Ship propulsion system and ship

Abstract

To provide a ship propulsion system that can improve stability of a hull and improve riding comfort during waves, and a ship.SOLUTION: A ship propulsion system 102 comprises: a propeller 1 provided on a hull 101; a vertical motion sensor 2b which measures at least one of a vertical speed and a vertical acceleration of the hull 101; and a control part 4 that performs wave control including posture control for reducing vertical postural change of the hull 101 by temporarily reducing a ship speed at each timing of overcoming each wave on the basis of the measurement result of the vertical motion sensor 2b during waves. The control part 4 performs wave direction determination for determining whether the wave state relative to the hull 101 is heading wave or following wave on the basis of at least the measurement result of the vertical motion sensor 2b in wave control. The control part performs the posture control when determining by wave direction determination that the wave state is heading wave, and does not perform the posture control when determining by wave direction determination that the wave state is following wave.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a boat propulsion system that controls propulsion speed, and to a boat. [Background technology]

[0002] 2. Description of the Related Art Conventionally, ships equipped with propulsion units whose drive is controlled in accordance with wave conditions are known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a boat including an outboard motor, an engine speed sensor that detects the rotation speed of the outboard motor's engine, and a control unit. The control unit is configured to detect the amount of wave load on the engine, which indirectly indicates the impact that the hull receives from waves, based on the detection result of the engine speed sensor, and to correct the throttle opening in accordance with the amount of load. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-97309 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the ship described in the above Patent Document 1, control is performed simply taking into consideration the magnitude of the impact the hull receives as the wave condition, and appropriate control according to the wave condition is not sufficiently performed, so it cannot be said that the stability of the hull is sufficiently ensured. Therefore, it is desired to improve the stability of the hull in rough waves and improve the ride comfort.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a ship propulsion system and a ship that can improve the stability of the hull in rough waves and improve the ride comfort. [Means for solving the problem]

[0007] In order to solve the above problems, a ship propulsion system according to a first aspect of the present invention comprises a propulsion unit provided on the hull, a vertical movement sensor that measures at least one of the vertical speed and vertical acceleration of the hull, and a control unit configured to control the drive of the propulsion unit and perform wave control including attitude control that temporarily reduces the ship speed each time the hull overcomes a wave based on the measurement results of the vertical movement sensor during rough waves, thereby reducing changes in the vertical attitude of the hull.The control unit is configured, in the wave control, to perform wave direction determination based on at least the measurement results of the vertical movement sensor to determine whether the wave conditions relative to the hull are head waves or following waves, and is configured to perform attitude control if the wave direction determination determines that the waves are heading waves, and not to perform attitude control if the wave direction determination determines that the waves are following waves.

[0008] In the ship propulsion system according to the first aspect, as described above, a control unit is provided that performs wave control including posture control to reduce the change in the vertical posture of the hull by temporarily reducing the ship speed at each time the hull rides over each wave based on the measurement results of the vertical movement sensor during rough waves, and the control unit is configured to perform wave direction determination to determine whether the wave state relative to the hull is a head wave or a following wave based on at least the measurement results of the vertical movement sensor in the wave control, and to perform posture control when the wave direction determination determines that the wave is a heading wave, and to not perform posture control when the wave direction determination determines that the wave is a following wave. This makes it possible to distinguish between following waves and head waves, and to stabilize the hull by temporarily reducing the ship speed at each time the hull rides over each wave in the case of a heading wave, which is likely to cause a large impact on the hull. It is also possible to avoid the ship speed temporarily reducing at each time the hull rides over each wave in the case of a following wave, in which the hull is likely to become unstable if the ship speed is reduced. Therefore, it is possible to perform control according to the wave direction by taking into account the wave direction, which was not considered in the past, and therefore it is possible to improve the stability of the hull during rough waves and improve the ride comfort. In addition, posture control can temporarily reduce the ship speed each time it rides over a head wave, thereby preventing the ship from riding over waves with too much force.

[0009] In the vessel propulsion system according to the first aspect, the control unit is preferably configured to perform speed control, which is included in wave control and adjusts the vessel speed to a target vessel speed, which is a target value for the vessel speed, in both head waves and following waves. With this configuration, not only is attitude control performed in head waves, but speed control is also performed in both head waves and following waves, making it possible to suppress speed in rough waves, thereby further improving the stability of the vessel in rough waves and improving the ride comfort.

[0010] In this case, the speed control is preferably a control that adjusts the ship speed to reduce the impact when riding over each wave, and the control unit is configured to perform speed control regardless of whether the result of the wave direction determination is a head wave or a following wave. With this configuration, not only is attitude control performed in the case of a head wave, but speed control is performed in both head waves and following waves, thereby further reducing the impact. As a result, the stability of the hull in rough waves can be further improved, further improving the ride comfort.

[0011] In a configuration in which the wave control includes speed control for adjusting the ship speed based on the measurement results of the vertical motion sensor to reduce the impact when riding over each wave, the control unit is preferably configured to perform wave direction determination based on a target ship speed for reducing at least the vertical acceleration / deceleration of the hull in the speed control. With this configuration, wave direction determination can be performed based on the target ship speed, which is a target value of the ship speed for reducing the vertical acceleration / deceleration of the hull, so that the vertical acceleration / deceleration of the hull can be effectively reduced.

[0012] In the configuration in which the control unit judges the wave direction based on the target vessel speed, the target vessel speed preferably includes a limited target vessel speed that sets a predetermined limit on the amount of vessel speed change so that the difference between the actual vessel speed and the target vessel speed is reduced. With this configuration, the limited target vessel speed that sets a predetermined limit on the amount of vessel speed change can suppress sudden acceleration and deceleration of the vessel.

[0013] In the configuration for determining wave direction based on the target ship speed, the control unit is preferably configured to determine that the waves are heading waves and perform posture control when it determines that the determined ship speed difference, which is the difference between the target ship speed and the ship speed at the start of speed control, is greater than a predetermined wave direction determination threshold, and to determine that the waves are following waves and not perform posture control when it determines that the determined ship speed difference is equal to or less than the wave direction determination threshold. With this configuration, it is possible to more appropriately determine heading waves, which make it difficult to bring the target ship speed close to the ship speed at the start of speed control, and following waves, which make it easy to bring the target ship speed close to the ship speed at the start of speed control.

[0014] In the above-mentioned configuration in which the control unit performs speed control to adjust the vessel speed to a target vessel speed, which is a target value of the vessel speed, in both head and following waves, preferably, in the speed control, an upper limit is set for the rate of change of the actual vessel speed that changes toward the target vessel speed, and the control unit performs control to increase the upper limit of the rate of change when the difference between the target vessel speed and the actual vessel speed is equal to or greater than a first threshold value. With this configuration, the vessel speed can be made to follow the target vessel speed according to the wave conditions more quickly.

[0015] In the vessel propulsion system according to the first aspect, the control unit is preferably configured to perform attitude control in addition to speed control when it is determined that the wave direction is a head wave in the wave direction determination, and when it is determined that the vertical speed or vertical acceleration of the hull is equal to or greater than a predetermined second threshold value based on the measurement result of the vertical movement sensor while performing speed control and not attitude control. With this configuration, compared to the case where only speed control is performed, when both speed control and attitude control are performed, it is possible to reduce sudden deceleration and reduction in average speed. In addition, by not performing attitude control for small waves and riding over waves only with speed control, it is possible to reduce speed change and improve the stability of the hull. For large waves equal to or greater than the second threshold value, it is possible to prevent takeoff and reduce impact and attitude change after riding over waves more than when only speed control is performed by performing both attitude control and speed control.

[0016] In the configuration for determining wave direction based on the target ship speed, the control unit is preferably configured to adjust the ship speed based on a moving average value of the vertical speed or vertical acceleration of the hull in the speed control to reduce the impact when riding over each wave, and to set the target ship speed based on the moving average value to determine the wave direction. With this configuration, the moving average value of the vertical speed or vertical acceleration of the hull can be taken into account in the speed control, so that instantaneous changes or changes over a relatively short period in the vertical speed or vertical acceleration of the hull can be suppressed from affecting the wave direction determination in the speed control.

[0017] In the marine vessel propulsion system according to the first aspect, the propulsion unit preferably includes at least one of an engine and an electric motor as a drive source that generates thrust, and the control unit performs attitude control by reducing the output of the engine or the electric motor to slow down the vessel speed. With this configuration, attitude control can be easily performed by reducing the vessel speed by adjusting the output of the engine or the electric motor.

[0018] The vessel propulsion system according to the first aspect preferably further comprises an attitude adjustment body that is provided on the hull and adjusts the pitch of the hull by changing its position relative to the hull to provide resistance to the water current, and the control unit performs attitude control that adjusts the attitude of the hull by varying the pitch of the hull with the attitude adjustment body during rough waves. With this configuration, it is possible to stabilize the hull while suppressing a decrease in vessel speed by adjusting the attitude adjustment body, compared to when the throttle valve is adjusted in attitude control.

[0019] In the vessel propulsion system according to the first aspect, the control unit is preferably configured in the wave control to perform high wave judgment based on the measurement results of the vertical motion sensor during high waves to determine whether the vertical speed or vertical acceleration of the hull is equal to or greater than a predetermined high wave judgment threshold, and is configured to perform attitude control regardless of the result of the wave direction judgment when it is determined by the high wave judgment that the vertical speed or vertical acceleration of the hull is equal to or greater than the high wave judgment threshold. With this configuration, attitude control can be reliably performed in high waves that tend to make the hull unstable, whether the waves are following or heading.

[0020] In the vessel propulsion system according to the first aspect, preferably, an operation unit is further provided that receives an operation to start wave control and an operation to end wave control, and the control unit is configured to determine a wave direction to determine whether the wave is a heading wave or a following wave when the operation unit is operated as a trigger. With this configuration, the operation unit can easily start and end wave control.

[0021] In the vessel propulsion system according to the first aspect, the control unit is preferably configured to maintain the vessel speed without performing attitude control when the wave direction is determined to be following waves. With this configuration, the vessel speed can be maintained in following waves, and it is possible to prevent the vessel speed from decreasing and the vessel becoming unstable in following waves.

[0022] In the marine vessel propulsion system according to the first aspect, the propulsion unit preferably includes an engine having a throttle valve, and the control unit is configured to perform subtraction processing for subtracting the opening of the throttle valve based on the vertical speed of the hull in attitude control, thereby reducing changes in the vertical attitude of the hull. With this configuration, the stability of the hull in rough waves can be improved, thereby improving the ride comfort, by subtracting the opening of the throttle valve of the engine-type propulsion unit in attitude control.

[0023] In a configuration in which the wave control includes speed control, the control unit is preferably configured to reduce impact by changing the ship speed to reduce the vertical acceleration / deceleration of the ship based on the moving average value of the vertical speed or vertical acceleration of the ship and the probability density distribution of wave height occurrence in the speed control. With this configuration, the moving average value of the vertical speed or vertical acceleration of the ship can be taken into account in the speed control, so that it is possible to suppress the influence of instantaneous changes or changes over a relatively short period of time in the vertical speed or vertical acceleration of the ship on the wave direction determination. In addition, the amount of reduction in the vertical acceleration / deceleration of the ship can be more accurately determined by changing the ship speed, taking into account the probability density distribution of wave height occurrence.

[0024] A ship according to a second aspect of the present invention comprises a hull and a ship propulsion system provided on the hull, the ship propulsion system including a propulsion unit provided on the hull, a vertical movement sensor that measures at least one of the vertical speed and vertical acceleration of the hull, and a control unit configured to control the drive of the propulsion unit and perform wave control including attitude control that temporarily reduces the ship speed each time the hull overcomes a wave based on the measurement results of the vertical movement sensor during rough waves to reduce changes in the vertical attitude of the hull, and the control unit is configured, in the wave control, to perform wave direction determination based on at least the measurement results of the vertical movement sensor to determine whether the wave conditions relative to the hull are head waves or following waves, and is configured to perform attitude control when the wave direction determination determines that the waves are heading waves, and not perform attitude control when the wave direction determination determines that the waves are following waves.

[0025] In the ship according to the second aspect, as described above, a control unit is provided that performs wave control including posture control for reducing the change in the vertical posture of the hull by temporarily reducing the ship speed at each time the ship rides over each wave based on the measurement results of the vertical movement sensor during rough waves, and the control unit is configured to perform wave direction determination for determining whether the wave state relative to the hull is a head wave or a following wave based on at least the measurement results of the vertical movement sensor in the wave control, and is configured to perform posture control when the wave direction determination determines that the wave is a heading wave, and not perform posture control when the wave direction determination determines that the wave is a following wave. This makes it possible to distinguish between following waves and head waves, and to stabilize the hull by temporarily reducing the ship speed at each time the ship rides over each wave in the case of a heading wave, which is likely to cause a large impact on the hull. It is also possible to avoid the ship speed temporarily reducing at each time the ship rides over each wave in the case of a following wave, in which the hull is likely to become unstable if the ship speed is reduced. Therefore, it is possible to perform control according to the wave direction by taking into account the wave direction, which was not considered in the past, and it is possible to provide a ship that can improve the stability of the hull during rough waves and improve the ride comfort. In addition, posture control can temporarily reduce the ship speed each time it rides over a head wave, thereby preventing the ship from riding over waves with too much force.

[0026] In the ship according to the second aspect, the control unit is preferably configured to perform speed control, which is included in wave control and adjusts the ship speed to a target ship speed, which is a target value for the ship speed, in both head waves and following waves. With this configuration, not only is attitude control performed in head waves, but speed control is also performed in both head waves and following waves, making it possible to suppress speed in rough waves, thereby further improving the stability of the hull in rough waves and improving the ride comfort.

[0027] In this case, the speed control is preferably a control that adjusts the ship speed to reduce the impact when riding over each wave, and the control unit is configured to perform speed control regardless of whether the result of the wave direction determination is a head wave or a following wave. With this configuration, not only is attitude control performed in the case of a head wave, but speed control is performed in both head waves and following waves, thereby further reducing the impact. As a result, the stability of the hull in rough waves can be further improved, and the ride comfort can be further improved.

[0028] In a configuration in which the wave control includes speed control for adjusting the ship speed based on the measurement results of the vertical motion sensor to reduce the impact when riding over each wave, the control unit is preferably configured to perform wave direction determination based on a target ship speed for reducing at least the vertical acceleration / deceleration of the hull in the speed control. With this configuration, wave direction determination can be performed based on the target ship speed, which is a target value of the ship speed for reducing the vertical acceleration / deceleration of the hull, so that the vertical acceleration / deceleration of the hull can be effectively reduced. Effect of the Invention

[0029] According to the present invention, as described above, it is possible to improve the stability of the hull in rough seas and thereby improve the riding comfort. [Brief description of the drawings]

[0030] [Figure 1] 1 is a perspective view showing a vessel equipped with a vessel propulsion system according to a first (second, third, or fourth) embodiment. [Diagram 2] 1 is a block diagram of a marine vessel propulsion system according to a first embodiment. [Diagram 3] 11 is a diagram for explaining a control configuration for attitude control of a control unit. FIG. [Figure 4] 13 is a graph showing the relationship between time, the up and down movement of the hull, and the throttle opening degree when attitude control is performed. [Diagram 5] 4 is a diagram for explaining a control configuration of speed control in a control unit. FIG. [Figure 6] 1 is a graph showing a probability density distribution of wave height occurrence. [Figure 7] 13 is a graph showing the relationship between time and the hull vertical acceleration when speed control is executed. [Figure 8] 5 is a flowchart of wave control performed by a control unit of the marine vessel propulsion system according to the first embodiment. [Figure 9] 10 is a flowchart of wave control performed by a control unit of a marine vessel propulsion system according to a second embodiment. [Figure 10] 13 is a flowchart of wave control performed by a control unit of a marine vessel propulsion system according to a third embodiment. [Figure 11] FIG. 11 is a block diagram of a marine vessel propulsion system according to a fourth embodiment. [Figure 12] 13 is a flowchart of wave control performed by a control unit of a marine vessel propulsion system according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, an embodiment will be described with reference to the drawings.

[0032] [First embodiment] (Overall configuration of the ship) The configuration of a vessel 100 equipped with a vessel propulsion system 102 according to a first embodiment will be described with reference to Figures 1 to 6. Note that FWD in Figure 1 indicates the forward direction of the vessel 100 (forward with respect to the hull 101), and BWD indicates the reverse direction of the vessel 100 (rearward with respect to the hull 101).

[0033] 1, a boat 100 includes a hull 101 and a boat propulsion system 102 including a propulsion unit 1. The boat propulsion system 102 is provided in the hull 101.

[0034] (Hull configuration) A propulsion unit 1 is attached to the transom of the hull 101. The propulsion unit 1 is an outboard motor. That is, the boat 100 is configured as an outboard motor boat having an outboard motor as the propulsion unit 1.

[0035] (Configuration of ship propulsion system) 2, the vessel propulsion system 102 includes a propulsion unit 1, a GPS 2a, a vertical movement sensor 2b, an operation panel 3a, a remote control lever 3b, and a control unit 4 that controls the drive of the propulsion unit 1. The operation panel 3a is an example of the "operation unit" in the claims.

[0036] (Propulsion unit configuration) As shown in FIG. 3, the propulsion unit 1 includes an engine 10, a propeller 11, a drive shaft 12, and a propeller shaft 13. The engine 10 is an internal combustion engine having a throttle valve 10a, and is configured to generate driving force by burning fuel and rotating a crankshaft (not shown). The opening of the throttle valve 10a is adjusted by a remote control lever 3b. The engine 10 is provided with a crank angle sensor (not shown) that measures the engine speed. The propeller 11 is configured to be rotationally driven by the driving force generated in the engine 10. The drive shaft 12 and the propeller shaft 13 are configured to transmit the driving force generated in the engine 10 to the propeller 11.

[0037] The GPS 2a is provided on the hull 101 and is configured to acquire position information of the hull 101. The control unit 4 acquires the current boat speed of the ship 100 using this position information. Note that the boat speed can be acquired not only by using a GPS but also by using a boat speed sensor (a boat speed sensor through water) or the like. The vertical movement sensor 2b is configured to measure at least one of the vertical speed and vertical acceleration of the hull 101. As an example, the vertical movement sensor 2b is configured by an IMU (Inertial Measurement Unit).

[0038] The operation panel 3a is provided with a plurality of switches. As a specific example, the operation panel 3a is configured to receive an operation to start wave control, which will be described later, and an operation to end wave control.

[0039] The remote control lever 3b is configured to adjust the magnitude of the thrust of the propulsion unit 1 (the opening of the throttle valve 10a) by tilting the lever portion. In short, the remote control lever 3b is an operating portion for adjusting the boat speed. Note that instead of the remote control lever, a joystick, a steering wheel with a paddle shifter, or the like may be provided.

[0040] The control unit 4 is configured to grasp the state of the vessel 100 based on signals acquired from each component of the vessel propulsion system 102, determine the magnitude and direction of the propulsion force of the propulsion unit 1, and transmit them to the propulsion unit 1. As an example, the control unit 4 is configured by a BCU (boat control unit) or a remote control ECU. The control unit 4 includes a CPU and a memory.

[0041] The control unit 4 of the first embodiment is configured to perform wave control including attitude control. Attitude control is a control that reduces the change in the up and down attitude of the hull 101 by temporarily reducing the ship speed at each timing of riding over each wave based on the measurement result of the vertical movement sensor 2b during waves. Note that attitude control using the throttle valve 10a aims to change the attitude (lower the bow) when riding over a wave, and prevents the ship from taking off by momentarily reducing the thrust. Even if the ship 101 does not take off from the water as a result of the speed reduction, the speed reduction has the effect of reducing the bounce (vibration) of the ship 101. In addition, attitude control using an attitude adjustment body (for example, a trim tab) corrects pitching that changes the attitude adjustment body in accordance with the wave surface. In addition, wave control is a control included in wave control, and includes speed control that adjusts the ship speed to a target ship speed, which is a target value of the ship speed, which will be described later. Speed ​​control is a control that adjusts the ship speed based on the measurement result of the vertical movement sensor 2b to reduce the impact when riding over each wave.

[0042] The wave control is a control that utilizes the above-mentioned attitude control and speed control to reduce the change in the up and down attitude of the hull 101 and to reduce the impact on the hull 101. When executing this wave control, the control unit 4 performs control taking into consideration the wave conditions, such as following waves, head waves, and high waves.

[0043] The vessel propulsion system 102 (control unit 4) of the first embodiment is configured to repeatedly and continuously perform speed control during wave control from start to end. Wave control is started when a predetermined switch on the operation panel 3a is operated. Wave control is ended when a predetermined switch on the operation panel 3a is operated.

[0044] In addition, the ship propulsion system 102 (control unit 4) of the first embodiment is configured to perform wave direction determination in wave control, determining whether the wave conditions relative to the hull 101 are head waves or following waves, based on at least the measurement results of the vertical movement sensor 2b.

[0045] The ship propulsion system 102 (control unit 4) is configured to perform attitude control when the wave direction is determined to be a heading wave, and not to perform attitude control when the wave direction is determined to be a following wave.

[0046] The attitude control, speed control, and wave control will be described in detail below.

[0047] (Details of posture control) A control configuration for performing attitude control of the control unit 4 will be described with reference to Fig. 3. The control unit 4 controls the opening of the throttle valve 10a (hereinafter referred to as "throttle opening") based on the vertical speed of the boat 100.

[0048] The control unit 4 has an upper limit throttle opening block 51, a Kalman filter 52, an up / down speed block 53, a coefficient multiplier 54, a gain multiplier 55, a subtractor 56, and a throttle opening command value block 57 as a control configuration for attitude control.

[0049] In attitude control, the control unit 4 is configured to perform subtraction processing to subtract the opening of the throttle valve 10a based on the vertical speed of the hull 101, thereby reducing changes in the vertical attitude of the hull 101. Details of the attitude control will be described below.

[0050] In the control unit 4, first, the upper limit throttle opening block 51 sets the throttle opening specified by the operator using the remote control lever 3b as the upper limit throttle opening based on the signal transmitted from the remote control lever 3b. The upper limit throttle opening block 51 also transmits the upper limit throttle opening to the coefficient multiplier 54 and the subtractor 56.

[0051] The Kalman filter 52 estimates the vertical speed of the vessel 100 based on the measurement results of the vertical movement sensor 2b and the GPS 2a, and the vertical speed block 53 transmits the estimated vertical speed to the gain multiplier 55. The coefficient multiplier 54 multiplies the upper limit throttle opening by the vertical speed gain coefficient to calculate a vertical speed gain (predetermined gain), and transmits the calculated vertical speed gain to the gain multiplier 55. As one example, the vertical speed gain coefficient is set to a negative value "-K" based on the amount of throttle opening return by an experienced operator when riding up a wave.

[0052] The gain multiplier 55 multiplies the vertical speed by the vertical speed gain to calculate a subtraction throttle opening and sends the calculated subtraction throttle opening to the subtractor 56. The subtractor 56 subtracts the subtraction throttle opening from the upper limit throttle opening to calculate a throttle opening command value, and the throttle opening command value block 57 sends the calculated throttle opening command value to the propulsion unit 1. The propulsion unit 1 controls the throttle opening based on the throttle opening command value to adjust the vessel speed of the vessel 100.

[0053] The control unit 4 controls the opening of the throttle valve 10a based on a throttle opening command value obtained by performing subtraction processing on the upper limit throttle opening using the subtraction throttle opening, and the subtraction throttle opening is obtained by multiplying the vertical speed by a vertical speed gain. For this reason, for example, the greater the vertical speed of the hull 101 when the ship 100 runs up against a large wave, the greater the subtraction throttle opening becomes, and as a result, the smaller the throttle opening command value becomes. In other words, the greater the vertical speed of the hull 101 becomes, the smaller the throttle opening command value becomes, and the smaller the opening of the throttle valve 10a becomes, so that the ship speed of the ship 100 decreases. This makes it possible to mitigate the impact caused by the ship 100 hitting water after running up against a wave.

[0054] When the boat 100 runs aground on a wave, the throttle opening command value becomes smaller than the upper limit throttle opening. This reduces the opening of the throttle valve 10a, and the boat speed of the boat 100 decreases. On the other hand, when the boat 100 descends from the crest of the wave, the throttle opening command value becomes larger than the throttle opening command value when the boat 100 runs aground, toward the upper limit throttle opening. This increases the opening of the throttle valve 10a, and the boat speed of the boat 100 increases.

[0055] Furthermore, if the subtraction throttle opening is constant when obtaining the throttle opening command value, the boat 100 will decelerate too much when the boat speed is low, and on the other hand, the boat 100 will not be able to decelerate sufficiently when the boat speed is high. In particular, in the latter case, the impact caused by the boat 100 hitting water after running ashore cannot be sufficiently alleviated.

[0056] Therefore, the vertical speed gain for obtaining the subtractive throttle opening is calculated by multiplying the upper limit throttle opening by the vertical speed gain coefficient. As a result, the subtractive throttle opening changes according to the upper limit throttle opening. Specifically, when the upper limit throttle opening is large (i.e., when the boat speed is high), the subtractive throttle opening becomes large and the throttle opening command value is subtracted by a large amount, so that the boat 100 is sufficiently decelerated. As a result, the impact of landing on water after the boat 100 runs aground on a wave can be sufficiently mitigated. Note that when the upper limit throttle opening is small (i.e., when the boat speed is low), the subtractive throttle opening becomes small, preventing the boat 100 from decelerating too much.

[0057] Incidentally, even if the vertical speed gain is calculated by multiplying the vessel speed by the vertical speed gain coefficient instead of the upper limit throttle opening, the subtractive throttle opening can be increased to sufficiently decelerate the vessel 100 when the vessel speed is high. Therefore, it is also conceivable to calculate the vertical speed gain using the vessel speed instead of the upper limit throttle opening. However, when posture control is executed, the vessel speed changes as a result, and the vessel speed also changes if a disturbance is applied to the vessel 100 (in other words, the vessel speed is not necessarily constant even if the throttle opening is constant), so the deceleration gain calculated using the vessel speed becomes unstable, and as a result, there is a possibility that the posture control will not be stable.

[0058] Therefore, as described above, the vertical speed gain is calculated using the upper limit throttle opening, not the vessel speed. For example, even when attitude control is performed or a disturbance is applied to the vessel 100, in principle, the vessel operator does not change the amount of operation of the remote control lever 3b, so the deceleration gain calculated using the upper limit throttle opening is stable, and as a result, attitude control can be stabilized. Note that since the vertical speed gain is calculated by multiplying the upper limit throttle opening by the vertical speed gain coefficient, the vertical speed gain is proportional to the upper limit throttle opening.

[0059] Furthermore, if the subtraction throttle opening is subtracted from the upper limit throttle opening when the ship 100 runs onto a wave regardless of the vertical speed of the hull 101, the ship 100 will repeatedly accelerate and decelerate every time it encounters a wave, which is not desirable from the standpoint of improving ride comfort.

[0060] Therefore, when the vertical speed of the hull 101 is equal to or lower than the vertical speed threshold (predetermined vertical speed), the vertical speed block 53 sets the vertical speed to 0 regardless of the estimation by the Kalman filter 52. This sets the subtraction throttle opening to 0, the upper limit throttle opening is not subtracted, and the vessel speed of the vessel 100 does not change. As a result, repeated acceleration and deceleration of the vessel 100 is suppressed, further improving the ride comfort, and unnecessary decreases in average vessel speed are suppressed, preventing delays in the vessel 100 reaching its destination.

[0061] 4, as a result of the attitude control by the control unit 4, the throttle opening (ship speed) temporarily decreases each time the ship overcomes a wave. As a result of the attitude control by the control unit 4, the up and down behavior of the ship 101 is suppressed.

[0062] (Details of speed control) 5 and 6, a control configuration for executing speed control by the control unit 4 will be described. The control unit 4 controls the opening of the throttle valve 10a (hereinafter referred to as the "throttle opening") based on the vertical speed of the boat 100.

[0063] The control unit 4 has a set acceleration block 6a, a set vertical speed block 6b, a Kalman filter 61, a moving average block 62, a delay compensation block 63, a conversion magnification block 64, a multiplier 65, a target ship speed block 66, a feedback controller 67, and a moving average block 68 as a control configuration for speed control.

[0064] In the speed control, the control unit 4 is configured to reduce impact by varying the ship speed to reduce the vertical acceleration / deceleration of the ship 101 based on a moving average value of the vertical speed or vertical acceleration of the ship 101 and the occurrence probability density distribution of wave height. Details of the speed control will be described below.

[0065] First, in the set acceleration block 6a, the operator or the like sets the vertical acceleration of the hull 101 (hereinafter referred to as the "set acceleration") corresponding to the impact input to the hull 101 that is tolerable to passengers on board. Then, in the set vertical speed block 6b, this vertical acceleration is converted into a vertical speed (hereinafter referred to as the "set vertical speed") by a predetermined calculation.

[0066] Next, in the speed controller, the Kalman filter 61 calculates the real-time vertical speed and current vessel speed of the vessel 100 based on the measurement results of the current position of the vessel 100 and the behavior of the vessel 100 transmitted from the GPS 2a and the vertical movement sensor 2b. Hereinafter, the former is referred to as the "vessel vertical speed."

[0067] However, since the hull vertical speed fluctuates from moment to moment each time the ship 100 overcomes waves, there is a possibility that the speed control will not converge if the hull vertical speed is used as is. Therefore, by using a vertical speed moving average value (first moving average value) obtained by taking a moving average of the hull vertical speed, the fluctuations in the hull vertical speed are smoothed and the speed control converges. Specifically, in the moving average block 62, the vertical speed moving average value is calculated by taking a moving average of the hull vertical speed over a predetermined time period. The fluctuations in the hull vertical speed are smoothed by the moving average.

[0068] However, since the vertical speed moving average value has a time lag with respect to the real-time vertical speed of the ship, if the vertical speed moving average value is used for speed control as is, the stability of the control may be impaired. Therefore, a predicted value of the current vertical speed moving average value (hereinafter referred to as the "vertical speed moving average predicted value") is calculated from the vertical speed moving average value in the lag compensation block 63. Specifically, the moving average value of the ship speed (second moving average value) is calculated by applying moving average processing to the ship speed calculated by the Kalman filter 61 in the moving average block 68, and further, the lag compensation block 63 compensates for the time lag of the vertical speed moving average value by calculating the vertical speed moving average predicted value from the calculated vertical speed moving average value, the moving average value of the ship speed, and the current ship speed.

[0069] Here, if the wave height is constant, the relationship between the vertical hull speed and the ship speed is linear, so the predicted vertical speed moving average value is obtained by multiplying the current ship speed, the moving average value of the ship speed, and the reciprocal of the moving average value of the vertical speed.

[0070] Incidentally, since the hull vertical speed is used as an index of the impact input to the hull 101, it is necessary to obtain the hull vertical speed at which the impact input is expected to be maximum in order to mitigate the impact input to the hull 101. It has been confirmed that if the hull speed is constant, the relationship between the hull vertical speed and the wave height is linear. Therefore, based on the maximum wave height that can occur with an allowable occurrence probability (predetermined probability) (for example, 5%) or less, the hull vertical speed corresponding to the maximum wave height (hereinafter referred to as the "expected maximum vertical speed") is calculated.

[0071] Here, a method using the Rayleigh distribution is known as a method for expressing the irregularity of wave height as a probability distribution (the probability density distribution of the occurrence of the above-mentioned wave height), and the probability density distribution of the occurrence of wave height follows the Rayleigh probability density distribution. The Rayleigh probability density distribution is expressed by the following formula (1).

[0072]

number

[0073] Furthermore, the relationship between the average wave height Have and the standard deviation σ of the wave height in the above equation (1) is shown in the following equation (2). Therefore, by substituting the following equation (2) into the above equation (1), the Rayleigh cumulative distribution function of the following equation (3), which shows the probability density distribution of the occurrence of wave height, is obtained.

[0074]

number

[0075] Each occurrence probability density distribution in Fig. 6 is obtained based on the above formula (3). The horizontal axis of the graph in Fig. 6 indicates the wave height that may occur, and the vertical axis of the graph indicates the cumulative probability of occurrence of the wave height (hereinafter simply referred to as "cumulative probability"). Here, the maximum wave height that may occur below the tolerable occurrence probability (hereinafter referred to as "allowable probability") (hereinafter referred to as "assumed maximum wave height") is the maximum wave height in the cumulative probability obtained by subtracting the allowable probability from 100% (total occurrence probability) in the wave height occurrence probability density distribution. For this reason, in Figure 6, the assumed maximum wave height when the allowable probability is 5% or less is the maximum wave height when the cumulative probability is 95%, and as shown by the dashed lines, when the wave height standard deviation σ is 0.5, the assumed maximum wave height is approximately 1.2 m, when the wave height standard deviation σ is 1.0, the assumed maximum wave height is approximately 2.4 m, when the wave height standard deviation σ is 2.0, the assumed maximum wave height is approximately 4.8 m, when the wave height standard deviation σ is 3.0, the assumed maximum wave height is approximately 7.2 m, and when the wave height standard deviation σ is 4.0, the assumed maximum wave height is approximately 9.6 m.

[0076] As these show, the ratio (variation) of the expected maximum wave height to the standard deviation σ of wave height at a certain allowable probability (hereinafter referred to as the "conversion factor") is constant regardless of the standard deviation σ of wave height; for example, in cases where the above allowable probability is set to 5% or less, the conversion factor is a constant value of 2.4. Also, as shown in the above formula (2), the standard deviation σ of wave height is a substitute index for the average wave height. Therefore, it can be said that the conversion factor of the expected maximum wave height to the average wave height at a certain allowable probability is constant regardless of the average wave height.

[0077] As described above, the relationship between the vertical speed of the ship and the wave height is linear, so the conversion factor of the assumed maximum vertical speed to the average moving average value of the vertical speed is the same as the conversion factor of the assumed maximum wave height to the average wave height at a certain allowable probability. Therefore, in the conversion factor block 64, the conversion factor of the assumed maximum wave height to the average wave height at a certain allowable probability is calculated using the Rayleigh probability density distribution, and in the multiplier 65, the assumed maximum vertical speed is estimated by multiplying the predicted moving average value of the vertical speed by the conversion factor. The assumed maximum vertical speed estimated here is the maximum vertical speed of the ship that can occur at or below the allowable probability, and is the maximum vertical speed of the ship in the cumulative probability obtained by subtracting the allowable probability from 100% (total occurrence probability). The allowable probability depends on the preference of the operator or passengers (how much impact input they can tolerate), so it is not limited to 5%, and any value can be used.

[0078] Next, in the speed controller, the target vessel speed block 66 calculates the target vessel speed based on the assumed maximum vertical speed, the set vertical speed, and the current vessel speed. Here, the target vessel speed is a vessel speed that can keep the impact input to the vessel 101 within a level that can be tolerated by the passengers, and corresponds to the set vertical speed. In addition, the assumed maximum vertical speed is also considered to be the maximum vertical speed that can occur when the vessel 100 navigates at the current vessel speed, so the current vessel speed corresponds to the assumed maximum vertical speed. Furthermore, as described above, the relationship between the vessel vertical speed and the vessel speed is linear. Therefore, the ratio of the set vertical speed to the assumed maximum vertical speed is the same as the ratio of the target vessel speed to the current vessel speed. Based on this idea, the target vessel speed block 66 determines the target vessel speed by multiplying the current vessel speed by the ratio of the set vertical speed to the assumed maximum vertical speed.

[0079] Next, in the speed controller, the feedback controller 67 determines a correction amount for the current engine 10 rotation speed based on the difference between the target boat speed and the current boat speed, and transmits the corrected engine 10 rotation speed to the propulsion unit 1. This executes feedback control so that the current boat speed approaches the target boat speed. The speed control of the ship 100 is executed by the control unit 4 repeating the above process.

[0080] As shown in FIG. 7, as a result of the speed control by the control unit 4, the impact that the hull 101 receives is suppressed.

[0081] (Details of wave control) With reference to Fig. 8, the flow of wave control including speed control and attitude control executed by the control unit 4 will be described. The wave control executed by the control unit 4 is started by operating a predetermined switch on the operation panel 3a as described above. The control unit 4 is configured to perform wave direction determination (step S3) to determine whether the waves are heading waves or following waves, which will be described later, when the operation to start wave control is performed on the operation panel 3a is used as a trigger. In the speed control, the control unit 4 performs control to adjust the ship speed so that the actual ship speed becomes a target ship speed, which is a target value of the ship speed for reducing the vertical acceleration and deceleration of the hull 101. This target ship speed is the ship speed described in "Details of speed control" above.

[0082] The above target ship speed includes a limited target ship speed that sets a predetermined limit on the amount of ship speed change so that the difference between the actual ship speed and the target ship speed is reduced. For example, if the difference between the target ship speed obtained by the calculations described in "Details of Speed ​​Control" above and the actual ship speed is greater than a predetermined value (limited target ship speed), the control unit 4 sets the target ship speed to the predetermined value (limited target ship speed) instead of the value obtained by the calculations described in "Details of Speed ​​Control" above.

[0083] In addition, in the speed control, an upper limit is set for the rate of change of the actual ship speed that changes toward the target ship speed. When the difference between the target ship speed and the actual ship speed is equal to or greater than a first threshold value, the control unit 4 performs control to increase the upper limit value of the rate of change. As a specific example, when the first threshold value is 5 km / h and the actual ship speed is 6 km / h, which is greater than the first threshold value, the upper limit value of the rate of change of the ship speed per second is set to 2 km / h, and when the first threshold value is 5 km / h and the actual ship speed is 4 km / h, which is smaller than the first threshold value, the upper limit value of the rate of change of the ship speed per second is set to 0.2 km / h.

[0084] In step S1, the control unit 4 performs speed control. This speed control is performed continuously from the start to the end of the wave control. That is, the control unit 4 is configured to perform speed control regardless of whether the result of the wave direction determination described later is a head wave or a following wave. Then, the process proceeds to step S2.

[0085] In step S2, the control unit 4 judges whether or not there are high waves. More specifically, in step S2, the control unit 4 performs high wave judgment in wave control, judging whether or not the vertical speed or vertical acceleration of the hull 101 is equal to or greater than a predetermined high wave judgment threshold based on the measurement result of the vertical movement sensor 2b during high waves. If it is judged to be equal to or greater than the high wave judgment threshold, the process proceeds to step S3, and if it is judged to be less than the high wave judgment threshold, the process proceeds to step S4.

[0086] In step S3, the control unit 4 performs attitude control in addition to speed control. In detail, when the control unit 4 determines that the vertical speed or vertical acceleration of the hull 101 is equal to or greater than the high wave determination threshold value based on the high wave determination, the control unit 4 is configured to perform attitude control regardless of the result of the wave direction determination. Then, the process proceeds to step S7.

[0087] In step S4, the control unit 4 performs wave direction determination in wave control to determine whether the wave state relative to the hull 101 is a head wave or a following wave based on at least the measurement results of the vertical movement sensor 2b. At this time, the control unit 4 is configured to perform wave direction determination based on a target ship speed, which is a target value of the ship speed for reducing at least the vertical acceleration / deceleration of the hull 101, in speed control.

[0088] More specifically, in step S4, the control unit 4 judges whether the judged vessel speed difference, which is the difference between the target vessel speed and the vessel speed at the start of the speed control, is greater than a predetermined wave direction judgment threshold in the wave direction judgment. If it is judged to be equal to or less than the wave direction judgment threshold, it is judged that the current wave state is a following wave and the process proceeds to step S6, whereas if it is judged to be greater than the wave direction judgment threshold, it is judged that the current wave state is a head wave and the process proceeds to step S5.

[0089] In step S4, when acquiring a judged vessel speed difference, which is the difference between the target vessel speed and the vessel speed at the start of speed control, the control unit 4 is configured to correct the target vessel speed based on the vessel structure including the vessel weight and the vessel shape. In detail, in step S4, when acquiring a judged vessel speed difference, which is the difference between the target vessel speed and the vessel speed at the start of speed control, the control unit 4 multiplies the target vessel speed by a predetermined correction coefficient set based on the vessel structure including the vessel weight and the vessel shape to acquire a corrected target vessel speed. Then, the control unit 4 acquires the judged vessel speed difference based on the corrected target vessel speed.

[0090] In step S5, the control unit 4 performs attitude control in addition to speed control, and then the process proceeds to step S7.

[0091] In step S6, the control unit 4 continues to perform the speed control and does not perform the attitude control, and then the process proceeds to step S7.

[0092] As explained in steps S4 to S6 above, when the control unit 4 determines that the judged ship speed difference, which is the difference between the target ship speed and the ship speed at the start of speed control, is greater than a predetermined wave direction judgment threshold, it is configured to judge that the waves are heading waves and perform posture control, and when it determines that the judged ship speed difference is equal to or less than the wave direction judgment threshold, it is configured to judge that the waves are following waves and not perform posture control.

[0093] In step S7, the control unit 4 judges whether or not an operation to end the wave control has been performed on the operation panel 3a. If an operation to end the wave control has been performed on the operation panel 3a, the wave control ends. If an operation to end the wave control has not been performed on the operation panel 3a, the process returns to step S2.

[0094] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0095] In the first embodiment, as described above, the control unit 4 is provided to perform wave control including posture control to reduce the vertical posture change of the hull 101 by temporarily reducing the ship speed at each time of riding over each wave based on the measurement result of the vertical movement sensor 2b during high waves, and the control unit 4 is configured to perform wave direction determination to determine whether the wave state for the hull 101 is a head wave or a following wave based on at least the measurement result of the vertical movement sensor 2b in the wave control, and to perform posture control when the wave direction determination determines that the wave is a heading wave, and to not perform posture control when the wave direction determination determines that the wave is a following wave. This makes it possible to distinguish between following waves and head waves, and to stabilize the hull 101 by temporarily reducing the ship speed at each time of riding over each wave in the case of a heading wave where the impact of the hull 101 is likely to be large. In addition, it is possible to avoid the ship speed temporarily reducing at each time of riding over each wave in the case of a following wave where the hull 101 is likely to become unstable if the ship speed is reduced. Therefore, control can be performed according to the wave direction by taking into account the wave direction, which was not considered in the past, and therefore the stability of the hull 101 during rough seas can be improved, improving the ride comfort. In addition, by controlling the attitude, the ship speed can be temporarily reduced each time a wave is overcome in a head wave, which can prevent the ship 100 from overriding waves with great force.

[0096] In the first embodiment, as described above, the control unit 4 is configured to perform speed control, which is included in wave control and adjusts the vessel speed to a target vessel speed, which is a target value for the vessel speed, in both head and following waves. This not only performs attitude control in the case of head waves, but also performs speed control in both head and following waves, making it possible to suppress the speed in rough waves, thereby further improving the stability of the hull 101 in rough waves and improving the ride comfort.

[0097] In the first embodiment, as described above, the speed control is a control for adjusting the ship speed to reduce the impact when riding over each wave, and the control unit 4 is configured to perform the speed control regardless of whether the result of the wave direction determination is a head wave or a following wave. This not only performs attitude control in the case of a head wave, but also performs speed control in both head waves and following waves, thereby making it possible to further reduce the impact. As a result, the stability of the hull 101 in rough waves can be further improved, further improving the ride comfort.

[0098] In the first embodiment, as described above, the control unit 4 is configured to perform wave direction determination based on a target ship speed for reducing at least the vertical acceleration / deceleration of the ship hull in speed control. This allows wave direction determination to be performed based on the target ship speed, which is a target value of the ship speed for reducing the vertical acceleration / deceleration of the ship hull 101, so that the vertical acceleration / deceleration of the ship hull 101 can be effectively reduced.

[0099] In the first embodiment, as described above, the target vessel speed includes a limited target vessel speed that sets a predetermined limit on the amount of vessel speed change so that the difference between the actual vessel speed and the target vessel speed is reduced. This makes it possible to suppress sudden acceleration and deceleration of the vessel by using the limited target vessel speed that sets a predetermined limit on the amount of vessel speed change.

[0100] In the first embodiment, as described above, when the controller 4 determines that the judged vessel speed difference, which is the difference between the target vessel speed and the vessel speed at the start of speed control, is greater than a predetermined wave direction judgment threshold, it is configured to judge that the waves are head waves and perform posture control, and when the judged vessel speed difference is equal to or less than the wave direction judgment threshold, it is configured to judge that the waves are following waves and not perform posture control. This makes it possible to more appropriately distinguish between head waves, which make it difficult to bring the target vessel speed close to the vessel speed at the start of speed control, and following waves, which make it easy to bring the target vessel speed close to the vessel speed at the start of speed control.

[0101] In the first embodiment, as described above, in the speed control, an upper limit is set for the rate of change of the actual vessel speed toward the target vessel speed, and the control unit 4 performs control to increase the upper limit of the rate of change when the difference between the target vessel speed and the actual vessel speed is equal to or greater than a first threshold value. This allows the vessel speed to more quickly follow the target vessel speed according to the wave conditions.

[0102] In the first embodiment, as described above, the control unit 4 is configured to adjust the ship speed based on a moving average value of the vertical speed or vertical acceleration of the hull 101 in speed control to reduce the impact when riding over each wave, and to set a target ship speed based on the moving average value to perform wave direction determination. This allows the moving average value of the vertical speed or vertical acceleration of the hull 101 to be taken into consideration in speed control, making it possible to suppress the effect of instantaneous changes or changes over a relatively short period of time in the vertical speed or vertical acceleration of the hull 101 on wave direction determination in speed control.

[0103] In the first embodiment, as described above, the propulsion unit 1 includes the engine 10 which is a drive source that generates thrust, and the control unit 4 performs attitude control by reducing the output of the engine 10 to slow down the boat speed. In this way, attitude control can be easily performed by adjusting the output of the engine 10 and slowing down the boat speed.

[0104] In the first embodiment, as described above, the control unit 4 is configured to perform high wave judgment in wave control to judge whether the vertical speed or vertical acceleration of the hull 101 is equal to or greater than a predetermined high wave judgment threshold based on the measurement results of the vertical movement sensor 2b during high waves, and is configured to perform attitude control regardless of the result of the wave direction judgment if it is judged by the high wave judgment that the vertical speed or vertical acceleration of the hull 101 is equal to or greater than the high wave judgment threshold. This allows attitude control to be reliably performed in the case of high waves that tend to make the hull 101 unstable, whether the waves are following or heading.

[0105] In the first embodiment, as described above, the control panel 3a is further provided for receiving an operation to start wave control and an operation to end wave control, and the control unit 4 is configured to determine the wave direction to determine whether the waves are heading waves or following waves when an operation to start wave control is performed on the control panel 3a as a trigger. This makes it easy to start and end wave control using the control panel 3a.

[0106] In the first embodiment, as described above, the propulsion unit 1 includes the engine 10 having the throttle valve 10a, and the control unit 4 is configured to perform subtraction processing in attitude control to subtract the opening of the throttle valve 10a based on the vertical speed of the hull 101, thereby reducing changes in the vertical attitude of the hull 101. In this way, by subtracting the opening of the throttle valve 10a of the engine-type propulsion unit 1 in attitude control, the stability of the hull 101 in rough waves can be improved, thereby improving the ride comfort.

[0107] In the first embodiment, as described above, the control unit 4 is configured to reduce impact by changing the ship speed to reduce the vertical acceleration / deceleration of the hull 101 based on the moving average value of the vertical speed or vertical acceleration of the hull 101 and the probability density distribution of wave height occurrence in the speed control. This allows the moving average value of the vertical speed or vertical acceleration of the hull 101 to be taken into consideration in the speed control, thereby reducing the impact on the hull 101 of instantaneous changes or changes over a relatively short period of time in the vertical speed or vertical acceleration of the hull 101. In addition, the amount of reduction in the vertical acceleration / deceleration of the hull 101 by changing the ship speed can be determined more accurately by taking into consideration the probability density distribution of wave height occurrence.

[0108] Second embodiment Next, a vessel propulsion system 202 according to a second embodiment will be described with reference to Fig. 1 and Fig. 9. In the second embodiment, unlike the first embodiment in which both speed control and attitude control are always performed when a head wave is determined in the wave direction determination in the wave control flow, an example will be described in which, when a head wave is determined in the wave direction determination in the wave control flow, both speed control and attitude control are performed, or only speed control is performed, as a result of the determination in step S4a shown in Fig. 9 described below. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0109] The vessel propulsion system 202 of the second embodiment includes a control unit 204.

[0110] (About wave control) A description will be given of the flow of wave control including speed control and attitude control executed by the control unit 204. The steps other than step S4a are similar to those in the first embodiment, and therefore the description will be omitted.

[0111] If it is determined in step S4 that the waves are head waves, the process proceeds to step S4a. In step S4a, the control unit 204, in wave control, determines whether the vertical speed of the hull 101 is equal to or greater than a predetermined second threshold value during high waves based on the measurement results of the vertical movement sensor 2b. The second threshold value is smaller than the high wave determination threshold value used in the high wave determination in step S4. If the vertical speed of the hull 101 is equal to or greater than the second threshold value, the process proceeds to step S5, and if the vertical speed of the hull 101 is less than the second threshold value, the process proceeds to step S6. In short, in step S4a, even if it is determined that the waves are head waves in the wave direction determination, in a state in which speed control and attitude control are not being performed, if the vertical speed is equal to or greater than the second threshold value, the control unit 204 proceeds to step S5 to start attitude control in addition to speed control, and proceeds to step S6 to perform only speed control for the vertical speed.

[0112] That is, the control unit 204 is configured to determine that there is a head wave in step S4, and then distinguish between a relatively rough wave state and a relatively calm wave state in step S4a. If the waves are relatively large and relatively rough, the process proceeds to step S5, and if the waves are relatively small and relatively calm, the process proceeds to step S6. The other configurations of the second embodiment are the same as those of the first embodiment.

[0113] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0114] In the second embodiment, as described above, a control unit 204 is provided that performs wave control including posture control to reduce the vertical posture change of the hull 101 by temporarily reducing the ship speed at each timing of riding over each wave based on the measurement result of the vertical movement sensor 2b during high waves, and the control unit 204 is configured to perform wave direction determination to determine whether the wave state for the hull 101 is a head wave or a following wave based on at least the measurement result of the vertical movement sensor 2b during wave control, and to perform posture control when the wave direction determination determines that the wave is a head wave, and to not perform posture control when the wave direction determination determines that the wave is a following wave. This can improve the stability of the hull 101 during high waves and improve the ride comfort, as in the first embodiment. In addition, by using posture control, the ship speed can be temporarily reduced at each timing of riding over each wave during high waves, so that the ship 100 can be prevented from riding over waves with force.

[0115] In the second embodiment, as described above, even if the wave direction is determined to be a head wave, the control unit 204 is configured to perform attitude control in addition to speed control when it is determined that the vertical speed or vertical acceleration of the hull 101 is equal to or greater than a predetermined second threshold based on the measurement results of the vertical movement sensor 2b while performing speed control and attitude control. As a result, compared to the case where only speed control is performed, when both speed control and attitude control are performed, it is possible to reduce sudden deceleration and reduction in average speed. In addition, by not performing attitude control for small waves and riding over waves only by speed control, it is possible to reduce speed change and improve the stability of the hull 101. For large waves equal to or greater than the second threshold, it is possible to prevent takeoff and reduce impact and attitude change after riding over waves more than when only speed control is performed by performing both attitude control and speed control.

[0116] Third embodiment Next, a vessel propulsion system 302 according to a third embodiment will be described with reference to Fig. 1 and Fig. 10. In the third embodiment, unlike the first embodiment in which the control unit 4 performs speed control to change the target vessel speed, an example will be described in which the control unit 304 performs speed control to maintain the vessel speed without changing the target vessel speed. Note that the same components as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

[0117] The vessel propulsion system 302 of the third embodiment includes a control unit 304. The control unit 304 is configured to be capable of performing speed control for maintaining the vessel speed without changing the target vessel speed.

[0118] (About wave control) The flow of wave control including attitude control executed by the control unit 304 will be described. Unlike the first embodiment, the control unit 304 performs high wave determination in step S2 without starting speed control that changes the target ship speed at the same time as starting wave control. If it is determined that the waves are high as a result of the high wave determination, the process proceeds to step S3a and attitude control is performed.

[0119] In step S4, the control unit 304 judges whether the judged vessel speed difference, which is the difference between the target vessel speed for reducing the vertical acceleration / deceleration of the vessel 101 described in the first embodiment above and the vessel speed at the start of control, is greater than a predetermined wave direction judgment threshold. If it is judged to be equal to or less than the wave direction judgment threshold, it judges that the current wave state is following waves and proceeds to step S6a, whereas if it is judged to be greater than the wave direction judgment threshold, it judges that the current wave state is head waves and proceeds to step S5a. Note that the above "vessel speed at the start of control" refers to the vessel speed at the start of the flow shown in FIG. 10.

[0120] If it is determined in step S4 that the wave direction is a head wave, the process proceeds to step S5a. In step S5a, the control unit 304 performs attitude control. The process proceeds to step S7.

[0121] If it is determined in step S4 that the wave direction is following, the process proceeds to step S6a. In step S6a, the control unit 304 performs control to maintain the boat speed. Then, the process proceeds to step S7. The other configurations of the third embodiment are the same as those of the first embodiment.

[0122] In the third embodiment, as in the first embodiment, the determination in step S4 is made using the target vessel speed described in "Details of Speed ​​Control" in the first embodiment, but the control unit 304 does not perform speed control that changes the target vessel speed. That is, in the third embodiment, the control unit 304 performs control to obtain the target vessel speed, but does not actually perform speed control that changes the target vessel speed using the target vessel speed. The same applies to the fourth embodiment described later.

[0123] (Effects of the third embodiment) In the third embodiment, the following effects can be obtained.

[0124] In the third embodiment, as described above, a control unit 304 is provided that performs wave control including posture control to reduce the vertical posture change of the hull 101 by temporarily reducing the ship speed at each timing of riding over each wave based on the measurement result of the vertical movement sensor 2b during high waves, and the control unit 304 is configured to perform wave direction determination to determine whether the wave state for the hull 101 is a head wave or a following wave based on at least the measurement result of the vertical movement sensor 2b in the wave control, and to perform posture control when the wave direction determination determines that the wave is a head wave, and to not perform posture control when the wave direction determination determines that the wave is a following wave. This can improve the stability of the hull 101 during high waves and improve the ride comfort, as in the first embodiment. In addition, by using posture control, the ship speed can be temporarily reduced at each timing of riding over each wave during high waves, so that the ship 100 can be prevented from riding over waves with force.

[0125] In the third embodiment, as described above, the control unit 304 is configured to maintain the boat speed without performing attitude control when it is determined that the waves are following waves based on the wave direction judgment. This allows the boat speed to be maintained in the case of following waves, and therefore prevents the boat speed from decreasing in the case of following waves, which causes the hull 101 to become unstable.

[0126] (Fourth embodiment) Next, a vessel propulsion system 402 according to a fourth embodiment will be described with reference to Fig. 1, Fig. 11 and Fig. 12. In the fourth embodiment, unlike the third embodiment in which the control unit 304 performs only attitude control using the throttle valve 10a when it is determined that there are head waves, an example will be described in which attitude control is performed using an attitude adjustment body 9 (for example, a trim tab) in addition to attitude control using the throttle valve 10a.

[0127] A vessel propulsion system 402 according to the fourth embodiment includes an attitude adjustment body 9 and a control unit 404. In the fourth embodiment, an example in which the attitude adjustment body 9 is configured by a trim tab will be described.

[0128] The attitude adjustment body 9 is provided on the hull 101, and is configured to adjust the pitch of the hull 101 by changing its position (the orientation of the flap of the trim tab) relative to the hull 101 to provide resistance to the water current. The attitude adjustment body 9 can also adjust the roll of the hull 101.

[0129] The control unit 404 of the fourth embodiment performs attitude control to adjust the attitude of the hull 101 by varying the pitch of the hull 101 using the attitude adjustment body 9 (for example, a trim tab) during rough seas. When it is determined that attitude control should be performed, the control unit 404 is configured to switch between performing attitude control using only the attitude adjustment body 9, performing attitude control using both the attitude adjustment body 9 and the throttle valve 10a, and performing attitude control using only the throttle valve 10a, depending on wave conditions.

[0130] (About wave control) A flow of wave control including attitude control executed by the control unit 404 will be described. The flow of the third embodiment differs from that of the third embodiment in the steps following the step S4 in which the wave direction is determined to be a head wave (except for step S7).

[0131] In the wave direction determination in step S4, if it is determined that the waves are coming from the head, the process proceeds to step S10.

[0132] In step S10, if the control unit 404 determines that the determined vessel speed difference is equal to or smaller than the first auxiliary judgment threshold, the process proceeds to step S11, and if the control unit 404 determines that the determined vessel speed difference is greater than the first auxiliary judgment threshold, the process proceeds to step S12. Note that the first auxiliary judgment threshold in step S10 is greater than the wave direction judgment threshold in step S4.

[0133] In step S10, if the control unit 404 determines that the determined vessel speed difference is greater than the first auxiliary judgment threshold, it proceeds to step S12, and if it determines that the determined vessel speed difference is equal to or less than the first auxiliary judgment threshold, it proceeds to step S11. Proceeding to step S11 means that the waves are relatively calm (slightly choppy due to wind waves), and proceeding to step S12 means that the waves are swelled and relatively rough compared to step S11 (choppy due to wind waves).

[0134] In step S11, attitude control is performed using only the attitude adjustment structure 9 (e.g., trim tabs). As a result of attitude control using only the attitude adjustment structure 9 (e.g., trim tabs), the attitude of the hull 101 is adjusted by changing the pitch and roll without (almost) reducing the speed. Then, proceed to step S7.

[0135] In step S12, if the control unit 404 determines that the determined vessel speed difference is equal to or smaller than the second auxiliary judgment threshold, the process proceeds to step S13, and if the control unit 404 determines that the determined vessel speed difference is greater than the second auxiliary judgment threshold, the process proceeds to step S14. Note that the second auxiliary judgment threshold in step S12 is greater than the first auxiliary judgment threshold in step S10.

[0136] In step S13, attitude control is performed using both the attitude adjustment mechanism 9 (for example, a trim tab) and the throttle valve 10a, and the process proceeds to step S7.

[0137] In step S14, attitude control is performed using only the throttle valve 10a, and the process proceeds to step S7.

[0138] (Effects of the fourth embodiment) In the fourth embodiment, the following effects can be obtained.

[0139] In the fourth embodiment, as described above, a control unit 404 is provided that performs wave control including posture control to reduce the vertical posture change of the hull 101 by temporarily reducing the ship speed at each timing of riding over each wave based on the measurement result of the vertical movement sensor 2b during high waves, and the control unit 404 is configured to perform wave direction determination to determine whether the wave state for the hull 101 is a head wave or a following wave based on at least the measurement result of the vertical movement sensor 2b during wave control, and to perform posture control when the wave direction determination determines that the wave is a head wave, and to not perform posture control when the wave direction determination determines that the wave is a following wave. This can improve the stability of the hull 101 during high waves and improve the ride comfort, as in the first embodiment. In addition, by posture control, the ship speed can be temporarily reduced at each timing of riding over each wave during high waves, so that the ship 100 can be prevented from riding over waves with force.

[0140] As described above, the fourth embodiment further includes an attitude adjustment body 9 that is provided on the hull 101 and adjusts the pitch of the hull 101 by changing its position relative to the hull 101 (the orientation of the flaps of the trim tabs) to provide resistance to the water current, and the control unit 404 performs attitude control in which the attitude adjustment body varies the pitch of the hull 101 to adjust the attitude of the hull 101 during rough waves. This makes it possible to stabilize the hull 101 while preventing the boat speed from decreasing by adjusting the attitude adjustment body 9, compared to when the throttle valve is adjusted in attitude control.

[0141] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0142] For example, in the above first to fourth embodiments, the propulsion unit of the present invention is an outboard motor, but the present invention is not limited to this. In the present invention, the propulsion unit may be an inboard motor or an inboard-outboard motor.

[0143] In the above first to fourth embodiments, the operation unit of the present invention is configured by an operation panel, but the present invention is not limited to this. In the present invention, the operation unit may be configured by a touch panel or the like.

[0144] In the fourth embodiment, the attitude adjustment body is configured by a trim tab, but the present invention is not limited to this. In the present invention, the attitude adjustment body may be configured by an interceptor or the like.

[0145] In the fourth embodiment, the auxiliary judgment threshold is included in two judgment steps as a two-stage threshold (first auxiliary judgment threshold, second auxiliary judgment threshold), but the present invention is not limited to this. In the present invention, the auxiliary judgment threshold may be included in one or three or more judgment steps as a multi-stage threshold.

[0146] Furthermore, the methods of attitude control explained in the first to fourth embodiments are merely examples, and attitude control may be performed by a different method.

[0147] Furthermore, the method of speed control for changing the target boat speed described in the first and second embodiments is merely an example, and speed control for changing the target boat speed may be performed using a different method.

[0148] In addition, in the above first to fourth embodiments, an example has been shown in which the propulsion unit includes an engine as a drive source, but the present invention is not limited to this. In the present invention, the propulsion unit may include an electric motor as a drive source.

[0149] In addition, in the above first to fourth embodiments, the control unit performs the high wave judgment, but the present invention is not limited to this. In the present invention, the control unit does not have to perform the high wave judgment.

[0150] Further, in the above first to fourth embodiments, an example has been shown in which the control unit determines the wave direction based on the target boat speed and the current boat speed, but the wave direction may be determined based on an index different from the target boat speed and the current boat speed.

[0151] In addition, in the above first to fourth embodiments, an example has been shown in which the propulsion unit includes an engine having a throttle valve, but the present invention is not limited to this. In the present invention, the propulsion unit may include an electric motor as a drive source that generates thrust instead of an engine. In this case, the control unit performs attitude control by reducing the output of the electric motor to slow down the boat speed. Note that the propulsion unit may include both an engine having a throttle valve and an electric motor.

[0152] In the above first to fourth embodiments, the opening of the throttle valve is adjusted to adjust the engine output, but the present invention is not limited to this. In the present invention, the engine output may be adjusted not by the opening of the throttle valve, but by cutting off fuel injection into the combustion chamber, reducing the amount of fuel injected into the combustion chamber, cutting off ignition in the combustion chamber, adjusting valve timing, or the like.

[0153] In addition, in the above first to fourth embodiments, an example has been shown in which one outboard motor is provided on the hull, but the present invention is not limited to this. In the present invention, a plurality of outboard motors may be provided on the hull.

[0154] In addition, in the fourth embodiment, an example has been shown in which the attitude adjustment body is a trim tab, but the present invention is not limited to this. In the present invention, the attitude adjustment body may be another structure such as an interceptor.

[0155] In the above first to fourth embodiments, for convenience of explanation, the processing operation of the control unit is explained using a flow-driven flowchart in which the processing is performed in order according to the processing flow, but the present invention is not limited to this. In the present invention, the processing operation of the control unit may be performed by event-driven processing in which processing is performed on an event-by-event basis. In this case, the processing may be performed completely event-driven, or may be performed in a combination of event-driven and flow-driven. [Explanation of symbols]

[0156] 1 Propulsion machine 2b Vertical movement sensor 3a Operation panel (operation section) 4, 204, 304, 404 Control section 9 Posture adjustment body 10 Engine 10a Throttle valve 100 ships 101 Hull 102, 202, 302, 402 Marine Propulsion Systems

Claims

1. A propulsion unit provided in the hull; A vertical movement sensor that measures at least one of the vertical speed and the vertical acceleration of the hull; a control unit configured to control the drive of the propulsion unit and performing wave control including attitude control for temporarily reducing the vessel speed at each timing of riding over a wave based on the measurement results of the vertical movement sensor during rough waves, thereby reducing changes in the vertical attitude of the vessel, The control unit is In the wave control, a wave direction determination is performed to determine whether the wave state relative to the hull is a head wave or a following wave based on at least the measurement result of the vertical movement sensor, When the wave direction is determined to be the head wave, the attitude control is performed. A vessel propulsion system configured not to perform the attitude control when the wave direction determination determines that the wave is a following wave.

2. The ship propulsion system of claim 1, wherein the control unit is configured to perform speed control, which is included in the wave control and adjusts the ship speed to a target ship speed that is a target value of the ship speed, in both the case of head waves and the case of following waves.

3. The speed control is a control for reducing an impact when riding over each wave by adjusting the ship speed, 3. The vessel propulsion system according to claim 2, wherein the control unit is configured to perform the speed control regardless of whether the result of the wave direction determination is the head wave or the following wave.

4. The vessel propulsion system according to claim 2 , wherein the control unit is configured to perform the wave direction determination in the speed control based on at least the target vessel speed for reducing vertical acceleration / deceleration of the vessel body.

5. 5. A vessel propulsion system according to claim 4, wherein the target vessel speed includes a limited target vessel speed that sets a predetermined limit on a change in vessel speed so that a difference between an actual vessel speed and the target vessel speed is reduced.

6. The control unit is When it is determined in the wave direction determination that a judged ship speed difference, which is the difference between the target ship speed and the ship speed at the start of the speed control, is greater than a predetermined wave direction judgment threshold, the wave direction is determined to be the head wave and the attitude control is performed; The vessel propulsion system according to claim 2 , further configured such that, when it is determined that the determined vessel speed difference is equal to or less than the wave direction determination threshold, it is determined that the wave is a following wave and the attitude control is not performed.

7. In the speed control, an upper limit is set for a rate of change of the actual vessel speed which changes toward the target vessel speed, The vessel propulsion system according to claim 2 , wherein the control unit performs control to increase the upper limit value of the rate of change when a difference between the target vessel speed and the actual vessel speed is equal to or greater than a first threshold value.

8. The ship propulsion system of claim 2, wherein the control unit is configured to perform the attitude control in addition to the speed control when, in a state where the speed control is being performed but the attitude control is not being performed, it determines that the vertical speed or vertical acceleration of the hull is equal to or greater than a predetermined second threshold value based on the measurement results of the vertical movement sensor, even if the wave direction determination determines that the wave is a head wave.

9. The control unit is The speed control is configured to reduce impacts when riding over each wave by adjusting the ship speed based on a moving average value of the vertical speed or vertical acceleration of the ship, The vessel propulsion system according to claim 3 , wherein the target vessel speed is set based on the moving average value, and the wave direction is determined.

10. the propulsion device includes at least one of an engine and an electric motor that are a drive source that generates thrust; The vessel propulsion system according to claim 1 , wherein the control unit performs the attitude control by reducing an output of the engine or the electric motor to slow down the vessel speed.

11. The vessel further includes an attitude adjustment body that is provided on the vessel and that adjusts the pitch of the vessel by changing its position relative to the vessel and acting as a resistance to the water flow, The vessel propulsion system according to claim 1 , wherein the control unit performs the attitude control by varying the pitch of the hull using the attitude adjustment body to adjust the attitude of the hull during rough waves.

12. The control unit is In the wave control, a high wave judgment is performed based on the measurement result of the vertical movement sensor during high waves to judge whether the vertical speed or vertical acceleration of the hull is equal to or greater than a predetermined high wave judgment threshold, The ship propulsion system of claim 1, wherein when the high wave determination determines that the vertical speed or vertical acceleration of the hull is equal to or greater than the high wave determination threshold, the attitude control is performed regardless of the result of the wave direction determination.

13. Further comprising an operation unit for receiving an operation to start the wave control and an operation to end the wave control, 2. The vessel propulsion system according to claim 1, wherein the control unit is configured to perform the wave direction determination, which determines whether the wave is a heading wave or a following wave, when the operation unit is operated as a trigger.

14. The vessel propulsion system according to claim 1 , wherein the control unit is configured to maintain the vessel speed without performing the attitude control when the wave direction determination determines that the wave is a following wave.

15. the propulsion device includes an engine having a throttle valve; 2. The vessel propulsion system according to claim 1, wherein the control unit is configured to perform a subtraction process in the attitude control that subtracts an opening degree of the throttle valve based on a vertical speed of the hull, thereby reducing changes in the vertical attitude of the hull.

16. The ship propulsion system according to claim 2, wherein the control unit is configured, in the speed control, to reduce impact by changing the ship speed to reduce the vertical acceleration / deceleration of the hull based on a moving average value of the vertical speed or vertical acceleration of the hull and a probability density distribution of wave height occurrence.

17. The hull and a vessel propulsion system provided on the vessel body, The marine vessel propulsion system includes: A propulsion unit provided on the hull; A vertical movement sensor that measures at least one of the vertical speed and the vertical acceleration of the hull; a control unit configured to control the drive of the propulsion unit, and performing wave control including attitude control for temporarily reducing the ship speed at each timing when the ship rides over a wave based on the measurement results of the vertical movement sensor during rough waves to reduce changes in the vertical attitude of the ship, The control unit is In the wave control, a wave direction determination is performed to determine whether the wave state relative to the hull is a head wave or a following wave based on at least the measurement result of the vertical movement sensor, When the wave direction is determined to be the head wave, the attitude control is performed. The ship is configured not to perform the attitude control when the wave direction determination determines that the wave is a following wave.

18. The control unit is configured to perform speed control, which is included in the wave control and adjusts the ship speed to a target ship speed that is a target value of the ship speed, in both the case of head waves and the case of following waves.

19. The speed control is a control for reducing an impact when riding over each wave by adjusting the ship speed, The ship according to claim 18 , wherein the control unit is configured to perform the speed control regardless of whether the result of the wave direction determination is the head wave or the following wave.

20. The ship according to claim 18 , wherein the control unit is configured to perform the wave direction determination in the speed control based on at least the target ship speed for reducing vertical acceleration / deceleration of the hull.

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