Optimal route calculation device and optimal route calculation method

Abstract

To provide an optimum sea route computation device and an optimum sea route computation method capable of automatically carrying out optimum sea route computation for an entire sea route including one or more ranges where a navigation-incapable region exists while suppressing a computation amount.SOLUTION: An optimum sea route computation device includes an input unit, a storage unit, and a computation unit. The storage unit stores data for sea route computation ranges for computing optimum sea routes and data for narrow waterway ranges that are each set beforehand for a part of the range in the sea route computation range, and the sea route computation range and the narrow waterway range include a first range where a vessel is capable of navigating and a second range where the vessel is incapable of navigating. The computation device generates a first sea route by computing the optimum sea route from a departure point to an arrival point by postulating that the narrow waterway range is a first range. Then, when the narrow waterway range is included in the first sea route, the computation device generates a second sea route by computing the optimum sea route to cause the second sea route to pass the first range in the narrow waterway range, taking the second range in the narrow waterway range into consideration regarding the sea route in a portion included in the narrow waterway range in the first sea route and then, connects the first sea route with the second sea route.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an optimum route calculation device and an optimum route calculation method for a ship. [Background technology]

[0002] Due to the increasing need to reduce operating costs due to rising fuel prices, reduce greenhouse gas (GHG) emissions, and maintain and improve safe operation and transport quality, optimal route calculation for ships is considered an important effective means of ship operation management.

[0003] Conventional optimal route calculations optimize only the route, i.e., latitude and longitude, for a large ocean such as the North Pacific, which has a high fuel consumption reduction effect, under the constraints of planned departure and arrival times, assuming that the ship will operate at a constant ship speed or a constant main engine rotation speed.

[0004] However, in order to perform optimal route calculations that cover the entire globe, it is necessary to take into account cases where the ship passes through sea areas with many islands or shallow waters, or sea areas that are separated by canals or straits.

[0005] For example, Patent Document 1 below proposes a configuration in which weights are assigned to grid points, also called nodes, for optimal route search. Also, Patent Document 2 below proposes setting mandatory waypoints along the route and calculating the optimal route so that the mandatory waypoints are always passed through. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4247497 [Patent Document 2] Patent No. 4934756 [Patent Document 3] Patent No. 6913536 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the cases of Patent Documents 1 and 2, in order to always set grid points or mandatory passing points in narrow sea areas, etc., it is necessary to shorten the distance between grid points. However, in the case of routes that pass through both narrow and wide sea areas, it becomes necessary to set the distance between grid points in the wide sea area short to match the narrow sea area, which increases the amount of calculation and reduces calculation efficiency.

[0008] In contrast to this, Patent Document 3 proposes that areas with many islands or shallows, or areas separated by canals or straits, are set as fixed route areas, and the remaining areas are divided into multiple areas separated by fixed route areas, and the optimal route is calculated for each divided area, thereby automatically calculating the optimal route while reducing the amount of calculation.

[0009] However, the optimal calculation in Patent Document 3 is based on the premise that the ship must pass through the sea area set in the fixed route area, and therefore it is not possible to compare routes that include fixed route areas with routes that do not include fixed route areas. Therefore, it cannot be said that all navigable routes are evaluated equally, and there is room for improvement in the calculation method for searching for the optimal route.

[0010] Therefore, the present disclosure aims to provide an optimal route calculation device and an optimal route calculation method that can automatically calculate the optimal route for the entire route, including areas where unnavigable areas such as islands or peninsulas exist, while minimizing the amount of calculation. [Means for solving the problem]

[0011] An optimum route calculation device according to one aspect of the present disclosure comprises an input device for inputting input data including a departure point and a destination point of a ship, a memory device for storing performance data of the ship, and a calculator for calculating an optimum route for the ship based on the input data, the performance data of the ship, and meteorological data for a route area in which the ship will navigate, wherein the memory device stores data for a route calculation area in which the optimum route is calculated, and data for a narrow waterway area that is preset in a part of the route calculation area, and the route calculation area and the narrow waterway area include a first area in which the ship can navigate and a second area in which the ship cannot navigate, and the calculator calculates an optimum route for the narrow waterway area in the route calculation area. A first route is generated by treating the area as the first area and calculating an optimal route from the departure point to the destination, determining whether the narrow waterway area is included in the first route, and if the narrow waterway area is included in the first route, calculating an optimal route for the portion of the first route included in the narrow waterway area by taking into account the second area within the narrow waterway area and passing through the first area within the narrow waterway area, thereby generating a second route, and the optimal route from the departure point to the destination is generated by connecting the first route in the route calculation area other than the narrow waterway area with the second route in the narrow waterway area.

[0012] An optimum route calculation method according to another aspect of the present disclosure includes a route calculation area including a first area in which a vessel can navigate and a second area in which the vessel cannot navigate, and a narrow waterway area including the first area and the second area is set in advance as a part of the area in which the optimum route of the vessel is calculated; input data including a departure point and a destination point of the vessel is received; and, based on the input data, performance data of the vessel, and meteorological data of the route area in which the vessel will navigate, the narrow waterway area of ​​the route calculation area is regarded as the first area, and an optimum route from the departure point to the destination point is calculated. a first route is generated by determining whether the first route includes the narrow waterway area, and if the narrow waterway area is included in the first route, an optimal route is calculated for the portion of the first route included in the narrow waterway area by taking into account the second area within the narrow waterway area and passing through the first area within the narrow waterway area, thereby generating a second route, and the optimal route from the departure point to the arrival point is generated by connecting the first route in the route calculation area other than the narrow waterway area with the second route in the narrow waterway area. [Effects of the Invention]

[0013] According to the present disclosure, it is possible to automatically calculate an optimal route for the entire route, including areas where unnavigable areas such as islands or peninsulas exist, while suppressing the amount of calculation. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of an optimum route calculation device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram showing a route calculation area in this embodiment. [Figure 3] FIG. 3 is a flowchart showing the flow of the optimum route calculation process in this embodiment. [Figure 4] FIG. 4 is an image diagram in which the narrow waterway area included in the route calculation area shown in FIG. 2 is regarded as the first area. [Figure 5]FIG. 5 is a diagram for explaining the optimum route calculation by the DP method. [Figure 6] FIG. 6 is an image diagram of the vicinity of a narrow waterway region for generating a second route in this embodiment.

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following, identical or corresponding elements will be designated by the same reference numerals throughout the drawings, and redundant description thereof will be omitted.

[0016] FIG. 1 is a block diagram showing a schematic configuration of an optimum route calculation device according to an embodiment of the present disclosure. The optimum route calculation device 1 shown in FIG. 1 includes an input device 2, a memory device 3, a calculator 4, and an output device 5. These components communicate data with each other via a bus 6. The optimum route calculation device 1 may be configured by a computer in a facility on land, or may be configured as a computer or control device installed on a ship. Furthermore, the optimum route calculation device 1 may be configured so that some of the functions constituting the optimum route calculation device 1 are performed by a computer installed on a ship and other functions are performed by a computer installed on land, with data being exchanged between them via communication means such as ship-to-shore communication.

[0017] The input device 2 is configured as an input device that allows a user to input input data including the ship's departure point, arrival point, departure time, arrival time, etc. The input data may include the average rotation speed or average output of the ship's main engine, i.e., the propeller shaft, instead of the arrival time. The memory 3 stores the input data input from the input device 2. The memory 3 also pre-stores ship performance data, an optimal route calculation program, and data on the route calculation area and narrow waterway area described below. The optimal route calculation device 1 also acquires weather data for at least the route area through which the ship will navigate and stores it in the memory 3. The memory 3 may be composed of multiple memories. For example, the memory 3 may include a first memory, such as a data server, that stores weather data, and a second memory that stores the input data, ship performance data, etc.

[0018] Ship performance data is data relating to the performance of each ship. Weather data is provided, for example, by an external organization. Weather data is data relating to weather or sea conditions in the route area, for example, for one week from now. Note that the weather data may be configured to be sequentially transmitted from an external source via a network and automatically stored in the memory 3.

[0019] The calculator 4 includes a computer such as a microcontroller or a personal computer. For example, the calculator 4 includes a CPU, a main memory such as RAM, etc. The calculator 4 executes an optimum route calculation process that calculates an optimum route for the ship based on various information stored in the memory 3. For this purpose, the calculator 4 executes an optimum route calculation program, thereby fulfilling the functions of an information input receiving unit 41, a first route generating unit 42, a determining unit 43, a second route generating unit 44, an optimum route generating unit 45, etc.

[0020] It should be noted that the functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this specification, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, unit, or means is a combination of hardware and software, and the software is used to configure the hardware or processor.

[0021] The information input receiving unit 41 receives input of the ship's departure point, arrival point, departure time, and arrival time, or, instead of the arrival time, information including the average rotation speed or average power of the ship's main engine. The first route generating unit 42 and the second route generating unit 44 calculate the ship's optimal route based on the ship's performance data, weather data for the route area in which the ship will navigate, and data for the route calculation area and narrow waterway area, and generate the first route C1 and the second route C2. The determining unit 43 performs a determination (described below) on the first route C1 generated by the first route generating unit 42. The optimal route generating unit 45 generates the optimal route from the first route C1 and the second route C2.

[0022] The output unit 5 outputs the calculation result of the calculator 4. For example, the output unit 5 displays a map, such as a nautical chart, showing a navigable area in which a ship can navigate, on a display device connected to the optimum route calculation device 1, and displays the optimum route calculated by the calculator 4 on the map. The output unit 5 may also be configured as a communication interface that transmits data including the optimum route to another computer.

[0023] [Optimal route calculation processing] A specific example of the optimum route calculation process will be described below: Figure 2 is a diagram showing a route calculation area in this embodiment.

[0024] In this embodiment, the memory 3 stores area data including data on a route calculation area AC for calculating an optimum route, and data on a narrow waterway area AD that is preset as part of the route calculation area AC. The route calculation area AC includes a first area A1 in which the ship is navigable and a second area A2 in which the ship is not navigable. For example, the data on the route calculation area AC is map data that shows a boundary line B between the first area A1 and the second area A2. For example, the first area A1 is set as an area in which the boundary line B is the minimum value of the water depth in which the ship can navigate.

[0025] The narrow waterway area AD also includes a first area A1 where ships can navigate and a second area A2 where ships cannot navigate. The narrow waterway area AD is set in an area that includes islands or peninsulas. In particular, the narrow waterway area AD can be set in a location where islands or peninsulas are relatively close to each other. In this case, the first area A1 in the narrow waterway area AD includes straits, canals, inland seas, etc., and the second area A2 in the narrow waterway area AD includes islands, peninsulas, shallow waters, etc.

[0026] Furthermore, the memory 3 stores a reference route fs from the departure point S to the destination G. The reference route fs may be, for example, a preset reference route fs stored in the memory 3. Alternatively, the reference route fs may be stored in the memory 3 by inputting the reference route fs via the input device 2 when starting the optimal route calculation. For example, the reference route fs may be route information issued by the International Hydrographic Organization or the like. Alternatively, routes obtained as optimal route calculation results for similar past routes may be stored in the memory 3, and the average route of the stored data or one route among the stored routes that satisfies predetermined conditions may be used as the reference route fs. For example, the reference route fs may be set to the route that minimizes an evaluation function with safety and fuel efficiency as parameters. Alternatively, the reference route fs may be set to a route set by a user, such as the captain or manager of the ship. In this case, the route setting may be input via the input device 2 each time the optimal route calculation is performed, and the set route may be stored in the memory 3. The reference route fs may be a route that connects great circle routes, which are the shortest routes for each predetermined area.

[0027] 3 is a flowchart showing the flow of the optimum route calculation process in this embodiment. As shown in FIG. 3, the information input receiving unit 41 receives the departure point S, the arrival point G, the departure time T S , arrival time T G , and the input of information including the reference route fs is accepted (step S1). S When sailing at a predetermined speed, power, or ship speed from the arrival time T GIt may be unnecessary to input the information. Sailing at a predetermined speed, power output, or boat speed includes cases where the boat is sailed at a constant speed, power output, or boat speed from the departure point S to the destination G, or where the distance from the departure point S to the destination G is divided into multiple sections and the boat is sailed at a speed, power output, or boat speed set for each section.

[0028] The first route generation unit 42 regards the narrow waterway area AD of the route calculation area AC as the first area A1 and generates the first route C1 by calculating the optimal route from the departure point S to the destination G (step S2). Figure 4 is an image diagram when the narrow waterway area included in the route calculation area shown in Figure 2 is regarded as the first area. As shown in Figure 4, in calculating the optimal route when generating the first route C1, the entire narrow waterway area AD is regarded as the first area A1 in which the ship can navigate. In other words, the first route C1 is calculated by regarding the entire narrow waterway area AD as sea in which the ship can navigate.

[0029] Therefore, the first route generation unit 42 can generate a first route C1 in the first area A1 in the area of ​​the route calculation area AC other than the narrow waterway area AD. The first route generation unit 42 can also generate a first route C1 in the entire narrow waterway area AD in the route calculation area AC. The first route generation unit 42 calculates a specific optimum route based on the following well-known method. In Figure 4, the first route generation unit 42 sets the entire route calculation area AC when all of the multiple narrow waterway areas AD included in the route calculation area AC are set as the first area A1 in which the ship can navigate, as the first route calculation area AC1, and calculates an optimum route for the first route calculation area AC1.

[0030] [Example of optimal route calculation] Here, an example of optimal route calculation will be given. The first route generation unit 42 calculates, as the optimal route, a route that minimizes an evaluation function of parameters related to navigation safety, such as wave height and hull rolling based on meteorological data, and fuel efficiency based on ship performance data.

[0031] The calculation of the optimum route itself can be performed using a general optimum route calculation. For example, the following dynamic programming method (hereinafter abbreviated as DP method) can be used. Figure 5 is a diagram for explaining the optimum route calculation using the DP method.

[0032] In the DP method, first, the first route generation unit 42 calculates a great circle route R0, which is the shortest distance route connecting the departure point S and the destination G. Then, the first route generation unit 42 divides the great circle route R0 into N equal parts and sets virtual line segments M, which are great circles that intersect at right angles at each dividing point. Furthermore, the first route generation unit 42 places grid points L at equal intervals on each virtual line segment M. The i-th grid point on the k-th virtual line segment M from the departure point S is defined as L(k,i k The first route generation unit 42 selects one of the grid points L on each virtual line segment M, and connects them in order between the departure point S and the destination G to generate an optimal route R. S That is, the optimal route R S is the starting point S, the grid point L(1,i1), the grid point L(2,i2), ..., L(k,i k ),..., destination G are connected in order.

[0033] The ship is located at the grid point L(k,i k ) at time t k Starting from the k+1th imaginary line segment M, the grid point L(k+1,i k+1 ) at time t k+1 At this time, the lattice point L(k,i k ) to the lattice point L(k+1,i k+1 ) evaluation value J(L(k,i k ),L(k+1,i k+1 ),t k ,n k ) to fuel consumption F(L(k,i k ),L(k+1,i k+1 ),t k ,n k ) and the penalty P(L(k,i k ),L(k+1,i k+1 ),t k ,n k) is expressed as the sum of the evaluation value J. In other words, the evaluation value J is expressed as J=F+P. Here, n k is the lattice point L(k,i k ) to the lattice point L(k+1,i k+1 ) and the penalty P for the operational limits indicates, for example, the wave height encountered between the grid points, and the motion of the ship's hull, such as the roll angle and pitch angle.

[0034] Lattice point L(k+1,i k+1 ) arrival time t k+1 is t k+1 =t k +T(L(k,i k ),L(k+1,i k+1 ),t k ,n k ) where T(L(k,i k ),L(k+1,i k+1 ),t k ,n k ) is the lattice point L(k,i k ) to the lattice point L(k+1,i k+1 ) indicates the sailing time to the destination.

[0035] The first route generation unit 42 k At the lattice point L(k,i k ) to destination G, the minimum evaluation value J min (L(ki k ),t k ) at the lattice point L(k,i k ) to the lattice point L(k+1,i k+1 ) and time t k+1 At the lattice point L(k+1,i k+1 ) to destination G, and the sum of the minimum evaluation value to destination G when sailing from i K+1 and n k and are parameters that are minimized.

[0036] That is, the first route generation unit 42 performs the following calculations. Jmin(L(k.ik), tk) = Min(i k+1 ,n k ){J(L(k,ik ),L(k+1,i k+1 ),t k ,n k )+J min (L(k+1,i k+1 ),t k +T(L(k,i k ),L(k+1,i k+1 ),t k ,n k ))} (k=N-2,…,1,0) … (1) Here, Min(i k+1 ,n k ){J} is a function that divides J into i k+1 ,n k This means minimizing the parameter. When k=0, the lattice point L(0,i0) is equal to the starting point S.

[0037] The first route generation unit 42 also calculates the distance between the grid point L(N-1,i N-1 ) to destination G. min (L(N-1,i N-1 ),t N-1 ) is calculated using the following formula: J min (L(N-1,i N-1 ),t N-1 )=Min(n N-1 ){J(L(N-1,i N-1 ),G,t N-1 ,n N-1 )} … (2)

[0038] The first route generation unit 42 uses the above formulas (1) and (2) as functional recursive equations in the DP method to calculate the minimum evaluation value from each lattice point L to the destination G while tracing back the virtual line segments M one by one from the N-1th virtual line segment M to the departure point S, and finally obtains the minimum evaluation value from the departure point S to the destination G. The first route generation unit 42 defines the set of lattice points L at which the minimum evaluation value can be obtained as the optimal route R. S Output as

[0039] In addition, the first route generation unit 42 may use the calculus of variations, Dijkstra's algorithm, A instead of the optimal route calculation using the DP method described above. * The optimum route may be calculated using the method of time approximation, the isochrone method, etc. In the above example, an example of optimization calculation was shown in which the operational limitations were added to the evaluation value as a penalty P, but the optimum route may also be calculated using the constraint of selecting a route that is equal to or smaller than the operational limitations.

[0040] In this way, the first route generation unit 42 sets the lattice points L(k,i k ) and generates a first route C1 by connecting the multiple first search points P1 extracted as a result of the above-mentioned optimum route calculation. For example, as shown in Figure 4, if a rough weather area AE with high waves exists in the route calculation area AC between the departure point S and the destination G, the first route C1 will be a route that detours around the rough weather area AE. Note that the first search point P1 is also set in the narrow waterway area AD. In other words, the first search point P1 is used to search for an optimum route that passes through the narrow waterway area AD in generating the first route C1.

[0041] The determination unit 43 determines whether the generated first route C1 includes a narrow waterway area AD (step S3). For example, the determination unit 43 determines whether the first search points P1 included in the first route C1 include a first search point P1 whose position coordinates are within the narrow waterway area AD.

[0042] If the first route C1 includes a narrow waterway area AD (Yes in step S3), the second route generation unit 44 generates a second route C2 by calculating an optimal route for the portion of the first route C1A that is included in the narrow waterway area AD so that it passes through the first area A1 within the narrow waterway area AD (step S4).

[0043] That is, in the narrow waterway area AD, the entire area of ​​which was previously considered to be a navigable area, the second route generation unit 44 performs optimal route calculations by distinguishing between a first area A1 in which the ship can navigate and a second area A2 in which the ship cannot navigate, and generates a second route C2 that passes through the first area A1 but does not pass through the second area A2.

[0044] In the example of Fig. 4, the first route C1 passes through a narrow waterway area AD that is set in a partial area of ​​the route calculation area AC that is close to the departure point S. In the example of Fig. 4, the second route generation unit 44 sets the narrow waterway area AD through which the first route C1 passes as the second route calculation area AC2, and calculates an optimal route for the second route calculation area AC2.

[0045] FIG. 6 is an image diagram of the vicinity of a narrow waterway area for generating a second route in this embodiment. FIG. 6 shows a schematic diagram of one narrow waterway area AD through which the first route C1 passes. In FIG. 6, the first search points P1 on the first route C1 near the narrow waterway area AD are arranged in order from the departure point S side, starting from P1 k ,P1 k+1 ,…,P1 k+6 Among these, the three first search points P1 k+2 ,P1 k+3 ,P1 k+4 is included in the narrow channel area AD.

[0046] In generating the first route C1, as described above, the entire narrow waterway area AD is considered to be the first area A1 where a ship can navigate, so the portion of the first route C1 that passes through the narrow waterway area AD does not necessarily actually pass through the first area A1. In the example of Figure 4, k+2 ,P1 k+3 is located within the second area A2, and the first route C1 includes the second area A2 in which ships cannot navigate within the narrow waterway area AD. Therefore, the second route generation unit 44 calculates an optimal route in the narrow waterway area AD through which the first route C1 passes using the data of the original first area A1 and second area A2.

[0047] The second route generation unit 44 calculates a specific optimal route based on the same method as that used to generate the first route C1. However, in the second route calculation area AC2, which is the narrow waterway area AD for generating the second route C2, multiple second search points P2 for generating the second route C2 are set at second intervals D2 that are narrower than the first intervals D1 between the first search points P1 in the optimal route calculation for generating the first route C1. As described above, the narrow waterway area AD may be set to a strait, canal, inland sea, etc., including islands, peninsulas, shallows, etc. Therefore, since the narrow waterway area AD may be filled with second areas A2 such as islands, peninsulas, or shallows, the intervals between the second search points P2, i.e., the node pitch, are set short so that the generated second route C2 can detour around the second areas A2 without coming into contact with them.

[0048] The second route generation unit 44 determines two intersection points Q1 and Q2 between the first route C1 and the boundary line BA that divides the narrow waterway area AD. For each of the two intersection points Q1 and Q2, the second route generation unit 44 identifies the first search point that is closest to each intersection point Q1 and Q2 on the first route C1 outside the narrow waterway area AD as the wayfinding point. In the example of Figure 4, the first search point P1 k+1 and P1 k+5 The second route generation unit 44 determines the two determined waypoints P1 k+1 ,P1 k+5 4, the second route generating unit 44 generates a second route C2 that sequentially connects six second search points P21, P22, ..., P26.

[0049] The optimum route generation unit 45 generates an optimum route from the departure point S to the destination G by connecting the first route C1 in the route calculation area AC other than the narrow waterway area AD with the second route C2 in the narrow waterway area AD (step S5). In the example of FIG. 4, the optimum route generation unit 45 generates an optimum route from the departure point S to the first search point P1 k+1 First search point P1 on first route C1 to k+1 and the second search point P21 of the second route C2, and the second search point P26 of the second route C2 and the first search point P1 k+5 First search point P1 on first route C1 from destination Gk+5 Therefore, the optimal route in this case is S, ..., P1 k ,P1 k+1 ,P21,…,P26,P1 k+5 ,P1 k+6 ,...,G is the route that connects each point in order.

[0050] If the first route C1 does not include a narrow waterway area AD (No in step S3), the optimum route generating unit 45 outputs the first route C1 as the optimum route (step S6).

[0051] [effect] According to the above configuration, by setting a sea area with many islands or shallows as a narrow waterway area AD, the narrow waterway area AD is initially regarded as a first area A1 in which ships can navigate, and an optimum route is calculated in the route calculation area AC that includes the narrow waterway area AD, generating a first route C1. This makes it possible to equally evaluate routes that pass through the narrow waterway area AD and routes that do not pass through the narrow waterway area AD. Furthermore, when the first route C1 passes through the narrow waterway area AD, an optimum route is calculated taking into account the second area A2 in which ships cannot navigate in the narrow waterway area AD, making it possible to determine an appropriate optimum route even in the narrow waterway area AD.

[0052] Furthermore, when the first route C1 passes through a narrow waterway area AD, the optimum route is calculated only within the narrow waterway area AD, and the optimum route is generated by connecting the generated second route C2 with the portion of the first route C1 other than the narrow waterway area AD. This reduces the amount of calculation required to calculate the optimum route passing through the narrow waterway area AD compared to calculating it again for the entire route calculation area AC. In this way, according to this embodiment, the optimum route for the entire route, including areas where there are unnavigable areas such as islands or peninsulas, can be calculated automatically while reducing the amount of calculation.

[0053] Furthermore, according to this embodiment, the spacing between the multiple second search points P2 used in the optimization calculation to generate the second route C2 is set narrower than the spacing between the multiple first search points P1 used to generate the first route C1, so that even if the second area A2 in the narrow waterway area AD is complicated, a second route C2 can be generated that can bypass the second area A2 without coming into contact with it.

[0054] [Other embodiments] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various improvements, changes, and modifications are possible within the scope of the spirit of the present invention.

[0055] For example, in the above embodiment, an example has been given in which an optimum route search process similar to the optimum route calculation for generating the first route C1 is performed as the optimum route calculation for generating the second route C2, but this is not limiting. For example, a plurality of fixed routes may be set in advance in the narrow waterway area AD, and the second route generation unit 44 may select one fixed route from the plurality of fixed routes as the second route C2. In this case as well, the optimum route generation unit 45 may select the first search point P1, which is one of two waypoints on the first route C1, k+1 and P1 k+5 and the selected fixed route, an optimal route is generated that connects the first route C1 in the route calculation area AC other than the narrow waterway area AD with the second route C2 in the narrow waterway area AD.

[0056] An example of a method for selecting one fixed route from a plurality of fixed routes is to select the fixed route that is closest to the waypoint. For example, the second route generation unit 44 may calculate the sum of the point-to-point distances between the midpoint of each fixed route and each of the two waypoints. Furthermore, the second route generation unit 44 may compare the sums of the point-to-point distances calculated for each fixed route, and select the fixed route with the smallest sum as the fixed route that is closest to the waypoint.

[0057] Furthermore, for example, the optimum route calculation for generating the second route C2 may be performed using an evaluation formula different from that used for the optimum route calculation for generating the first route C1. For example, the optimum route calculation for generating the first route C1 may use an evaluation formula that gives a higher evaluation to routes with low fuel consumption, and the optimum route calculation for generating the second route C2 may use an evaluation formula that gives a higher evaluation to routes with short sailing distances.

[0058] Furthermore, the second area A2 within the narrow waterway area AD may be set to different areas depending on the type, width, draft, etc. of the ship. This makes it possible to exclude in advance routes that cannot be selected in the actual operation of the ship.

[0059] In the above embodiment, the interval between the second search points P2 used in the optimal route calculation for generating the second route C2 is the second interval D2, which is narrower than the first interval D1, which is the interval between the first search points P1 used in the optimal route calculation for generating the first route C1. However, the interval between the second search points P2 may be the same as the interval between the first search points P1. In other words, the second route C2 may be generated using the first search points P1. Furthermore, the interval between the second search points P2 may be changeable depending on the location where the narrow waterway area AD is set.

[0060] In the above embodiment, an example has been given in which one route calculation area AC is set between the departure point S and the destination G. However, a fixed route that the ship must take may also be included between the departure point S and the destination G. In this case, the generated optimum route will always include the fixed route. Furthermore, if the fixed route is set at a location away from the departure point S and the destination G, the route calculation area AC is divided into multiple areas. For example, if there is one area in which a fixed route is set between the departure point S and the destination G, a first route calculation area is set from the departure point S to the start point of the fixed route, and a second route calculation area is set from the end point of the fixed route to the destination G. In this case, the first route generation unit 42 may generate a first route C1 for each divided route calculation area.

[0061] In the above embodiment, it is assumed that the optimum route calculation is performed before the ship departs, but the above embodiment can be performed not only before the ship departs but also after the ship departs. In this case, the current position or future position (planned navigation position) of the ship becomes the departure point S, and the current time or the planned time of arrival at the planned navigation position becomes the departure time T. S is entered as

[0062] Summary of this disclosure An optimum route calculation device according to one aspect of the present disclosure comprises an input device for inputting input data including a departure point and a destination point of a ship, a memory device for storing performance data of the ship, and a calculator for calculating an optimum route for the ship based on the input data, the performance data of the ship, and meteorological data for a route area in which the ship will navigate, wherein the memory device stores data for a route calculation area in which the optimum route is calculated, and data for a narrow waterway area that is preset in a part of the route calculation area, and the route calculation area and the narrow waterway area include a first area in which the ship can navigate and a second area in which the ship cannot navigate, and the calculator calculates an optimum route for the narrow waterway area in the route calculation area. A first route is generated by treating the area as the first area and calculating an optimal route from the departure point to the destination, determining whether the narrow waterway area is included in the first route, and if the narrow waterway area is included in the first route, calculating an optimal route for the portion of the first route included in the narrow waterway area by taking into account the second area within the narrow waterway area and passing through the first area within the narrow waterway area, thereby generating a second route, and the optimal route from the departure point to the destination is generated by connecting the first route in the route calculation area other than the narrow waterway area with the second route in the narrow waterway area.

[0063] According to the above configuration, by setting a sea area with many islands or shallows as a narrow waterway area, the narrow waterway area is initially regarded as a first area in which a ship can navigate, and an optimum route is calculated in the route calculation area that includes the narrow waterway area, and a first route is generated. This makes it possible to evaluate routes that pass through narrow waterway areas and routes that do not pass through narrow waterway areas equally. Furthermore, when the first route passes through a narrow waterway area, an optimum route is calculated that takes into account a second area in which a ship cannot navigate in the narrow waterway area, making it possible to determine an appropriate optimum route even in a narrow waterway area.

[0064] Furthermore, when the first route passes through a narrow waterway area, the optimum route is calculated only within that narrow waterway area, and the optimum route is generated by connecting the generated second route with the portion of the first route other than the narrow waterway area. This reduces the amount of calculation required to calculate an optimum route that passes through a narrow waterway area compared to calculating it again for the entire route calculation area. In this way, according to this embodiment, it is possible to automatically calculate an optimum route for the entire route, including areas where there are unnavigable areas such as islands or peninsulas, while suppressing the amount of calculation.

[0065] A plurality of first search points for generating the first route may be set in the route calculation area at first intervals, and a plurality of second search points for generating the second route may be set in the narrow waterway area at second intervals narrower than the first intervals. This makes it possible to generate a second route that can detour around the second area without coming into contact with the second area, even if the second area in the narrow waterway area is complicated.

[0066] A plurality of first search points for generating the first route are set in the route calculation area at first intervals, and when generating the second route, the calculator may determine two intersections between the first route and the boundary line that separates the narrow waterway area, and for each of the two intersections, identify a first search point on the first route that is closest to each intersection outside the narrow waterway area, and calculate the optimal route between the two identified first search points to generate the second route.

[0067] The narrow waterway region may be set in a region including an island or a peninsula.

[0068] An optimum route calculation method according to another aspect of the present disclosure includes a route calculation area including a first area in which a vessel can navigate and a second area in which the vessel cannot navigate, and a narrow waterway area including the first area and the second area is set in advance as a part of the area in which the optimum route of the vessel is calculated; input data including a departure point and a destination point of the vessel is received; and, based on the input data, performance data of the vessel, and meteorological data of the route area in which the vessel will navigate, the narrow waterway area of ​​the route calculation area is regarded as the first area, and an optimum route from the departure point to the destination point is calculated. a first sea route is generated by determining whether the narrow waterway area is included in the first sea route, and if the narrow waterway area is included in the first sea route, an optimal sea route is calculated for the portion of the first sea route included in the narrow waterway area by taking into account the second area within the narrow waterway area, so as to pass through the first area within the narrow waterway area, thereby generating a second sea route, and the optimal sea route from the departure point to the arrival point is generated by connecting the first sea route in the sea route calculation area other than the narrow waterway area with the second sea route in the narrow waterway area. [Explanation of symbols]

[0069] 1. Optimal route calculation device 2 Input Device 3 Memory device 4 Arithmetic unit

Claims

1. an input device for inputting input data including the ship's departure and arrival points; a memory that stores performance data of the vessel; a calculator that calculates an optimal route for the ship based on the input data, performance data for the ship, and meteorological data for the route area in which the ship will navigate, the storage device stores data of a route calculation area for calculating the optimum route and data of a narrow waterway area that is preset in a part of the route calculation area; the route calculation area and the narrow waterway area include a first area in which the vessel is navigable and a second area in which the vessel is not navigable, The computing unit generating a first route by calculating an optimal route from the departure point to the arrival point, regarding the narrow waterway area of ​​the route calculation area as the first area; determining whether the first route includes the narrow waterway region; When the narrow waterway region is included in the first route, an optimal route is calculated for a portion of the first route included in the narrow waterway region, taking into account the second region within the narrow waterway region, so as to pass through the first region within the narrow waterway region, thereby generating a second route; An optimal route calculation device that generates the optimal route from the departure point to the arrival point by connecting the first route in the route calculation area other than the narrow waterway area and the second route in the narrow waterway area.

2. a plurality of first search points for generating the first route are set in the route calculation area at first intervals; 2. The optimum route calculation device according to claim 1, wherein a plurality of second search points for generating the second route are set in the narrow waterway region at second intervals narrower than the first intervals.

3. a plurality of first search points for generating the first route are set in the route calculation area at first intervals; The computing unit An optimal route calculation device as described in claim 1 or 2, wherein when generating the second route, two intersections between the first route and the boundary line that separates the narrow waterway area are determined, and for each of the two intersections, a first search point that is closest to each intersection outside the narrow waterway area on the first route is identified, and the second route is generated by calculating the optimal route between the two identified first search points.

4. 4. The optimum route calculation device according to claim 1, wherein the narrow waterway area is set to an area including an island or a peninsula.

5. A method for calculating an optimal route by a computer, comprising: The computer a first area in which a vessel can navigate and a second area in which the vessel cannot navigate, and a narrow waterway area including the first area and the second area is set in advance in a part of a route calculation area in which an optimum route for the vessel is calculated; accepting input data including a departure point and a destination point of the vessel; generating a first route by calculating an optimal route from the departure point to the arrival point, regarding the narrow waterway area of ​​the route calculation area as the first area based on the input data, performance data of the ship, and meteorological data of the route area in which the ship will navigate; determining whether the first route includes the narrow waterway region; When the narrow waterway region is included in the first route, an optimal route is calculated for a portion of the first route included in the narrow waterway region, taking into account the second region within the narrow waterway region, so as to pass through the first region within the narrow waterway region, thereby generating a second route; generating the optimal route from the departure point to the arrival point by connecting the first route in the route calculation area other than the narrow waterway area and the second route in the narrow waterway area.

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