the use of a The data-processing unit841is also tailored for communication with a data port849by the use of a data bus854. The method according to the present invention can be executed by the data-processing unit841, by the data-processing unit841running the program stored in the memory844or the program stored in the nonvolatile storage medium845.

It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.