Energy saving navigation method for vessel and energy saving navigation system for vessel

Abstract

To provide an energy saving navigation method for vessel and an energy saving navigation system for vessel capable of carrying out energy saving navigation by integrally selecting actuation points when control of a governor and a variable pitch propeller are combined.SOLUTION: A plurality of ALC setting curves expressing the relationship between rotational number in ALC (automatic load control) of a variable pitch propeller for propelling a vessel and output of a main engine driving the variable pitch propeller, one of the plurality of ALC setting curves is selected according to load state of the main engine as well as controlling the governor and the variable pitch propeller according to control condition for the governor adjusting fuel supplied to the main engine and the selected ALC setting curve in an energy saving navigation method for vessel.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an energy-saving operation method for a ship equipped with a controllable pitch propeller, and an energy-saving operation system for a ship. [Background technology]

[0002] In ships equipped with a controllable pitch propeller (CPP), the diesel engine (main engine) is generally controlled at a constant speed by an engine governor, but to save fuel, there are also constant power control, which controls the output at a constant level by the governor, and fuel index (FI) control, which limits the amount of fuel input. Figure 10 shows conventional governor control, with the horizontal axis representing the propeller speed NP [rpm] and the vertical axis representing the output P [kW]. Figure 10(a) shows constant speed control, Figure 10(b) shows constant power control, and Figure 10(c) shows fuel index control. In constant speed control, where the rotation speed is used as a command value, output increases when the main engine load increases due to weather and sea conditions, as can be seen in Figure 10(a) where output increases when the Beaufort wind scale changes from BF0 to BF7. In constant output control, where the output is used as a command value, the rotation speed decreases so that the output remains constant, as can be seen in Fig. 10(b) where the rotation speed decreases when the Beaufort wind scale changes from BF0 to BF7. Fuel index control is a control method in which if the output according to the command value of the RPM is above the FI line, the RPM is lowered to below the FI line, and both the output and the RPM change. In the example of Figure 10(c), when the Beaufort wind scale changes from BF0 to BF7 and the output reaches point A, which is above the FI line, the RPM is reduced to lower the output to the intersection of the FI line and the BF7 line.

[0003] On the other hand, a controllable pitch propeller can change output while keeping the rotation speed constant by changing the blade angle (pitch angle). There are two control methods: (1) a method in which both the rotation speed and pitch angle are set arbitrarily, and (2) a method in which a combination of rotation speed and pitch angle is preset using a combinator and then controlled simultaneously. Furthermore, with a controllable pitch propeller, ALC (Automatic Load Control) can be used to optimize output, and in either of the above two control methods, control by ALC can be performed using the initial values. Specifically, in the case of control method (1) above, arbitrary initial values ​​are set for both the rotation speed and pitch angle, and if the main engine load is not optimal, the pitch angle is automatically changed to satisfy the ALC setting. In the case of control method (2) above, an initial value is set for a combination of rotation speed and pitch angle, and if the main engine load is not optimal, the pitch angle is automatically changed to satisfy the ALC setting. There is also a constant speed control technology called ASC (Automatic Speed ​​Control), which automatically changes the blade angle of the controllable pitch propeller to keep the ship speed constant when the ship speed changes due to external disturbances. Thus, technologies related to controllable pitch propellers include ALC, which automatically controls the propeller blade angle by linking the propeller rotation speed, and ASC, which automatically changes the blade angle so that the ship speed remains constant. Figure 11 shows conventional controllable pitch propeller control, with Figure 11(a) showing the relationship between the ship speed V [knots] or propeller rotation speed Np [rpm] and output P [kW] when the blade angle is changed, Figure 11(b) showing the relationship between the ship speed V [knots] or propeller rotation speed Np [rpm] and output P [kW] when ALC is used, and Figure 11(c) showing the control of a controllable pitch propeller using ALC. In Fig. 11(a), θp is the blade angle, with θp1 being the minimum and θp6 being the maximum. As shown in Fig. 11(a), in a controllable pitch propeller, the relationship between the propeller rotation speed and the output (horsepower) changes when the blade angle is changed. In the right diagram of Fig. 11(b), the dashed line is the optimum line for ALC, and the dotted lines are the upper and lower dead zone lines that show the width of the dead zone.As shown in Fig. 11(b), when ALC is used to control a controllable pitch propeller, the relationship between propeller speed and output (horsepower) is optimized. In Figure 11(c), the center of the three dotted lines is the optimum ALC line, and the other two are upper and lower dead zone lines that indicate the width of the dead zone. The horizontal axis is the propeller speed NP [rpm], and the vertical axis is the output P [kW]. ALC is a control method in which if the output corresponding to the command value of the speed is outside the range of the ALC line, the blade angle is changed while keeping the speed constant to bring it within the range of the ALC line (the speed is not changed until it reaches the maximum blade angle). In the example of Figure 11(c), when the Beaufort wind scale changes from BF0 to BF7 and the output reaches point A, which is above the upper limit line of the ALC dead zone, the blade angle is changed while keeping the speed constant to reduce the output to the upper limit line of the ALC dead zone.

[0004] Patent Document 1 discloses a main engine output control device including: a main engine that drives and rotates a controllable pitch propeller; a fuel injection pump for supplying fuel to the main engine; a speed governor that controls the rotational speed of the main engine; a governor output shaft that moves backward or forward as the speed governor is controlled to reduce the rotational speed of the main engine; a pump rack that increases or decreases the injection amount of the fuel injection pump by moving forward or backward; a connecting member that connects the pump rack to move in the same direction as the rearward movement of the governor output shaft; a stopper that stops the forward movement of the pump rack in the event of an overload; a spring that is provided between the connecting members and is compressed when the movement of the pump rack is stopped by the stopper to allow movement of only the governor output shaft; a main engine output detector that detects the forward and backward movement of the governor output shaft to detect the output of the main engine; and a controller that detects an overload state of the main engine from the main engine output obtained from the detector and controls to reduce the pitch of the controllable pitch propeller. Furthermore, Patent Document 2 discloses an automatic ship speed control method for a ship equipped with a dual-engine, single-shaft propulsion system, in which the two engines are used separately to expand the engine output range and perform a wide range of ship speed control. Patent Document 3 discloses a method of operating a controllable pitch propeller in which an optimal fuel consumption curve is set in advance for the rotational speed of the controllable pitch propeller drive engine, the set fuel consumption corresponding to a certain rotational speed of the drive engine is converted into an electrical quantity, and a command fuel consumption indicator that operates with this electrical quantity and an actual fuel consumption indicator that operates with an electrical quantity corresponding to the actual fuel consumption of the drive engine are provided opposite each other on a common fuel consumption scale plate, and the blade angle is controlled so that the actual fuel consumption indicator matches the command fuel consumption indicator. Furthermore, Patent Document 4 discloses a marine engine control system in which a target rotational speed is set as a control command, a load resistance coefficient is calculated from an actual fuel index and an actual rotational speed of the main engine in a load resistance coefficient calculation block, and when a second control mode in which output control is performed is selected, the target rotational speed is converted to a target output using an average value of the load resistance coefficient over a predetermined time in a rotational speed / output conversion block, and when a third control mode in which fuel index control is performed is selected, the target rotational speed is converted to a target fuel index using the average value in the rotational speed / fuel index conversion block. Patent Document 5 discloses a method of operating a ship having an automatic load control function that can change the blade angle of a controllable pitch propeller in accordance with the load on the diesel engine, in which a calm operation mode is preset in which the diesel engine speed and the blade angle of the controllable pitch propeller are set in accordance with the characteristics of the ship, and a rough weather operation mode in which the diesel engine speed and the blade angle of the controllable pitch propeller are set to a smaller blade angle than in the calm operation mode, and the ship is operated by selecting either the calm operation mode or the rough weather operation mode at the discretion of the operator depending on the sea conditions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Microfilm of Utility Model Application No. 58-188656 (Utility Model Application No. 59-111797) [Patent Document 2] Japanese Patent Application Publication No. 61-291296 [Patent Document 3] Japanese Patent Application Publication No. 51-139097 [Patent Document 4] JP 2011-52577 A [Patent Document 5] JP 2015-6848 A Summary of the Invention [Problem to be solved by the invention]

[0006] Currently, the optimal operating points of the main engine and controllable pitch propeller are determined through the individual controls described above, but no technology has been proposed to comprehensively select operating points when governor and controllable pitch propeller controls are combined. Patent Document 1 aims to make it possible to detect the degree of overload even when the main engine's overload condition progresses and the pump rack is stopped, preventing the fuel injection amount from increasing. It does not aim to achieve energy-saving operation by comprehensively selecting the operating point when the governor and controllable pitch propeller controls are combined. Patent Document 2 describes how, when switching from dual engine operation to single engine operation, or from single engine operation to dual engine operation, an automatic load control device is used to adjust the blade angle of a controllable pitch propeller based on the set engine speed to target an optimal fuel pump rack value, and the output of the propulsion engine is set to set the ship speed, but it does not attempt to achieve energy-saving operation by comprehensively selecting an operating point when governor and controllable pitch propeller control are combined. Patent Document 3 changes the blade angle of a controllable pitch propeller based on fuel consumption, and does not attempt to achieve energy-saving operation by comprehensively selecting the operating point when governor and controllable pitch propeller controls are combined. Patent Document 4 describes governor control that matches the sea conditions by switching between rotational speed control, output control, and fuel index control, and does not aim to achieve energy-saving operation by comprehensively selecting the operating point when governor and controllable pitch propeller control are combined. In Patent Document 5, an operator sets a calm operation mode, a rough weather operation mode, etc. depending on sea conditions, and the diesel engine speed and the blade angle of the controllable pitch propeller are controlled according to the set mode, but it does not attempt to achieve energy-saving operation by comprehensively selecting the operating point when the governor and controllable pitch propeller controls are combined. Therefore, an object of the present invention is to provide an energy-saving operation method for a ship, and an energy-saving operation system for a ship, which can achieve energy-saving operation by comprehensively selecting operating points when combining control of a governor and a controllable pitch propeller. [Means for solving the problem]

[0007] An energy-saving operation method for a ship corresponding to the one described in claim 1 is characterized in that a plurality of ALC setting curves are set which represent the relationship between the rotation speed at ALC (automatic load control) of the controllable pitch propeller which propels the ship and the output of the main engine which drives the controllable pitch propeller, one of the plurality of ALC setting curves is selected according to the load condition of the main engine, and the governor and the controllable pitch propeller are controlled according to the control conditions of the governor which adjusts the fuel supplied to the main engine and the selected ALC setting curve. According to the present invention as described in claim 1, for example, it is possible to select the optimal operating points for the blade angle and rotation speed of the controllable pitch propeller according to the load state of the main engine due to meteorological and sea conditions, and by combining governor control and controllable pitch propeller control, it is possible to achieve more energy-efficient operation than in the past.

[0008] The present invention as set forth in claim 2 is characterized in that the multiple ALC setting curves include a curve with good fuel consumption rate and a curve with low boat speed but small output and fuel consumption. According to the present invention as set forth in claim 2, it is possible to select an ALC setting curve that provides control with good fuel consumption rate at an optimal load, or an ALC setting curve that provides control that suppresses fuel consumption at a low load, depending on the load condition of the main engine.

[0009] The present invention as recited in claim 3 is characterized in that the multiple ALC setting curves are curves that provide a ship speed. According to the present invention as set forth in claim 3, an ALC setting curve that performs control that makes it easy to maintain ship speed despite a high load can be selected according to the purpose of ship operation, thereby achieving highly efficient operation.

[0010] The present invention as recited in claim 4 is characterized in that, when the load state exceeds the selected ALC setting curve, the rotation speed is controlled to be constant as a control condition of the governor, and is stabilized at the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 4, since the rotation speed is not changed, it is possible to settle at the operating point of the selected ALC setting curve with little load fluctuation in the main engine.

[0011] The present invention as recited in claim 5 is characterized in that, when the load state exceeds the selected ALC setting curve, the output is controlled to be constant as a control condition of the governor, and is settled at the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 5, the output of the main engine can be settled to the operating point of the selected ALC setting curve without changing the output of the main engine.

[0012] The present invention as recited in claim 6 is characterized in that, when the load state exceeds the selected ALC setting curve, the control conditions of the governor are controlled based on the fuel index and are settled to the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 6, the governor fuel index control and ALC control can be combined and settled to the operating point of the selected ALC setting curve.

[0013] The present invention as recited in claim 7 is characterized in that when the ship speed changes and exceeds the selected ALC setting curve, the governor and the controllable pitch propeller are controlled in accordance with the governor control conditions, and are settled at the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 7, the ship speed can be controlled to remain within a predetermined range in response to changes in the ship speed, and can be stabilized at the operating point of the selected ALC setting curve, thereby contributing to energy-saving operation.

[0014] The energy-saving operation method for a ship corresponding to the one described in claim 8 is characterized in that meteorological and oceanographic information is acquired, and the energy-saving operation method for a ship described in any one of claims 4 to 7 is combined with weather routing based on the meteorological and oceanographic information to operate the ship taking into account the number of days the ship is at sea. According to the present invention as set forth in claim 8, by combining with weather routing, optimal control according to the purpose can be selected, thereby achieving energy-saving operation while keeping to the scheduled arrival date.

[0015] An energy-saving ship navigation system corresponding to the one described in claim 9 comprises a controllable pitch propeller for propelling the ship, a main engine for driving the controllable pitch propeller, a governor for adjusting the fuel supplied to the main engine, a rotation speed detection means for detecting the rotation speed of the main engine, a power detection means for detecting the power output of the main engine, and a navigation control means for controlling the controllable pitch propeller and the governor based on the rotation speed and the power output, wherein the navigation control means has a plurality of ALC setting curves that represent the relationship between the rotation speed and the power output of the main engine in the ALC (automatic load control) of the controllable pitch propeller, selects one of the plurality of ALC setting curves according to the load state of the main engine, and controls the governor and the controllable pitch propeller in accordance with the set governor control conditions and the selected ALC setting curve. According to the present invention as described in claim 9, for example, the optimum operating points of the controllable pitch propeller blade angle and rotation speed according to the load state of the main engine due to meteorological and sea conditions are selected, and a combination of governor control and controllable pitch propeller control can be used to achieve more energy-efficient operation than in the past.

[0016] The present invention as set forth in claim 10 is characterized in that the plurality of ALC setting curves of the navigation control means are a curve with good fuel consumption rate and a curve with low ship speed but small output and fuel consumption. According to the present invention as set forth in claim 10, it is possible to select an ALC setting curve that provides control with good fuel consumption rate at an optimal load, or an ALC setting curve that provides control that suppresses fuel consumption at a low load, depending on the load condition of the main engine.

[0017] The present invention as recited in claim 11 is characterized in that the multiple ALC setting curves of the navigation control means are curves that result in ship speed. According to the present invention as set forth in claim 11, an ALC setting curve that performs control that makes it easy to maintain ship speed despite a high load can be selected according to the purpose of ship operation, thereby achieving highly efficient operation.

[0018] The present invention as described in claim 12 is characterized in that, when the load state exceeds the selected ALC setting curve, the operation control means controls the rotation speed to a constant value as a control condition of the governor, and settles it at the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 12, since the rotation speed is not changed, it is possible to settle the operating point of the selected ALC setting curve with little load fluctuation in the main engine.

[0019] The present invention as described in claim 13 is characterized in that, when the load state exceeds the selected ALC setting curve, the operation control means controls the output to a constant value as a control condition of the governor, and settles it at the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 13, the output of the main engine can be settled to the operating point of the selected ALC setting curve without changing the output of the main engine.

[0020] The present invention as described in claim 14 is characterized in that, when the load state exceeds the selected ALC setting curve, the operation control means controls the control conditions of the governor based on the fuel index and settles them to the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 14, the governor fuel index control and ALC control can be combined and settled to the operating point of the selected ALC setting curve.

[0021] The present invention as described in claim 15 is characterized in that, when the ship speed changes and exceeds the selected ALC setting curve, the operation control means controls the governor and the controllable pitch propeller in accordance with the governor control conditions, and settles them to the operating point of the selected ALC setting curve. According to the present invention as set forth in claim 15, the ship speed can be controlled to remain within a predetermined range in response to changes in the ship speed, and can be stabilized at the operating point of the selected ALC setting curve, thereby contributing to energy-saving operation.

[0022] An energy-saving ship operation system corresponding to the one described in claim 16 is characterized in that it is equipped with a meteorological and oceanographic information acquisition means for acquiring meteorological and oceanographic information, and the operation control means in the energy-saving ship operation system described in any one of claims 9 to 15 controls in combination with weather routing based on the meteorological and oceanographic information. According to the present invention as set forth in claim 16, the optimal control according to the purpose is selected in combination with weather routing, so that energy-saving operation can be achieved while keeping to the scheduled arrival date.

[0023] The present invention as recited in claim 17 is characterized in that it comprises a load information acquisition means for acquiring load information applied to the ship, and the operation control means predicts and controls the load condition of the main engine based on the load information. According to the present invention as set forth in claim 17, it is possible to prepare for main engine load fluctuations by selecting an ALC setting curve suitable for a predicted load state before the main engine load actually fluctuates. Effect of the Invention

[0024] According to the energy-saving operation method for a ship of the present invention, for example, it is possible to select optimal operating points for the blade angle and rotation speed of a controllable pitch propeller according to the load state of the main engine due to meteorological and sea conditions, and by combining governor control and controllable pitch propeller control, it is possible to achieve more energy-saving operation than in the past.

[0025] In addition, when the multiple ALC setting curves include a curve with good fuel consumption rate and a curve that does not increase the ship speed but has low output and fuel consumption, it is possible to select, depending on the load condition of the main engine, an ALC setting curve that provides control with good fuel consumption rate at optimal load, or an ALC setting curve that provides control with reduced fuel consumption at low load.

[0026] In addition, when multiple ALC setting curves are available, an ALC setting curve that provides control that is high load but makes it easy to maintain ship speed can be selected according to the ship's operational purpose, thereby achieving highly efficient operation.

[0027] In addition, when the load condition exceeds the selected ALC setting curve, the governor control condition is to control the speed to a constant value and settle it to the operating point of the selected ALC setting curve, so that since the speed is not changed, it is possible to settle it to the operating point of the selected ALC setting curve with little load fluctuation in the main engine.

[0028] In addition, when the load condition exceeds the selected ALC setting curve, the output is controlled to a constant value as the control condition of the governor, and when the output is to be settled at the operating point of the selected ALC setting curve, the output of the main engine can be settled at the operating point of the selected ALC setting curve without changing it.

[0029] In addition, when the load condition exceeds the selected ALC setting curve, the governor control conditions are controlled based on the fuel index, and when the governor control conditions are to be settled at the operating point of the selected ALC setting curve, the governor fuel index control and ALC control are combined to settle the governor control conditions at the operating point of the selected ALC setting curve.

[0030] In addition, if the ship's speed changes and exceeds the selected ALC setting curve, the governor and controllable pitch propeller are controlled in accordance with the governor's control conditions, and when the ship is to be set to the operating point of the selected ALC setting curve, the ship speed is controlled to remain within a specified range in response to the change in ship speed, and the ship is set to the operating point of the selected ALC setting curve, thereby contributing to energy-saving operation.

[0031] In addition, when obtaining weather and ocean condition information and combining the ship's energy-saving operation method with weather routing based on the weather and ocean condition information to operate taking into account the number of days the ship is at sea, the optimal control according to the purpose can be selected in combination with the weather routing, achieving energy-saving operation while maintaining the scheduled arrival date.

[0032] Furthermore, according to the energy-saving ship operation system of the present invention, for example, optimal operating points for the blade angle and rotation speed of the controllable pitch propeller are selected according to the load state of the main engine due to meteorological and sea conditions, and a combination of governor control and controllable pitch propeller control can be used to achieve more energy-saving operation than in the past.

[0033] In addition, if the multiple ALC setting curves of the operation control means are a curve with good fuel consumption rate and a curve with low ship speed but low output and fuel consumption, an ALC setting curve that provides control with good fuel consumption rate at optimal load, or an ALC setting curve that provides control with reduced fuel consumption at low load, can be selected according to the load condition of the main engine.

[0034] In addition, when the multiple ALC setting curves of the operation control means are curves that result in ship speed, an ALC setting curve that provides control that is high load but makes it easy to maintain ship speed can be selected according to the ship's operation purpose, thereby achieving highly efficient operation.

[0035] In addition, when the load condition exceeds the selected ALC setting curve, the operation control means controls the rotation speed to a constant value as a control condition of the governor, and when settling to the operating point of the selected ALC setting curve, since the rotation speed is not changed, it is possible to settle to the operating point of the selected ALC setting curve with little load fluctuation of the main engine.

[0036] In addition, when the load condition exceeds the selected ALC setting curve, the operation control means controls the output to a constant value as the governor control condition, and when settling it to the operating point of the selected ALC setting curve, it can settle it to the operating point of the selected ALC setting curve without changing the output of the main engine.

[0037] In addition, when the load condition exceeds the selected ALC setting curve, the operation control means controls the governor control conditions based on the fuel index, and when settling to the operating point of the selected ALC setting curve, it combines the governor fuel index control and ALC control to settle to the operating point of the selected ALC setting curve.

[0038] In addition, when the ship's speed changes and exceeds the selected ALC setting curve, the operation control means controls the governor and controllable pitch propeller in accordance with the governor's control conditions, and when settling the ship to the operating point of the selected ALC setting curve, controls the ship speed to be within a specified range in response to the change in ship speed, and sets the ship speed to the operating point of the selected ALC setting curve, thereby contributing to energy-saving operation.

[0039] In addition, the ship's energy-saving operation system is equipped with a weather and ocean condition information acquisition means for acquiring weather and ocean condition information, and when the operation control means controls in combination with weather routing based on the weather and ocean condition information, the optimal control according to the purpose is selected in combination with the weather routing, thereby achieving energy-saving operation while keeping to the scheduled arrival date.

[0040] In addition, the ship is equipped with a load information acquisition means for acquiring load information on the ship, and when the operation control means predicts and controls the load condition of the main engine based on the load information, it can prepare for fluctuations in the main engine load by selecting an ALC setting curve suitable for the predicted load condition before the main engine load actually fluctuates. [Brief description of the drawings]

[0041] [Figure 1]FIG. 1 is a block diagram of an energy-saving ship operation system according to an embodiment of the present invention. [Diagram 2] A diagram showing an example of multiple ALC setting curves [Diagram 3] FIG. 1 is a diagram showing the relationship between the propeller speed and the output in the first control method. [Figure 4] FIG. 11 is a diagram showing the relationship between the propeller speed and the output in the second control method. [Diagram 5] FIG. 11 is a diagram showing the relationship between the propeller speed and the output in the third control method. [Figure 6] FIG. 11 is a diagram showing the relationship between the propeller speed and the output in the third control method. [Figure 7] FIG. 11 is a diagram showing the relationship between the propeller speed and the output in the third control method. [Figure 8] FIG. 13 shows a first pattern of the fourth control method. [Figure 9] FIG. 11 is a diagram showing the relationship between boat speed and power output in the second pattern of the fourth control method. [Figure 10] Diagram showing conventional governor control [Figure 11] Diagram showing conventional controllable pitch propeller control DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] An energy-saving operation method for a ship equipped with a controllable pitch propeller and an energy-saving operation system for a ship according to an embodiment of the present invention will be described. Fig. 1 is a configuration diagram of an energy-saving navigation system for a ship. The energy-saving navigation system for a ship includes a controllable pitch propeller 10 for propelling the ship, a main engine 20 for driving the controllable pitch propeller 10, a governor 30 for adjusting the fuel supplied to the main engine 20, a rotation speed detection means 40 for detecting the rotation speed of the main engine 20, an output detection means 50 for detecting the output of the main engine 20, a navigation control means 60 for controlling the controllable pitch propeller 10 and the governor 30 based on the rotation speed and the output, a meteorological and oceanographic information acquisition means 70 for acquiring meteorological and oceanographic information, and a load information acquisition means 80 for acquiring load information on the ship, and executes an energy-saving navigation method. The governor 30 is preferably a non-mechanical type, and is particularly preferably an electronically controlled governor. In a ship equipped with an energy-saving navigation system, the following items are monitored by the rotation speed detection means 40, the output detection means 50, the weather and ocean condition information acquisition means 70, and the load information acquisition means 80, etc. (1) Main engine rotation speed, main engine load (main engine torque or main engine output) (2) Waves (wave height, wave period, wave direction, and preferably directional spectrum information) (3) Wind (wind speed / direction) (4) Water velocity (5) Steering angle, steering angle control information (autopilot control ON / OFF, etc.) (6) Engine governor control information (fuel index information, etc.) (7) Wind propulsion device control information (sail angle, rotor speed, operation / non-operation, etc.) The waves, wind, and water current speed may be meteorological and oceanographic forecast information.

[0043] The navigation control means 60 has multiple ALC setting curves set that represent the relationship between the rotation speed during ALC (automatic load control) of the controllable pitch propeller 10 and the output of the main engine 20. The navigation control means 60 automatically selects one of the multiple ALC setting curves according to the load condition of the main engine 20 (increase or decrease in main engine load), which varies depending on the magnitude and direction of waves, wind, and currents, and controls the governor 30 and the controllable pitch propeller 10 in accordance with the set control conditions of the governor 30 and the selected ALC setting curve.

[0044] Figure 2 shows examples of ALC setting curves. The horizontal axis shows the propeller speed NP [rpm], and the vertical axis shows the power output P [kW]. In the conventional ALC, one ALC setting curve (target load setting line) and upper and lower dead zone lines (also called upper and lower dead zone lines) indicating the upper and lower limits of the dead zone are set, but in the present invention, a plurality of ALC setting curves are prepared and one ALC setting curve is selected according to the load state of the main engine 20. In the example of FIG. 2, a total of three ALC setting curves are set in advance: a center ALC setting curve 1 (solid line), an upper ALC setting curve 2 (dotted line), and a lower ALC setting curve 3 (dash-dotted line). Although not shown, each ALC setting curve has upper and lower dead zone lines set. The dead zone may overlap with other ALC setting curves, for example, the upper dead zone line of the center ALC setting curve 1 overlaps with the upper ALC setting curve 2 and the lower dead zone line overlaps with the lower ALC setting curve 3. The multiple ALC setting curves as shown in Fig. 2 are set by a person or a computer based on the output and fuel consumption rate characteristics of the main engine 20. For example, the center ALC setting curve 1 is set to follow the BF0 line and has the best specific fuel consumption (SFC) among the three ALC setting curves, the upper ALC setting curve 2 is set to have the highest load and the fastest boat speed among the three ALC setting curves, and the lower ALC setting curve 3 is set to have the lowest load and the slowest boat speed but with low output and fuel consumption. Among the multiple ALC setting curves, there are curves with good fuel consumption rate and curves with low boat speed but low output and fuel consumption, so that it is possible to select an ALC setting curve that performs control with good fuel consumption rate at an optimal load or an ALC setting curve that performs control with reduced fuel consumption at a low load according to the load state of the main engine 20. In addition, by having multiple ALC setting curves available as one of the options, including a curve that can determine the ship speed, it is possible to select an ALC setting curve that provides control that is high load but makes it easy to maintain ship speed, depending on the ship's operational purpose, thereby achieving highly efficient operation. Although it is preferable that the number of ALC setting curves is three as in this embodiment, it is also possible to have two or four or more types.

[0045] In a ship in operation, the operation control means 60 controls the governor 30 and the controllable pitch propeller 10 using one ALC setting curve selected from three types of ALC setting curves. Which ALC setting curve is selected depends on the load state of the main engine 20, and may be selected, for example, as shown in (1) to (3) below. In addition, when combined with wind propulsion control (or rudder angle control), the speed of the wind propulsion control (or rudder angle control) may be, for example, as shown in (4) or (5) below. (1) In conditions where the weather and sea conditions are relatively calm, such as when the Beaufort wind scale is BF0 or BF1, the central ALC setting curve 1, which has the best fuel consumption rate, should be selected as the basic rule. (2) When wind speed (wave height, wave period, current speed) increases, center ALC setting curve 1 or lower ALC setting curve 3 is selected according to the amount of increase in wind speed. When it is predicted that the load on the main engine 20 will increase, frequent changes in the blade angle can be suppressed when the load on the main engine 20 increases by automatically setting the operating point to center ALC setting curve 1 or lower ALC setting curve 3 when the amount of increase in wind speed exceeds a threshold value. (3) When wind speed (wave height, wave period, and current speed) decreases, center ALC setting curve 1 or upper ALC setting curve 2 is selected depending on the amount of decrease in wind speed. When it is predicted that the load on the main engine 20 will decrease, frequent changes in the blade angle can be suppressed when the load on the main engine 20 decreases by automatically setting the operating point to center ALC setting curve 1 or upper ALC setting curve 2 when the amount of decrease in wind speed exceeds a threshold value. (4) When the wind direction (wave direction, current direction) is horizontal to the ship, the speed of wind propulsion control (or rudder angle control) is made faster than normal to prevent the ship from drifting sideways. (5) When the wind (wave or current) direction is following within a harbor, the wind propulsion control (or rudder angle control) speed is made faster than normal to prevent the speed limit from being exceeded due to gusts of wind. The navigation control means 60 can also predict the load state of the main engine 20 based on the load information on the ship acquired by the load information acquisition means 80, and control the governor 30 and the controllable pitch propeller 10 based on the predicted load state. In this case, before the main engine load actually changes, an ALC setting curve suitable for the predicted load state can be selected to prepare for the change in the main engine load.

[0046] The operation control means 60 selects one of a number of ALC setting curves and selects the operating point (rpm, main engine output) by combining each control of the governor 30 (constant rpm control, constant output (horsepower) control, fuel index control). The control of the governor 30 and the controllable pitch propeller 10 differs depending on the control method of the governor 30 that is combined with the ALC. First, a first control method that combines constant speed control in the governor 30 and the ALC will be described. FIG. 3 is a graph showing the relationship between the propeller rotation speed NP [rpm] and the output P [kW] in the first control method. In the first control method, the navigation control means 60 reselects one of the three types of ALC setting curves when the main engine output according to the designated rotation speed (the rotation speed of the command value) has exceeded or is expected to exceed the dead band line of the currently selected ALC setting curve due to a change in wind speed, etc. For example, when the load has increased or is expected to increase due to an increase in wind speed, the navigation control means 60 selects the center ALC setting curve 1 or the lower ALC setting curve 3 according to the increase in wind speed, and when the load has decreased or is expected to decrease due to a decrease in wind speed, the navigation control means 60 selects the center ALC setting curve 1 or the upper ALC setting curve 2 according to the decrease in wind speed. Note that the case where the dead band line of the ALC setting curve has been exceeded or is expected to be exceeded includes both the case where the upper limit line of the dead band is exceeded or is expected to be exceeded upward, and the case where the lower limit line of the dead band is exceeded or is expected to be exceeded downward. After reselecting the ALC setting curve, the navigation control means 60 performs automatic control to control the rotation speed to a constant value as a control condition of the governor 30, and to change the blade angle of the controllable pitch propeller 10 to bring the operating point within the range of the ALC setting curve. Here, the range of the ALC setting curve refers to the area within the upper and lower dead zone lines centered on the ALC setting curve. In the example of FIG. 3, when the Beaufort wind scale becomes BF7 and the output according to the specified rotation speed exceeds the ALC setting curve and becomes point A on the BF7 line, the ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the output is reduced by changing the blade angle while keeping the rotation speed constant, and the operating point is set to point A' on the ALC setting curve (A → BF0). Note that if the operating point falls within the range of the ALC setting curve without changing the blade angle of the controllable pitch propeller 10 due to the reselection of the ALC setting curve, the control proceeds to constant rotation speed control, and automatic control is performed so that the operating point does not deviate from the range of the reselected ALC setting curve. In this way, in the first control method, when the load state of the main engine 20 exceeds the selected ALC setting curve, the rotation speed is controlled to be constant as a control condition of the governor 30, and is settled at the operating point of the selected ALC setting curve. Since the first control method does not change the rotation speed, it is possible to settle it at the operating point of the selected ALC setting curve with little load fluctuation of the main engine 20.

[0047] Next, a second control method that combines the constant output control and the ALC in the governor 30 will be described. Figure 4 shows the relationship between the propeller speed NP [rpm] and the power output P [kW] in the second control method. The second control method is divided into three patterns. FIG. 4(a) shows the first pattern in the second control method. When the designated output (output of command value) exceeds or is expected to exceed the upper and lower dead zone lines of the currently selected ALC setting curve due to a change in wind speed, etc., the navigation control means 60 selects a new ALC setting curve from among the three types. Then, as the control condition of the governor 30, the output is controlled to be constant, and the blade angle of the controllable pitch propeller 10 is changed to perform automatic control to bring the operating point within the range of the ALC setting curve. In the example of FIG. 4(a), when the Beaufort wind scale becomes BF7 and the designated output exceeds the ALC setting curve to point A on the BF7 line, the ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the blade angle is changed with the output constant to increase the rotation speed and set the operating point to point A' on the setting curve (A → BF0). If the operating point falls within the range of the ALC setting curve without changing the rotation speed due to the reselection of the ALC setting curve, the system will transition to constant output control, and automatic control will be performed to ensure that the operating point does not fall outside the range of the reselected ALC setting curve. In this way, in the second control method, when the load state of the main engine 20 exceeds the selected ALC setting curve, the output is controlled to a constant value as a control condition of the governor 30, and is settled at the operating point of the selected ALC setting curve. In the second control method, the output of the main engine 20 can be settled at the operating point of the selected ALC setting curve without changing it.

[0048] Fig. 4(b) shows the second pattern in the second control method. When the designated output has exceeded or is expected to exceed the upper and lower dead zone lines of the currently selected ALC setting curve due to changes in wind speed, etc., the navigation control means 60 reselects one of the three ALC setting curves. Then, as a control condition for the governor 30, the rotation speed is controlled to be constant, and automatic control is performed to change the blade angle of the controllable pitch propeller 10 and bring the operating point within the range of the ALC setting curve. After the operating point falls within the range of the ALC setting curve, constant output control is performed again. In the example of Figure 4(b), when the Beaufort wind scale becomes BF7 and the output exceeds the ALC setting curve to point A on the BF7 line, an ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the output is reduced by changing the blade angle while keeping the rotation speed constant, and the operating point is set to point A' on the ALC setting curve (A → A'). Note that if the operating point falls within the range of the ALC setting curve without changing the blade angle of the controllable pitch propeller 10 due to the reselection of the ALC setting curve, the system will switch to constant output control as it is, and automatic control will be performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The second pattern can improve the fuel saving effect more than the first pattern, and can achieve the optimum load while keeping the output and the rotation speed as small as possible.

[0049] Fig. 4(c) shows a third pattern in the second control method. When the designated output has exceeded or is expected to exceed the upper and lower dead zone lines of the currently selected ALC setting curve due to changes in wind speed, etc., the navigation control means 60 reselects one of the three ALC setting curves. Then, automatic control is performed to simultaneously change the rotation speed by the governor 30 and the blade angle of the controllable pitch propeller 10 toward a target operating point set within the range of the ALC setting curve. After the operating point falls within the range of the ALC setting curve, constant output control is performed again. In the example of Figure 4(c), when the Beaufort wind scale becomes BF7 and the output exceeds the ALC setting curve, reaching point A on the BF7 line, an ALC setting curve along the BF0 line is selected from the three ALC setting curves, the rotation speed is increased and the blade angle is changed to decrease the output, and the operating point is set to point C on the ALC setting curve (A → C). Note that if the operating point falls within the range of the ALC setting curve by reselecting the ALC setting curve without changing the rotation speed or the blade angle of the controllable pitch propeller 10, the system will transition to constant output control, and automatic control will be performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The third pattern makes it possible to select the optimal operating point (engine speed, main engine output) based on fuel efficiency and vessel speed conditions. Also, as shown in Figure 4(c), by setting the main engine load as the optimal line, it is possible to select an operating point that suppresses engine speed fluctuations while mitigating vessel speed reduction more than in the second pattern.

[0050] Next, a third control method in which the fuel index control and the ALC in the governor 30 are combined will be described. 5 to 7 are diagrams showing the relationship between the propeller rotation speed NP [rpm] and the output P [kW] in the third control method. In the third control method, as in the first control method, when the main engine output corresponding to the specified engine speed has exceeded or is expected to exceed the upper or lower dead zone lines of the currently selected ALC setting curve due to changes in wind speed, etc., the operation control means 60 performs automatic control to newly select one ALC setting curve from the three types and bring the operating point within the range of the ALC setting curve; however, this control differs depending on the positional relationship between the FI line, BF line, etc. at the main engine output at the specified engine speed, and therefore will be explained below by dividing into cases.

[0051] Figure 5 shows the case where the main engine output at the specified RPM is at the position where the FI line, BF line, and upper limit line of the dead zone of the ALC setting curve are located from the top when the ALC setting curve is reselected (case α). In this case, there are two control patterns. In the first control pattern, the operation control means 60 controls the rotation speed to a constant as a control condition of the governor 30, and performs automatic control to place the operating point within the range of the ALC setting curve by changing the blade angle of the controllable pitch propeller 10. In this control pattern, the operation is the same whether the control of the controllable pitch propeller 10 is followed by control of the governor 30, or the control of the governor 30 is followed by control of the controllable pitch propeller 10. Figure 5(a) is an example of the first control pattern. In Figure 5(a), when the Beaufort wind scale becomes BF7, the output exceeds the ALC setting curve, and the operating point becomes point A on the BF7 line, and an ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the order is from top to bottom: FI line, BF7 line, and the upper limit line of the dead zone of the ALC setting curve. The output is reduced by changing the blade angle while keeping the rotation speed constant, and the operating point becomes point A' on the ALC setting curve. Note that if the operating point falls within the range of the ALC setting curve without changing the blade angle of the controllable pitch propeller 10 due to the reselection of the ALC setting curve, the control proceeds directly to fuel index control, and automatic control is performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The first control pattern of case α does not change the rotation speed, so the load on the main engine 20 is small, and the operating point can be selected by changing the ALC setting curve.

[0052] In the second control pattern, the operation control means 60 performs automatic control to simultaneously change the rotation speed by the governor 30 and the blade angle of the controllable pitch propeller 10 toward a target operating point set within the range of the ALC setting curve. The operating point is set according to the purpose while satisfying the control conditions of the governor 30 and the controllable pitch propeller 10. Figure 5(b) is an example of the second control pattern. In Figure 5(b), when the Beaufort wind scale becomes BF7, the output exceeds the ALC setting curve, and the operating point becomes point A on the BF7 line, and an ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the order is from top to bottom: FI line, BF7 line, and the upper limit line of the dead zone of the ALC setting curve. The rotation speed is increased and the output is decreased by changing the blade angle, and the operating point becomes point C on the upper limit line of the dead zone of the ALC setting curve. Note that if the operating point falls within the range of the ALC setting curve without changing the rotation speed or the blade angle of the controllable pitch propeller 10 due to the reselection of the ALC setting curve, the control proceeds to fuel index control, and automatic control is performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The second control pattern of Case α makes it possible to select the optimal operating point (engine speed, main engine output) based on fuel efficiency and vessel speed conditions, and as shown in Figure 5(b), makes it possible to select an operating point that minimizes fluctuations in engine speed while mitigating vessel speed reduction more than the third pattern of the second control method (see Figure 4(c)).

[0053] Figure 6 shows the case where the main engine output at the specified RPM is at the position where, from the top, the BF line, the FI line, and the upper limit line of the dead zone of the ALC setting curve are located when the ALC setting curve is reselected (Case β). In this case, there are three control patterns. The lower diagram in Figure 6 is an enlarged portion of the upper diagram. In the first control pattern, the ship operation control means 60 controls the rotation speed to a constant as a control condition of the governor 30, and performs automatic control to place the operating point within the range of the ALC setting curve by changing the blade angle of the controllable pitch propeller 10. In this control pattern, the control of the controllable pitch propeller 10 is followed by the control of the governor 30. The black arrow in the lower diagram of Figure 6 shows an example of the first control pattern. When the Beaufort wind scale becomes BF7 and the main engine output at the specified speed exceeds the ALC setting curve and becomes point A on the BF7 line, an ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the order is from top to bottom: BF7 line, FI line, and the upper limit line of the dead zone of the ALC setting curve. The output is reduced by changing the blade angle while keeping the speed constant, and the operating point is set to point A' on the ALC setting curve (A → BF0). Note that if the operating point falls within the range of the ALC setting curve without changing the blade angle of the controllable pitch propeller 10 due to the reselection of the ALC setting curve, the control will switch to fuel index control as it is, and automatic control will be performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The first control pattern of case β makes it possible to select an operating point without changing the rotation speed.

[0054] In the second control pattern, the operation control means 60 changes the rotation speed using the governor 30 to reduce the output to the intersection of the BF line and the FI line for the wind speed at that time, then controls the rotation speed to a constant as a control condition for the governor 30, and performs automatic control by changing the blade angle of the controllable pitch propeller 10 to bring the operating point within the range of the ALC setting curve. In this control pattern, the control of the controllable pitch propeller 10 is performed after the control of the governor 30. The white arrow in the lower diagram of Figure 6 shows an example of the second control pattern. When the Beaufort wind scale becomes BF7 and the main engine output at the specified speed exceeds the ALC setting curve and becomes point A on the BF7 line, the ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the order is from top to bottom: BF7 line, FI line, and the upper limit line of the dead zone of the ALC setting curve. First, the speed is reduced to reduce the output to point B (the intersection of the BF7 line and the FI line), and then the blade angle is changed while keeping the speed constant, reducing the output to point B' on the ALC setting curve (B → BF0). Note that if the operating point falls within the range of the ALC setting curve without changing the speed or the blade angle of the controllable pitch propeller 10 by reselecting the ALC setting curve, the control will proceed to fuel index control, and automatic control will be performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The second control pattern of case β can improve the fuel saving effect more than the first control pattern of case β. Also, the operating point can be selected without changing the output and the rotation speed as much as possible.

[0055] In the third control pattern, the ship operation control means 60 performs automatic control to simultaneously change the rotation speed by the governor 30 and the blade angle of the controllable pitch propeller 10 toward a target operating point set within the range of the ALC setting curve. The operating point is set according to the purpose while satisfying the control conditions of the governor 30 and the controllable pitch propeller 10. The diagonal arrow in the lower diagram of Figure 6 shows an example of the third control pattern. When the Beaufort wind scale becomes BF7 and the main engine output at the specified speed exceeds the ALC setting curve and becomes point A on the BF7 line, an ALC setting curve along the BF0 line is selected from the three ALC setting curves, and the order is from top to bottom: BF7 line, FI line, and the upper limit line of the dead zone of the ALC setting curve. The operating point is set to point C on the ALC setting curve by increasing the speed and changing the blade angle. The output at point C is approximately the same as the output at point A. Note that if the operating point falls within the range of the ALC setting curve without changing the speed or the blade angle of the controllable pitch propeller 10 due to the reselection of the ALC setting curve, the control proceeds to fuel index control, and automatic control is performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The third control pattern of Case β allows the operating point to be freely set, such as an operating point that does not change the boat speed while satisfying the ALC and FI control conditions.

[0056] In this way, in case β, all control patterns have an operating point on the ALC setting curve. However, the final operating point differs between the first control pattern (when controlling in the order of controllable pitch propeller 10 → governor 30), the second control pattern (when controlling in the order of governor 30 → controllable pitch propeller 10), and the third control pattern (when an operating point according to the purpose is set while satisfying the control conditions of the controllable pitch propeller 10 and governor 30). The condition of selecting one of multiple ALC setting curves can be applied to all control patterns, and operation according to the purpose is possible.

[0057] Figure 7 shows the case where the main engine output at the specified RPM is located at the BF line, the upper limit line of the dead zone of the ALC setting curve, and the FI line (Case γ) when the ALC setting curve is reselected. In this case, there are three control patterns. The lower diagram in Figure 7 is an enlarged portion of the upper diagram. In the first control pattern, the operation control means 60 controls the rotation speed to a constant as a control condition of the governor 30, changes the blade angle of the controllable pitch propeller 10 to bring the output within the range of the ALC setting curve, and then changes the rotation speed to perform automatic control to align the operating point with the intersection of the ALC setting curve and the FI line. In this control pattern, the control of the controllable pitch propeller 10 is followed by the control of the governor 30. The black arrow in the lower diagram of Figure 7 shows an example of the first control pattern. When the Beaufort wind scale becomes BF7 and the main engine output at the specified speed exceeds the ALC setting curve and becomes point A on the BF7 line, the ALC setting curve along the BF0 line is selected from the three ALC setting curves. From the top, the BF7 line, the upper dead zone line of the ALC setting curve, the ALC setting curve, and the FI line are in this order. First, the output is reduced by changing the blade angle while keeping the speed constant, and the output is set to point A' on the ALC setting curve (A → BF0). Next, the output is reduced by decreasing the speed, and the operating point is set to point A'' which is the intersection point of the ALC setting curve and the FI line (BF0 → A''). If the operating point falls within the range of the ALC setting curve without changing the speed or the blade angle of the controllable pitch propeller 10 by reselecting the ALC setting curve, the control proceeds to fuel index control, and automatic control is performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The first control pattern of case γ can select an operating point while changing the rotation speed as little as possible.

[0058] In the second control pattern, the operation control means 60 changes the rotation speed using the governor 30 to change the output to the intersection of the BF line and the FI line at the wind speed at that time, then controls the rotation speed to a constant as a control condition of the governor 30, and performs automatic control by changing the blade angle of the controllable pitch propeller 10 to bring the operating point within the range of the ALC setting curve. In this control pattern, the control of the controllable pitch propeller 10 is performed after the control of the governor 30. The white arrow in the lower diagram of Figure 7 shows an example of the second control pattern. When the Beaufort wind scale becomes BF7 and the main engine output at the specified speed exceeds the ALC setting curve and becomes point A on the BF7 line, the ALC setting curve along the BF0 line is selected from the three ALC setting curves. From the top, the BF7 line, the upper dead zone line of the ALC setting curve, the ALC setting curve, and the FI line are selected in this order. First, the speed is reduced to reduce the output to point B (the intersection of the BF7 line and the FI line), and then the blade angle is changed while keeping the speed constant to reduce the output to point B' on the ALC setting curve. If the operating point falls within the range of the ALC setting curve without changing the speed or the blade angle of the controllable pitch propeller 10 by reselecting the ALC setting curve, the control proceeds to fuel index control, and automatic control is performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The second control pattern of case γ can improve the fuel saving effect more than the first control pattern of case γ.

[0059] In the third control pattern, the ship operation control means 60 performs automatic control to simultaneously change the rotation speed by the governor 30 and the blade angle of the controllable pitch propeller 10 toward a target operating point set within the range of the ALC setting curve. The operating point is set according to the purpose while satisfying the control conditions of the governor 30 and the controllable pitch propeller 10. The diagonal arrow in the lower diagram of Figure 7 shows an example of the third control pattern. When the Beaufort wind scale becomes BF7 and the main engine output at the specified speed exceeds the ALC setting curve and becomes point A on the BF7 line, an ALC setting curve along the BF0 line is selected from the three ALC setting curves. From the top, the BF7 line, the upper dead zone upper line of the ALC setting curve, the ALC setting curve, and the FI line are in this order, and the speed is increased while the blade angle is changed to decrease the output, and the operating point is set to point C on the lower dead zone lower line of the ALC setting curve. Point C is the intersection point of the FI line and the lower dead zone lower line of the ALC setting curve. Note that if the operating point falls within the range of the ALC setting curve without changing the speed or the blade angle of the controllable pitch propeller 10 by reselecting the ALC setting curve, the control proceeds to fuel index control, and automatic control is performed so that the operating point does not deviate from the range of the reselected ALC setting curve. The third control pattern for case γ allows the operating point to be freely set while satisfying the conditions for ALC and FI control.

[0060] In this way, the third control method combines the fuel index control and ALC control of the governor 30 by controlling the control conditions of the governor 30 based on the fuel index and settling them to the operating point of the selected ALC setting curve when the load condition exceeds the selected ALC setting curve, thereby enabling the governor 30 to be set to the operating point of the selected ALC setting curve.

[0061] Next, a fourth control method will be described in which a plurality of ALC setting curves are set for the ALC and an operating point is selected in combination with the control of the governor 30 and the automatic ship speed control (ASC). The fourth control method is to control the governor 30 and the controllable pitch propeller 10 according to the control conditions of the governor 30 when the vessel speed changes and exceeds the selected ALC setting curve, and to settle them to the operating point of the selected ALC setting curve. There are two patterns as follows: Figure 8 shows the first pattern of the fourth control method, where Figure 8(a) is a diagram showing the relationship between ship speed V [knots] and output P [kW], and Figure 8(b) is a diagram showing the relationship between propeller speed NP [rpm] and output P [kW]. The first pattern of the fourth control method is a control method when the ship does not use wind propulsion. When the ship speed exceeds the ASC lower limit or the ASC upper limit, the navigation control means 60 reselects one of the three ALC setting curves. If the relationship between the propeller speed and the output is within the range of the reselected ALC setting curve, the speed is controlled to be constant as a control condition of the governor 30, and the blade angle of the controllable pitch propeller 10 is changed to control the ship speed to be within the range of the ASC. On the other hand, if the relationship between the propeller speed and the main engine output is outside the range of the reselected ALC setting curve, automatic control is performed to bring the operating point within the range of the ALC setting curve. In the example of Figure 8, when the Beaufort wind scale changes from BF0 to BF7 and the ship speed drops below the ASC lower limit to point A on the BF7 line, if an ALC setting curve along the BF0 line is selected from the three ALC setting curves, the output will exceed the upper limit of the dead zone of the ALC setting curve and reach point A on the BF7 line. Therefore, the output is increased by increasing the rotation speed and changing the blade angle, and the ship speed is set to point D within the ASC range as shown in Figure 8(a), and the operating point is set to point D on the upper limit of the dead zone of the ALC setting curve as shown in Figure 8(b). In this way, if a change in the ship's speed causes the main engine output to exceed the selected ALC setting curve, the governor and controllable pitch propeller are controlled in accordance with the governor's control conditions and set to the operating point of the selected ALC setting curve, thereby controlling the ship speed to remain within a specified range in response to the change in ship speed and settling it to the operating point of the selected ALC setting curve, thereby contributing to energy-saving operation.

[0062] FIG. 9 is a graph showing the relationship between boat speed V [knots] and power P [kW] in the second pattern of the fourth control method, where FIG. 9(a) shows the case of a tailwind and FIG. 9(b) shows the case of a headwind. The second pattern of the fourth control method is a control method when the ship is wind-propulsed. When the ship speed exceeds the upper or lower limit of the ASC, the navigation control means 60 reselects one of the three ALC setting curves. In ASC mode, when sailing using wind propulsion in a port where port regulations limit speed, tailwinds can cause the ship's speed to exceed the speed limit. Therefore, when a tailwind occurs while sailing in a port using wind propulsion, the control speed is adjusted to the ASC lower limit to allow for some leeway. In the example of Figure 9(a), when the Beaufort wind scale changes from BF0 to BF7 and the ship's speed exceeds the ASC upper limit and rises to point A on the BF7 line, control is performed at point A' where the BF7 line and the ASC lower limit line intersect. By setting the control speed to the lower speed side in this way, it is possible to prevent the ship from exceeding the speed limit due to tailwinds. On the other hand, when a ship's speed drops due to a headwind while sailing in a harbor using wind propulsion, the control speed is adjusted to the ASC upper limit so that the ship can withstand sudden gusts of wind. In the example of Figure 9(b), when the Beaufort wind scale changes from BF0 to BF7 and the ship's speed drops below the ASC lower limit to point A on the BF7 line, control is performed at point A'' where the BF7 line and the ASC upper line intersect. By setting the control speed to the higher side in this way, the ship's speed can be quickly restored by adjusting the blade angle when the speed drops in response to gusts of wind.

[0063] Furthermore, the navigation control means 60 in the fourth control method automatically changes the speed in the wind propulsion control (or rudder angle control). How the speed is changed depends on the size and direction of the waves, wind, and currents, but for example, it is changed as follows. (1) In conditions where the weather and sea conditions are relatively calm, such as when the Beaufort wind scale is BF0 or BF1, the speed of wind propulsion control (or rudder angle control) should basically be normal speed. (2) When wind speed (wave height, wave period, and current speed) increases, the speed of wind propulsion control (or rudder angle control) is made faster than the normal speed. (3) When wind speed (wave height, wave period, and current speed) decreases, the wind propulsion control (or rudder angle control) speed is set to the normal speed or slower than the normal speed. (4) When the wind direction (wave direction, current direction) is horizontal to the ship, the speed of wind propulsion control (or rudder angle control) is made faster than normal to prevent the ship from drifting sideways. (5) When the wind direction (wave direction, current direction) is following in a harbor, the wind propulsion control (or rudder angle control) speed is made faster than normal to prevent the speed limit from being exceeded due to gusts of wind.

[0064] As described above, by setting a plurality of ALC setting curves that represent the relationship between the rotational speed at ALC of the controllable pitch propeller 10 that propels the ship and the output of the main engine 20 that drives the controllable pitch propeller 10, and selecting one of the plurality of ALC setting curves in accordance with the load state of the main engine 20, and controlling the governor 30 and the controllable pitch propeller 10 in accordance with the control conditions of the governor 30 that adjusts the fuel supplied to the main engine 20 and the selected ALC setting curve, it is possible, from the standpoint of energy conservation, to select the optimal operating point for the blade angle and rotational speed of the controllable pitch propeller 10 in accordance with the load state of the main engine due to weather and sea conditions, for example. The combination of control of the governor 30 and control of the controllable pitch propeller 10 maximizes the energy-saving effect as a whole, thereby achieving more energy-saving operation than ever before.

[0065] In addition, in the above-mentioned first to fourth control methods, the final rotation speed and therefore the ship speed may change depending on the order in which the governor 30 and the controllable pitch propeller 10 are controlled, but in actual operation, the duration of the voyage is fixed, and if the rotation speed drops too much, the ship will not arrive on the scheduled date. Therefore, it is preferable that the weather and sea condition information acquisition means 70 acquires weather and sea condition information, and the operation control means 60 controls the governor 30 and the controllable pitch propeller 10 by combining any one of the first to fourth control methods with weather routing based on the voyage schedule and the weather and sea condition information. This allows the optimal control to be selected according to the purpose, taking into account the number of days the ship is at sea, enabling energy-saving operation to be achieved while keeping to the scheduled arrival date. [Industrial Applicability]

[0066] The present invention focuses on a method of combining control of a ship's governor with automatic load control of a controllable pitch propeller, and can be used for energy-saving operation of ships sailing in actual sea areas, ship control systems, etc. [Explanation of symbols]

[0067] 1,2,3 ALC setting curve 10 Controllable Pitch Propeller 20 Main engine 30 Governor 40 Rotational speed detection means 50 Output detection means 60 Navigation control means 70 Means of acquiring weather and oceanographic information 80 Load information acquisition means

Claims

1. An energy-saving operation method for a ship, comprising: a governor that adjusts fuel supplied to the main engine and a control condition of the governor and the controllable pitch propeller in accordance with the selected ALC setting curve; and a control condition of the governor that adjusts fuel supplied to the main engine and the selected ALC setting curve.

2. 2. The energy-saving operation method for a ship according to claim 1, wherein the plurality of ALC setting curves are a curve with good fuel consumption rate and a curve with low ship speed but small output and fuel consumption.

3. 3. The energy-saving operation method for a ship according to claim 2, wherein the plurality of ALC setting curves are curves that produce a ship speed.

4. 4. The energy-saving operation method for a ship as described in claim 3, characterized in that, when the load state exceeds the selected ALC setting curve, the rotation speed is controlled to be constant as the control condition of the governor, and is stabilized at an operating point of the selected ALC setting curve.

5. 4. The energy-saving operation method for a ship as described in claim 3, characterized in that, when the load state exceeds the selected ALC setting curve, the output is controlled to be constant as the control condition of the governor, and is stabilized at an operating point of the selected ALC setting curve.

6. 4. The energy-saving operation method for a ship as described in claim 3, characterized in that, when the load state exceeds the selected ALC setting curve, the control conditions of the governor are controlled based on a fuel index and are set to an operating point of the selected ALC setting curve.

7. 4. The energy-saving operation method for a ship as described in claim 3, characterized in that when the ship speed changes and exceeds the selected ALC setting curve, the governor and the controllable pitch propeller are controlled in accordance with the control conditions of the governor, and are set to an operating point of the selected ALC setting curve.

8. An energy-saving operation method for a ship, comprising: An energy-saving ship operation method, comprising: acquiring meteorological and oceanographic information; combining the energy-saving ship operation method described in any one of claims 4 to 7 with weather routing based on the meteorological and oceanographic information; and operating the ship while taking into account the number of days the ship is at sea.

9. An energy-saving navigation system for a ship, comprising:

1. An energy-saving ship operation system comprising: a controllable pitch propeller for propelling the ship; a main engine for driving the controllable pitch propeller; a governor for adjusting fuel supplied to the main engine; rotation speed detection means for detecting the rotation speed of the main engine; output detection means for detecting the output of the main engine; and operation control means for controlling the controllable pitch propeller and the governor based on the rotation speed and the output, wherein the operation control means has a plurality of ALC setting curves that represent the relationship between the rotation speed and the output of the main engine in ALC (automatic load control) of the controllable pitch propeller, selects one of the plurality of ALC setting curves in accordance with the load state of the main engine, and controls the governor and the controllable pitch propeller in accordance with the set control conditions of the governor and the selected ALC setting curve.

10. 10. An energy-saving ship operation system as described in claim 9, wherein the plurality of ALC setting curves of the operation control means are a curve with good fuel consumption rate and a curve with low ship speed but small output and fuel consumption.

11. 11. The energy-saving navigation system for a ship according to claim 10, wherein the plurality of ALC setting curves of the navigation control means are curves that result in a ship speed.

12. The energy-saving navigation system for a ship as described in claim 11, characterized in that, when the load state exceeds the selected ALC setting curve, the navigation control means controls the rotation speed to a constant value as the control condition of the governor, and settles it at an operating point of the selected ALC setting curve.

13. The energy-saving navigation system for a ship as described in claim 11, characterized in that, when the load state exceeds the selected ALC setting curve, the navigation control means controls the output to a constant value as the control condition of the governor, and settles it at an operating point of the selected ALC setting curve.

14. The energy-saving navigation system for a ship as described in claim 11, characterized in that, when the load state exceeds the selected ALC setting curve, the navigation control means controls the control conditions of the governor based on a fuel index and sets them to an operating point of the selected ALC setting curve.

15. 12. The energy-saving ship navigation system according to claim 11, wherein the navigation control means controls the governor and the controllable pitch propeller in accordance with the control conditions of the governor when the ship speed changes and exceeds the selected ALC setting curve, and settles them to an operating point of the selected ALC setting curve.

16. An energy-saving navigation system for a ship, comprising: An energy-saving ship operation system comprising a meteorological and oceanographic information acquisition means for acquiring meteorological and oceanographic information, and an operation control means in the energy-saving ship operation system described in any one of claims 9 to 15, characterized in that it controls weather routing based on the meteorological and oceanographic information in combination.

17. An energy-saving ship operation system as described in claim 16, characterized in that it is equipped with a load information acquisition means for acquiring load information applied to the ship, and the operation control means predicts and controls the load condition of the main engine based on the load information.

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