WO2006136157A1

WO2006136157A1 - Maritime information system

Info

Publication number: WO2006136157A1
Application number: PCT/DK2006/000322
Authority: WO
Inventors: Poul Buchholz Hansen
Original assignee: A.P. Møller - Mærsk A/S
Priority date: 2005-06-24
Filing date: 2006-06-09
Publication date: 2006-12-28

Abstract

Disclosed is a method of tracking a voyage of a maritime vessel, the method comprising performing the following steps under control of a computer program executed on a data processing system: storing a route data item in a database of the data processing system, the route data item defining a current route from a start position to a destination position along which current route the vessel is scheduled to travel; storing voyage data indicative of at least an arrival time for a voyage along said current route; determining, at a current position along said current route, a required speed for at least a part of a remainder of said voyage from the current position to the arrival position, said speed being required for on-time arrival at the destination position.

Description

Maritime information system

TECHNICAL FIELD: The present invention relates to a maritime information system and, in particular, to a method and system for planning and tracking a voyage of a maritime vessel.

BACKGROUND: The operation of maritime vessels is a complex task and influenced by a large number of parameters. It is generally desirable to ensure that maritime vessels observe their sailing schedules, in particular their scheduled arrivals at their arrival port. Early and/or late arrival may cause a significant cost increase, e.g. due to increased port fees, delays in the delivery of the cargo carried by the vessel, and the like. Furthermore, it is desirable to reduce the energy consumption of the vessel, in order to reduce the costs of operation.

Published US patent application no. 2004/0193367 discloses a maritime vessel tracking system which determines the progress of a vessel during a voyage, and extrapolates the determined progress to estimate whether the vessel is projected to arrive on-time, early, or late. The calculation takes the possibility of different speed zones into account.

Japanese patent abstract of application no. 61124361 discloses an integrated navigation device which plans a course for a maritime vessel as to obtain a maximum saving of energy based on input related to weather, ocean weather, sea chart information and propulsive performance. The system controls a steering control system and a main engine control system.

However, it remains a problem to improve the timeliness of a maritime voyage while performing the voyage in a cost efficient manner. SUMMARY:

The above and other problems are solved by a method of tracking a voyage of a maritime vessel, the method comprising performing the following steps under control of a computer program executed on a data processing system: - storing a route data item in a database of the data processing system, the route data item defining a current route from a start position to a destination position along which current route the vessel is scheduled to travel,

- storing voyage data indicative of at least an arrival time for a voyage along said current route;

- determining, at a current position along said current route, a required speed for at least a part of a remainder of said voyage from the current position to the arrival position, said required speed being a minimum speed suitable for on-time arrival at the destination position.

Hence, an improved information system is provided that supports the decision making process involved in operating a large maritime vessel. By providing a maritime information system that calculates a required speed at a current position for ensuring an on-time arrival, an improved speed selection is achieved, since both too low speeds which would cause a late arrival and too high speeds which result in an increased energy consumption are avoided. Hence, a more accurate control of the operation of the vessel is achieved, thereby optimising the efficiency of the operation of the vessel.

In one embodiment, the method further comprises

- representing the current route by a sequence of hub points, each hub point of the sequence representing a corresponding location within a predetermined proximity to the current route;

- receiving sea current data observed by at least one other vessel during a previous voyage along a previous route, the previous route having at least two hub points of the determined subset of hub points in a predetermined proximity of the previous route.

Consequently, an efficient method for sharing sea current information among vessels travelling along the same or similar routes is provided. When the method includes determining updated sea-current estimates for the remainder of the route during an ongoing voyage, a more accurate basis for decisions regarding sailing schedule, routing, speed, etc. are provided, in order to optimise the operation of the vessel, e.g. by reducing fuel consumption and/or increase the timeliness of the voyage. Furthermore, when vessels travelling along routes that lie in the proximity of the same hub points exchange observed sea current information, the quality of the sea current predictions performed by each vessel is improved. By requiring that two routes only need at least two hub points in common, the routes of the two vessels need not be identical in order to benefit from each others sea current observations. Firstly, the routes are merely required to pass through a predetermined proximity of the common hub points. Secondly, the routes may have a common route segments with common hub points, while other parts of the two routes may be different from each other. Nevertheless, the two vessels may still exchange sea current information for the common route segments.

In one embodiment, the method further comprises selecting the hub points of the sequence of hub points as a subset of a plurality of predetermined hub points, such that each hub point of the subset is located in predetermined proximity to the current route. Hence the hub points related to the route are selected from a predetermined set of hub points, e.g. a set of globally defined hub points common to all vessels. In one embodiment, each hub point is stored as a hub point data item having a hub point position and a hub point area, e.g. a circle of a predetermined radius, associated to it. The process determines a hub point to be in a predetermined proximity to the route, when the route passes through the area associated to the hub point. Examples of suitable hub points include ports that may serve as departure and/or arrival port and other positions that are frequently passed by vessels.

In one embodiment, the route is stored as a series of waypoints, each waypoint defining a position along the route. In such an embodiment, the hub point may be determined to be in a predetermined proximity of the route, if the route includes a waypoint within the associated area of the hub point.

Hence, an efficient mechanism is provided for comparing different routes and determining routes that at least in part overlap, without unduly restricting the freedom of each user to freely define routes for a vessel.

When the method further comprises determining an average predicted sea current for at least a part of the current route based on the received sea current data, an efficient method is provided for accurately estimating the sea currents expected along the route / remainder of the route of a vessel.

In one embodiment, the determination of the average predicted sea current is based on sea current data received from the at least one other vessel only, if said at least one other vessel has completed at least one segment of the previous route between two hub points of the sequence of hub points.

Consequently, the sea current information from another vessel is only utilised once the other vessel has completed at least one route segment delimited by two hub points, thereby increasing the reliability of the sea current prediction.

The sea current information between vessels can be performed directly between vessels or via a central data processing system. When the method comprises transmitting sea current data observed by the vessel at a position along its current route to a land-based data processing system, and when receiving sea current data comprises receiving sea current data from the land-based data processing system, a land-based central system is provided that collects all sea current information and distributes them to other vessels, thereby simplifying the required communications infrastructure. When the land-based data processing system receives route information from all vessels, the land-based system can limit the distribution of sea current information to relevant vessels travelling on the same or at least partially overlapping routes, thereby reducing the amount of data to be communicated.

In another embodiment, determining a required speed comprises

- determining a remainder of said current route from the current position to the destination position;

- determining a set of speed constraints along the remainder of the route; - determining a desired arrival time a the destination position;

- determining a required current speed from the remainder of the route, the desired arrival time and the set of speed constraints.

Consequently, the required speed for those parts of the remainder of the route where there are no speed constraints is accurately determined. Examples of areas with speed constraints include shallow water zones and/or port areas.

In one embodiment, the required speed is determined as a fix point of a ratio of an effective distance function and an effective time function; wherein the effective distance function determines a distance of the remainder of the current route corrected for a distance travelled at reduced speed due to speed constraints; and wherein the effective time function determines an available remaining time until the desired arrival time corrected for a time during which the vessel travels at reduced speed due to said speed constraints, thereby providing a particularly accurate speed determination. When the distance travelled at reduced speed due to speed constraints and the time during which the vessel travels at reduced speed due to said speed constraints include corresponding distances and times during ramp-up and ramp-down of the speed, an increased accuracy of the required speed is achieved, since the time and distance travelled during the decrease/increase in speed from/to the required speed in the areas without constraints to/from the maximum speed possible in the constraint areas.

When the speed constraints are stored as a part of the route data item, the areas with speed constraints are automatically available for the speed calculation. The speed constraints are typically the same for each voyage along a given route. Therefore, when the speed constraints are stored in association with each route as part of a route data item, the speed constraints need only be entered once, and may be reused during each voyage along that route.

When the method further comprises determining an engine performance parameter required for achieving the determined required speed, a direct control parameter is provided that can directly be used for controlling the main engine as to ensure on-time arrival at a low energy consumption. In one embodiment, the engine performance parameter is the number of revolutions per minute (RPM) of the main propeller, and determining the number of revolutions per minute comprises determining the number of revolutions per minute from the required speed and the current draught of the vessel. Consequently, the RPM are determined based on the particular characteristics of the vessel. When the required number of revolutions per minute is determined from a predetermined look-up table, an efficient calculation is achieved that may be based on historic data, in particular actual performance during previous voyages. When the route information comprises a sequence of waypoint data items, each waypoint data item representing a location on said current route, a compact, easy-to-edit representation of a route is provided.

In yet another embodiment, the method further comprises

- storing vessel data indicative of at least draught data of the vessel;

- comparing the draught data with tide information about the destination position; and generating a warning when the draught data exceeds a maximum allowable draught at the destination position. Consequently, during setup and/or tracking of a voyage, an automatic check of the input data is performed as to ensure that arrival at the arrival port and at the scheduled arrival time is possible with the current draught of the vessel. If such an arrival is not possible, a warning is automatically generated and presented to the user, thereby avoiding inappropriate voyage schedules which may result in additional costs due to delays and/or additional fuel consumption.

When the method further comprises, in response to said warning, automatically invoking a user interface for displaying tide information about the destination position at the arrival time, an expedient tool is provided to the user for generating an appropriate schedule that allows arrival at a scheduled time. In particular, the method and system avoid an unnecessarily high fuel consumption that may otherwise result form e.g. a schedule with an earlier arrival time at which no arrival at the arrival port is possible due to a too high draught. It is a further advantage that accurate and easy to interpret tidal information is provided, thereby facilitating an effective voyage scheduling.

In yet another embodiment, the method further comprises tracking a progress of the voyage, and automatically sending a message to a land-based data processing system when a predetermined progress has been reached, said message requesting updated port information about the destination position. Consequently, the method ensures that the information about the destination port available to the user on board the vessel is correct and up-to-date.

When the method further comprises tracking a progress of the voyage, and automatically generating a reminder when a predetermined progress has been reached, said reminder reminding a user to perform a predetermined action, an improved decision support system is provided as late actions which may cause delays and additional costs are avoided.

It is noted that the features of the method described above and in the following may be implemented in software and carried out in a data processing system or other processing means caused by the execution of computer-executable instructions. Alternatively, the described features may be implemented by hardwired circuitry instead of software or in combination with software. The term "processing means" comprises any suitable general- or special-purpose programmable microprocessor, Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), Programmable Logic Array (PLA), Field Programmable Gate Array (FPGA), special purpose electronic circuits, etc., or a combination thereof.

Embodiments of the present invention can be implemented in different ways, including the method described above and in the following, a suitably configured data processing system, and further product means, each yielding one or more of the benefits and advantages described in connection with the first-mentioned method, and each having one or more embodiments corresponding to the embodiments described in connection with the first- mentioned method and/or disclosed in the dependent claims.

In particular, an embodiment of the invention further relates to a data processing system configured to perform the steps of the method described above and in the following. The data processing system may comprise a suitably programmed computer, e.g. a personal computer. In some embodiments the data processing system may comprise a plurality of computers, e.g. one or more server computers and one or more client computers suitably connected via a computer network.

In one embodiment, the data processing system comprises a local data processing system located on board the vessel, and a land-based data processing system. The local data processing system and the land-based data processing system are configured to communicate with each other via a suitable communications link, e.g. a wireless communications link such as a satellite-based communications link.

In one embodiment, the local data processing system on board the vessel comprises a local database configured to store

- a plurality of route data items indicative of respective routes,

- one or more voyage data items indicative of voyage parameters defining a voyage along one of the stored routes,

- vessel data indicative of vessel specific parameters.

In one embodiment, the local database is further configured to store at least one of sea current data observed by other vessels and received from the land-based data processing system, port data indicative of information about a plurality of ports that may be departure or arrival ports of routes, and tide data associated with a number of ports.

In one embodiment, the local data processing system is configured to provide one or more user interfaces allowing a user to enter/view/modify the route data, voyage data, and/or vessel data. In one embodiment, the local data processing system is further configured to provide at least one of a user interface for viewing sea current data observed by other vessels, a user interface for viewing tidal information at a selected position associated to a selected port, a user interface for tracking the progress of an ongoing voyage.

The land-based processing system is configured to communicate with a plurality of local data processing systems on board respective vessels. In one embodiment, the land-based data processing system comprises a central database configured to store route data indicative of the routes along which different vessels sail, and sea current data received from different ones of the vessels. In one embodiment, the land-based processing system is further adapted to distribute sea current data related to a given route to all vessels currently sailing on the same route or a route that is at least partially overlapping with said route.

In one embodiment, the central database is further adapted to store at least one of port information, tidal information, for a plurality of ports, and the land- based processing system is adapted to send such information to one or more of the vessels, e.g. upon request of a vessel for updated information.

BRIEF DESCRIPTION OF THE DRAWINGS:

The invention will be explained more fully below in connection with embodiments and with reference to the drawings, in which:

Fig. 1 shows a schematic block diagram of an embodiment of a voyage efficiency system.

Fig. 2 illustrates another schematic view of an embodiment of a voyage efficiency system.

Fig. 3 shows a flow diagram of an embodiment of a method of tracking the voyage of a vessel. Fig. 4 illustrates a user interface of a vessel setup module of a voyage efficiency system.

Fig. 5 illustrates an interface of a route module of a voyage efficiency system.

Fig. 6 illustrates an interface of a port module of a voyage efficiency system.

Fig. 7 illustrates a user interface of a voyage module of a voyage efficiency system for planning a voyage.

Fig. 8 illustrates a user interface of a voyage module of a voyage efficiency system for tracking a voyage.

Fig. 9 illustrates a user interface of a sea current prediction module of a voyage efficiency system for entering sea current observations.

Fig. 10 illustrates a user interface of a sea current prediction module of a voyage efficiency system for viewing sea current predictions.

Fig. 11 illustrates a method of predicting sea currents.

Fig. 12 shows a first example illustrating a method of predicting sea currents.

Fig. 13 shows a second example illustrating a method of predicting sea currents.

Fig. 14 illustrates a method of calculation of the required RPM to ensure timely arrival.

Fig. 15 shows a user interface of a tide calculation system. DETAILED DESCRIPTION:

Fig. 1 shows a schematic block diagram of an embodiment of a maritime information and decision-support system, hereafter also referred to as voyage efficiency system (VES). The voyage efficiency system is a computer-implemented information, planning, tracking and decision-support system enabling a user, e.g. a ship master, to make better decisions regarding the voyage/journey of a maritime vessel. In particular, the voyage efficiency system enables the ship master to set the propeller speed of the ship propeller in a more efficient manner in order to reach the destination port at the scheduled time.

The voyage efficiency system comprises a data processing system 101 that executes one or more software programs which provide a system framework 114, a database 106, and a number of application modules 115, 116, 117, 118, 119, 120, 121. The system allows the addition of further application modules and/or the removal of one or more application modules. The framework 114 includes functionality that provides a basic infrastructure, for example one or more of the following functions: user interfaces, a communications interface, task management, interfaces for receiving vessel related data, data related to the performance of the vessel, position data, weather data, etc. In particular, the system framework 114 provides a communications interface for communicating data with a central system 112 including a central database 113.

The vessel setup module 115 provides functionality for entering, storing, displaying, analysing, and maintaining of vessel related data. The route module 116 provides functionality for entering, storing, displaying, editing of routes. The port module 117 provides functionality for entering, storing, displaying, editing of port information. The voyage module 118 provides functionality for entering, analysing, and storing of voyage data during a planning stage, for tracking and analysing the progress of a voyage, and for editing/maintaining voyage data during the voyage. The sea current module 119 provides functionality for receiving sea current observations, communicating sea current observation data to the central system 112, to receive and display sea current observations made by other vessels, and to analyse the received observations. The tide module 120 provides functionality for displaying tide information for different positions. The RPM module 121 provides functionality for calculating the required revolutions per minute (RPM) of the propeller, or another parameter indicated of the required engine performance, in order to ensure an on-time arrival at the destination and in order to minimise the required energy consumption. The functionality provided by the above application modules will be described in more detail below. It is understood that the above application modules may be implemented as distinct software components, e.g. concurrently executed programs, or they may be combined into a smaller number of software components. It is further understood that a different division of the functionality described herein into modules may be used. Furthermore, additional and/or alternative functionalities may be provided.

The data processing system 101 may be implemented as a single computer, such as a personal computer, or as a system comprising more than one computer, e.g. a client/server system with one or more application servers and one or more client computers connected to a computer network, e.g. a local area network, thereby allowing access to the system from multiple locations on the vessel and/or by multiple simultaneous users. User access may be limited to authorised users via a user log-in with an ID plus password, thereby allowing the assignment of different levels of access rights to different users.

As will be described in greater detail, the on-board voyage efficiency system provides user interfaces 122 for receiving and/or displaying data related to the performance of the vessel, the voyage, tidal information, sea current information, etc. In particular, the voyage efficiency system provides user interfaces for receiving vessel data 102, route data 103, port information 104, and tide information 105. The received data is stored in the database 106 for subsequent use by the application modules, e.g. for analysing the performance of the vessel, and/or for subsequent display.

The central data processing system 112 is located on shore and it includes a database 113 for storing data related to one or more vessels, thereby allowing a central tracking of the vessels, e.g. their positions, their performance, their estimated arrival times, etc. The database 113 further has stored therein data relevant for one or more of the vessels, e.g. port information, sea current information, tidal information, etc. Accordingly, the local data processing system 101 comprises a communications interface 123 for communicating data with the central system 112, in particular for receiving port information, in the following also called safe port memos 107, port codes 108 identifying respective ports, sea current data 109 obtained by other vessels, and for transmitting measured sea current data 110 and other reports 111 , e.g. position information, departure times, estimated arrival times, etc.

Fig. 2 illustrates another schematic view of an embodiment of a voyage efficiency system. As described above, the voyage efficiency system comprises a local data processing system 101 located on board each vessel 202 and a central land-based system 112. The local data processing system 101 comprises a communications interface for communicating data with a land-based central data processing system 112, e.g. via a radio communications link, e.g. a satellite communications link, as illustrated by satellite 201 in fig. 2. The vessel 202 is driven by an engine 204 via a propeller 205. The engine 204 is controlled by a control system 203. In some embodiments, the voyage efficiency system 101 is connected to the control system 203 to allow direct exchange of performance data and/or direct control via the voyage efficiency system. Furthermore, the vessel may include one or more sensors 206 for obtaining measurements of one or more quantities relevant for the performance of the vessel. Examples of such measurements include but are not limited to weather data, such as wind speed, temperature, visibility, etc, ocean data, such as sea current, height of the sea, etc. a positioning system such as GPS, or the like.

Even though fig. 2 only shows one vessel 202 communicating with the central data processing system 112, it will be appreciated that a plurality of vessels may communicate and exchange data with the central system 112.

The central system 112 may further be connected, e.g. via the internet or other communications networks, with other databases, thereby allowing the collection of data and the distribution of the collected data to one or more of the vessels. The central system 112 may further facilitate communication and/or data exchange between different vessels.

One of the functions performed by the voyage efficiency system is the tracking of a voyage of the vessel, including the planning of the voyage, an embodiment of which will be described in the following.

Fig. 3 shows a flow diagram of an embodiment of a method of tracking the voyage of a vessel. In one embodiment, the process is carried out by - or at least under control of - the local data processing system on board the vessel. The process is initiated at step S301 where the voyage efficiency system receives and stores relevant vessel related data which is stored in the database 106. Examples of relevant vessel data include an IMO number, the name of the vessel, a displacement table, engine data, trim data, and information about fouling of the hull of the vessel. An example of a user interface allowing a user to enter vessel data is shown in fig. 4. In subsequent step S302 the voyage efficiency system receives and stores route data, i.e. data defining a number of routes. Each route is defined as a sequence of waypoints, where each waypoint defines a position, e.g. by defining latitude and longitude of the position. Each route may further include additional information such as information about shallow zones, reminders, and/or safe port details. The route data may be input by a user, imported from other route planning systems, received from the central database 113, or the like. For example, the voyage efficiency system may provide functionality for importing and/or exporting of waypoints to/from electronic chart systems and/or weather prognosis systems. An example of a user interface allowing a user to enter route data is shown in fig. 5. The route setup may further include the input of port information about the departure and/or arrival port.

In subsequent step S303, the process generates a voyage data item comprising data related to a specific voyage, typically from a departure port via a route to an arrival port. To this end, the voyage efficiency system provides a user interface facilitating the planning of a route. An example of such a user interface is shown in fig. 7. The user interface allows a user to select a route, enter information about the departure time, the desired arrival time and draught. The voyage module further receives information generated by the route module, the port module. The voyage efficiency system then calculates further relevant voyage parameters, such as the required speed, revolutions per minute for the main engine, and fuel consumption for the route. The voyage efficiency system further analyses the voyage parameters and issues alerts if necessary, e.g. if the draught is to high for the arrival and/or departure port.

In subsequent step S304, the route is initiated, i.e. the tracking of a voyage along the selected route is started, e.g. by receiving a corresponding user command. Furthermore, the voyage efficiency systems transmits a "start of route" message to the central land-based system indicating that the voyage has been initiated and including relevant data such as the route data, arrival and departure times, etc. After receipt of the start message, the central land- based system sends relevant data to the vessel, e.g. sea current data received from other vessels on the same route. Furthermore, the central land-based system may send other updates of other information to the vessel, e.g. by implementing a version control mechanism that checks for available updates of information stored in the local database of the vessel.

For example, the central land-based system sends updated data for port information, hereafter also referred to as safe port memos, sea-current data to the voyage efficiency system. Furthermore, the central land-based system may forward the data received from the vessel to other systems, e.g. a fleet schedule system.

In subsequent step S305, the route progress is tracked. During tracking, the voyage efficiency system receives relevant data, such as the vessel position, sea current data, etc. Some or all of the received data may be manually entered by an operator, e.g. via a suitable user interface. Some or all of the data may be received automatically from other systems, e.g. position data from a positioning system, current vessel performance data from a control system of the vessel, weather and sea current data from respective sensors, predicted sea current data from the central land-based system, etc. For example, sea current may be calculated by measuring the difference between the observed distance and the speedlog distance. The observed distance is the distance Over land¹ and is available through e.g. GPS information. The speedlog distance is the distance relative to the water and may be measured with a free propeller under the vessel and a sensor that counts the number of rotations of that propeller. For example, if the vessel is anchored in a strong current water, the observed distance will be 0 and the speedlog distance corresponds directly to the sea current. The voyage efficiency system displays the updated data via a suitable user interface. An example of such a user interface is shown in fig. 8.

At predetermined points along the route, the voyage efficiency system automatically triggers certain functions. Accordingly, at predetermined locations along the route, at predetermined times, or when other trigger conditions are fulfilled, the voyage efficiency system initiates corresponding functions. Examples of functions triggered by the voyage efficiency system include:

- The generation of reminders/alerts 331. For example, at predetermined times the voyage efficiency system issues a reminder to perform certain actions, such as contacting port authorities, or the like. Such reminders may be configured as part of the route data as will be described below. Similarly, the voyage efficiency system may generate certain reminders and/or alerts when predetermined trigger conditions are fulfilled, e.g. when the draught exceeds a certain maximum value allowed at the arrival port, when the speed exceeds a certain maximum speed, when the speed is so low that an estimated buffer time decreases under a certain limit, when the arrival to a port will be after deadline time for arrival, when the hull has become so foul that it is advisable to have the hull and/or propeller cleaned, when a speed factor that takes account for the hulls fouling level is outdated, when the trim is outside a normal range, etc. - The generation and transmission of reports 332 to the central land- based system. For example, the voyage efficiency system sends sea current observations and other relevant information to the central land-based system.

- The transmission of requests for safeport memos 333 or other data from the central land-based system. In one embodiment, at predetermined times prior to the estimated time of arrival, e.g. 72 hours prior to arrival and then every 12 hours, the voyage efficiency system sends a request to the central land-based system to forward updates of safeport memos and/or other relevant information regarding the destination port. Such information may include depths at different locations in the port, draft, under keel clearance, etc.

- The invocation of the tide module 120. The tide module may be invoked, if the draught exceeds a maximum allowable value for the arrival port, as will be described in greater detail below.

- The invocation of the sea current module 119. The sea current module may be invoked upon receipt of updated sea current data from the central land-based system in order to update the calculation of the predicted sea current value. Similarly, the sea current module may generate a report to be sent to the central land-based system upon measurement of the local sea current. - The invocation of the RPM module 121 , e.g. in order to update the calculated required RPM in order to ensure on-time arrival with a minimum energy consumption.

- The invocation of one or more other sub-modules of the voyage efficiency system.

Some trigger conditions may be related to the time, e.g. the time left to the estimated time of arrival, to position, e.g. when the vessel reaches a predetermined waypoint of the route, or predetermined global locations also referred to as HUB points. Furthermore, one or more of the above functions may be triggered in response to an operator input.

The results of the above triggered actions are displayed by the voyage efficiency system. Hence, the voyage efficiency system provides updated information about the required speed and revolutions for main engine, the remaining time, and reminders when due. At the end of the route (step S306), i.e. when the last waypoint has been reached or when the voyage efficiency system receives an operator input indicative of the end of the route, the voyage efficiency system stops the route tracking and transmits a corresponding report/message with relevant data to the central land-based system, e.g. about actual time of arrival, sea current observations, vessel performance data, any messages entered by a user, etc.

Hence, in the above, an embodiment of the overall voyage planning and tracking process was described. In the following, some of the functions performed by the voyage efficiency system will be described in greater detail. In particular, Figs. 4-10 and 15 show examples of a graphical user interface provided by an embodiment of a voyage efficiency system to a user on board the vessel.

Fig. 4 illustrates a user interface of a vessel setup module of a voyage efficiency system. The user interface, generally designated 400, provides active elements that allow an operator to enter, view, and modify vessel related data. The data is received by a vessel setup module of the voyage efficiency system, analysed, and stored in the database associated with the voyage efficiency system. The analysis of the received data may result in the issuance of alarms and/or reminders.

In particular, the user interface 400 comprises a number of input screens embodied as tabs 401 for entering different categories of input data, such as general information, displacement data engine data, speed performance data. In the example of fig. 4, the tab corresponding to engine data is selected. This tab allows an operator to enter relevant data about the engine of the vessel, such as breake horse power at sea trial, speed used at sea trial, draught at sea trial, main engine usage, auxiliary engine usage, fuel price, the duration and start/end RPM values for the load programs for ramping up/down of the speed. Furthermore, the tab 401 comprises a lookup table 402 comprising required RPM values (or RPM/speed ratios) for maintaining different speeds at different draughts. The tab 401 allows an operator to modify the table entries and to add/delete table entries of the look-up table 402.

The user interface comprises an active button element 403 allowing an operator to commit any entered changes to the database.

Fig. 5 illustrates an interface of a route module of a voyage efficiency system. The user interface, generally designated 500 provides active elements allowing an operator to enter, view, and modify route related data. The data is received by a route module of the voyage efficiency system, analysed, and stored in the database associated with the voyage efficiency system. The analysis of the received data may result in the issuance of alarms and/or reminders.

The user interface comprises a selection box 501 or other active element allowing a user to select one of a number of stored routes, e.g. by entering/selecting a route name. Furthermore, the user interface includes buttons 504 and 505 allowing a user to add a new route and delete a selected route, respectively. For a selected route, the user interface comprises a number of input screens embodied as tabs 502 for entering/viewing/modifying different categories of input data related to the selected route, such as general route information, reminders associated to that route, shallow zones on that route, waypoints defining the route, and charts and lights.

In the example of fig. 5, the tab corresponding to waypoint data is selected. This tab allows an operator to enter/view/modify/delete waypoints. In particular, the user interface includes a table 510 where each row corresponds to a waypoint and the table columns correspond to different data fields related to each waypoint. As already mentioned, a route is represented as a sequence of waypoints where each waypoint corresponds to a corresponding position. Correspondingly, in the table 510, the waypoints are consecutively numbered according to their position in the sequence of waypoints defining the route. Furthermore, each waypoint has a latitude and longitude associated with it defining the geographic position of the waypoint. The first waypoint corresponds to the departure berth, and the last waypoint of the sequence correspond to the arrival berth. Optionally, each waypoint has further related data associated with it, e.g. a check box /flag 510 indicating whether the waypoint is a pilot station, information about course changes, a turning radius, a trajectory type (rhumb line or great circle), and a text field for comments related to the waypoint. The user interface allows a user to edit the various data fields and, via buttons 506 and 507, to add additional waypoints and to remove waypoints, respectively.

The user interface further provides functionality, via buttons 508 and 509, to import waypoint data from external systems, e.g. electronic charting systems, and to export waypoints, e.g. for the purpose of generating reports, to external systems, respectively. For example, the system provides functionality for printing of waypoints and all route information, e.g. in a suitable format that fulfils the requirements of port authorities and can as such be used as voyage planning documentation.

The user interface comprises an active button element 503 allowing an operator to commit any entered changes to the database.

One of the tabs 502 is related to general information and allows a user to enter the departure and arrival ports for the route, e.g. by specifying corresponding port codes. Corresponding default port information may be stored in the local database or can be received from the central land-based system. The user may further specify whether safe port memos for the arrival port are desired, thereby causing the voyage efficiency system to request newest update of information. The user may further specify a maximum speed that is believed to be maintainable.

Another of the tabs 502 is related to reminders and allows a user to define various reminders, e.g. by associating reminders with waypoints or with times, such as remaining time to arrival. The reminders will then be displayed during the planning and tracking of a voyage along the route.

Yet another of the tabs 502 is related to shallow zones, i.e. areas with so low water that a vessel cannot pass through these areas with full engine power and/or where the speed for a given RPM is reduced. This tab allows a user to enter/modify the location and further data of the shallow zones along the route. The voyage efficiency system further includes a shallow water tool that calculates the resulting speed in a shallow area for a given RPM, based on input data such as the width of the vessel, a mean draught, under keel water depth, The calculation results in a calculated speed and a shallow factor specifying the loss of speed, e.g. using Schlichting's formula. Furthermore, the voyage efficiency system calculates the distance during which the route lies within the shallow area. This distance is used in calculations of speed and revolutions per minute as will be described below.

Fig. 6 illustrates an interface of a port module of a voyage efficiency system. The user interface, generally designated 600 provides active elements allowing an operator to enter, view, and modify port related data. The data is received by a port module of the voyage efficiency system, analysed, and stored in the database associated with the voyage efficiency system. The analysis of the received data may result in the issuance of alarms and/or reminders. The user interface comprises a selection box 601 or other active element allowing a user to select one of a number of stored ports, e.g. by entering/selecting a port code. Data related to port codes not yet known to the voyage efficiency system may be received from the central land-based system. For a selected port, the user interface comprises a number of input screens embodied as tabs 602 for entering/viewing/modifying different categories of input data related to the selected port, such as general port information, pilot information, reminders associated to that port, and zone time.

In the example of fig. 6, the tab corresponding to reminders is selected. This tab allows an operator to enter/view/modify/delete reminders associated to the selected port. In particular, the user interface includes a table 610 where each row corresponds to a reminder and the table columns correspond to different data fields related to each reminder, in particular a reminder text, a time, e.g. relative to the estimated time of arrival, when the reminder is to be displayed, and a check box indicating whether the reminder should be activated or not. Examples of reminders include a reminder when the maximum draught in a given port is exceeded, a reminder that port authorities must be informed of arrival time etc. In some embodiments, a reminder may be configured to invoke another application, e.g. a telex application with a suitable telex document template.

One of the tabs 602 is related to time zone information and allows to enter/view/modify the correct zone time for the selected port. This time will then be shown and used in calculations related to the arrival time. The voyage efficiency system automatically performs changes from standard to summertime and vice versa.

One of the tabs 602 is related to general information and allows the user to enter/view/modify the slowdown time/distance at a selected port, i.e. the time/distance during which a reduced speed is required when arriving at or departing from the selected port. These data are used in the calculation of the required speed between ports, as will be described below.

It is understood that the vessel data, the route data, and the port data do not have to be entered at the beginning of each voyage but, once entered during an initial setup, is stored in the database and may only require infrequent updates.

Fig. 7 illustrates a user interface of a voyage module of a voyage efficiency system for planning a voyage. The user interface, generally designated 700 provides active elements allowing an operator to enter, view, and modify data related to a voyage of the vessel along a selected route. The data is received by a voyage module of the voyage efficiency system, analysed, and stored in the database associated with the voyage efficiency system. The analysis of the received data may result in the issuance of alarms and/or reminders.

The user interface comprises a selection box 701 or other active element allowing a user to select one of a number of stored routes, e.g. by entering/selecting a route name, thereby causing the voyage efficiency system to load the stored data for the selected route, including waypoints, shallow water data, reminders, etc. The user interface further provides input fields 702 and 703 for entering a scheduled departure date and time and arrival date and time. The user interface further provides input fields 705 for entering the forward and aft draught of the vessel. The user interface further includes an input field 704 for entering a predicted average sea current along the route. If the user does not enter a value for predicted sea current, the voyage efficiency system calculates a predicted sea current as will be described below. The user interface further provides input fields for entering further information, such as time zone information for the arrival and/or departure times, an expected time loss due to weather conditions, a total load on the generators of the vessel, and/or the like.

When the user has entered the relevant data, the voyage efficiency system analyses the data, performs a number of calculations, retrieves additional data from the local database, and displays the results of the analysis/calculation. To this end, the user interface comprises a button 706 allowing a user to initiate the analysis. The user interface further includes text fields for viewing the calculated/retrieved values, for example a calculated sailing time, a hull resistance factor, an average historical fuel consumption, a predicted fuel consumption, a fuel consumption per hour, a total fuel cost, a required bottom speed to ensure on-time arrival, a required RPM to ensure on-time arrival, a displacement, an immersion, a predicted sea current, and/or the like. The calculation of the required speed/RPM and the sea current will be described in greater detail below. The user interface further comprises a text field 710 where reminders and/or warnings are displayed, e.g. reminders/warnings stored in relation to the route data, or reminders warnings generated during the analysis/calculation process.

The user interface further comprises a button 707 for invoking the shallow water tool described above, and a button 708 for invoking a trim tool. The trim tool allows a user to enter alternative trim values, i.e. alternative forward and aft draughts, and calculates new predicted fuel consumption and corresponding costs for the alternative trim by adding an appropriate speed factor, thereby allowing the user to optimise the trim as to improve the energy efficiency of the operation of the vessel.

The user interface further comprises a button 709 allowing the user to start the tracking of the voyage as described in connection with fig. 3. Once a voyage is started, the voyage efficiency system tracks the progress along the route, calculates and displays updated values for relevant performance parameters.

Fig. 8 illustrates a user interface of a voyage module of a voyage efficiency system for tracking a voyage. The user interface, generally designated 800, provides active elements allowing an operator to view updated data and modify data related during the voyage of the vessel along a selected route. The voyage/route progress user interface 800 displays a number of relevant parameters, such as the route name, a voyage number, the distance of the route from pilot station to pilot station, the pilot departure date and time, the present data/time, the scheduled pilot arrival date and time including the corresponding time zones, the expected time loss due to weather conditions, the pilot in time (i.e. the time from when the inbound pilot is on board until the vessel is all fast alongside), the predicted and/or a user-specified custom sea current, the current latitude and longitude, the remaining distance, the current draught aft and forward, the displacement and immersion, the required bottom speed and RPM required for an on-time arrival, the estimated remaining sailing time, the predicted fuel consumption, the total load on the generators, the fuel consumption per hour, the total fuel cost, a new arrival time if applicable. Some of the displayed data may be modified/corrected/overridden by the user, e.g. the scheduled pilot arrival date/time and time zone, the expected time loss due to weather conditions, the present date/time and time zone, the latitude and longitude, the forward and aft draught, the total load on generators. Some of the above data may be automatically retrieved from the database, calculated, and/or received from corresponding sensors, e.g. the longitude and latitude may be received from a positioning system. However, a user may be authorised to override the automatically generated/received values.

The user interface further comprises a text field 810 for displaying reminders/warnings, as described in connection with fig. 3. The user interface further comprises a button 807 for invoking the shallow water tool described above, and a button 808 for invoking the trim tool described above, thereby allowing a user to continuously optimising the performance of the vessel. The user interface further comprises a button 809 allowing the user to stop the tracking of the voyage and signal the end of the route as described in connection with fig. 3.

The voyage efficiency system provides an efficient mechanism for predicting the sea current along the route. To this end the voyage efficiency system provides user interfaces allowing a user to enter observed sea current observations and to view the predicted sea current observations. These interfaces will now be described with reference to figs. 9 and 10.

Fig. 9 illustrates a user interface of a sea current prediction module of a voyage efficiency system for entering sea current observations. The user interface comprises active elements allowing the user to enter a number of observations, e.g. date/time of the observation, the logged/speedlog distance and the observed distance, the latitude and longitude, the direction and force of wind, the direction and height of sea, the observed sea current, etc. In some embodiments, the sea current is determined automatically based on other observed and logged distances as described above.

The input data may be entered manually, e.g. by the officer on duty, or semi- or fully automatically, where some or all of the data are received automatically by the voyage efficiency system from respective external systems.

The entered/received data is logged in the database and used by the voyage efficiency system to generate updated calculations displayed in the voyage/route progress user interface. To this end, the user interface comprises a refresh/update button 902, causing the system to transfer the latest position to the route progress screen and to recalculate the relevant data. Furthermore, when the user activates the refresh button 902, the system generates a message including the latest sea current observation data and sends the message to the central land-based system, which distributes the data to other vessels travelling at least partially on the same route.

After a route has been started, the system generates an alarm if no current observation has been done within a predetermined time period, e.g. the last 8 hours.

Fig. 10 illustrates a user interface of a sea current prediction module of a voyage efficiency system for viewing sea current predictions. The user interface, generally designated 1000, displays sea-current observations observed by other vessels. In particular, the user interface displays a number of graphs 1001 showing the observed sea currents by a number of other vessels that have sailed along at least parts of the same route. The sea current graphs are plotted as functions of the remaining distance to the arrival port. The voyage efficiency system further calculates a predicted average sea current until arrival from the data observed by the other vessels, e.g. as an average of the sea currents in each segments weighted by the distance of each segment. The sea currents in each segment may be calculated as an average over the observations from the other vessels. The calculated value 1002 is displayed and used, e.g. as a correction term, in the calculation of required RPM.

The user interface further displays a table 1010 showing the individual observations from a selected one of the other vessels. The user may select the vessel for which detailed information is to be displayed, e.g. by clicking on the name of the vessel in a list of vessels. Fig. 11 illustrates a method of predicting sea currents. The voyage efficiency system has stored in its database a number of so-called hub points, each defining a position (e.g. by a longitude and latitude) and a predetermined radius. Hence, each hub point corresponds to a circle at a predetermined position. However, other shapes of areas may be used to define hub points as well. The hub points are defined globally, e.g. in the central land-based system. They are typically defined as ports and other frequently passed positions. Fig. 11 shows as an example five hub points 1101 , 1102, 1103, 1104, and 1120, each defining a circle around a predetermined position. Fig. 11 further shows parts of two routes 1105 and 1106. Route 1105 is defined as a sequence of waypoints 1107, 1108, 1109, 1110, and 1111 , while route 1106 is defined as a sequence of waypoints 1112, 1113, 1114, 1115, 1116, and 1117. It is understood that the number and location of hub points may vary, and hub points may be redefined. Furthermore, different hub points may have the same or different radii associated with them.

For a given route, the voyage efficiency system determines which hub points the route passes through. To this end, the system determines whether the route includes any waypoints that lie within the circle of one of the hub points defined in the system. In one embodiment, this determination is performed by the central land-based system, e.g. for each route for which the land-based system has received a "start route" message. Alternatively, the local onboard system determines the hub points associated with a route and transmits the hub points to the central system, e.g. as part of a "start route" message. In the example of fig. 11 , the route 1105 includes waypoint 1108 in the circle associated to waypoint 1101 , waypoint 1109 in the circle associated to waypoint 1102, and waypoint 1110 in the circle associated to waypoint 1103. Hence, route 1105 way be viewed as a passage through hub points 1101 , 1102, and 1103. Route 1106, on the other hand, includes waypoint 1114 in the circle associated to waypoint 1102 and waypoint 1115 in the circle associated to waypoint 1103. Hence, route 1106 may be viewed as a passage through hub points 1102 and 1103. It will be appreciated that other conditions for assigning a hub point to a route may be used. For example, in some embodiments, a hub point may be associated with a route if a waypoint lies within the circle associated to the hub point or if a route section connecting two waypoints intersect the circle of the hub point.

The voyage efficiency system further determines whether two vessels are travelling/ have travelled along the same route, if their respective routes pass through the same hub points. If a route has a subset of hub points in common with another route, as in the example of fig. 11 , their routes are determined two be partially overlapping. Preferably, the determination of overlapping / partially overlapping routes is performed by the central land- based system, since this system has information about current voyages of all vessels and has stored historical information of previous routes/voyages.

In the sea current graph 1001 of fig. 10, the hub points through which the current route passes are marked by vertical dotted lines 1003, each line being labelled by the name of the corresponding hub point. Sea current observations from other vessels that have travelled along a route that at least partially overlap with the vessel's current route are displayed as one of the graphs 1001. Vessels sailing between two hub points share the sea-current information even when they are not on same route. When a vessel starts a route, its local on-board system sends a "start route" message to the central system as described above. The signal constitutes the first sea-current observation and is rerouted to all vessels on same route. Whenever a vessel has passed a hub point, it sends a signal to the central system, causing the central system to forward the sea current information of this vessel to other vessels with overlapping routes, where the corresponding sea current information for the previous route section is displayed. For example, in the scenario of fig. 11 , assuming that vessel 1122 has travelled along route 1106 and reported sea current observations to the central land-based system 112 for the route section between hub points 1102 and 1103, and assuming that vessel 1121 has started travelling along route 1105, the reported sea current observations of vessel 1122 between hub points 1102 and 1103 are forwarded to vessel 1121 where they are displayed and used in the calculation of a predicted sea current.

For a route with no intermediate hub points between the start and the end of the route, a predicted sea-current is first available when at least one vessel has completed the same route. If the route includes at least one hub point, a predicted sea-current is calculated when there are sea current observations available between all hub points. However, in this case the sea current observations between different hub points do not have to originate from the same vessel. If information is available only for part of a route, (e.g. the beginning and end of the route), there will be no prediction available before the rest of the route is covered by sea-current information.

In the following the distribution of sea current data between vessels is further described with reference to examples and with reference to figs. 12-14.

Fig. 12 shows a first example illustrating a method of predicting sea currents. Fig. 12 shows a route from a departure port 1201 to an arrival port 1202. The route passes through two hub points labelled "HUB 1" and "HUB 2" respectively. In fig. 12a, a vessel travelling along the route has made three observations between the departure port and hub point "HUB 1", as indicated by arrows 1203, 1204, and 1205, respectively. Each time a sea-current observation is made, the observation is sent via the central land-based system to all vessels on the same route or vessels having some hub points in common, as described above. The initial observation 1203 after departure resets the system and will not be used by other vessels. Hence, the sea current data between the departure port and the first hub point is only shown on other vessels, if there are more than one observation between the departure port and the first hub point. Furthermore, as long as the reporting vessel has not yet passed the first hub point, as indicated by the lack of any observations beyond the first hub point "HUB 1", the observations are forwarded to other vessels but not yet shown.

In Fig. 12b the vessel has made a first observation 1206 after the hub point "HUB 1". Hence, upon receipt of this observation, other vessels having the part of the route from the departure port to "HUB 1" as part of their route will display a graph between departure and first HUB point with the first three observations of this vessel. Sea current prediction will be available for the part from departure to the first HUB point.

In Fig. 12c, the vessel has made four observations 1206, 1207, 1208, and 1209 between the two hub points "HUB 1" and "HUB 2", but no observations after "HUB 2". Hence, other vessels on this route will receive data of all observations but only display the sea current graph between the departure port and the first hub point.

In fig. 12d, the vessel has completed the distance between the two hub points "HUB 1" and "HUB 2" and has made one observation 1210 after "HUB 2". The other vessels receiving the data will now display two parts of a graph, one part from the departure port to "HUB 1" and another part from "HUB 1" to "HUB 2". Accordingly, predictions are now available for these two parts.

In fig. 12e, the vessel has made two observations 1210 and 1211 between "HUB 2" and the arrival port 1202, but has not yet ended its route. The other vessels receiving the observed data do not display a graph for the part between "HUB 2" and the arrival port.

Finally, in fig. 12f, the vessel has ended its route, i.e. has sent an "end of route" message to the central land-based system. Accordingly, the other vessels receiving the sea current observation will now display a graph for the whole route including predicted sea-current for all parts.

Fig. 13 shows a second example illustrating a method of predicting sea currents. Fig. 13 shows a route 1300 from a departure port 1301 to an arrival port 1302. The route passes through four hub points labelled "HUB 1", "HUB 2", "HUB 3", and "HUB 4" respectively. In this example, we assume that another vessel has sailed on a different route that has "HUB 2" and "HUB 3" in common with the present route 1300. In this case, the vessel travelling on the route 1300 displays a graph representing received observations 1303, 1304, 1305 from the other vessel between "HUB 2" and "HUB 3", once the other vessel has passed "HUB 3" and has made an observation 1306 after the HUB point.

It is understood that, in some embodiments, sea current data from other vessels is only received by a vessel, if the other vessel has sailed on the route no longer than a predetermined period prior to the present voyage. For example, in one embodiment, sea current data are included for the previous 30 days.

Fig. 14 illustrates a method of calculation of the required RPM to ensure timely arrival. Fig. 14a shows an example of a route from a departure port 1401 to an arrival port 1402. In particular, reference numerals 1401 and 1402 designate the pilot stations at the departure and arrival ports respectively. Furthermore, the route passes through an area 1406 with shallow water, i.e. an area where the keel has a reduced clearance resulting in the need to reduce the speed of the vessel. Furthermore, at the departure port and at the arrival port, the vessel can only sail with a reduced speed, as indicated by zones 1403 and 1409, respectively. Generally a route is sailed in the following manner:

- Start at berth.

- Sail to pilot station where the pilot is dropped. - Departure from pilot (this is Departure time).

- Navigate away from pilot (route segment 1403.

- Use ramp up to get to desired speed s.

- Sail at desired speed, but ramp down/up for each shallow zone. - Use ramp down to slow down vessel.

- Navigate to pilot.

- Arrival at pilot (this is Arrival time).

- Sail to berth.

- End at berth.

In the present example, the speed calculation between the pilot stations is considered.

Hence, in the route segments 1403, 1406, and 1409, the speed of the vessel is determined by corresponding speed limitations/constraints. Furthermore, the speed calculations take the load program of the vessel into account, i.e. the time it takes for the engine to increase/decrease its performance. Accordingly, when the vessel leaves the zone 1403 with reduced speed, it takes a certain time - and thus distance - for the vessel to reach its desired speed, as indicated by zone 1404. Similarly, around the shallow water zone 1406 there is a ramp down zone 1405 and a ramp up zone 1407 accounting for the time/distance required to reduce/increase the speed. Finally, prior to the reduced speed zone 1409 at the arrival port, there is a ramp down zone 1408. Fig. 14b shows an example of a speed profile for the route of fig. 14a.

The above speed constraints and the characteristics of the load program are stored in the route data and the vessel data, as described above. Furthermore, the voyage data includes a departure time and a scheduled arrival time. Based on these data, and for a given vessel position P, the voyage efficiency system calculates the required speed in the remaining route segments 1410 where there are no speed constraints, i.e. the speed required to ensure an on-time arrival at the scheduled arrival time. In particular, the required speed is calculated as the fix point of the effective speed function f(s) = D (P,s) / T(s), where s is the speed in segments 1410. D(P,s) is the total remaining distance within non-constraint segments 1410 from the current position to the arrival port/end of route, and T(s) is the time available for travelling through the segments 1410, i.e. the total remaining time until the scheduled arrival corrected for the time lost due to the remaining speed constraint zones. In particular,

N_s+-\ /V_s+1 N_s

D(P,s) = RD(P)- ^₁DL(S₁M₁ )- ∑D, - J]DL(M_nS) ι=1 I=Q 1=0

W₅ +1 N_s+1 N s

T(S) = ST -TL_W - J]TL(S₁M₁ )- ∑T, -∑TL(M_ns).

/=1 /=0 /=0

where RD(P) is the remaining distance from position P to the end of route calculated as the distance to the closest forward looking waypoint plus the remaining distance as calculated from the waypoints of the route, where N₃ is the number of speed restricted zones in addition to the initial and final navigation from/to the pilot station in zones 1401 and 1402, i.e. in the example if fig. 14 N_s=1. D, is the distance to be sailed in speed restricted zone ie{0,...,N_s+1} minus the distance already covered, if any. T, is the time lost in speed restricted zone ie{0,...,N_s+1} minus the time already used, if any. M, is the speed in speed restricted zone i. In particular, T₀, D₀, M₀ and TN_S+I, DN_S+I, MNS+I denote the time, distance, and speed in the initial and final zones 1401 and 1402 from/to the pilot station. In some embodiments the distances D₀ and DN_S+I and the corresponding speeds Mo and IVWi may be approximated as zero. DL(x,y) denotes the distance to be sailed during ramp- up/ramp down from speed x to speed y in connection with speed restricted zone i minus the distance already covered, if any, while TL(x,y) denotes the corresponding time lost during ramp-up/ramp-down minus the time already used, if any. ST denotes the remaining sailing time until the scheduled arrival, and TL_W is the time lost during weather conditions.

The distance DL(x,y) lost going from speed x to speed y is determined as a function of the initial speed x, the final speed y, the corresponding required RPM values for these speeds as determined from the stored vessel data described above, and the load program for the vessel as described above. Optionally DL(x,y) may depend on further parameters, e.g. a hull correction factor and/or the like.

Similarly, the time TL(x,y) lost going from speed x to speed y is determined similar to DL(x,y) as a function of the initial speed x, the final speed y, the corresponding required RPM values for these speeds, the load program for the vessel, and, optionally, on further parameters, e.g. a hull correction factor and/or the like.

The fix point s=f(s) of the above equation is determined for a given initial value, e.g. the maximum possible speed.

From the calculated required speed, the vessel efficiency system determines the required revolutions per minute of the main engine, e.g. from the RPM data stored as part of the vessel data. Hence, the voyage efficiency system looks up the draught data in the database and then looks up the required RPM corresponding to the calculated required speed and the draught.

During the tracking of the progress of a voyage, the vessel efficiency system re-calculates the required speed and the resulting required RPM, when one or more parameters that influence the above calculation change, e.g. the current position, the predicted sea current, etc. Alternatively or additionally, the re-calculation is performed in response to a user command, e.g. in response to a user activating an update/refresh button of the user interface.

Fig. 15 shows a user interface of a tide calculation system. The user interface, generally designated 1500, provides active elements that allow an operator to view tidal data stored in a separate database. In particular, the user interface 1500 comprises a dropdown box 1501 or other selection and/or search element for selecting a port for which tidal calculations are desired. As default, tidal calculations are shown for the arrival port and for the scheduled date of arrival. The user interface further displays a graph 1502 illustrating the predicted tide data for the selected position and a selected time interval. To this end, the user interface comprises input fields 1503 and 1504 for entering a UTC date for which calculations are to be displayed and a number of days for which predictions are to be shown, respectively.

The user interface further comprises radio buttons 1505 or other selection elements for selecting a specific position for which tidal calculations are to be shown. Calculations are available for the pilot station, at berth, or at a custom position. When the Berth radio button is selected, the vessel efficiency system determines the actual position of the berth from the waypoint data of the route, in particular, the first waypoint of the route is the departure berth, and the last waypoint is the arrival berth. Similarly, when the pilot radio button is selected, the vessel efficiency system determines the actual position for the tidal calculation from the waypoint data of the route: The first waypoint having a pilot flag represents the position for the departure pilot station and the last waypoint having a pilot flag represents the position of the arrival pilot station. When the custom radio button is selected the system performs a custom calculation for a user-selected position and date.

If no data is available at the requested position, the system displays data from an alternative position in the proximity of the selected position. The tide module automatically determines the nearest reference point for which tide data is available. The user interface displays a note 1506 indicating from what position data is available and the distance and direction to the selected position.

During the voyage planning step and during the tracking of an ongoing voyage, the voyage module takes the tidal calculations for the departure and arrival ports/dates into consideration, and a reminder is raised in case of any conflict with restrictions. If the draught exceeds the maximum allowed draught in either departure or arrival port, the tide calculator raises an alarm which will be shown in the user interfaces for planning and/or tracking a voyage. Has a route/voyage been started, the tide module verifies the maximum draught when new draught values are entered, e.g. in response to a daily draught input, or when the estimated/scheduled arrival date is changed. An alarm is raised if the draught exceeds the maximum allowed draught in the arrival port.

Although some embodiments have been described and shown in detail, the invention is not restricted to them, but may also be embodied in other ways within the scope of the subject matter defined in the following claims.

The invention can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed microprocessor. In the device claims enumerating several means, several of these means can be embodied by one and the same item of hardware, e.g. a suitably programmed microprocessor, one or more digital signal processor, or the like. The mere fact that certain measures are recited in mutually different dependent claims or described in different embodiments does not indicate that a combination of these measures cannot be used to advantage.

It should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims

CLAIMS:

1. A method of tracking a voyage of a maritime vessel, the method comprising performing the following steps under control of a computer program executed on a data processing system:

- storing a route data item in a database of the data processing system, the route data item defining a current route from a start position to a destination position along which current route the vessel is scheduled to travel,

- determining, at a current position along said current route, a required speed for at least a part of a remainder of said voyage from the current position to the arrival position, said speed being suitable for on-time arrival at the destination position.

2. A method according to claim 1 , further comprising

3. A method according to claim 2, further comprising selecting the hub points of the sequence of hub points as a subset of a plurality of predetermined hub points, such that each hub point of the subset is located in predetermined proximity to the current route.

4. A method according to claim 2 or 3, further comprising determining an average predicted sea current for at least a part of the current route based on the received sea current data.

5. A method according to claim 4, wherein the determination of the average predicted sea current is based on sea current data received from the at least one other vessel only if said at least one other vessel has completed at least one segment of the previous route between two hub points of the sequence of hub points.

6. A method according to any one of claims 2 through 5, further comprising transmitting sea current data observed by the vessel at a position along its current route to a land-based data processing system; and wherein receiving sea current data comprises receiving sea current data from the land-based data processing system.

7. A method according to any one of claims 1 through 6, wherein determining a required speed comprises

- determining a set of speed constraints along the remainder of the route;

- determining a desired arrival time a the destination position;

8. A method according to claim 7, wherein the required speed is determined as a fix point of a ratio of an effective distance function and an effective time function; wherein the effective distance function determines a distance of the remainder of the current route corrected for a distance travelled at reduced speed due to speed constraints; and wherein the effective time function determines an available remaining time until the desired arrival time corrected for a time during which the vessel travels at reduced speed due to said speed constraints.

9. A method according to claim 8, wherein the distance travelled at reduced speed due to speed constraints and the time during which the vessel travels at reduced speed due to said speed constraints include corresponding distances and times during ramp-up and ramp-down of the speed.

10. A method according to any one of claims 7 through 9, wherein the speed constraints are stored as a part of the route data item.

11. A method according to any one of claims 1 through 10, further comprising determining an engine performance parameter required for achieving the determined required speed.

12. A method according to claim 11 , wherein the engine performance parameter is the number of revolutions per minute of the main propeller, and determining the number of revolutions per minute comprising determining the number of revolutions per minute from the required speed and the current draught of the vessel.

13. A method according to claim 12, comprising determining the required number of revolutions per minute from a predetermined look-up table.

14. A method according to any one of claims 1 through 13, wherein the route information comprises a sequence of waypoint data items, each waypoint data item representing a location on said current route.

15. A method according to any one of claims 1 through 14, further comprising - storing vessel data indicative of at least draught data of the vessel; - comparing the draught data with tide information about the destination position; and generating a warning when the draught data exceeds a maximum allowable draught at the destination position.

16. A method according to claim 15, further comprising, in response to said warning, automatically invoking a user interface for displaying tide information about the destination position at the arrival time.

17. A method according to any one of claims 1 through 16, further comprising tracking a progress of the voyage; and automatically sending a message to a land-based data processing system when a predetermined progress has been reached, said message requesting updated port information about the destination position.

18. A method according to any one of claims 1 through 17, further comprising tracking a progress of the voyage; and automatically generating a reminder when a predetermined progress has been reached, said reminder reminding a user to perform a predetermined action.

19. A computer program product comprising program code means adapted to cause a data processing system to perform the steps of the method according to any one of claims 1 through 18, when said program code means are executed on the data processing system.

20. A data processing system configured to perform the steps of the method according to any one of claims 1 through 18.

21. A data processing system according to claim 20, comprising a local data processing system located on board the vessel, and a land-based data processing system, the local data processing system and the land-base processing system being configured to communicate via a communications link.

22. A data processing system according to claim 21 , wherein the local data processing system on board the vessel comprises a local database configured to store

- a plurality of route data items indicative of respective routes,

- one or more voyage data items indicative of voyage parameters defining a voyage along one of the stored routes, and - vessel data indicative of vessel specific parameters.

23. A data processing system according to claim 22, wherein the local database is further configured to store at least one of sea current data observed by other vessels and received from the land-based data processing system, port data indicative of information about a plurality of ports that may be departure or arrival ports of routes, and tide data associated with a number of ports.

24. A data processing system according to claim 22 or 23, wherein the local data processing system is configured to provide user interfaces allowing a user to enter/view/modify at least one of the route data items, the voyage data item, and the vessel data.

25. A data processing system according to claim 24, wherein the local data processing system is further configured to provide at least one of a user interface for viewing sea current data observed by other vessels, a user interface for viewing tidal information at a selected position associated to a selected port, and a user interface for tracking the progress of an ongoing voyage.

26. A data processing system according to any one of claims 21 through 25, wherein the land-based data processing system is configured to communicate with a plurality of local data processing systems on board respective vessels.

27. A data processing system according to any one of claims 21 through 26, wherein the land-based data processing system comprises a central database configured to store route data indicative of a plurality of routes of respective vessels, and sea current data received from a plurality of vessels along respective routes.

28. A data processing system according to claim 27, wherein the land-based processing system is further adapted to distribute sea current data related to a predetermined first route to all vessels currently sailing on the first route or a second route that is at least partially overlapping with said first route.

29. A data processing system according to claim 28, wherein the central database is configured to store a plurality of hub points, each hub point representing a predetermined area around a corresponding position, and wherein the data processing system is adapted to determine whether a first and a second route are at least partially overlapping by determining whether the first and second route pass through the area of at least one common hub point.

30. A data processing system according to any one of claims 27 through 29, wherein the central database is further adapted to store at least one of port information and tidal information for a plurality of ports, and the land-based data processing system is adapted to send such information to one or more vessels.

31. A method of determining a predicted sea current along a first route along which first route a first maritime vessel is scheduled to travel; the method comprising

- determining a sequence of hub points, each hub point representing a corresponding location within a predetermined proximity to said first route;

- receiving sea current data from at least a second vessel, said sea current data having been measured by said second vessel during a previous voyage along a second route, wherein at least two of said hub points lie in a predetermined proximity of said first and said second;

- determining a predicted sea current based on the received sea current data.

32. A method of controlling the speed of a maritime vessel, the vessel travelling along a predetermined route to a target location, the method comprising:

- determining a remainder of said route from a current position to the target location; - determining a set of speed constraints along the remainder of the route;

- determining a desired arrival time a the target location;

- determining a desired current speed from the remainder of the route, the desired arrival time and the set of speed constraints.