CN115551776A

CN115551776A - Ship navigation method, navigation system and ship

Info

Publication number: CN115551776A
Application number: CN202180037067.0A
Authority: CN
Inventors: 平泽宏章; 平川真一; 宫下哲治; 关纪明; 吉田智美
Original assignee: Japan Marine United Corp
Current assignee: Japan Marine United Corp
Priority date: 2020-05-22
Filing date: 2021-03-11
Publication date: 2022-12-30
Also published as: KR20230002731A; KR102609675B1; JP6793273B1; WO2021235053A1; JP2021183446A

Abstract

Estimating the actual wave moment (Mw (r) generated by sea conditions on a vessel (S) in a route based on predicted sea conditions in the route) Predicted wave moment (Mw (r)) based on a predicted value of actual wave moment (Mw (r)) _pv ) The loading plan is made such that the moment generated to the ship (S) does not exceed the design allowable value (Ma) during the navigation.

Description

Ship navigation method, navigation system and ship

Technical Field

The present invention relates to a method for sailing a ship after loading the ship with cargo, a system capable of performing the method, and a ship to which the system is applied.

Background

Generally, a vessel for transporting cargo, such as a container ship, is designed in such a manner that: it is possible to secure strength capable of withstanding long-term use while loading as much cargo as possible. Specifically, for example, assuming that the ship is used in the sea state of the north atlantic ocean for 25 years, the maximum load moment (set as the design wave moment Mw (d)) that can be generated to the hull by the sea state condition during this period is estimated. The maximum load capacity of the cargo is determined based on the difference between design allowable values of the load moment of the ship. That is, the design allowable value (Ma) of the load moment of the ship is expressed by the following expression (1). Further, ms (d) is a load moment (designed hydrostatic moment) generated by the weight of the ship, the weight of the cargo, and buoyancy in still water when the cargo of the maximum load amount is loaded.

On the other hand, when the ship is used, the sum of the actual load moment due to the sea condition during navigation and the actual load moment due to the self weight of the ship, the weight of the cargo, and the buoyancy needs to be not more than the allowable value of the hull. At this time, the load moment (which is assumed as the actual wave moment Mw (r)) generated under the sea state conditions is conveniently estimated as Mw (d) to determine the amount of the cargo. That is, the amount of cargo to be loaded on the ship is determined within a range satisfying the following expression (2) so that the total value of the load moment (actual hydrostatic moment Ms (r)) generated in the still water when the cargo is loaded and the design wave moment Mw (d) does not exceed the design allowable value Ma of the ship.

As a technique for supporting safe use of a ship while satisfying such conditions, for example, techniques described in patent documents 1 and 2 listed below have been proposed. These are techniques performed from the viewpoint of ensuring safety when the ship is used, and it can be said that patent document 1 describes a technique for cargo stowage while satisfying the above expression (2), and patent document 2 describes a technique for sailing so that the actual wave moment Mw (r) does not substantially exceed Mw (d).

Documents of the prior art

Patent document

Patent document 1: international publication No. 2006/003708 specification

Patent document 2: japanese patent laid-open publication No. 2019-12029.

Disclosure of Invention

Problems to be solved by the invention

However, although ensuring safety is certainly the most important issue for ships transporting cargos, it is also important to increase the cargo load as much as possible. However, in the conventional ship, the expansion of the load amount is mainly studied at the time of design together with the securing of safety, and in the use aspect, almost only the safety aspect is regarded as important. In other words, even when a large amount of cargo can be loaded sufficiently while ensuring safety in design, the amount of cargo that can be loaded is evaluated too low with safety being emphasized too much, which becomes an obstacle to improvement of transportation efficiency.

In view of the above circumstances, the present disclosure describes a method, a system, and a vessel for running a ship, which can ensure safety and easily improve cargo transportation efficiency.

Means for solving the problems

The present disclosure relates to a method for sailing a ship, in which an actual wave moment generated by a sea state for the ship in a route is estimated based on a sea state predicted in the route, a plan for stowage is made based on a predicted value of the actual wave moment, that is, a predicted wave moment, and, when sailing, sailing is performed in such a manner that the moment generated for the ship does not exceed a design allowable value.

In the ship navigation method of the present disclosure, the difference between the predicted wave moment and the design wave moment can be calculated as a stowage margin, and whether or not to change the stowage can be determined based on the stowage margin.

In the ship navigation method of the present disclosure, the torque generated in the ship can be measured, and navigation is performed so that the value of the torque grasped based on the measured value does not exceed the threshold value.

In the navigation method of a ship of the present disclosure, a predicted wave torque of a candidate of a route can be calculated, and navigation is performed so that the predicted wave torque does not exceed a threshold value.

In the ship navigation method according to the present disclosure, the warning may be issued to the passenger when a value of the moment grasped based on the measured value of the moment generated by the ship or a predicted value of the moment generated by the ship exceeds a threshold value.

In the ship navigation method according to the present disclosure, a method for reducing the moment can be presented when a value of the moment grasped based on a measured value of the moment generated by the ship or a predicted value of the moment generated by the ship exceeds a threshold value.

In the ship navigation method of the present disclosure, a ship driving method can be prompted as a method of reducing the moment.

In the sailing method for a ship of the present disclosure, as a method of reducing the moment, a route in which the value of the predicted wave moment is less than a threshold value can be presented.

The present disclosure also relates to a vessel navigation system configured to be able to execute the above-described vessel navigation method.

Further, the present disclosure relates to a ship to which the above-described ship's navigation system is applied.

Effects of the invention

According to the ship navigation method, the ship navigation system and the ship disclosed by the invention, the following excellent effects can be realized: the transportation efficiency of the goods can be improved safely and simply.

Drawings

Fig. 1 is a block diagram showing an example of the structure of a navigation system of a ship according to an embodiment of the present invention;

fig. 2 is a schematic side view showing an example of the arrangement of sensors in a ship;

FIG. 3 is a schematic plan view showing an example of the arrangement of sensors;

FIG. 4 is a graph showing an example of the distribution of the torque of the ship;

FIG. 5 is a flowchart showing an example of the order of creating the stowage plan;

FIG. 6 is a flowchart showing an example of a sequence during a ship's voyage;

FIG. 7 is a graph illustrating the relationship of the torque generated on a vessel to the measured torque;

fig. 8 is a diagram schematically showing an example of a guidance screen displayed on the display unit of the ship.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 shows a manner of a navigation system of a ship of an embodiment of the present disclosure. In the present embodiment, a system is constructed so as to straddle the ship S and the land L, a stowage plan made on the land L side is transmitted to the ship S side, stowage is performed on the ship S side based on the stowage plan, and navigation can be performed in accordance with the contents of stowage.

The land L side is provided with a route selection unit 1, a sea state data storage unit 2, a stowage planning unit 3, a stowage data storage unit 4, a wave torque calculation unit 5, a hydrostatic torque calculation unit 6, a stowage margin determination unit 7, a display unit 8, an operation input unit 9, and a communication unit 10. The ship S side is provided with a route selection unit 11, a sea state data storage unit 12, a stowage data storage unit 13, a wave torque calculation unit 14, a torque measurement unit 15, a measurement data storage unit 16, a torque margin calculation unit 17, a determination unit 18, a display unit 19, an alarm unit 20, an operation input unit 21, and a communication unit 22.

The course selection unit 1 on the land L side has a function of assisting the selection of the course of the ship S. The route selection unit 1 is connected to an information service such as Sea-Navi (registered trademark), for example, and can extract and present candidates of routes suitable for each condition based on conditions such as departure place, destination, transit place, water area, and date and time. Further, the route selecting unit 1 may be configured as follows: rather than using an external service like Sea-Navi, the appropriate routes are extracted from internally stored repositories.

The sea state data storage unit 2 has a function of storing sea state data relating to various routes, and can acquire the sea state data relating to the route presented by the route selection unit 1 as necessary. The sea state data stored in the sea state data storage unit 2 may be forecast data acquired from an external entity such as a weather bureau, past sea state data, or both.

The stowage planning unit 3 has a function of creating a stowage plan of the cargo in the ship S, and can calculate the total weight of the cargo loaded at a predetermined time of navigation, the stowage amount in each section in the ship, and the like for the ship S based on each condition such as the type or the maximum stowage amount of the ship S, the design strength, and the type or the amount of the cargo.

The stowage data storage unit 4 has a function of storing data (hereinafter, referred to as stowage data) relating to the stowage plan of the cargo in the ship S created by the stowage planning unit 3. The stowage data includes, for example, the total weight of the predetermined cargo during the voyage, the amount of stowage in each partition in the ship, the type of cargo to be loaded, the distribution of the weight of the ship S, the filling amount of ballast water in each ballast tank of the ship S, and the like.

The wave torque calculation unit 5 has a function of calculating a sea state (encounter sea state) predicted to be encountered in the course presented by the course selection unit 1 with reference to the sea state data stored in the sea state data storage unit 2. The wave moment calculation unit 5 is provided with a prediction value (predicted wave moment Mw (r)) for calculating the wave moment (actual wave moment Mw (r)) generated on the ship S on the corresponding route based on the calculated encounter sea state and information (self weight, ship speed, outer plate shape, etc.) on the ship S itself _pv ) The function of (c).

The hydrostatic moment calculation unit 6 has a function of calculating a hydrostatic moment Ms (r) in the still water, which is generated on the ship S by the weight of the ship S, the weight of the cargo and the ballast water, and the buoyancy, based on the stowage data stored in the stowage data storage unit 4.

The loading margin determining section 7 includes a waveform torque based on the predicted waveform torque Mw (r) calculated by the waveform torque calculating section 5 _pv And a function of calculating an amount of margin (defined as a load margin Δ M) by which additional load can be added from the actual hydrostatic moment Ms (r) calculated by the hydrostatic moment calculation unit 6. Furthermore, with respect to predicting the wave moment Mw (r) _pv The calculation of the actual hydrostatic moment Ms (r) and the stowage margin Δ M will be described later.

The display unit 8 is a display for displaying the following contents as necessary: information on the route prompted by the route selection unit 1; sea state data stored in the sea state data storage unit 2; the stowage data created by the stowage planning unit 3 and stored in the stowage data storage unit 4; information such as calculation results of the wave moment calculation unit 5, the hydrostatic moment calculation unit 6, and the loading margin determination unit 7; inputting an interface screen for the operation of each unit; other information, etc.

The operation input unit 9 is an interface for inputting the above-described operations for the respective units, and is, for example, a keyboard, a mouse, a touch panel display, or the like. When the operation input unit 9 is a touch panel display, the operation input unit 9 may also have a part or all of the functions of the display unit 8.

The communication unit 10 has a function of communicating with the outside of the system, and can exchange various information (for example, data of a flight route, sea state data, stowage data, and the like).

The course selecting unit 11, the sea state data storing unit 12, the stowage data storing unit 13, and the wave torque calculating unit 14 on the ship S side have substantially the same functions as the course selecting unit 1, the sea state data storing unit 2, the stowage data storing unit 4, and the wave torque calculating unit 5 on the land L side. That is, the route selection unit 11 has a function of assisting the selection of the route of the ship S, the sea state data storage unit 12 has a function of storing the sea state data related to various routes, and the stowage data storage unit 13 has a function of storing the stowage data created by the stowage planning unit 3 on the land L side. The stowage data stored in the stowage data storage unit 13 further includes an actual hydrostatic moment Ms (r) calculated by the hydrostatic moment calculation unit 6 on the land L side. The wave torque calculation unit 14 has a function of calculating a sea state (encounter sea state) predicted to be encountered in the course presented by the course selection unit 11 with reference to the sea state data stored in the sea state data storage unit 12.

The moment measuring unit 15 is, for example, a strain sensor, and has a function of measuring a moment actually generated on the ship S. When the moment measuring units 15 as strain sensors are provided on the ship S, for example, as shown in fig. 2 and 3, the moment measuring units 15 are disposed at a plurality of positions in the fore-and-aft direction of the hull, the strain generated in the ship S is measured, and the moment generated in the ship S is grasped based on the measured strain. Here, a case is illustrated in which 4 strain gauges (moment measuring units 15) are provided in the fore-and-aft direction 3 of the hull (at respective positions on the left, right, upper, and lower sides of the hull). The structure, the number of installation, the installation position, and the like of the strain gauges and the moment measuring unit 15 are not limited to those shown here, and may be appropriately changed according to the structure of the ship S and other conditions.

The measurement data storage unit 16 has a function of storing, as measurement data, measurement values related to the moments of the ship S at various locations measured by the moment measurement unit 15.

The torque margin calculation unit 17 has a function of calculating a margin (referred to as a torque margin Mm) of a degree of a current value or a predicted value of the torque generated in the ship S with respect to a design value. Specifically, the torque margin calculation unit 17 includes a measurement value (referred to as a measurement torque M (r)) that refers to the torque stored as measurement data in the measurement data storage unit 16 _mv ) The actual hydrostatic moment Ms (r) stored in the stowage data storage unit 13, and the predicted wave moment Mw (r) calculated by the wave moment calculation unit 14 _pv Etc., the value of the moment to be measured in the vessel S (measuring moment M (r) _mv ) Or is predicted to calculate the moment margin Mm by comparing the value of the moment generated by the ship S with the design wave moment Mw (d), the design hydrostatic moment Ms (d), or the design allowable value Ma at various positions of the ship S. The moment margin Mm is represented by, for example, the following equations (3) and (4). Here, mm _mv Representing a moment margin based on a measure of the moment generated by the vessel S, mm _pv A torque margin based on a predicted value of the torque generated by the ship S is indicated.

Furthermore, the above numerical expressions are only one example, and for example, with respect to the expression (3), there may be a case where the measurement torque M (r) is obtained from the measured torque _mv The following form is adopted (regarding the measurement torque M (r)) _mv And will be described in detail later).

The determination unit 18 has a function of determining whether or not to issue an alarm and display an appropriate guidance screen based on the value of the moment margin Mm calculated by the moment margin calculation unit 17.

The display unit 19 is a display for displaying, as necessary, various data such as the course information presented by the course selecting unit 11, sea state data, stowage data, measurement data, calculation results of various moments, interface screens for inputting operations to the respective units constituting the system, and other information.

The alarm unit 20 has a function of warning a person involved in the navigation of the ship S as necessary based on the determination by the determination unit 18. The designer can appropriately select an appropriate form such as an audio alarm or a visual alarm as the alarm, and can determine the configuration of the alarm unit 20 according to the content. The display unit 19 may also function as the alarm unit 20.

The operation input unit 21 is an interface for inputting the above-described operations to the respective units, and is, for example, a keyboard, a mouse, a touch panel display, or the like. When the operation input unit 21 is a touch panel display, the operation input unit 21 may also have a part or all of the functions of the display unit 19.

The communication unit 22 has a function of communicating with the outside of the system, and can exchange various information (for example, data of a route, sea state data, stowage data, and the like) with the communication unit 10 on the land L side and the like.

Here, the following case is exemplified: a system is constructed so as to straddle the ship S side and the land L side, and the land L side is mainly used for making a stowage plan and a navigation plan based on stowage is made on the ship S side; however, in implementing the navigation system of a ship of the present invention, the system configuration is not limited to the example shown here. For example, in the present day with advanced information processing and communication technologies, it is possible to construct most of the system on the ship S, or to have the same function for planning and navigating the stowage on the land L side and the ship S side. Further, the navigation system of the ship can be configured appropriately as long as the functions described below can be realized.

A method of scheduling a distribution using the above-described system will be described. The idea of the invention is to estimate the waves generated during the voyage of a ship SThe wave moment (actual wave moment Mw (r)) and the plan for stowage is based thereon. That is, if the conventional method is used, when the load is loaded with the difference between the design allowable value Ma and the design wave torque Mw (d) as the maximum load amount (see the above equation (2)), the predicted value (predicted wave torque Mw (r)) of the actual wave torque Mw (r) is used _pv ) Instead of the design wave moment Mw (d), the design strength of the ship is equivalent to the design wave moment Mw (d) and the predicted wave moment Mw (r) _pv The difference (the margin Δ M) is used in the loading plan because the difference (the margin Δ M) is more than necessary.

As described above, the design wave moment Mw (d) is set to, for example, the maximum wave moment assumed to be generated in the ship S during a long-term use of the ship S. The value is the maximum value of the wave moment specific to each ship S, and in many actual sails, the wave moment actually generated to the ship S (the actual wave moment Mw (r)) varies with each sailing within a range not more than the design wave moment Mw (d). That is, even if the difference (the stowage margin Δ M) is used in the stowage plan, for example, even if the amount of the cargo equivalent to the stowage margin Δ M is loaded in large amount, there is no problem in terms of safety, and the transportation efficiency of the cargo can be improved while still maintaining safety.

For example, if the total value of the design wave moment Mw (d) and the design hydrostatic moment Ms (d) is distributed in the vessel S as shown by the broken line in fig. 4, and if the stowage is performed by the conventional method until the design hydrostatic moment Ms (d) (that is, ms (r) = Ms (d)), the total value of the actual wave moment Mw (r) and the actual hydrostatic moment Ms (r) is distributed at a value lower than the total value of the design wave moment Mw (d) and the design hydrostatic moment Ms (d) as shown by the one-dot chain line. In the present example, the difference between the two (a value corresponding to Mw (d) -Mw (r)) is calculated and used as the stowage margin Δ M.

When the ship S is sailing, at least a part of the moment actually generated on the ship S is used as the measurement moment M (r) _mv Making a measurement based on the measurementMoment of mass M (r) _mv The selection of the route and the sailing are appropriately performed so that the grasped moment (in fig. 4, the value of the moment grasped at each measurement point is shown as a point) does not exceed the design allowable value Ma (the total value of the design wave moment Mw (d) and the design hydrostatic moment Ms (d)). In other words, the predicted values (Mm) of the moment margin in the above equations (3) and (4) are performed _pv ) And measured value (Mm) _mv ) And the navigation can not become less than zero.

To achieve such stowage and sailing, it is first necessary to calculate the predicted wave moment Mw (r) with sufficient accuracy _pv And the actual hydrostatic moment Ms (r). Therefore, the procedure of calculating the values of these moments and making a stowage plan will be described with reference to the flowchart of fig. 5.

In order to predict the actual wave moment Mw (r), it is necessary, as a prerequisite, to select a route and predict the sea states encountered in that route. Therefore, first, a candidate of the lane is extracted (step S1). Using the function of the route selection unit 1, a candidate of a route is extracted using an external service such as Sea-Navi or based on information of the route stored in the route selection unit 1. When conditions such as a departure place, a destination, a transit place, a water area, and the like are input, routes suitable for the respective conditions are extracted and presented as candidates.

Next, the predicted sea state is acquired for the route presented as a candidate (step S2). The sea state data in the same water area and the same season in the past is referred to using the function of the sea state data storage unit 2. Alternatively, forecast data provided from a weather bureau or the like is referred to.

The sea state data acquired in step S2 includes the maximum wave height that the ship S encounters in the corresponding route. The wave height most directly affects the comfort of navigation, the load generated on the ship S, and the like. Therefore, in step S3, a threshold value (avoidance limit) of the wave height is set, and the route having the wave height predicted to exceed the avoidance limit is excluded from the candidates. Then, the route that actually navigates is selected and determined from the remaining candidates (step S4).

On the other hand, the stowage planning unit 3 plans the stowage of the ship S (step S5). The total load amount of the cargo, the load amount of the cargo in each section of the ship S, and the filling amount of the ballast water in each ballast tank are determined and stored as stowage data in the stowage data storage unit 4.

The wave torque calculation unit 5 calculates a predicted wave torque Mw (r) based on the sea state predicted to be encountered in the selected route _pv (step S6).

For the use of the strip method (strip method) as a prediction of the wave moment Mw (r) _pv The case of the calculation method of (2) will be explained. The load generated by the ship S can be evaluated by the longitudinal bending moment, and the longitudinal bending moment generated by the waves can be expressed by the following formula (5). Furthermore, hs is the wave height, χ is the wave direction, and Ts is the wave period.

Sea state (Hs, ts) is included in the sea state data acquired by step S2. Therefore, these values (values predicted based on past data or predictions) are substituted into the above equation (5), and the value of Mw is calculated. Furthermore, since draft also has an influence on the Mw value and the draft varies depending on the stowage, stowage data is also referred to in the calculation of Mw. The maximum value of the Mw thus obtained is used as a predicted value of the actual wave moment Mw (r) encountered during navigation, i.e., a predicted wave moment Mw (r) _pv . It is to be noted that, in addition to the stripe method, the wave moment Mw (r) can be predicted _pv Various methods are used in the calculation of (2).

On the other hand, the actual hydrostatic moment Ms (r) is determined by stowage independently of course or sea state. The hydrostatic moment calculation unit 6 calculates the actual hydrostatic moment Ms (r) by referring to the stowage data of the stowage data storage unit 4 (step S7).

In the stowage margin determination unit 7, the predicted wave moment Mw (r) calculated in step S6 is calculated _pv And the difference between the design wave moment Mw (d) as the stowage margin Δ M (step S8). The stowage margin Δ M is in view of the loading force of the ship SThe design allowance Ma for moments and the condition of the course may further load the vessel S by an increased amount.

In this case, the stowage margin Δ M may be further calculated for other routes, and the route may be selected with reference to this margin. For example, such a procedure is effective in a case where the loading margin Δ M calculated in step S8 is not too large and another lane is also to be studied, or a case where the loading margin Δ M is to be compared among a plurality of lanes. At the time of the selection of the route in the previous step S4, the stowage margin Δ M is not used as a judgment material, and therefore, after the stowage margin Δ M is calculated here, the selection of the route is newly studied.

After the stowage margin Δ M is calculated in step S8, the process proceeds to step S8a, and it is determined whether or not another route is studied. In the case of studying other routes, the process returns to step S4, and a new route different from the previous route is selected from the prompted options. And (5) executing the steps S6 to S8 again aiming at the newly selected air route, and calculating the stowage margin delta M. Since the actual hydrostatic moment Ms (r) does not change if the stowage is not changed, the value of the actual hydrostatic moment Ms (r) calculated in the previous step S7 may be used without re-executing the second and subsequent steps S7 when the steps S6 to S8 are repeated a plurality of times.

After the stowage margin Δ M is calculated for one or a plurality of routes in this way, the procedure proceeds to step S8b at any time point (time point at which it is determined that another route is not to be studied) with reference to the value of the stowage margin Δ M, and a route is determined from the candidates. Then, step S9 is executed for the decided route. In step S9, it is determined whether or not to change the stowage plan temporarily created in step S5, based on the size of the stowage margin Δ M regarding the determined route, the amount of cargo to be stowed, and the like. When the allocation is not changed, the allocation is ended, but when the allocation is changed, the process proceeds to step S10, and the allocation plan is changed by the allocation plan unit 3 and stored in the allocation data storage unit 4 as new allocation data.

If the stowage is changed, the actual hydrostatic moment Ms (r) generated for the ship S changes.In addition, as a result of the change in the draft of the ship S, the wave moment Mw (r) is predicted _pv Variations are also possible. Thus, if the stowage plan is altered, the predicted wave moment Mw (r) is recalculated _pv And an actual hydrostatic moment Ms (r) (steps S6, S7), calculates a stowage margin Δ M (step S8), and changes the stowage plan according to the value of the stowage margin Δ M (steps S9, S10). In this way, the loading plan can be easily changed such as an increase in loading based on the value of the loading margin Δ M. Further, if this is repeated, the stowage plan is optimized so that the actual hydrostatic moment Ms (r) becomes maximum within a range that satisfies the design allowable value Ma of the ship S.

Each part on the ship S side stores necessary information such as course information, sea state data, stowage data, and the like. The stowage data changed based on the stowage margin Δ M is also transmitted to the ship S side via the communication units 10 and 22 and stored in each unit. And carrying out stowage according to the new stowage data on the ship S side.

Such a method can be executed in various vessels S in such a manner that the load increase (increase of the actual hydrostatic moment Ms (r) due to the weight of the cargo) is performed only within the range of the calculated stowage margin Δ M, but the use of a slightly different method is effective particularly in the case of a container ship.

In general, although ballast water is sometimes injected into a ship hull for the purpose of maintaining draft and correcting load moment generated on the ship hull, there are many opportunities for ballast water to be injected particularly in a container ship because the specific gravity of cargo is low. Therefore, in the case where the ship S is a container ship and much ballast water is injected in the initial stowage plan, the above stowage plan method can be applied by the procedure described below, for example.

First, the sequence of steps S1 to S8 shown in fig. 3 is executed, and the load of the loads is increased within the calculated stowage margin Δ M (steps S9 and S10). At this time, regarding the section where the increase in the load is performed, ballast water of the same weight as the amount of the increase in the load is discharged. In this way, the value of the actual hydrostatic moment Ms (r) hardly changes from before the change of the stowage plan, and the stowage margin Δ M remains, so that the stowage plan can be further changed to increase the stowage.

In addition, if it is assumed that the value of the actual hydrostatic moment Ms (r) does not change when the ballast water is loaded in an increased amount in a decreased amount, theoretically, the load can be increased without considering the stowage margin Δ M as in the present embodiment. However, in the case where the stowage is actually performed, the position of the ballast tank in the hull is different from the position where the cargo is loaded, and therefore, even if the ballast water of the ballast tank located as close as possible to the position of the section where the loading is increased is reduced, the value of the actual hydrostatic moment Ms (r) changes somewhat. Therefore, if the load increase is performed without considering the calculated stowage margin Δ M, there is no reference as to what degree of the load increase can be allowed, and therefore, even if the ballast water is reduced, as a result, the possibility that the load amount exceeds the allowable value cannot be excluded. If the stowage margin Δ M is used as in the present embodiment, the stowage increase can be safely performed in a range without hindrance.

Further, the use of the mode of utilizing the stowage margin Δ M for the reduction of the ballast water can also be realized. In the container ship, as described above, the ballast water may be injected for the purpose of correcting the load moment generated on the hull, and in this case, the load of the ballast water acts in a direction in which the actual hydrostatic moment Ms (r) is reduced. That is, if the amount of water injected into the ballast water is reduced, the actual hydrostatic moment Ms (r) increases, but the stowage margin Δ M calculated by the above method is used to increase the actual hydrostatic moment Ms (r) due to the reduction in the ballast water. That is, the ballast water in the ship S may be discharged within the range of the stowage margin Δ M.

Such use is effective, for example, in a case where ballast water remains in the tank but a larger number of containers cannot be loaded due to a limitation in cargo space or the like, or in a case where there is no cargo to be loaded. Thus, the vessel S as a container ship can be made to travel with a small amount of ballast water, and the entire weight of the vessel S can be reduced to travel with a low fuel consumption. Of course, the above-described "reduction of ballast water by an amount of increased cargo load" and "reduction of ballast water within the range of the stowage margin Δ M" may be appropriately combined. Alternatively, it is of course possible to perform only the increase in the ballast water without decreasing the ballast water only within the range of the stowage margin Δ M.

As described above, the stowage margin Δ M can be used not only at the time of stowage before starting navigation but also during navigation. That is, since the filling and draining of the ballast water during the travel can be regarded as one of the changes in the cargo allocation and affects the moment generated in the hull, the following can be used: when the ballast water is required to be filled and drained during the voyage, the ballast water is filled and drained within the range of the stowage margin Δ M.

Next, the procedure for navigating the ship S loaded in the above-described procedure will be described with reference to the flowchart of fig. 6.

During the course of the ship S, the moment measuring unit 15 constantly measures moments generated at various places of the ship S (step S11). The value obtained by the torque measuring unit 15 is stored as measurement data in the measurement data storage unit 16.

Here, the measured torque M (r) obtained by the torque measuring unit 15 is measured _mv The description is given.

Fig. 7 shows an example of fluctuation of the moment actually generated in the ship S. Here, the following is assumed: for the vessel S in the unloaded state, from the time t ₀ To time t ₂ Make a load at a later time t ₃ And starting sailing.

If the moment generated by the ship S is evaluated as a longitudinal bending moment, the moment generated by the sag (sagging) is negative, and the moment generated by the arch (hogging) is positive, the moment due to buoyancy is positive, and the moment due to the weight of the cargo is positive with respect to the fore-and-aft direction of the hull and in the center portion, as a rough tendencyThe load loaded near the ends is negative, and the load loaded near the ends is positive. In the unloaded state (time t) ₀ ) Next, a positive moment is generated to the ship S due to the buoyancy. If from this to time t ₂ When the cargo is loaded, the weight of the cargo loaded on the ship S as a whole generates a negative moment, and the positive moment is cancelled out and a negative moment is applied. At time t ₂ The moment generated to the ship S is a hydrostatic moment in a state where the stowage is completed. When the stowage is performed according to the stowage plan, the moment generated at the time point of the ship S theoretically matches the actual hydrostatic moment Ms (r) finally calculated in step S7 in the sequence shown in fig. 5. The torque evolution associated with the load described here is merely an example, and the torque does not necessarily fluctuate as described above. Depending on the position or amount of the load, for example, the total of the moments due to the load may take a positive value.

When the vessel S starts to navigate (time t) ₃ Thereafter) an actual wave moment Mw (r) is generated for the vessel S. The actual wave moment Mw (r) varies at any time during the course of the flight, if at time t ₂ Time t ₃ The value of the moment in between (Ms (r)) is the base value, then the actual wave moment Mw (r) is expressed as the difference from the baseline. When the actual wave moment Mw (r) is grasped as the longitudinal bending moment, the actual wave moment Mw (r) takes a positive value in the midspan and a negative value in the sag.

The moment measured by the moment measuring part 15 as a strain gauge during navigation is detected as a measured moment M (r) _mv The measured value of the moment of (b) is set based on which time point is set in the above-described process. Suppose that, in the middle of the stowage, the moment generated by the cargo exactly cancels the moment generated by the buoyancy (time t) ₁ ) Setting the measured value to zero, then, while underway (time t) ₃ Later) obtained measurement (measuring moment M (r) _mv ) The sum of the actual hydrostatic moment Ms (r) and the actual wave moment Mw (r).

However, in reality, it is difficultDetermining the time t ₁ Actually, the measurement value of the torque measuring section 15 is set to zero at a timing other than this. For example, zero setting is performed during the stowage operation, at which timing a time t is reached ₁ Time t ₂ In between (shown as time t in fig. 7) _a ) At time t ₃ The measured values taken later are part of the actual hydrostatic moment Mw (r) (shown in the figure as Ms) ₂ Value of) and the actual wave moment Ms (r). In addition, for example, at time t ₂ To time t ₃ The time point in between (shown as time t in fig. 7) _b ) With the measured value set to zero, at time t ₃ The only measurement taken later is the actual wave moment Mw (r).

In either case, however, the torque M (r) is measured _mv The actual wave moment Mw (r) is obtained, and the moment generated on the ship S can be obtained. I.e. if time t is to be reached ₂ To time t ₃ The measured value at any time point in between is recorded as a base value, so that the actual wave moment Mw (r) currently occurring can be determined as the value at the time t ₃ Later detected measuring moment M (r) _mv The difference of the value of (c) and the base value. Note that the actual hydrostatic moment Ms (r) may be a value finally calculated in step S7 in the procedure shown in fig. 5. In this way, regardless of the timing of the zero setting, the moment generated to the ship S can be grasped.

In step S12, a determination is made regarding the value of the moment acquired in step S11. Here, the measurement value by the torque measurement unit 15 (measurement torque M (r)) _mv ) Whether the value of the grasped torque is larger than a preset threshold value. For example, as described above, based on the measured torque M (r) _mv The value of the actual wave moment Mw (r) is grasped and compared with a threshold value. Here, as the threshold value serving as a criterion for the determination, for example, a difference (Ma-Ms (r)) obtained by subtracting the actual hydrostatic moment Ms (r) from the design allowance Ma may be used, or a difference (Ma-Ms (r)) may be used so that the moment generated in the ship S does not actually exceed the design allowance MaThe method of (1) is set to a threshold value of an appropriate value less than the Ma-Ms (r) with a margin.

Here, the value of the torque or the threshold value used for the determination may be set as appropriate in addition to the above description. For example, it may be based on the measured torque M (r) _mv The sum of the grasped actual wave moment Mw (r) and the actual hydrostatic moment Ms (r) is compared with an appropriate threshold value of the design allowable value Ma or the insufficient design allowable value Ma. Alternatively, for example, the moment margin may be calculated by the moment margin calculation unit 17 based on the actual measurement value Mm of the moment margin Mm calculated by the above equation (3) _mv Whether or not it is smaller than zero (or a threshold value set to an appropriate value equal to or larger than zero with a margin). Furthermore, mm _mv The calculation formula (c) of (d) differs depending on the situation. For example, when only the actual wave moment Mw (r) is detected as the measured moment M (r) _mv Time, mm _mv Is composed of

。

Further, for example, the sum of the actual wave moment Mw (r) and the actual hydrostatic moment Ms (r) is detected as the measured moment M (r) _mv In the case of (2), mm _mv Is shown as

。

When the torque is within the threshold value, the process returns to step S11 to continue to obtain the measured torque M (r) _mv . Based on measuring moment M (r) _mv If the value of the detected moment is greater than the threshold value, the process proceeds to steps S13 and S14, where an alarm is issued by the alarm unit 20 and the navigation is performed by the display unit 19. The contents of steps S13 and S14 will be described again later.

The above are based on torque measurements (measuring torque M (r) _mv ) While the ship is supported, on the other hand, a predicted value based on the moment (predicted wave moment Mw (r) is also performed _pv Or the sum of the actual hydrostatic moment Ms (r)Is supported by the driving ship. The wave moment calculating unit 14 on the ship S side refers to the route selecting unit 11, the sea state data storing unit 12, and the stowage data storing unit 13, and acquires candidates of routes that can be selected to reach a destination from the current position, sea state data predicted for each candidate, and stowage data (including the actual hydrostatic moment Ms (r)) (step S15). The wave moment calculating unit 14 obtains the measurement moment M (r) obtained by the moment measuring unit 15 in step S11 _mv (step S16).

The wave torque calculation unit 14 calculates the value of the predicted wave torque Mw (r) for each route candidate (the predicted wave torque Mw (r)) based on the acquired data _pv ) (step S17). Predicting wave moment Mw (r) _pv Can be calculated by the banding method described above or other suitable methods. In addition, the predicted wave moment Mw (r) is calculated _pv The calculation formula (2) may be combined with a measurement torque M (r) which is a measurement value of the torque generated by the ship S _mv The comparison is made, and the correction is made at any time, so that the predicted wave torque Mw (r) can be calculated more accurately _pv 。

Next, a determination is made regarding the calculated predicted value of the moment (step S18). Here, for example, the predicted value of the wave moment calculated by the wave moment calculation unit 14 (predicted wave moment Mw (r)) _pv ) And whether the total value of the actual hydrostatic moment Ms (r) (i.e., the value predicted to be the moment generated on the hull) is greater than a predetermined threshold value. Here, as the threshold value serving as a criterion for determination, for example, a design allowable value Ma can be used. Alternatively, a threshold value set to an appropriate value that is less than the design allowable value Ma with a margin may be used in order to reduce the possibility that the total value of the moments generated on the ship S in the course selected in the future actually exceeds the design allowable value Ma. The determination in step S18 may be made, for example, by calculating the predicted value Mm of the moment margin Mm by the moment margin calculation unit 17 based on the above equation (4) _pv Whether or not the value is less than zero (or a threshold value set to an appropriate value equal to or greater than zero with a margin). Alternatively, the method can also be used in advanceMeasuring wave moment Mw (r) _pv Whether it is larger than the design wave moment Mw (d) or Ma-Ms (r) (or a threshold value set to an appropriate value less than them).

If the torque is within the threshold value in any route that can be selected in the future, the process returns to step S15, and the acquisition of various data and the prediction of the wave torque Mw (r) are repeated _pv And (4) calculating. If the predicted value of the moment is greater than the threshold value, the process proceeds to steps S13 and S14.

In steps S13 and S14, the measurement torque M (r) is measured _mv Value of the moment of interest (which may be a measured moment M (r)) _mv In itself, it can also be based on the measured torque M (r) _mv When the obtained actual wave moment Mw (r) or the total value of the actual hydrostatic moment Ms (r) and the actual wave moment Mw (r) exceeds a threshold value, or when a predicted value of the moment (which may be the predicted wave moment Mw (r)) is obtained _pv It is also possible to predict the wave moment Mw (r) _pv And the total value of the actual hydrostatic moments Ms (r) exceeds the threshold value, the warning unit 20 issues a warning indicating that they exceed the threshold value (step S13), and a driving method or an operation method for making each moment smaller than the threshold value is presented (step S14). The contents of the warning, the presented driving method, and the operation method may be appropriately changed according to conditions such as which moment exceeds the threshold value and the extent of the exceeding.

For example, in step S13, an alarm is notified that the total value of the moments generated on the ship S (Ms (r) + Mw (r)) approaches the design allowable value Ma by a buzzer, a turn light, or another method, or that it is predicted that the moment generated on the ship S may be larger than the design allowable value Ma on any of the predetermined routes to be navigated in the future.

In step S14, in order to reduce the moment generated or the moment predicted to be generated in the ship S, a method of changing the ship speed or the orientation of the hull to the orientation along the wave direction is displayed on the display unit 19, for example. In addition, for example, a guide as shown in fig. 7 may be displayed on the display unit 19And (6) leading the picture. In the example shown here, the moment may be close to (or larger than) the allowable value in the future in the route shown by the symbol R1, and the other routes R2 and R3 show the meaning that such prediction is not currently possible. The occupant may select one of the route lines R2 and R3 with reference to the guidance screen. The guide screen shown here is an example, and the guide screen to be displayed can be changed as appropriate according to necessary information or other conditions. For example, the predicted value Mm of the moment margin Mm may be used _pv The security level of the flight route is evaluated and displayed for each flight route.

After steps S13 and S14 are finished, the flow is once ended. Alternatively, steps S11, S15, and thereafter may be repeated again.

In the case of implementing the method and system as described above, it is not necessary to change the hull or other structures in order to secure safety or expand the load capacity, for example, and the method and system can be easily applied to an existing ship to improve the cargo transportation efficiency.

As described above, in the marine vessel sailing method of the present embodiment, the actual wave moment Mw (r) generated on the marine vessel S by the sea state in the course is estimated based on the sea state predicted in the course, and the predicted wave moment Mw (r) which is the predicted value of the actual wave moment Mw (r) is used as the predicted wave moment Mw (r) _pv The loading plan is made such that the moment generated in the ship S does not exceed the design allowable value Ma during the navigation. Thus, instead of the design wave moment Mw (d) inherent to each ship S, the actual wave moment Mw (r) having the following value is used to plan the stowage, and the measurement moment M (r) is caused to occur while the ship is underway _mv The total value of the design wave moment Mw (d) and the design hydrostatic moment Ms (d) is not exceeded, whereby the efficiency of cargo transportation can be improved while still maintaining safety.

Further, in the sailing method of the ship of the present embodiment, the predicted wave moment Mw (r) is calculated _pv And the difference between the design wave moment Mw (d) and the design wave moment Mw (d) is used as a stowage margin delta M, and whether to change stowage is judged based on the stowage margin delta M. Thus, the load margin Δ M can be used as a basisAccurately, the stowage plan is easily changed.

Further, in the method of sailing a ship of the present embodiment, the torque generated on the ship S can be measured to be based on the measured value (measurement torque M (r) _mv ) And navigating in a mode that the value of the grasped moment does not exceed the threshold value.

In the method for sailing a ship according to this embodiment, the predicted wave torque Mw (r) of the candidate course can be calculated _pv To predict the wave moment Mw (r) _pv Sailing in a mode of not exceeding a threshold value.

In the method for sailing a ship according to the present embodiment, the warning can be issued to the crew when the value of the moment grasped based on the measured value of the moment generated by the ship S or the predicted value of the moment generated by the ship S exceeds the threshold value.

In the method for sailing a ship according to the present embodiment, when the value of the moment grasped based on the measured value of the moment generated by the ship S or the predicted value of the moment generated by the ship S exceeds the threshold value, a method for reducing the moment can be presented.

In the method for sailing a ship according to the present embodiment, a method for driving a ship can be presented as a method for reducing the moment.

In the ship navigation method according to the present embodiment, a route in which the predicted value of the wave moment is less than the threshold value can be presented as a method of reducing the moment.

Further, since the ship navigation system according to the present embodiment is configured to be able to execute the above-described ship navigation method, the same operational advantages as described above can be achieved.

In addition, since the ship of the present embodiment employs the above-described ship navigation system, the same operational effects as described above can be achieved.

Therefore, according to the present embodiment described above, the efficiency of transporting the cargo can be improved safely and easily.

The method, system, and vessel for sailing the vessel described in the present disclosure are not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the scope of the invention.

Description of the reference numerals

1: route selection part

2: sea state data storage unit

3: distribution planning section

4: stowage data storage part

5: wave moment calculating part

6: static water moment calculation part

7: loading margin determination unit

8: display unit

9: operation input unit

10: communication unit

11: route selection part

12: sea state data storage unit

13: stowage data storage part

14: wave moment calculating part

15: torque measuring unit

16: measurement data storage unit

17: moment margin calculation unit

18: determination unit

19: display unit

20: alarm part

21: operation input unit

22: communication unit

L: land area

S: ship with a detachable cover

And Ma: design allowable value

Mw (d): design of wave moment

Mw (r): actual wave moment

Mw（r） _pv : predicting wave moment

M（r） _mv : measuring torque

Δ M: and (4) load margin.

Claims

1. A method of sailing a ship, wherein,

estimating an actual wave moment generated by the sea state on the vessel in the route based on the predicted sea state in the route,

planning the stowage based on the predicted value of the actual wave moment, i.e. the predicted wave moment,

when sailing, sailing is carried out in a way that the moment generated on the ship does not exceed the design allowable value.

2. The method of sailing a ship according to claim 1, wherein,

calculating the difference between the predicted wave moment and the design wave moment as a loading margin,

based on the stowage margin, it is determined whether or not to change the stowage.

3. The method of sailing a ship according to claim 1 or 2, wherein,

the moment generated to the vessel is measured and,

the navigation is performed in such a manner that the value of the moment grasped based on the measurement value does not exceed the threshold value.

4. The method of sailing a ship according to any one of claims 1 to 3, wherein,

a predicted wave moment for the candidate of the course is calculated,

sailing in such a way that the predicted wave moment does not exceed a threshold value.

5. The method of sailing a ship according to any one of claims 1 to 4, wherein,

when a value of a moment grasped on the basis of a measured value of a moment generated by the ship or a predicted value of the moment generated by the ship exceeds a threshold value, an alarm is issued to a passenger.

6. The method of sailing a ship according to any one of claims 1 to 5, wherein,

when a value of a moment grasped based on a measured value of a moment generated by the ship or a predicted value of the moment generated by the ship exceeds a threshold value, a method for reducing the moment is presented.

7. The method of sailing a ship according to claim 6, wherein,

a method for reducing the moment is a method for prompting the driving of the ship.

8. The method of sailing a ship according to claim 6 or 7, wherein,

as a method of reducing the moment, a route in which the value of the predicted wave moment is less than a threshold value is prompted.

9. A navigation system for a ship, wherein,

the ship navigation system is configured to be able to execute the ship navigation method according to claim 1.

10. A ship, wherein,

the ship to which the navigation system of the ship according to claim 9 is applied.