JP2016078472A - Vessel speed calculation device and vessel speed calculation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vessel speed calculation device and a vessel speed calculation method which can reliably calculate an optimum solution which satisfies constraint conditions.SOLUTION: A vessel speed distribution optimizing device divides a sea route from a departure point to an arrival point into a plurality of intervals in a pseudo manner, and calculates a vessel speed for each of the intervals. The vessel speed distribution optimizing device sets a target navigation time from the departure time to the arrival time and a maximum vessel speed and a minimum vessel speed per interval as constraint conditions. The vessel speed distribution optimizing device, by setting a vessel speed per interval as a control variable, and setting a fuel consumption from the departure point to the arrival point as an object function, calculates the a vessel speed per interval at which the object function is set to be minimum as an optimum solution (S102). But, when the optimum solution is not calculated (104), the vessel speed distribution optimizing device gives tolerance to the target navigation time, and makes a backup calculation in which a vessel speed per interval at which the object function is set to be minimum is an optimum solution (S110).SELECTED DRAWING: Figure 6

Description

  The present invention relates to a ship speed calculation device and a ship speed calculation method.

For example, a ship navigating a long distance is required to create an optimal ship speed plan for the purpose of both energy saving operation and scheduled operation that arrives at the arrival point on time in consideration of the energy demand of the ship.
Patent Document 1 discloses a voyage planning support system that controls ship speed and steering based on weather and sea state information so that a ship passes a passing point at a scheduled passing time and matches the scheduled arrival time. Has been.

Japanese Patent No. 3950975

In Patent Document 1, as disclosed in FIG. 2 (b), the design variables are the main engine load and the propeller blade angle, the constraint conditions are the operational limit, the rudder amount, and the like, and the objective function is the minimum combustion consumption and the minimum CO. It is suggested to use an optimization calculation with ₂ emissions.
That is, in the navigation planning support system disclosed in Patent Document 1, the main engine load and propeller blade angle that minimize the minimum combustion consumption and the minimum CO ₂ emission, which are objective functions, while satisfying the constraint conditions are obtained as the optimum solutions. It is understood that

  However, depending on the setting of the constraint condition, the optimal solution by the optimization calculation may not be calculated.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a boat speed calculation device and a boat speed calculation method that can more reliably calculate an optimal solution that satisfies the constraint conditions.

  In order to solve the above problems, the ship speed calculation device and the ship speed calculation method of the present invention employ the following means.

  A boat speed calculation device according to a first aspect of the present invention is a boat speed calculation device that divides a route from a departure point to an arrival point into a plurality of sections in a pseudo manner, and calculates a boat speed for each section. Setting means for setting the target voyage time from the point to the arrival point and the maximum ship speed and the minimum ship speed for each section as constraints, and the ship speed for each section as control variables, from the departure point to the arrival point The optimal solution is determined by a first optimal solution calculation means that uses the fuel consumption until reaching the objective function as an objective function, and the boat speed for each section that minimizes the objective function, and the first optimization derivation means. A second optimum solution calculating means for giving a margin to the target voyage time when it is not calculated and setting the boat speed for each section that minimizes the objective function as an optimum solution;

  The ship speed calculation device according to this configuration calculates the optimum ship speed of a ship, divides the route from the departure point to the arrival point into a plurality of sections in a pseudo manner, and calculates the optimum ship speed for each section. calculate. This ship speed calculation is, for example, a method for obtaining a solution (control variable) that minimizes or maximizes the objective function while satisfying the constraint condition.

  In this configuration, the target voyage time from the departure point to the arrival point and the maximum and minimum boat speeds for each section are set by the setting means as constraints. The ship speed for each section is set as a control variable, and the fuel consumption amount from the departure point to the arrival point is set as an objective function. The boat speed for each section that minimizes this objective function is calculated by the first optimal solution calculation means as the optimal solution.

However, there are cases where the optimal solution that satisfies the constraint condition is not calculated by the first optimal solution calculation means.
Therefore, when the optimal solution is not calculated, the optimal solution is calculated by the second optimal solution calculation means. The second optimum solution calculation means gives a margin to the target voyage time set as the constraint condition, and sets the ship speed for each section that minimizes the objective function as the optimum solution. In other words, the second optimal solution calculation means does not include the target voyage time in the constraint condition, and the constraint condition is reduced compared to the first optimal solution calculation means, and the calculated voyage time is a solution close to the target voyage time ( Approximate solution) is obtained.

  In this way, in this configuration, the target voyage time is not substantially a constraint condition in the second optimal solution calculation means, and the constraint condition is reduced, so that an optimal solution that satisfies the constraint condition can be calculated more reliably. .

  In the first aspect, the second optimum solution calculating means calculates the total voyage time and the fuel consumption amount from the departure point to the arrival point, using the ship speed for each section as a control variable, and the target voyage time And the sum of the difference between the total voyage times and the fuel consumption may be used as an objective function.

According to this configuration, the total voyage time and the fuel consumption amount from the departure point to the arrival point are calculated by the second optimum solution calculation means using the ship speed for each section as a control variable. Then, the sum of the difference between the target voyage time and the total voyage time and the fuel consumption is taken as the objective function.
For the total voyage time, for example, the voyage time for each section is calculated by multiplying the distance for each section by the ship speed for each section, and the sum of the voyage times is taken as the total voyage time.
In this configuration, since the difference between the target voyage time and the total voyage time is included in the objective function, the target voyage time has a margin, so that the optimum solution can be calculated easily and more reliably.

  In the first aspect, the second optimum solution calculating means may multiply the difference between the target voyage time and the total voyage time, or the fuel consumption amount by a coefficient.

According to this configuration, the coefficient determines the deviation of the total voyage time from the target voyage time or the weight for the objective function of the fuel consumption. For example, when multiplying the difference between the target voyage time and the total voyage time by a coefficient, increasing the coefficient increases the effect of the deviation from the target voyage time in the objective function, resulting in a deviation from the target voyage time rather than the fuel consumption. Will be emphasized. On the other hand, if the coefficient is reduced, the influence of the fuel consumption amount increases in the objective function, and the fuel consumption amount is more important than the deviation from the target voyage time.
As described above, according to this configuration, an objective function that emphasizes either the deviation from the target voyage time or the fuel consumption amount can be set, so that it is possible to determine the ship speed distribution according to the purpose.

  A boat speed calculation device according to a second aspect of the present invention is a boat speed calculation device that divides a route from a departure point to an arrival point into a plurality of sections in a pseudo manner, and calculates a boat speed for each section. The target voyage time to reach the arrival point from the point, the setting means for setting the maximum boat speed and the minimum boat speed for each section as a constraint, and the departure point from the departure point using the boat speed for each section as a control variable Calculating the total voyage time to reach the fuel consumption of the ship, the difference between the target voyage time and the total voyage time and the sum of the fuel consumption as an objective function, and the interval that minimizes the objective function And an optimum solution deriving unit that makes the ship speed optimum for each ship.

  A boat speed calculation method according to a third aspect of the present invention is a boat speed calculation method for dividing a route from a departure point to an arrival point into a plurality of sections in a pseudo manner and calculating a boat speed for each section. The first step to set the target voyage time from the point to the arrival point, and the maximum and minimum ship speeds for each section as constraints, and the ship speed for each section as control variables, and arrive from the departure point A second step in which the fuel consumption until reaching the point is an objective function and the boat speed for each section that minimizes the objective function is an optimal solution, and the optimal solution is not calculated by the second step And a third step in which a margin is given to the target voyage time and the boat speed for each section that minimizes the objective function is set as an optimal solution.

  A boat speed calculation method according to a fourth aspect of the present invention is a boat speed calculation method for dividing a route from a departure point to an arrival point into a plurality of sections in a pseudo manner and calculating a ship speed for each section. The first step to set the target voyage time from the point to the arrival point and the maximum and minimum ship speeds for each section as the constraint conditions, and the arrival from the departure point using the ship speed for each section as a control variable Calculate the total voyage time to reach the point and the fuel consumption of the ship, and use the difference between the target voyage time and the total voyage time and the sum of the fuel consumption as an objective function, and minimize the objective function And a second step in which the boat speed for each section is the optimum solution.

  According to the present invention, there is an excellent effect that an optimal solution that satisfies a constraint condition can be calculated more reliably.

It is a schematic diagram which shows the optimization calculation which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the area input at the input step which concerns on embodiment of this invention, the ship speed limit value for every area, and ship speed distribution. It is a block diagram which shows the electric constitution of the ship speed distribution optimization apparatus which concerns on embodiment of this invention. It is a functional block diagram of a ship speed distribution optimization device concerning an embodiment of the present invention. It is the schematic diagram which showed the concept of the backup calculation which concerns on embodiment of this invention. It is a flowchart which shows the flow of the optimization calculation which concerns on embodiment of this invention.

  Hereinafter, an embodiment of a boat speed calculation device and a boat speed calculation method according to the present invention will be described with reference to the drawings.

  The ship speed calculation according to this embodiment is to calculate the optimum ship speed of the ship. The route from the departure point to the arrival point is divided into a plurality of sections in a pseudo manner, and the optimum ship speed for each section is calculated. The ship speed distribution to be calculated is optimized (hereinafter also referred to as “optimization calculation”). This optimization calculation is, for example, a technique for obtaining a solution (control variable) that minimizes or maximizes the objective function while satisfying the constraint condition.

FIG. 1 is a schematic diagram illustrating an example of the concept of optimization calculation.
The optimization calculation shown in the example of FIG. 1 has an input step, a calculation condition determination step, a fuel consumption calculation step, and a ship speed distribution optimization step.

In the input step, for example, navigation plan, meteorological sea forecast information, initial conditions, etc. are input (set) as information necessary for calculating the ship speed.
In the voyage plan, for example, the departure time from the departure point of the ship, the arrival time at the arrival point, and the limit values of the ship speed for each section (maximum ship speed and minimum ship speed, hereinafter referred to as “ship speed limit value”). ) Etc. The ship speed limit value is determined by the draft and trim of the ship in the section, the depth of the section, and the like. The target voyage time can be obtained from the departure time and arrival time of the ship.
These target voyage time and ship speed limit value are the constraint conditions.
The weather and sea state forecast information includes wind direction, wind speed, tidal current velocity and tidal current direction, wave height, and wave direction.
The initial condition is the distribution of ship speed for each section.

In the calculation condition determination step, calculation conditions for each section are determined.
The calculation conditions are, for example, the passage time of the ship for each section, the latitude and longitude when the ship passes for each section, and weather and sea state prediction information when the ship passes for each section.

In the fuel consumption calculation step, the movement of the route, in other words, the fuel consumption of the ship in all sections is calculated.
In the fuel consumption calculation step, a propulsion model is used in which the propulsion load of the ship fluctuates depending on the ship speed and weather conditions. In this propulsion model, fuel consumption is calculated from the propulsion load, and fuel consumption is calculated from the fuel consumption and the distance of each section. Is calculated. The propulsion model is, for example, a ship that is propelled by a main engine that is an engine rotating a propeller. However, the propulsion model is not limited to this. For example, a motor that converts engine power into electric power and that is driven by electric power is a propeller. A ship propelled by rotating may be modeled.

  In the propulsion model, as an example, the power consumed in the guest room or the air conditioner is a fixed value. However, the propulsion model is not limited to this, and may vary according to the weather and the time zone. In the propulsion model, as an example, on / off of auxiliary power is switched according to the load condition for the main engine.

The ship speed distribution optimization step changes the ship speed distribution for each section, which is the initial condition in the input step, so that the fuel consumption is an objective function and the fuel consumption is minimized.
That is, the ship speed for each section is set as the control variable.

  FIG. 2 is a schematic diagram showing an example of sections input in the input step, ship speed limit values for each section, and ship speed distribution. As shown in FIG. 2, the ship speed distribution is controlled (changed) so as to satisfy the maximum ship speed and the minimum ship speed. The fixed ship speed distribution is a predetermined value for the speed of the section, for example, when leaving or entering a port. That is, the ship speed for each section is determined within the range of the maximum ship speed and the minimum ship speed for each section so as to reach the arrival point in the target voyage time. For example, the voyage time for each section is calculated by multiplying the distance for each section by the ship speed (control variable) for each section, and the total voyage time is taken as the total voyage time and compared with the target voyage time. .

  In the fuel consumption calculation step, the fuel consumption corresponding to the newly input ship speed distribution is calculated.

  As described above, in the optimization calculation, the target voyage time (departure time and arrival time) from the departure point to the arrival point, and the maximum ship speed and the minimum ship speed for each section are set as constraints. The ship speed for each section is set as a control variable, and the fuel consumption amount from the departure point to the arrival point is set as an objective function. The ship speed for each section that minimizes this objective function is calculated as the optimum solution.

  As the optimization calculation algorithm, a known interior point method, sequential quadratic programming, or the like is used.

FIG. 3 is a block diagram showing an electrical configuration of the ship speed distribution optimizing apparatus 10 which is an information processing apparatus that executes the optimization calculation according to the present embodiment.
A ship speed distribution optimizing device 10 according to the present embodiment includes a CPU (Central Processing Unit) 12 that executes a program related to optimization calculation, a ROM (Read Only Memory) 14 that stores various programs and various data, and the like. RAM (Random Access Memory) 16 used as a work area at the time of execution of various programs according to the above, and an HDD (Hard Disk Drive) 18 as storage means for storing various programs and various data.

  Further, the ship speed distribution optimizing device 10 includes a keyboard, a mouse, and the like. The operation input unit 20 that receives input of various operations, displays various images, for example, an image display unit 22 such as a liquid crystal display device, and an external interface 24. And an external interface 24 that transmits and receives various data to and from other information processing apparatuses and printing apparatuses.

  The CPU 12, ROM 14, RAM 16, HDD 18, operation input unit 20, image display unit 22, and external interface 24 are electrically connected to each other via a system bus 26. Accordingly, the CPU 12 accesses the ROM 14, the RAM 16, and the HDD 18, grasps the operation state of the operation input unit 20, displays an image on the image display unit 22, and various types of information processing apparatuses via the external interface 24. Data can be transmitted and received.

FIG. 4 is a functional block diagram of the boat speed distribution optimization apparatus 10 according to the present embodiment.
The ship speed distribution optimizing device 10 includes a setting unit 30, an optimal solution calculation unit 32A, a determination unit 34, and an optimal solution recalculation unit 32B.

  The setting unit 30 receives and sets input of various calculation conditions and the like used in optimization calculation such as constraint conditions (target voyage time and ship speed limit value) via the operation input unit 20. The setting unit 30 corresponds to the above-described input step and calculation condition determination step.

  The optimum solution calculation unit 32A uses the ship speed for each section as a control variable, uses the fuel consumption from the departure point to the arrival point as an objective function, and calculates the ship speed for each section that minimizes the objective function as an optimum solution. To do.

  The determination unit 34 determines whether or not an optimal solution has been calculated by the optimal solution calculation unit 32A.

  The optimum solution recalculation unit 32B provides a margin for the target voyage time as a constraint condition and optimizes the boat speed for each section that minimizes the objective function when the optimum solution is not calculated by the optimum solution calculation unit 32A. Calculate as a solution.

  The optimum solution calculation unit 32A and the optimum solution recalculation unit 32B correspond to a fuel consumption calculation step and a ship speed distribution optimization step.

  Next, optimization calculation by the boat speed distribution optimization apparatus 10 according to the present embodiment will be described.

  In the optimization calculation shown in FIG. 1, if there is no optimal solution that satisfies the constraint condition, the optimization calculation outputs only the error code without outputting the solution. In such a case, the calculation condition of the optimization calculation is manually changed by the user and the optimization calculation is executed again. However, if the calculation conditions are not properly set, the optimum solution cannot be obtained and an error occurs again, and this is repeated.

  Therefore, the boat speed distribution optimizing device 10 according to the present embodiment recalculates the optimum solution by the optimum solution recalculation unit 32B when the optimum solution is not calculated by the optimum solution calculation unit 32A.

  The optimum solution recalculation unit 32B gives a margin to the target voyage time (target arrival time) set as a constraint condition by the optimum solution calculation unit 32A, and determines the optimum ship speed for each section that minimizes the objective function. And In other words, the optimal solution recalculation unit 32B does not include the target voyage time in the constraint condition, and the constraint condition is reduced as compared to the optimal solution calculation unit 32A, and the calculated voyage time is a solution (approximate to the target voyage time). Solution). That is, the optimal solution recalculation unit 32B performs backup calculation for more reliably calculating the solution when the optimal solution calculation unit 32A does not calculate the optimal solution.

  Thus, the ship speed distribution optimizing device 10 according to the present embodiment is more reliable because the target voyage time is not substantially a constraint condition and the constraint condition is reduced in the optimal solution recalculation unit 32B. The optimal solution will be calculated.

FIG. 5 is a schematic diagram showing the concept of backup calculation.
A line A (broken line) in FIG. 5 shows an example where the optimum solution is not calculated by the optimum solution calculation unit 32A. Although the optimization calculation shown in the example of the line A satisfies the target voyage time (target arrival time T _A ) which is a constraint condition, the ship speed of a certain section exceeds the maximum ship speed. For this reason, the result of this optimization calculation is an error.

On the other hand, the line B (solid line) in FIG. 5 shows an example in which the optimal solution is calculated by the backup calculation executed by the optimal solution recalculation unit 32B. In the example of line B, although the arrival time T _B to point of arrival obtained in the optimization calculation is deviated from a target arrival time, boat speed does not exceed the maximum vessel speed in all sections. Then, the backup calculation calculates the ship speed for each section where the difference between the calculated arrival time and the target arrival time is minimized.

  In the following description, the time from the departure point to the arrival point calculated by the backup calculation by the optimum solution recalculation unit 32B is referred to as the total voyage time.

The optimal solution recalculation unit 32B is intended to give a margin to the target voyage time, as shown in the following equation (1), to obtain the sum of the absolute value of the difference between the target voyage time and the total voyage time and the fuel consumption. Let it be a function. The constraint condition is only a ship speed limit value that is the maximum ship speed and the minimum ship speed for each section.

  As shown in Equation (1), the difference between the target voyage time and the total voyage time is included in the objective function, so that the target voyage time has a margin, so the optimal solution can be calculated easily and more reliably. Is done. In addition, as a result of the objective function being minimized within a range that satisfies the constraint conditions, a ship speed distribution result that is closest to the target voyage time can be obtained.

In the equation (1), a difference between the target voyage time and the total voyage time is multiplied by a predetermined weight coefficient α.
The weighting coefficient α is an adjustment parameter, and determines a weight for the objective function of the fuel consumption amount or a deviation of the total voyage time from the target voyage time (hereinafter referred to as “voyage time difference”).
That is, if the weighting coefficient α is increased in the equation (1), the influence of the voyage time difference is increased in the objective function, and the voyage time difference is more important than the fuel consumption. On the other hand, when the weighting factor α is reduced, the influence of the fuel consumption amount increases in the objective function, and the fuel consumption amount is more important than the navigation time difference.
As described above, according to the equation (1), an objective function that emphasizes either the voyage time difference or the fuel consumption amount can be set, so that the ship speed distribution according to the purpose can be determined.

  In the example of equation (1), the weighting factor α is multiplied by the navigation time difference. However, the present invention is not limited to this, and the fuel consumption may be multiplied by the weighting factor α.

  FIG. 6 is a flowchart showing the flow of optimization calculation performed by the ship speed distribution optimization apparatus 10.

  First, in step 100, calculation conditions are input by the user via the operation input unit 20, and calculation conditions are set by the setting unit 30.

  In the next step 102, the optimum solution calculator 32A calculates the boat speed for each section that minimizes the objective function. The constraint conditions for optimization calculation by the optimal solution calculation unit 32A are the target voyage time and the ship speed limit value, the objective function is the fuel consumption, and the control variable is the ship speed of each section.

  In the next step 104, it is determined whether or not an optimal solution has been calculated by the optimal solution calculation unit 32A. If the determination is affirmative, the process proceeds to step 112, where the image display unit 22 calculates the calculation result by the optimal solution calculation unit 32A. Is displayed, and this optimization calculation ends. On the other hand, if a negative determination is made, the routine proceeds to step 106.

  In step 106, the image display unit 22 displays an error code indicating that the optimum solution could not be calculated. The image display unit 22 includes an error code, a button image for selecting correction of calculation conditions such as a constraint condition (hereinafter referred to as “condition correction button”), and a button image for selecting backup calculation (hereinafter referred to as “backup calculation selection”). Button ") is displayed.

  In the next step 108, it is determined whether or not the calculation condition is to be corrected. The case where the calculation condition is corrected is, for example, a case where the user presses the condition correction button via the operation input unit 20. In this case, the process returns to step 100 and the corrected calculation condition is input.

  On the other hand, when the user presses the backup calculation selection button via the operation input unit 20, the process proceeds from step 108 to step 110.

  In step 110, backup calculation is executed by the optimal solution recalculator 32B. The constraint condition for the optimization calculation by the optimal solution recalculation unit 32B is a ship speed limit value, the objective function is expressed by the above equation (1), and the control variable is the ship speed of each section.

  Then, in step 112, which has shifted from step 110, the image display unit 22 displays the calculation result obtained by the optimum solution recalculation unit 32B, and the optimization calculation ends.

  As described above, the ship speed distribution optimizing apparatus 10 according to the present embodiment divides the route from the departure point to the arrival point in a plurality of sections in a pseudo manner, and calculates the ship speed for each section. The ship speed distribution optimizing device 10 sets the target voyage time from the departure point to the arrival point, and the maximum ship speed and the minimum ship speed for each section as constraints. The ship speed distribution optimizing device 10 uses the ship speed for each section as a control variable, the fuel consumption amount from the departure point to the arrival point as an objective function, and the ship for each section that minimizes the objective function. Speed is calculated as the optimal solution. However, when the optimal solution is not calculated, the ship speed allocation optimizing device 10 performs a backup calculation with a margin for the target voyage time and the ship speed for each section that minimizes the objective function as the optimal solution. .

  As a result, the ship speed distribution optimizing device 10 can more reliably calculate the optimal solution that satisfies the constraint condition because the target voyage time is not a constraint condition and the constraint condition is reduced in the backup calculation.

  As mentioned above, although this invention was demonstrated using the said embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which the changes or improvements are added are also included in the technical scope of the present invention. Moreover, you may combine the said embodiment suitably.

  For example, in the above-described embodiment, the form in which the objective function used in the backup calculation is multiplied by the weighting coefficient α has been described. However, the present invention is not limited to this, and the objective function used in the backup calculation is set to the weighting coefficient α. It is good also as a form which does not multiply.

  Moreover, although the said embodiment demonstrated the form which makes two constraint conditions a ship speed limit value and a target voyage time in the optimization calculation by 32 A of optimal solution calculation parts, this invention is not limited to this. . For example, the restriction condition may be three or more including the ship speed limit value and the target voyage time, such as adding the arrival time of the relay point to the restriction condition. In the case of this form, even in the backup calculation by the optimum solution recalculation unit 32B, the constraint conditions other than the target voyage time are made the same as those of the optimum solution recalculation unit 32A.

In the above embodiment, in the backup calculation, only the ship speed limit value is set as the constraint condition, and the difference between the target voyage time and the total voyage time and the sum of the fuel consumption are described as the objective function. It is not limited to this. For example, in the backup calculation, the ship speed limit value may be set as a constraint condition, and a value obtained by giving a predetermined time width to the target voyage time may be set as a constraint condition, and the objective function may be left as fuel consumption.
In the case of this form, the target voyage time has a tolerance by having the predetermined voyage time as the constraint condition.

  Moreover, although the said embodiment demonstrated the form which performs the backup calculation by the optimal solution recalculation part 32B when the optimal solution is not obtained by the optimization calculation by the optimal solution calculation part 32A, this invention is limited to this. The optimization calculation similar to the backup calculation by the optimal solution recalculation unit 32B may be performed without performing the optimization calculation by the optimal solution calculation unit 32A.

  For example, in the above-described embodiment, the form in which the ship speed is included in the constraint condition has been described. However, the present invention is not limited to this, and the load of the main engine may be used as the constraint condition instead of the ship speed. . The load on the main engine is, for example, the total value of the propulsion load for driving the propeller and the power load for supplying power in the ship.

  Further, the flow of optimization calculation described in the above embodiment is also an example, and unnecessary steps are deleted, new steps are added, and the processing order is changed within a range not departing from the gist of the present invention. May be.

10 Ship Speed Allocation Optimization Device 30 Setting Unit 32A Optimal Solution Calculation Unit 32B Optimal Solution Recalculation Unit

Claims (6)

A ship speed calculation device that divides a route from a departure point to an arrival point into a plurality of sections in a pseudo manner and calculates a ship speed for each section,
Setting means for setting the target voyage time from the departure point to the arrival point, and the maximum and minimum boat speeds for each section as constraints,
A first optimal solution in which the ship speed for each section is a control variable, the fuel consumption from the departure point to the arrival point is an objective function, and the ship speed for each section that minimizes the objective function is the optimal solution. Calculation means;
If the optimal solution is not calculated by the first optimization deriving means, a second optimal is set such that a margin is given to the target voyage time and the boat speed for each section that minimizes the objective function is the optimal solution. Solution calculation means;
A ship speed calculation device comprising:   The second optimal solution calculation means calculates the total voyage time and the fuel consumption amount from the departure point to the arrival point using the ship speed for each section as a control variable, and calculates the target voyage time and the total voyage time. The ship speed calculation apparatus according to claim 1, wherein a sum of the difference and the fuel consumption is an objective function.   The boat speed calculation device according to claim 2, wherein the second optimal solution calculation means multiplies a difference between the target voyage time and the total voyage time, or the fuel consumption amount by a coefficient. A ship speed calculation device that divides a route from a departure point to an arrival point into a plurality of sections in a pseudo manner and calculates a ship speed for each section,
Setting means for setting the target voyage time from the departure point to the arrival point, and the maximum boat speed and the minimum boat speed for each section as a constraint condition;
Calculate the total voyage time from the departure point to the arrival point and the fuel consumption amount of the ship with the ship speed as a control variable for each section, the difference between the target voyage time and the total voyage time and the fuel consumption amount An optimal solution derivation means that sets the objective function as the objective function and the boat speed for each section that minimizes the objective function as an optimal solution;
A ship speed calculation device comprising: A ship speed calculation method for dividing a route from a departure point to an arrival point into a plurality of sections in a pseudo manner and calculating a ship speed for each section,
A first step of setting the target voyage time from the departure point to the arrival point, and the maximum and minimum boat speeds for each section as constraints;
A second step in which the ship speed for each section is a control variable, the fuel consumption from the departure point to the arrival point is an objective function, and the ship speed for each section that minimizes the objective function is an optimal solution; ,
If the optimal solution is not calculated in the second step, a third step is to set a margin for the target voyage time, and to set the boat speed for each section that minimizes the objective function as the optimal solution;
Ship speed calculation method including A ship speed calculation method for dividing a route from a departure point to an arrival point into a plurality of sections in a pseudo manner and calculating a ship speed for each section,
A first step of setting a target voyage time from the departure point to the arrival point, and a maximum boat speed and a minimum boat speed for each section as a constraint condition;
Calculate the total voyage time from the departure point to the arrival point and the fuel consumption amount of the ship with the ship speed as a control variable for each section, the difference between the target voyage time and the total voyage time and the fuel consumption amount A second step in which the objective function is the sum of and the boat speed for each section that minimizes the objective function is the optimal solution;
Ship speed calculation method including

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