EP3583587A1

EP3583587A1 - System and method for managing navigation plan of a marine vessel

Info

Publication number: EP3583587A1
Application number: EP18708156.7A
Authority: EP
Inventors: Esa JOKIOINEN; Mika Petri HYVÖNEN; Antti KOLU; Jukka Tapio Ranta
Original assignee: Kongsberg Maritime Finland Oy
Current assignee: Kongsberg Maritime Finland Oy
Priority date: 2017-02-16
Filing date: 2018-02-16
Publication date: 2019-12-25
Also published as: WO2018150101A1; FI20175138L

Abstract

A system and method for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels is provided. The system and method comprises generating identification data, by the identification unit, indicative of at least manoeuvrability of the marine vessel. The system and method also comprises calculating, by the computing unit, priority factors of all the marine vessels involved in the potential collision course based on corresponding identification data thereof, then comparing the calculated priority factors of all the marine vessels, and then determining a required change in the navigation plan of the marine vessel based on the comparison, such that the marine vessel(s) with a lower calculated priority factor out of all the marine vessels alter the navigation plan(s) thereof to give way to the marine vessel(s) with a comparatively higher calculated priority factor.

Description

SYSTEM AND METHOD FOR MANAGING NAVIGATION PLAN OF A

MARINE VESSEL

FIELD OF THE INVENTION The present disclosure relates to a system and a method for managing navigation plan of a marine vessel, and more particularly for managing navigation plan of the marine vessel to avoid a potential collision course with one or more other marine vessels.

BACKGROUND

In maritime navigation, a marine vessel's operation involves following standardized navigation rules to avoid collisions or counter any other navigation conditions. The International Regulations for Preventing Collisions at Sea, known as COLREGS, defines the standardized navigation rules that are followed by all marine vessels, from small boats to commercial ships when operating under conventional operating conditions. In particular, COLREGS defines procedures to determine the action that needs to be taken when a marine vessel encounter another vessel in its navigation plan in order to avoid collision, among other considerations.

However, sometimes these standardized navigation rules may not scale properly, for example in a condition involving multiple vessels on a potential collision course. At times, COLREGS be ambiguous as multiple rules may be applicable simultaneously, with some of those recommending entirely different course of action. In such situations, usually it is expected that the vessel's operator uses his/her judgment to change the navigation course if required, in order to avoid the collision or any undesired accident. As may be understood, this may be a challenge with unmanned marine vessels that sail at sea without any human operator on-board the vessel.

OBJECTIVE OF THE DISCLOSURE

It is an objective of the present disclosure to provide a system and method to manage navigation plans of marine vessels on a potential collision course.

It is also an objective of the present disclosure that the present system and method supplement COLREGS, in ambiguous situations, to avoid collisions of the marine vessels.

It is also an objective of the present disclosure that the present system and method is effective and flexible to manage potential collision scenarios.

It is further an objective of the present disclosure that the proposed system and method provides autonomous management of the navigation plans of the marine vessels.

SUMMARY

According to a first aspect, a system for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels is provided. The system comprises an identification unit configured to generate identification data indicative of at least manoeuvrability of the marine vessel. The system further comprises a computing unit. The computing unit is configured to calculate priority factors of all the marine vessels involved in the potential collision course based on corresponding identification data thereof. The computing unit is also configured to compare the calculated priority factors of all the marine vessels. The computing unit is further configured to determine a required change in the navigation plan of the marine vessel based on the comparison, such that the marine vessel (s) with a lower calculated priority factor out of all the marine vessels alter the navigation plan(s) thereof to give way to the marine vessel (s) with a comparatively higher calculated priority factor.

In one embodiment of the system, the system comprises a transmitter configured to broadcast the identification data of the marine vessel to each of the one or more other marine vessels.

In one embodiment of the system, the system comprises a transceiver configured to receive the identification data from each of the one or more other marine vessels, the identification data comprises information about at least manoeuvrability of the corresponding one or more other marine vessels. In one embodiment of the system, the identification data indicative of the manoeuvrability of the marine vessel is based at least in part on one or more of: - a length of the corresponding marine vessel

(L) ,

- a width of the corresponding marine vessel

(W) , and

- a draught of the corresponding marine vessel (D) .

In one embodiment of the system, the identification data further comprises information about a manoeuvrability modifier (M) which is dependent on one or more of a status and a type of the corresponding marine vessel.

In one embodiment of the system, the identification data further comprises information about urgency of the marine vessel (U) , which at least in part is proportional to a need to maintain a timetable of the corresponding marine vessel.

In one embodiment of the system, the identification data further comprises information about a space limitation to manoeuvrability of the marine vessel (S) , which at least in part is due to lack of space for movement of the corresponding marine vessel. In one embodiment of the system, the identification data further comprises information about a risk level to cargo in the marine vessel (R) , which at least in part is proportional to a risk posed by leakage of cargo loaded in the corresponding marine vessel.

In one embodiment of the system, the identification data further comprises information about required change in speed of the corresponding marine vessel (V) , to avoid the potential collision course.

In one embodiment of the system, the identification data further comprises information about required deviation in the navigation plan of the corresponding marine vessel (H) , to avoid the potential collision course .

In one embodiment of the system, the computing calculates the priority factor (PF) as:

PF = (L + W) * D * M * U * S * (1 + R) * (H + H_MIN) (V + V_MIN) ; where H_Mi_N and V_Mi_N are constants. In one embodiment of the system, the computing unit is configured to implement a priority factor margin (PFM) which is multiplied by the calculated priority factor (PF) , for determining the required change in the navigation plan of the marine vessel.

In one embodiment of the system, the system configures a steering unit of the marine vessel to make the marine vessel execute a manoeuvre to implement the required change in the navigation plan of the marine vessel.

In one embodiment of the system, the transmitter is further configured to broadcast a confirmation to implement the corresponding determined required change in the navigation plan of the marine vessel. In one embodiment of the system, the transceiver is configured to check for corresponding confirmation ( s ) , from the one or more other marine vessels, to implement the corresponding determined required changes in the navigation plan(s) of the one or more other marine vessels.

In one embodiment of the system, the computing unit is configured to override the determined required change in the navigation plan of the marine vessel, in case the transceiver fails to receive corresponding confirmation ( s ) from the one or more other marine vessels . In one embodiment of the system, the system comprises a sensor unit configured to monitor the one or more other marine vessels to check if the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof. By a sensor unit is herein meant a unit comprising one or more sensors, lidars (light detection and ranging devices) , visual spectrum or non-visual spectrum cameras, microphones, hydrophones, and any other means of making observations of the other vessels.

In one embodiment of the system, the computing unit is configured to override the determined required change in the navigation plan of the marine vessel, in case the sensor unit monitors that the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof .

In one embodiment of the system, the computing unit is configured to override the determined required change in the navigation plan of the marine vessel in case a distance between the marine vessel and the one or more other marine vessels is less than or equal to a predefined minimum safe distance ( D_MIN ) ·

In one embodiment of the system, the computing unit is configured to:

determine, via the comparison, if a difference between the calculated priority factors of the marine vessel and any of the one or more other marine vessels is less than a threshold value, and - determine required change in the navigation plans of the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value.

In one embodiment of the system, the steering unit is configured to implement the required change in the navigation plans of the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value, with a certain degree of caution.

In one embodiment of the system, the identification unit is implemented as an Automatic Identification System (AIS) of the marine vessel. The reception of AIS data by the identification unit supports the sensor unit in determining the position and speed of the vessel and also its future intentions. In particular, the rate of turn parameter in the AIS data is a good indicator that another vessel has started changing its course, i.e. is taking an action to avoid a collision.

In one embodiment of the system, the system is implemented in an unmanned marine vessel.

In one embodiment of the system, the system is implemented in a remote operation centre of the marine vessel . Further, the system may be implemented in a manned marine vessel.

According to a second aspect, a method for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels is provided. The method comprises generating identification data indicative of at least manoeuvrability of the marine vessel. The method also comprises calculating priority factors of all the marine vessels involved in the potential collision course based on corresponding identification data thereof. The method further comprises comparing the calculated priority factors of all the marine vessels. The method further comprises determining a required change in the navigation plan of the marine vessel based on the comparison, such that the marine vessel (s) with a lower calculated priority factor out of all the marine vessels alter the navigation plan(s) thereof to give way to the marine vessel (s) with a comparatively higher calculated priority factor. In one embodiment of the method, the method comprises broadcasting the identification data of the marine vessel to each of the one or more other marine vessels . In one embodiment of the method, the method comprises receiving the identification data from each of the one or more other marine vessels, the identification data comprises information about at least manoeuvrability of the corresponding one or more other marine vessels.

In one embodiment of the method, the identification data indicative of the manoeuvrability of the marine vessel is based at least in part on one or more of:

- a length of the corresponding marine vessel (L),

- a width of the corresponding marine vessel

(W) , and

a draught of the corresponding marine vessel (D) .

In one embodiment of the method, the identification data further comprises information about:

a manoeuvrability modifier (M) which is dependent on one or more of a status and a type of the corresponding marine vessel, urgency of the marine vessel (U) , which at least in part is proportional to a need to maintain a timetable of the corresponding marine vessel,

- a space limitation to manoeuvrability of the marine vessel (S) , which at least in part is due to lack of space for movement of the corresponding marine vessel ,

- risk level to cargo in the marine vessel (R) , which at least in part is proportional to a risk posed by leakage of cargo loaded in the corresponding marine vessel ,

- required change in speed of the corresponding marine vessel (V) , to avoid the potential collision course, and

- required deviation in the navigation plan of the corresponding marine vessel (H) , to avoid the potential collision course.

In one embodiment of the method, the priority factor (PF) is calculated as:

PF = (L + W) * D * M * U * S * (1 + R) * (H + H_MIN) * (V + V_MIN) ; where H_Mi_N and V_Mi_N are constants.

In one embodiment of the method, the method implements a priority factor margin (PFM) which is multiplied by the calculated priority factor (PF) , for determining the required change in the navigation plan of the marine vessel. In one embodiment of the method, the method further comprises the marine vessel making a manoeuvre to implement the required change in the navigation plan of the marine vessel.

In one embodiment of the method, the method comprises broadcasting, by the marine vessel, a confirmation to implement the corresponding determined required change in the navigation plan thereof.

In one embodiment of the method, the method comprises checking for corresponding confirmation ( s ) , from the one or more other marine vessels, to implement the corresponding determined required changes in the navigation plan(s) thereof. In one embodiment of the method, the method comprises overriding the determined required change in the navigation plan of the marine vessel, in case of not receiving corresponding confirmation ( s ) from the one or more other marine vessels.

In one embodiment of the method, the method comprises monitoring the one or more other marine vessels to check if the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof.

In one embodiment of the method, the method comprises overriding the determined required change in the navigation plan of the marine vessel, in case the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof. In one embodiment of the method, overriding the determined required change in the navigation plan of the marine vessel is implemented, in case a distance between the marine vessel and the one or more other marine vessels is less than or equal to a predefined minimum safe distance ( D_MIN ) ·

In one embodiment of the method, the method comprises:

- determining, via the comparison, if a difference between the calculated priority factors of the marine vessel and any of the one or more other marine vessels is less than a threshold value, and

determining a required change in the navigation plans of both the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value.

In one embodiment of the method, the method comprises implementing the required change in the navigation plans of the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value. In one embodiment of the method, the method is implemented in an unmanned marine vessel.

In one embodiment of the method, the method is implemented in a remote operation centre of the marine vessel . Further, the method may be implemented in a manned marine vessel.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the disclosure and constitute a part of this specification, illustrate embodiments of a system and method for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels, with the description help to explain the principles thereof. In the drawings:

FIG. 1 is a diagrammatic plan view of an environment involving two or more marine vessels, on a potential collision course, with a system for managing navigation plan of the two or more marine vessels to avoid a collision, according to one embodiment of the disclosure,

FIG. 2 is a flowchart depicting the steps involved in a method for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels, and

FIG. 3 illustrates a flowchart depicting the steps involved in a method to determine when to implement procedures for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels. DETAILED DESCRIPTION

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. It will be apparent, however, to one skilled in the art that the present disclosure can be practiced without these specific details. In other instances, apparatuses and methods are shown in block diagram form only in order to avoid obscuring the present disclosure.

Reference in this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. The appearance of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not for other embodiments.

Moreover, although the following description contains many specifics for the purposes of illustration, anyone skilled in the art will appreciate that many variations and/or alterations to said details are within the scope of the present disclosure. Similarly, although many of the features of the present disclosure are described in terms of each other, or in conjunction with each other, one skilled in the art will appreciate that many of these features can be provided independently of other features. Accordingly, this description of the present disclosure is set forth without any loss of generality to, and without imposing limitations upon, the present disclosure.

FIG. 1 illustrates an exemplary environment 1 in which a marine vessel 2 along with one or more other marine vessels (e.g., two other marine vessels, a first other marine vessel 3 and a second other marine vessel 4 shown therein) may be navigating along their corresponding navigation plans. It may be contemplated that the shape, size, and position of various components in FIG. 1 are exemplary only and shall not be considered limiting to the disclosure in any manner. The marine vessels 2,3,4 may be civil or military marine vessels including, for example, sailing boats, fishing boats, cruise ships, cargo ships, patrol ships, oil tankers, submarines and the like. The marine vessels 2,3,4, in the environment 1, may be performing tasks such as, for example, reaching certain waypoints, patrolling a designated sector, and on a military mission.

In one example, all the marine vessels 2,3,4 may be similar type of marine vessels; for example, all the involved marine vessels 2,3,4 may be cruise ships. In other examples, the involved marine vessels 2,3,4 may differ in type from each other without any limitations. A status of any of the involved marine vessels 2,3,4 may be defined by the type of task it may be performing. In one example, the marine vessels 2,3,4, involved in the environment 1, may have similar or different statuses, without any limitations.

In the illustrated example, the marine vessel 2 and the other marine vessels 3,4 may be leading towards each other on a potential collision course. That is, if the marine vessels 2,3,4 may continue on their current navigation plans, there may be a possible risk of collision between two or more of these marine vessels 2,3,4. The situation, as presented in the environment 1, may be such that the marine vessels 2,3,4 even if properly following the rules and regulations as outlined in the standards like COLREGS, may still have a risk that two or more of these marine vessels 2,3,4 end up colliding with each other. It may be understood that although three marine vessels 2,3,4 have been shown in the illustrated example, in other cases, the total number of marine vessels involved in the potential collision course may be less, for example two, or more, for example four or five; without any limitations. In an embodiment of the present disclosure, the marine vessel 2, on the potential collision course with the other marine vessels 3,4, is equipped with a system 5 for managing navigation plan thereof. In one example, all the marine vessels, including the marine vessel 2 and the other marine vessels 3,4, are equipped with the present system 5 for managing corresponding navigation plans thereof. Further embodiments of the present disclosure have been described in terms of the implementation of the system 5 in the marine vessel 2 ; however, it may be understood that the other marine vessels 3,4 may have the same implementations of the system 5 for managing the corresponding navigation plans thereof.

The system 5 may include multiple components working in co-ordination to determine a required change in the navigation plan of the marine vessel 2 to avoid the collision with one or more of the other marine vessels 3,4. In other words, the system 5 may determine an alternative navigation plan for the marine vessel 2 to avoid the collision. In general, the system 5 is configured to control the steering and speed of marine vessel 2 in order to implement the required change in the navigation plan of the marine vessel, as discussed later in detail. In one implementation, the system 5 is configured to provide autonomous navigation management of the marine vessels 2,3,4.

In an embodiment, the system 5 comprises an identification unit 6 configured to generate identification data related to the corresponding marine vessel of the marine vessels 2,3,4. In one example, the identification unit 6 may implement standards like automatic identification system (AIS) which is a well-known automatic tracking system used for collision avoidance. The identification data may include information, such as unique identification of the marine vessel, position, course, and speed, among others, as discussed in the subsequent paragraphs of the description. The reception of AIS data by the identification unit 6 supports the sensor unit 11 in determining the position and speed of the vessel and also its future intentions. In particular, the rate of turn parameter in the AIS data is a good indicator that another vessel has started changing its course, i.e. is taking an action to avoid a collision.

In one embodiment, the identification data comprises information indicative of at least manoeuvrability of the marine vessel 2. It may be understood that the manoeuvrability of the marine vessel 2 is based on the dimensions thereof, i.e. a length of the corresponding marine vessel (represented by ^XL' ) and a width of the corresponding marine vessel (represented by ^XW ) . It may be understood that the manoeuvrability of the marine vessel is, generally, inversely proportional to the dimensions thereof, as a smaller ship may usually be more agile to make manoeuvres than a larger ship. Further, in one example, the manoeuvrability of the marine vessel 2 is based on a draught of the corresponding marine vessel (represented by ^XD' ) . As may be understood that the draught of the marine vessel is indicative of the loading (i.e., weight of cargo) of the marine vessel; therefore, the manoeuvrability of the marine vessel is inversely proportional to current value of the draught thereof, as an empty ship is more agile than a ship full of cargo .

In one embodiment, the identification data also comprises information about a manoeuvrability modifier (represented by ^λΜ' ) which is dependent on one or more of a status and a type of the corresponding marine vessel 2. The identification data further comprises information about urgency of the marine vessel (represented by ^XU' ) , which at least in part is proportional to a need to maintain a timetable of the corresponding marine vessel 2. The identification data further comprises information about a space limitation to manoeuvrability of the marine vessel (represented by ^XS' ) , which at least in part is due to lack of space for movement of the corresponding marine vessel 2. The identification data further comprises information about a risk level to cargo in the marine vessel (represented by ^XR' ) , which at least in part is proportional to a risk associated with the leakage of the cargo loaded in the corresponding marine vessel 2.

Further, in one embodiment, the identification data comprises information about a required change in speed of the corresponding marine vessel 2 (represented by ^XV ) , so that the required change in the navigation plan may be implemented to avoid the potential collision course. In one example, the required change in speed (V) is determined in knots. Similarly, the identification data further comprises information about required deviation in the navigation plan of the corresponding marine vessel 2 (represented by ^λΗ' ) , so that the required change in the navigation plan may be implemented to avoid the potential collision course. In one example, the required deviation (H) is determined in degrees. The techniques for determination of the required change in speed (V) and the required deviation (H) are known in the art and thus have not been described herein for the brevity of the disclosure. In some cases, the values of parameters, like the required change in speed of the marine vessel 2 (V) and the required deviation in the navigation plan of the marine vessel 2 (H) may be small. In such cases, constants, namely V_Mi_N and H_Mi_N are added to the corresponding values of the required change in speed (V) and the required deviation (H) , respectively, so that all the marine vessels needing just a small change each may be treated equally. For the examples of the present disclosure, the value of V_MIN = 2 and the value of H_Mi_N = 10.

In one embodiment, the system 5 comprises a transmitter 7 configured to broadcast the identification data of the marine vessel 2 to each of the one or more other marine vessels. Further, the system 5 comprises a transceiver 8 configured to receive the identification data from each of the one or more other marine vessels 3,4. In one example, the transmitter 7 and the transceiver 8 may utilize Very High Frequency (VHF) based communication channels for exchange of information with corresponding devices of the other marine vessels 3,4. Construction and functionality of such devices are well known in the art and thus have not been described herein. It may be understood that the identification data received, by the marine vessel 2, from the one or more other marine vessels 3,4 may comprise information about same parameters for the marine vessels 3,4 as transmitted by the marine vessel 2 itself.

These parameters from the identification data may be utilized by the system 5, in the marine vessel 2, to calculate a priority factor (PF) of each of the marine vessel 2,3,4 involved in the potential collision course. Particularly, in an embodiment, the system 5 includes a computing unit 9 configured to calculate priority factors of all the marine vessels 2,3,4 involved in the potential collision course based on corresponding identification data thereof.

For this purpose, the computing unit 9 may include a memory and a processor. The memory is capable of storing machine executable instructions, and the processor is capable of executing the stored machine executable instructions. The memory may be embodied as one or more volatile memory devices, one or more non- volatile memory devices, and/or a combination of one or more volatile memory devices and non-volatile memory devices. Further, the processor may be embodied in a number of different ways, e.g., the processor may be embodied as one or more of various processing devices, such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP) , processing circuitry with or without an accompanying DSP, or various other processing devices including integrated circuits such as, for example, an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) , a microcontroller unit (MCU) , a hardware accelerator, a special-purpose computer chip, or the like.

According to an embodiment of the present disclosure, the computing unit 9 calculates the priority factor (PF) of a marine vessel, such as the marine vessel 2, as :

PF = (L + W) * D * M * U * S * (1 + R) * (H + H_MIN) * (V + V_MIN) where H_Mi_N and V_Mi_N are constants as

discussed later in the description

It may be understood that the above formula may be stored as an algorithm in the memory of the computing unit 9 and the algorithm is then executed by the processor of the computing unit 9, as and when required .

The computing unit 9, of the system 5, is further configured to compare the calculated priority factors (PF) of all the marine vessels 2,3,4. In one example, the computing unit 9 is configured to sort all the marine vessels, such as the marine vessels 2,3,4 involved in the potential collision course of the environment 1, based on the comparison of the corresponding calculated priority factors (PF) . In some examples, the computing unit 9 may compare the priority factors pairwise between the own marine vessel, such as the marine vessel 2, and each of the other marine vessels 3,4. Such techniques for comparison and sorting are well known in the art and are pre-programmed in the computing unit 9. The computing unit 9, of the system 5, is further configured to determine a required change in the navigation plan of the marine vessel 2 based on the comparison, such that the marine vessel (s) , of any of the marine vessels 2,3,4, with a lower calculated priority factor out of all the marine vessels 2,3,4 alter its navigation plan(s) to give way to the marine vessel (s) , of any of the marine vessels 2,3,4, with a comparatively higher calculated priority factor. In other words, the determined required change in the navigation plan of the marine vessel 2 is such that the marine vessel (s) , of any of the marine vessels 2,3,4, with the comparatively higher calculated priority factor proceed with none or minimal alteration to its navigation plan, compared to the marine vessel (s) , of any of the marine vessels 2,3,4, with the comparatively lower calculated priority factor . Taking an example of the environment 1, with the marine vessel 2 having the highest priority factor, the marine vessel 3 having the priority factor lower than the priority factor of the marine vessel 2 but higher than the priority factor of the marine vessel 4, and the marine vessel 4 having the lowest priority factor. In such example, the determined required change in navigation plans may be such that the marine vessel 2 may hold its course, the marine vessel 3 may give way to the marine vessel 2, and the marine vessel 4 may give way to both the marine vessel 2 and the marine vessel 3. In some examples, the change in the navigation plan of a marine vessel requires that such marine vessel executes evasive manoeuvres to give way.

In some examples, the computing unit 9 is configured to implement a priority factor margin (PFM) which is multiplied by the calculated priority factor (PF) , for determining the required change in the navigation plan of the marine vessel 2. The priority factor margin (PFM) provides a safety margin and is usually multiplied with the lower of the one or more calculated priority factors (PF) in the comparison. For example, if the PF of marine vessel 2 is greater than the value of PF * PFM of the other marine vessel 3, it is the other marine vessel 3 which may execute evasive manoeuvres. Otherwise, if the PF of the other marine vessel, say the marine vessel 4, is greater than the value of PF * PFM of the marine vessel 2, it is the marine vessel 2 which may execute evasive manoeuvres. For the examples of the present disclosure, the value of the priority factor margin (PFM) is 1.5.

In one embodiment, the system 5 configures a steering unit 10 of the marine vessel 10 to make the marine vessel 2 execute a manoeuvre to implement the determined required change in the navigation plan thereof. In an example, the steering unit 10 is configured to implement required change in speed of the corresponding marine vessel (V) as well as the required deviation in the navigation plan of the corresponding marine vessel (H) , to avoid the potential collision course. As discussed, the proper values of the various parameters for each marine vessel 2,3,4 are available or derived from their corresponding identification data. Some parameters may also be determined by other observations, including shape of the marine vessel, recognition of lights, etc. In some cases, the system 5 may not be able to generate or receive the proper values of one or more of these parameters for the marine vessel 2 and/or the other marine vessels 3,4. This may be caused by any of the reasons, such as device malfunction, transmission failure, data corruption, or the like. In such circumstances, the known default values of such parameters may be employed as provided in Table 1 below:

Table 1

Parameter description Default value

Length of the marine vessel (L) 200 (metres)

1 Width of the marine vessel (W) j 20 (metres)

\ Draught of the marine vessel (D) 5 (metres)

Urgency of the marine vessel (U) \ 1

! Risk level of the cargo (R) 0

Manoeuvrability modifier (M) \ 1

! Required deviation (H) i 30 (degrees)

Required change of speed (V) 10 (knots)

Space limitation to manoeuvrability (S) \ 1

! Type of the marine vessel i Other vessel ! ype of cargo : o cargo

Status of the marine vessel Normal

In some cases, the values of the various parameters particularly ^λΜ' , ^XU' , ^XS' , ^XR' , ^XV , ^λΗ' , as discussed above, may be modified based on the type and status of the marine vessel 2, and/or the type of the cargo loaded in the marine vessel 2. In particular, various modifier constants may be used which is usually multiplied with the corresponding parameter value. That is, the modifications to the parameters are usually achieved by multiplications with a modifier constant. The tables below provide the information about the modifier constants utilized in various cases, and further provide the resulting values or the changes to the values of the said parameters. It may be understood that, in some cases, more than one modifier constant may be applied to a single parameter. Further, it may be understood that the multiplications with the modifier constant is applied after absolute values are given to the parameters .

Table 2 below lists the various modifier constants based on the type of the marine vessel and the resulting change in values of the parameters.

Table 2

Type of marine vessel Resulting parameter

Pilot vessel \ None ! Wing-in-Ground (WIG) M = M * MWIG

High Speed Craft (HSC) M = M * MHSC

Passenger ship (PAS) U = U * UPAS

Cargo ship (CAR) U = U * UCAR

j Tanker (TAN) R = R * RTAN

! Other ship None

Table 3 below lists the various modifier constants based on the status of the marine vessel and the resulting change in values of the parameters.

Table 3

Status of marine vessel Resulting parameter

Fishing (FIS) M = M * MFIS

Towing (TOW) M = M * MTOW

Towing with length of the tow

exceeds 200 m or breadth exceeds 25 M = M * MLTO m) (LTO)

! Engaged in dredging or underwater

M = MDUW

\ operations (DUW)

Engaged in diving operations (DIV) M = MDIV

! Engaged in military operations

M = M * MMIL

! (MIL)

Sailing (SAI) M = M * MSAI

! Pleasure craft (LEA) U = U * ULEA

Table 4 below lists the various modifier constants based on the type of the cargo loaded in the marine vessel and the resulting change in values of the parameters .

Table 4

Type of cargo Resulting parameter

DG, HS, or MP, IMO hazard or

R = RX

pollutant category (X)

j DG, HS, or MP, IMO hazard or

R = RY

! pollutant category (Y)

DG, HS, or MP, IMO hazard or

R = RZ

pollutant category (Z)

DG, HS, or MP, IMO hazard or

R = ROS

pollutant category (OS)

! o hazardous cargo R = 0 j

Table 5 below lists the values for the various modifier constants (as discussed above) . It may be understood that the given values for the various modifier constants are exemplary only. The exact values for the modifier constants may be determined by conducting simulations and field tests for various possible scenarios. Table 5

Modifier Constant Example value

MDIV loo 1

MFIS 0.3

MHSC 0.5

MLTO 0.3

MMIL 2

MSAI 2 1

MTOW 0.5 MDUW 50

MWIG 0.5

ROS 0.1

RTAN 2

RX 4

RY 2

RZ 1

UCAR 1.5

ULEA 0.3

UPAS 3

Further, the parameter, the space limitation to manoeuvrability of the marine vessel (S) is determined as follows. For the marine vessel 2, the corresponding system 5 assumes the value of the parameter, S = 1. For all other marine vessels 3,4, if there are any static obstacles (including too shallow water) that prevent such marine vessel to make a change in navigation plan, the system 5 of the marine vessel 2 assumes S = SLIM. It may be understood that the reason for the system 5 of the marine vessel 2 to assume S = 1 for the corresponding marine vessel 2 is that in case of lack of space, every marine vessel should still take all possible measures to avoid the collision. For the examples of the present disclosure, the value of SLIM = 10.

It may be understood that the lack of space would often apply to more than one vessel and it is safer to assume that all the marine vessels 2,3,4 take possible measures to avoid the collision, within the available space. If the lack of space happens to hinder the changes in navigation plan of just one marine vessel, the actions of the other vessel will soon change the situation in such a way that the marine vessel near the obstacle may resume its original route after a while. In congested straits, for instance, the marine vessels 2,3,4 may proceed with caution and probably reduce speed in addition to employing other available collision avoidance manoeuvres.

In one embodiment of the system 5, the transmitter 7 is further configured to broadcast a confirmation to implement the determined required change in the navigation plan for the corresponding marine vessel 2. Further, the transceiver 8 is configured to check for confirmation ( s ) , from the one or more other marine vessels 3,4, to confirm if those marine vessels have implemented the corresponding determined required changes in the navigation plan(s) thereof. In one example, the system 5 comprises a sensor unit 11 configured to monitor the one or more other marine vessels 3,4 to check if the one or more other marine vessels 3,4 fail to implement the corresponding determined required change in the navigation plan(s) thereof.

Further, in one embodiment, the computing unit 9 is configured to override the determined required change in the navigation plan of the marine vessel 2, in case the transceiver 8 fails to receive corresponding confirmation ( s ) from the one or more other marine vessels 3,4 and/or the sensor unit 11 monitors that the one or more other marine vessels 3,4 failed to implement the corresponding determined required change in the navigation plan(s) thereof. The overriding of the determined required change in the navigation plan of the marine vessel 2 may involve determining a new change in the navigation plan as per the current situation that may avoid the collision with the other marine vessels 3,4. In one embodiment, the computing unit 9 is configured to override the determined required change in the navigation plan of the marine vessel 2 only in case a distance between the marine vessel 2 and the one or more other marine vessels 3,4 is less than or equal to a predefined minimum safe distance (D_MIN) · That is, the system 5 delays the overriding step as much as possible to give chance to the other marine vessels 3,4 to implement the required change. The system 5 finally implements the overriding step when the marine vessels are within the threshold of the minimum safe distance (D_MIN) · For the examples of the present disclosure, the value of D_MIN is 1.5 nautical miles. It may be contemplated by a person skilled in the art that such additional procedures of confirmations and monitoring are employed as a precaution to ascertain that the other marine vessels are taking the determined steps to avoid the collision.

Further, in one embodiment, the computing unit 9 is configured to determine, via the comparison, if a difference between the calculated priority factors of the marine vessel 2 and any of the one or more other marine vessels 3,4 is less than a threshold value. In such case, the computing unit 9 is configured to determine required change in the navigation plans of the marine vessel 2 as well as the other marine vessel (s) 3,4 with which the difference in the priority factor is less than the threshold value. Further, the steering unit 10 is configured to implement the required change in the navigation plans of the marine vessel 2 as well as the other marine vessel (s) 3,4 with which the difference in the priority factor is less than the threshold value, with a certain degree of caution. In other words, if the priority factors for two marine vessels, in the environment 1, differs by less than the given threshold value, then both marine vessels implement the change in the navigation plan to give way to each other as a precautionary measure. Further, such marine vessels may implement the collision avoidance manoeuvres with possibly reduce speed so as to proceed with extra caution, and may even stop if needed, to avoid the collision.

The present disclosure further provides a method 20 for managing navigation plan of the marine vessel 2 on the potential collision course with the one or more other marine vessels 3,4, as illustrated in the form of a flowchart in FIG. 2. At step 21, the method 20 comprises generating identification data of all the marine vessels 2,3,4, by the corresponding identification units 6, to determine the various parameters of the marine vessels 2,3,4. At step 22, the method 20 further comprises calculating, by the corresponding computing units 9, priority factors of all the marine vessels 2,3,4 based on the corresponding identification data thereof. At step 23, the method 20 further comprises comparing, by the corresponding computing units 9, the calculated priority factors of all the marine vessels 2,3,4. At step 24, the method 20 further comprises determining, by the corresponding computing units 9, the required change in the navigation plan of the marine vessels 2,3,4 based on the comparison, such that the marine vessel with a lower calculated priority factor alter its navigation plan to give way to the marine vessel with a comparatively higher calculated priority factor .

It may be understood that as the marine vessel, say the marine vessel 2, makes manoeuvre during implementation of the determined required change in navigation plan thereof, the situation may change continuously, as all the marine vessels 2,3,4 are changing their course and speed relative to each other. So it is required that the steps as per the method 20 of the present disclosure shall be applied iteratively to keep in consideration the changing scenario. In one example, the system 5 and the method 20 of the present disclosure may repeatedly implement the disclosed steps every 30 seconds or the like.

It may be understood that the COLREGS rules specify, for example, which vessel is responsible for giving way to the other and to which side of the "stand-on" vessel to manoeuvre. Three primary COLREGS rules are considered: crossing, overtaking, and head-on situations. In one embodiment, the method 20 of the present disclosure is implemented when COLREGs are not applicable. That is, the present system 5 and method 20 shall be implemented only as a ^xPlan B' , if the normal COLREGs rules do not give a clear guidance to the situation and it is not clear which marine vessel (s) should change their course or speed to avoid the collision or any other dangerous situation.

FIG. 3 further illustrates a flowchart depicting a method 30 to determine when to implement procedures for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels. At step 31, the method 30 comprises determining if the two or more marine vessels are on a potential collision course. It may be contemplated that various known techniques in the art such as use of GPS, satellites, RADAR, etc. may be employed for such purpose. If the determination in step 31 is ^λΝ0' , then, at step 32, the marine vessels are allowed to continue as per their navigation plans. If the determination in step 31 is ^XYES' , then, at step 33, it is determined whether COLREGS rules apply to the situation. If the determination in step 33 is ^XYES' , then at step 34, the navigation plan of the marine vessels may be altered as per the guidelines provided in the COLREGS standards. If the determination in step 33 is ^λΝ0' , then at step 35, the method 20 of the present disclosure for managing the navigation plans of the two or more vessels may be implemented, where the method 20 involves determining the required change in the navigation plan of the marine vessels based on the comparison of their corresponding priority factors, such that the marine vessel with a lower calculated priority factor alter its navigation plan to give way to the marine vessel with a comparatively higher calculated priority factor.

The systems and methods of the present disclosure are based on the practise that small and agile vessels will take the evasive manoeuvres rather than the big vessels, and the marine vessel needing the smallest change in navigation plan (speed or deviation) from the original route should be the one to change the navigation plan. The give-way vessel is determined by calculating the priority factor (PF) for each marine vessel. In practice, the big and clumsy vessels generally have a higher PF than the small and agile vessels; and therefore the present methods allow such vessels to move with none or minimal deviation in course or change in speed, while the smaller vessels are made to make manoeuvres.

The present disclosure utilizes communication, via AIS/VHF, between the corresponding systems of the marine vessels on a potential collision course to negotiate on appropriate actions, based on the calculated PF values, to avoid the collision. It may be understood that the PF value is determined for each marine vessel, including the marine vessel for which the system 5 is part of. Therefore, it is important the identification data used for calculation of the PF value for the own marine vessel should be the same as the identification data broadcasted by the corresponding identification unit to the other marine vessels. Further, the same rules and formulas should be used for calculation of PF value for all the marine vessels, as it is imperative that each marine vessel carrying out the calculations, in their corresponding systems, end up to approximately same results.

As discussed, the PF value is defined with a formula containing several parameters. Each parameter has a numerical value and the way these parameters are determined is defined separately for each parameter. The disclosed formula is simple enough such that the PF value may be calculated by the human operator on a manned vessel. It is probable that electronic equipment in the marine vessels may aid the human operator in practice. In most cases, the disclosed formula is simple enough that the human operator can intuitively estimate the PF value with sufficient accuracy without the need of properly calculating it, to quickly decide which marine vessel has to give way.

The purpose of providing a discrete formula for calculating the PF value is to make it possible for the unmanned marine vessels to imitate the common sense of a human operator. Therefore, the present system and method enable unmanned marine vessels on a potential collision course to avoid collision. The present system and method also provide that a Remote Operation Centre (ROC) of the marine vessels, involved in the potential collision course, are immediately alerted when an ambiguous traffic situation arises. So it may be possible that the human operator in the ROC may take charge to determine the necessary course of action to avoid the collision. For example, a human operator at the ROC may enter instructions regarding constraints on the manoeuvre of the marine vessel, if required. For example, the operator may define restricted zones, for example, an area with shallow water or underwater obstacles, a region surrounding a fixed buoy, areas in which boat traffic is not permitted, areas of heavy boat traffic and mined areas. Further, the operator may may have look at the plan which the autonomous vessel is about to execute and, if it looks good, let the vessel continue in autonomous mode. But if the navigation plan looks dubious, the operator may take remotely control over the vessel and start steering it manually, and thus overrule the system 5. Also, the operator may speak over VHF with the other vessels or send and receive digital messages over VHF (or another communication channel) to/from the other vessels.

Further, the present system and method may be implemented in a manned marine vessel. In a manned vessel, the computing unit 9 would calculate and the system 9 could display the priority factors of each nearby vessel and possibly propose changes in the route plan, but the officer on the watch (so called OOW) on the vessel would steer the ship and take care of any needed communications.

Although, the present disclosure has been explained in terms of implementation in marine vessels, it may be contemplated by a person skilled in the art that the systems and methods of the present disclosure may also be implemented in unmanned aerial vehicles (UAVs) like drones, unmanned land vehicles (ULVs) like self- driving vehicles, or any other similar arrangement, to avoid collisions.

The foregoing descriptions of specific embodiments of the present disclosure have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present disclosure to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present disclosure and its practical application, to thereby enable others skilled in the art to best utilize the present disclosure and various embodiments with various modifications as are suited to the particular use contemplated .

It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this specification .

While the present disclosures have been described in connection with a number of exemplary embodiments, and implementations, the present disclosures are not so limited, but rather cover various modifications, and equivalent arrangements, which fall within the purview of prospective claims.

Claims

1. A system (5) for managing navigation plan of a marine vessel (2) on a potential collision course with one or more other marine vessels, the system comprises :

an identification unit (6) configured to generate identification data indicative of at least manoeuvrability of the marine vessel; and

- a computing unit (9) configured to:

calculate priority factors of all the marine vessels (2,3,4) involved in the potential collision course based on corresponding identification data thereof, compare the calculated priority factors of all the marine vessels (2,3,4), and

determine a required change in the navigation plan of the marine vessel based on the comparison, such that the marine vessel (s) with a lower calculated priority factor out of all the marine vessels alter the navigation plan(s) thereof to give way to the marine vessel (s) with a comparatively higher calculated priority factor,

c h a r a c t e r i z e d in that the system comprises a transmitter (7) configured to broadcast the identification data of the marine vessel to each of the one or more other marine vessels (2,3,4) and

a transceiver (8) configured to receive the identification data from each of the one or more other marine vessels (2,3,4), the identification data comprises information about at least manoeuvrability of the corresponding one or more other marine vessels.

2. A system according to claim 1, c h a r a c t e r i z e d in that the identification data indicative of the manoeuvrability of the marine vessel is based at least in part on one or more of:

- a length of the corresponding marine vessel

(L) ,

- a width of the corresponding marine vessel

(W) , and

- a draught of the corresponding marine vessel (D) .

3. A system according to any previous claim, c h a r a c t e r i z e d in that the identification data further comprises information about a manoeuvrability modifier (M) which is dependent on one or more of a status and a type of the corresponding marine vessel.

4. A system according to any previous claim, c h a r a c t e r i z e d in that the identification data further comprises information about urgency of the marine vessel (U) , which at least in part is proportional to a need to maintain a timetable of the corresponding marine vessel.

5. A system according to any previous claim, c h a r a c t e r i z e d in that the identification data further comprises information about a space limitation to manoeuvrability of the marine vessel (S) , which at least in part is due to lack of space for movement of the corresponding marine vessel.

6. A system according to any previous claim, c h a r a c t e r i z e d in that the identification data further comprises information about a risk level to cargo in the marine vessel (R) , which at least in part is proportional to a risk posed by leakage of cargo loaded in the corresponding marine vessel.

7. A system according to any previous claim, c h a r a c t e r i z e d in that the identification data further comprises information about required change in speed of the corresponding marine vessel (V) , to avoid the potential collision course.

8. A system according to any previous claim, c h a r a c t e r i z e d in that the identification data further comprises information about required deviation in the navigation plan of the corresponding marine vessel (H) , to avoid the potential collision course.

9. A system according to claims 2 to 8, c h a r a c t e r i z e d in that the computing unit calculates the priority factor (PF) as:

10. A system according to claim 9, c h a r a c t e r i z e d in that the computing unit is configured to implement a priority factor margin (PFM) which is multiplied by the calculated priority factor (PF) , for determining the required change in the navigation plan of the marine vessel.

11. A system according to any previous claim, c h a r a c t e r i z e d in that the system configures a steering unit of the marine vessel to make the marine vessel execute a manoeuvre to implement the required change in the navigation plan of the marine vessel.

12. A system according to claims 1 and 11, c h a r a c t e r i z e d in that the transmitter is further configured to broadcast a confirmation to implement the corresponding determined required change in the navigation plan of the marine vessel.

13. A system according to claims 1 and 11, c h a r a c t e r i z e d in that the transceiver is configured to check for corresponding confirmation ( s ) , from the one or more other marine vessels, to implement the corresponding determined required changes in the navigation plan(s) of the one or more other marine vessels.

14. A system according to claim 13, c h a r a c t e r i z e d in that the computing unit is configured to override the determined required change in the navigation plan of the marine vessel, in case the transceiver fails to receive corresponding confirmation ( s ) from the one or more other marine vessels .

15. A system according to any previous claim, c h a r a c t e r i z e d in that the system comprises a sensor unit configured to monitor the one or more other marine vessels to check if the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof .

16. A system according to claim 15, c h a r a c t e r i z e d in that the computing unit is configured to override the determined required change in the navigation plan of the marine vessel, in case the sensor unit monitors that the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof .

17. A system according to claim 14 or 16, c h a r a c t e r i z e d in that the computing unit is configured to override the determined required change in the navigation plan of the marine vessel in case a distance between the marine vessel and the one or more other marine vessels is less than or equal to a predefined minimum safe distance (D_MIN) ·

18. A system according to any previous claim, c h a r a c t e r i z e d in that the computing unit is configured to:

- determine, via the comparison, if a difference between the calculated priority factors of the marine vessel and any of the one or more other marine vessels is less than a threshold value, and

- determine required change in the navigation plans of the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value.

19. A system according to claims 11 and 18, c h a r a c t e r i z e d in that the steering unit is configured to implement the required change in the navigation plans of the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value, with a certain degree of caution.

20. A system according to any previous claim, c h a r a c t e r i z e d in that the identification unit is implemented as an Automatic Identification System (AIS) of the marine vessel.

21. A system according to any previous claim, c h a r a c t e r i z e d in that the system is implemented in an unmanned marine vessel.

22. A system according to any previous claim, c h a r a c t e r i z e d in that the system is implemented in a remote operation centre of the marine vessel .

23. A method for managing navigation plan of a marine vessel on a potential collision course with one or more other marine vessels, the method comprises: generating (21) identification data indicative of at least manoeuvrability of the marine vessel ;

calculating (22) priority factors of all the marine vessels involved in the potential collision course based on corresponding identification data thereof;

comparing (23) the calculated priority factors of all the marine vessels; and

- determining (24) a required change in the navigation plan of the marine vessel based on the comparison, such that the marine vessel (s) with a lower calculated priority factor out of all the marine vessels alter the navigation plan(s) thereof to give way to the marine vessel (s) with a comparatively higher calculated priority factor, c h a r a c t e r i z e d in that the method comprises broadcasting the identification data of the marine vessel to each of the one or more other marine vessels, and

receiving the identification data from each of the one or more other marine vessels, the identification data comprises information about at least manoeuvrability of the corresponding one or more other marine vessels .

24. A method according to claim 23, c h a r a c t e r i z e d in that the identification data indicative of the manoeuvrability of the marine vessel is based at least in part on one or more of: - a length of the corresponding marine vessel

(L) ,

- a width of the corresponding marine vessel

(W) , and

- a draught of the corresponding marine vessel (D) .

25. A method according to any of claims 23 or 24, c h a r a c t e r i z e d in that the identification data further comprises information about:

a manoeuvrability modifier (M) which is dependent on one or more of a status and a type of the corresponding marine vessel,

urgency of the marine vessel (U) , which at least in part is proportional to a need to maintain a timetable of the corresponding marine vessel,

- a space limitation to manoeuvrability of the marine vessel (S) , which at least in part is due to lack of space for movement of the corresponding marine vessel,

26. A method according to claims 24 and 25, c h a r a c t e r i z e d in that the priority factor (PF) is calculated as:

27. A method according to claim 26, c h a r a c t e r i z e d in that the method implements a priority factor margin (PFM) which is multiplied by the calculated priority factor (PF) , for determining the required change in the navigation plan of the marine vessel.

28. A method according to any of claims 23 to 27, c h a r a c t e r i z e d in that the method further comprises the marine vessel making a manoeuvre to implement the required change in the navigation plan of the marine vessel.

29. A method according to claim 28, c h a r a c t e r i z e d in that the method comprises broadcasting, by the marine vessel, a confirmation to implement the corresponding determined required change in the navigation plan thereof.

30. A method according to claim 28, c h a r a c t e r i z e d in that the method comprises checking for corresponding confirmation ( s ) , from the one or more other marine vessels, to implement the corresponding determined required changes in the navigation plan(s) thereof.

31. A method according to claim 30, c h a r a c t e r i z e d in that the method comprises overriding the determined required change in the navigation plan of the marine vessel, in case of not receiving corresponding confirmation ( s ) from the one or more other marine vessels.

32. A method according to any of claims 23 to 31, c h a r a c t e r i z e d in that the method comprises monitoring the one or more other marine vessels to check if the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof.

33. A method according to claim 32, c h a r a c t e r i z e d in that the method comprises overriding the determined required change in the navigation plan of the marine vessel, in case the one or more other marine vessels fails to implement the corresponding determined required change in the navigation plan(s) thereof.

34. A method according to claim 31 or 33, c h a r a c t e r i z e d in that overriding the determined required change in the navigation plan of the marine vessel is implemented, in case a distance between the marine vessel and the one or more other marine vessels is less than or equal to a predefined minimum safe distance (D_MIN) ·

35. A method according to any of claims 23 to 34, c h a r a c t e r i z e d in that the method comprises: determining, via the comparison, if a difference between the calculated priority factors of the marine vessel and any of the one or more other marine vessels is less than a threshold value, and

- determining a required change in the navigation plans of both the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value .

36. A method according to claim 35, c h a r a c t e r i z e d in that the method comprises implementing the required change in the navigation plans of the marine vessel as well as the other marine vessel (s) with which the difference in the priority factor is less than the threshold value.

37. A method according to any of claims 23 to 36, c h a r a c t e r i z e d in that the method is implemented in an unmanned marine vessel.

38. A method according to any of claims 23 to 37, c h a r a c t e r i z e d in that the method is implemented in a remote operation centre of the marine vessel.