WATERCRAFT

Abstract

A watercraft includes a propulsion device, an accelerator operator, a trim adjuster, a trim operator, and a controller configured or programmed to control a trim position. The trim positions include a bow-up position to attain a bow-up attitude in which a bow is raised and at least one ordinary position to attain an ordinary attitude in which the bow is closer to a water surface than in the bow-up attitude. The controller is configured or programmed to determine whether or not a hull is in the bow-up attitude and, when a duration of the bow-up attitude reaches a predetermined time limit, executes a forced trim down control by which the trim position is controlled to the ordinary position. The controller may be configured or programmed to prohibit a change to the bow-up position for a predetermined resume prohibit time after executing the forced trim down control.

Claims

1. A watercraft comprising: a propulsion device to generate a propulsive force to propel a hull; an accelerator operator operable by a user to change an output of the propulsion device; a trim adjuster including a plurality of trim positions to change a trim of the hull; a trim operator operable by the user to change the trim of the hull; and a controller configured or programmed to control the output of the propulsion device according to an operation of the accelerator operator and to control the trim position of the trim adjuster according to an operation of the trim operator; wherein the plurality of trim positions include a bow-up position to attain a bow-up attitude in which a bow is raised and at least one ordinary position to attain an ordinary attitude in which the bow is closer to a water surface than in the bow-up attitude; and the controller is configured or programmed to determine whether or not the hull is in the bow-up attitude, and to execute, when a duration of the bow-up attitude reaches a predetermined time limit, a forced trim down control by which the trim position of the trim adjuster is controlled to the ordinary position.

2. The watercraft according to claim 1, wherein the controller is configured or programmed to prohibit a change of the trim position of the trim adjuster to the bow-up position for a predetermined resume prohibit time after executing the forced trim down control.

3. The watercraft according to claim 2, wherein the controller is configured or programmed to execute an automatic restore control to restore the trim position of the trim adjuster to the bow-up position after an elapse of the predetermined resume prohibit time.

4. The watercraft according to claim 1, wherein the controller is configured or programmed to interrupt measurement of the duration of the bow-up attitude when the watercraft is brought into an attitude other than the bow-up attitude before the duration reaches the predetermined time limit, to resume the measurement of the duration when after the interruption the attitude of the watercraft is restored to the bow-up attitude within a predetermined hold time, and to end the measurement of the duration when the attitude of the watercraft is not restored to the bow-up attitude even after passage of the predetermined hold time.

5. The watercraft according to claim 1, wherein the controller is configured or programmed to change the trim position of the trim adjuster at a first speed according to operation of the trim operator and to change the trim position at a second speed slower than the first speed when changing the trim position of the trim adjuster independently of the operation of the trim operator.

6. The watercraft according to claim 1, wherein the propulsion device includes an engine; and the controller is configured or programmed to: acquire an alert related to the engine; and prohibit the change of the trim position of the trim adjuster to the bow-up position when the alert related to the engine is generated.

7. The watercraft according to claim 6, wherein the alert related to the engine includes at least one of an abnormality determination information about the engine, an overheat warning determination information about the engine, or an oil pressure warning determination information about the engine.

8. The watercraft according to claim 1, wherein the propulsion device includes an engine; and the controller is configured or programmed to prohibit the change of the trim position of the trim adjuster to the bow-up position until a predetermined prohibit-at-start time elapses from a start of running of the engine.

9. The watercraft according to claim 1, wherein the controller is configured or programmed to determine that the hull is in the bow-up attitude when the trim position of the trim adjuster is the bow-up position and the output of the propulsion device is not less than a predetermined determination threshold.

10. The watercraft according to claim 1, wherein the propulsion device is a waterjet propulsion device including an engine and a jet propulsion pump drivable by the engine.

11. The watercraft according to claim 10, wherein the watercraft is a personal watercraft including a steering handle bar.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a left side view of a watercraft according to an example embodiment of the present invention.

[0021] FIG. 2 is a vertical sectional view taken anteroposteriorly of a propulsion device provided in the watercraft.

[0022] FIG. 3 is a plan view showing a portion of the watercraft around a steering handle bar.

[0023] FIG. 4 shows an example of a bow-up attitude of the watercraft.

[0024] FIG. 5 is a block diagram showing an electrical configuration of the watercraft.

[0025] FIG. 6 shows a display screen image of a display.

[0026] FIG. 7A shows an outline of a trim position control when an automatic restore control is disabled or uninstalled.

[0027] FIG. 7B shows an outline of the trim position control when the automatic restore control is enabled.

[0028] FIG. 8 is a flowchart that shows an example of processes that a controller (an SCU) executes repeatedly at a predetermined control cycle.

[0029] FIG. 9 is a flowchart that describes an example of an initial process.

[0030] FIGS. 10A, 10B, and 10C are flowcharts that describe a specific example of an execution permission determination process.

[0031] FIG. 11 is a flowchart that describes an example of an execution determination process.

[0032] FIGS. 12A and 12B are flowcharts that describe an example of a cancel process.

[0033] FIG. 13 is a time chart showing an action example when transition to a bow-up mode is performed by a trim up operation by a user.

[0034] FIG. 14 is a time chart showing an action example when a resume prohibit timer is not 0.

[0035] FIG. 15 is a time chart showing an action example related to automatic cancellation of the bow-up mode.

[0036] FIG. 16 shows an example of a displayed message when in the bow-up attitude.

[0037] FIG. 17 shows an example of a displayed message when the bow-up attitude is forcibly canceled.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0038] FIG. 1 is a left side view of a watercraft 1 according to an example embodiment of the present invention. FIG. 2 is a vertical sectional view taken anteroposteriorly of a propulsion device 9 of the watercraft 1. FIG. 3 is a plan view showing a portion of the watercraft 1 around a steering handle bar 6. In the present example embodiment, the watercraft 1 is a waterjet propulsion watercraft, more specifically, a personal watercraft (PWC) by way of example.

[0039] The watercraft 1 includes a watercraft hull 2 (a hull) that floats on a water surface, and a propulsion device 9 to propel the watercraft hull 2. The watercraft hull 2 includes a body 3 defining a watercraft bottom portion and watercraft side portions, and a deck 4 provided above the body 3. The propulsion device 9 is provided inside the watercraft hull 2. The propulsion device 9 is a waterjet propulsion device that generates a thrust by sucking in water from the watercraft bottom portion and jetting the water rearward.

[0040] The watercraft 1 further includes a seat 5 on which a user (a watercraft operator) sits, and a steering handle bar 6 to be operated by the user to steer the watercraft 1. The seat 5 may be a single seat or may be a double seat or a triple seat. There are also cases where a personal watercraft is not provided with a seat. The watercraft 1 further includes an accelerator lever 7 to be operated by the user to change the magnitude of a thrust to be generated by the propulsion device 9 to advance the watercraft hull 2, and a reverse lever 8 (reverse operator) to be operated by the user to change the magnitude of a thrust to be generated by the propulsion device 9 to reverse the watercraft hull 2. The accelerator lever 7 is an example of an accelerator operator.

[0041] The steering handle bar 6 includes two handle grips 6g respectively attached to opposite ends thereof to be gripped by the right and left hands of the user. The steering handle bar 6 is pivotable leftward and rightward with respect to the watercraft hull 2 about a steering shaft (not shown) extending diagonally forward and downward from the steering handle bar 6. The accelerator lever 7 and the reverse lever 8 are pivotable together with the steering handle bar 6 leftward and rightward with respect to the watercraft hull 2.

[0042] The accelerator lever 7 and the reverse lever 8 are attached to the steering handle bar 6. The accelerator lever 7 is disposed forward of the right handle grip 6g. The reverse lever 8 is disposed forward of the left handle grip 6g. The accelerator lever 7 is supported in a cantilevered manner so as to be pivotable forward and rearward with respect to the steering handle bar 6. The reverse lever 8 is also supported in a cantilevered manner so as to be pivotable forward and rearward with respect to the steering handle bar 6.

[0043] The accelerator lever 7 is movable in a range from a maximum output position to a minimum output position with respect to the steering handle bar 6. The maximum output position is an operation position indicating the maximum output of an engine 10 which is a drive source of the propulsion device 9. The minimum output position is an operation position indicating the minimum output of the engine 10. The minimum output position is an engine idling position at which the engine 10 is idled. The accelerator lever 7 is generally kept at the minimum output position when it is not operated. The output of the engine 10 (specifically, the engine rotation speed), that is, the output of the propulsion device 9 is increased as the accelerator lever 7 approaches the maximum output position.

[0044] As shown in FIG. 2, the propulsion device 9 includes a jet propulsion pump 11 to generate the thrust by sucking in water from the watercraft bottom portion and jetting the water rearward, and the engine 10 functioning as a drive source to drive the jet propulsion pump 11. The jet propulsion pump 11 includes a water inlet port 12 that opens in the watercraft bottom portion, a nozzle 16 from which water sucked in through the water inlet port 12 is jetted rearward, and a flow channel 13 through which the water is guided from the water inlet port 12 to the nozzle 16. The jet propulsion pump 11 further includes an impeller 15 disposed in the flow channel 13, and a drive shaft 14 to transmit the rotation of the engine 10 to the impeller 15.

[0045] The propulsion device 9 further includes a deflector 17 to deflect the water jetted rearward from the nozzle 16 leftward and rightward. The water supplied from the nozzle 16 is jetted rearward from a jet port 17p of the deflector 17 such that the deflector 17 generates a straight water stream jetted from the jet port 17p. The deflector 17 is pivotable leftward and rightward with respect to the nozzle 16. The nozzle 16 is fixed to the body 3 of the watercraft hull 2. With the deflector 17 tilted leftward or rightward with respect to the nozzle 16, the flow of the water jetted rearward from the deflector 17 is also tilted leftward or rightward with respect to the nozzle 16. Thus, a thrust is generated to turn the watercraft 1.

[0046] When the user moves the steering handle bar 6, the deflector 17 is pivoted leftward or rightward with respect to the nozzle 16. The watercraft 1 may include a push/pull cable (not shown) that transmits the movement of the steering handle bar 6 to the deflector 17. The watercraft 1 may include, instead of the push/pull cable, a steering actuator (not shown) that pivots the deflector 17 leftward and rightward with respect to the nozzle 16 based on the detection value of a steering position sensor (not shown) that detects the position of the steering handle bar 6.

[0047] The propulsion device 9 includes a bucket 18 to change the direction of the water jetted rearward from the deflector 17 to a forward direction. The bucket 18 includes jet ports 18p through which the water jetted rearward from the deflector 17 is jetted forward. The bucket 18 is attached to the nozzle 16. The bucket 18 is pivotable upward and downward within a range from an F-position (a position shown in FIG. 2) to an R-position with respect to the nozzle 16. At the F-position, the bucket 18 does not overlap any portion of the jet port 17p of the deflector 17 as viewed from behind. At the R-position, the bucket 18 is located behind the jet port 17p of the deflector 17, and completely overlaps the jet port 17p of the deflector 17 as viewed from behind.

[0048] The propulsion device 9 includes a reverse actuator 19 to pivot the bucket 18 upward and downward within the range from the F-position to the R-position. The reverse actuator 19 includes an electric motor. The reverse actuator 19 may include an actuator other than the electric motor. The reverse actuator 19 is connected to an ECU 31 to be described below. When the user operates the reverse lever 8, the ECU 31 drives the reverse actuator 19 to move the bucket 18 such that the bucket 18 is located at a position corresponding to the position of the reverse lever 8.

[0049] When the water is jetted rearward from the deflector 17 with the bucket 18 located at the F-position, the jetted water is not hindered by the bucket 18 and flows rearward. Thus, the thrust is generated in a watercraft advancing direction. When the water is jetted rearward from the deflector 17 with the bucket 18 located at the R-position, the jetted water hits the bucket 18, and flows forward from the jet ports 18p of the bucket 18. Thus, the thrust is generated in a watercraft reversing direction.

[0050] In the following description, it is stated at times that a shift mode of the watercraft 1 is an F-mode (advancing mode), etc., when the bucket 18 is located at the F-position and the propulsive force generated by the propulsion device 9 is the advancing direction. Similarly, it is stated at times that the shift mode of the watercraft 1 is an R-mode (reversing mode), etc., when the bucket 18 is located at the R-position and the propulsive force generated by the propulsion device 9 is the reversing direction. The shift mode of the watercraft 1 is determined by the position of the bucket 18. The bucket 18 can also be located at an N-position (a predetermined position between the F-position and the R-position) at which the advancing direction propulsive force and the reversing direction propulsive force are balanced. An effective propulsive force in the forward or rearward direction is not applied to the watercraft 1 in this state. The shift mode in this case is referred to as an N-mode (neutral mode).

[0051] The deflector 17 is pivotable about a vertical steering axis As leftward and rightward with respect to the nozzle 16, and is pivotable about a horizontal trim axis At upward and downward with respect to the nozzle 16. With the deflector 17 tilted upward or downward with respect to the nozzle 16, the flow of the water jetted rearward from the deflector 17 is also tilted upward or downward with respect to the nozzle 16. When the water is jetted from the deflector 17 with the deflector 17 tilted upward or downward with respect to the nozzle 16 and with the bucket 18 located at the F-position, the thrust is generated to move the bow B1 of the watercraft hull 2 (see FIG. 1) upward or downward with respect to the stern S1 of the watercraft hull 2 (see FIG. 1) such that the trim of the watercraft 1 is changed.

[0052] The trim is one of indexes to be used to determine how much the watercraft 1 is tilted anteroposteriorly with respect to the water surface. The trim refers to a difference between a vertical distance from the water surface to the bow B1 to the keel of the watercraft hull 2 and a vertical distance from the water surface to the stern S1 to the keel of the watercraft hull 2. In other words, the trim refers to a difference between a vertical distance from a waterline WL at the bow B1 (see FIG. 1) to the keel (bow draft) and a vertical distance from a waterline WL at the stern S1 to the keel (stern draft).

[0053] When the water is jetted from the deflector 17 with the deflector 17 tilted upward with respect to the nozzle 16 and with the bucket 18 located at the F-position, the thrust is generated to move the bow B1 upward with respect to the stern S1. When the water is jetted from the deflector 17 with the deflector 17 tilted downward with respect to the nozzle 16 and with the bucket 18 located at the F-position, on the other hand, the thrust is generated to move the bow B1 downward with respect to the stern S1. That is, the trim of the watercraft hull 2 is increased or reduced according to the vertical position of the deflector 17.

[0054] In the following description, the upward movement of the bow B1 with respect to the stern S1 is often referred to as trim up and the downward movement of the bow B1 with respect to the stern S1 is often referred to as trim down. In the following description, the vertical position of the deflector 17 with respect to the nozzle 16 is often referred to as trim position. The trim position is herein synonymous with the trim angle of the deflector 17 indicating the upward or downward angle of the center line of the deflector 17 with respect to the center line of the nozzle 16. The trim of the watercraft hull 2 is increased as the trim position becomes higher. The trim of the watercraft hull 2 is reduced as the trim position becomes lower.

[0055] The watercraft 1 includes a trim adjuster 21 to adjust the trim position to adjust the trim of the watercraft hull 2. In FIG. 2, the trim adjuster 21 is illustrated as including the deflector 17 that jets the water rearward and is pivotable upward and downward with respect to the body 3 of the watercraft hull 2, and a trim actuator 20 to pivot the deflector 17 upward and downward with respect to the body 3 by way of example. The trim actuator 20 is driven to increase or reduce (raise or lower) the trim position of the deflector 17 such that the trim of the watercraft 1 can be changed. The trim actuator 20 includes an electric motor. The trim actuator 20 may include an actuator other than the electric motor. The trim actuator 20 is connected to an SCU (Shift Control Unit) 32 to be described below. The SCU 32 controls the trim actuator 20 to cause the trim actuator 20 to change the trim position of the deflector 17 such that the bow B1 is moved upward and downward with respect to the stern S1 to change the trim. In the present example embodiment, the steering handle bar 6 is provided with a trim switch 41 (see FIG. 3), which is an example of a trim operator, for manual adjustment of the trim.

[0056] The deflector 17 is pivotable upward and downward in a range from a lower limit trim position to a higher limit trim position with respect to the nozzle 16. In FIG. 2, the deflector 17 is illustrated as being pivotable upward and downward with respect to the nozzle 16 in a range from a trim down position D1 to a third trim up position U3 by way of example. The trim actuator 20 can locate the deflector 17 at any trim position between the trim down position D1 and the third trim up position U3. Where the user manually adjusts the trim by operating the trim switch 41, however, the trim actuator 20 is controlled so as to change the trim position stepwise among the trim down position D1, a neutral trim position N (the position shown in FIG. 2), a first trim up position U1, a second trim up position U2, and the third trim up position U3. The neutral trim position N is a position at which the trim angle is zero and the main jetting direction of the nozzle 16 coincides with the main jetting direction of the deflector 17 with respect to the vertical direction. The first trim up position U1, the second trim up position U2, and the third trim up position U3 are higher in this order than the neutral trim position N. The trim down position D1 is lower than the neutral trim position N. For example, the neutral trim position N may be a position at which the deflector 17 is directed approximately 10 degrees downward with respect to the waterline WL. Also, the first trim up position U1 may be a position at which the deflector 17 is directed approximately 6 degrees downward with respect to the water line. Also, the second trim up position U2 may be a position at which the deflector 17 is directed approximately 5 degrees upward with respect to the water line. Also, the third trim up position U3 may be a position at which the deflector 17 is directed approximately 13 degrees upward with respect to the water line. And the trim down position D1 may be a position at which the deflector 17 is directed approximately 15 degrees downward with respect to the water line. Here, a trim down position may be set farther downward than the trim down position D1.

[0057] The third trim up position U3 is an example of a bow-up position to attain a bow-up attitude that is a predetermined hull attitude in which the bow B1 is raised. The trim down position D1, the neutral trim position N, the first trim up position U1, and the second trim up position U2 are examples of ordinary positions to bring the hull attitude to ordinary attitudes in which the bow B1 is closer to the water surface than in the bow-up attitude.

[0058] As shown for example in FIG. 4, the bow-up attitude is a hull attitude in which the bow B1 is raised higher than in an ordinary attitude and refers, for example, to an attitude (for example, an upright attitude) in which the bow B1 is lifted at an elevation angle exceeding 45 degrees with respect to the hull attitude in a stationary state. The watercraft 1 can be made to travel with the watercraft hull 2 (the hull) being put in the bow-up attitude by setting the trim position to the third trim up position U3 and making the engine rotation speed not less than a predetermined bow-up starting speed (for example, 5000 rpm) with the shift mode being the F-mode.

[0059] FIG. 5 is a block diagram showing the electrical configuration of the watercraft 1. The watercraft 1 includes the ECU 31 (Electronic Control Unit) as a main controller to control electric devices provided in the watercraft 1, and the SCU 32 as an auxiliary controller to control the electric devices provided in the watercraft 1 according to a command supplied from the ECU 31. The ECU 31 is connected to the SCU 32 via a communication network N1 configured in conformity with communication standards such as a CAN (Controller Area Network). The ECU 31 and the SCU 32 transmit and receive information and commands necessary for the control of the watercraft 1 via the communication network N1. In this example embodiment, the SCU 32 is an example of a controller that controls the trim position of the trim adjuster 21.

[0060] The ECU 31 and the SCU 32 each include a computer. The ECU 31 is programmed to cause the watercraft 1 to perform processes to be described below. The ECU 31 includes a memory 31m that stores a program and other information, and a processor 31c (for example, a CPU: Central Processing Unit) that performs computations and provides commands according to the program stored in the memory 31m. The ECU 31 further includes an input interface 31i to acquire the detection values of sensors provided in the watercraft 1, an output interface 310 to drive the electric devices provided in the watercraft 1, and a communication interface 31co to communicate via the communication network N1. Similarly, the SCU 32 also includes a memory 32m that stores a program and other information, a processor 32c (a CPU) that performs computations and provides commands according to the program stored in the memory 32m, an input interface 32i to acquire the detection values of sensors provided in the watercraft 1, an output interface 320 to drive the electric devices provided in the watercraft 1, and a communication interface 32co to communicate via the communication network N1. The communication network N1 is typically a CAN (control area network).

[0061] In this example embodiment, the SCU 32 controls the reverse actuator 19 and the trim actuator 20 according to an operation of the trim switch 41 and an internal process of the SCU 32. However, the ECU 31 may be enabled to control the reverse actuator 19 and the trim actuator 20 via the SCU 32 or the ECU 31 may be configured to directly control the reverse actuator 19 and the trim actuator 20 without the provision of the SCU 32. In FIGS. 8 to 16 described below, an example where the SCU 32 controls the reverse actuator 19 and the trim actuator 20 according to the operation of the trim switch 41 and the internal process of the SCU 32 is illustrated.

[0062] The watercraft 1 includes an accelerator position sensor 33 to detect the position of the accelerator lever 7, a reverse position sensor 34 to detect the position of the reverse lever 8, and an engine speed sensor 35 to detect the rotation speed of the engine 10 (the engine rotation speed). The watercraft 1 further includes a bucket position sensor 36 to detect the position of the bucket 18 and a trim position sensor 37 to detect the trim position of the deflector 17. The watercraft 1 may further include a watercraft speed sensor 38 to detect a watercraft speed (the speed of the watercraft 1). Also, the watercraft 1 may further include a capsize sensor 39 to detect whether or not the watercraft hull 2 is capsized. All of these sensors are connected to the communication network N1 and therefore, the ECU 31 and the SCU 32 can acquire output signals of these sensors.

[0063] The watercraft speed sensor 38 includes, for example, a GNSS (Global Navigation Satellite System) receiver, and outputs information indicating the speed of the watercraft hull 2, for example, by utilizing a GPS (Global Positioning System). Alternatively, a sensor such as a Pitot tube may be used as the watercraft speed sensor 38. The watercraft speed may be estimated, for example, by performing a computation process on the engine rotation speed detected by the engine speed sensor 35 instead of detecting the watercraft speed by the watercraft speed sensor 38.

[0064] The ECU 31 changes the output of the engine 10 based on the detection value of the accelerator position sensor 33. The ECU 31 and the SCU 32 acquire information about the output of the engine 10, more specifically, the engine rotation speed detected by the engine speed sensor 35. Also, based on the detection value of the reverse position sensor 34, the SCU 32 drives the reverse actuator 19 to change the position of the bucket 18 and the ECU 31 changes the output of the engine 10. Further, the ECU 31 and the SCU 32 detect, based on the detection value of the bucket position sensor 36, where the bucket 18 is located in the range from the F-position to the R-position. Therefore, the ECU 31 or the SCU 32 can determine, based on the detection value of the bucket position sensor 36, whether the shift mode of the watercraft 1 is an F-mode in which a forward propulsive force is applied to the watercraft 1, an R-mode in which a reverse propulsive force is applied to the watercraft 1, or an N-mode in which no effective propulsive force in the forward or reverse direction is applied to the watercraft 1.

[0065] The watercraft 1 includes a display 40 to display information about the watercraft 1. The display 40 may include a touch panel display including a touch panel as an exemplary input device. Of course, an input device other than the display 40 may be provided. The display 40 is provided in the vicinity of the steering handle bar 6 (see FIG. 3). The display 40 may be disposed at any location in the watercraft 1, as long as the user can view the display 40 while operating the steering handle bar 6. The ECU 31 controls the display 40 to display the watercraft speed, the trim position, and other information useful to maneuver the watercraft 1 (watercraft maneuvering information).

[0066] The watercraft 1 includes the trim switch 41 to be operated by the user to move the bow B1 upward or downward with respect to the stern S1. Specifically, the trim switch 41 includes a trim up switch 41u to be operated by the user for the trim up, and a trim down switch 41d to be operated by the user for the trim down. The trim switch 41 may include a single button that functions as both the trim up switch 41u and the trim down switch 41d. In FIG. 3, the trim switch 41 is disposed in the vicinity of the left handle grip 6g by way of example.

[0067] When the trim switch 41 is operated, the SCU 32 causes the trim actuator 20 to move the deflector 17 to locate the deflector 17 at any one of the trim down position D1, the neutral trim position N, the first trim up position U1, the second trim up position U2, and the third trim up position U3. However, the movement of the deflector 17 to the third trim up position U3 may be prohibited even when the trim up switch 41u is operated. Also, the deflector 17 may be moved automatically from the third trim up position U3 to a lower trim position even when the trim switch 41 is not operated. These cases shall be described more specifically below.

[0068] FIG. 6 shows an exemplary display screen image of the display 40, showing an ordinary display screen. The display screen includes a plurality of display items for the watercraft maneuvering. Specifically, the display screen includes a watercraft speed display 51, an engine rotation speed display 52, a remaining fuel amount display 53, a trim setting display 54, a remaining battery charge display 55, a shift mode display 56, an alert display 57, and the like.

[0069] The trim setting display 54 displays the trim position. In this example, a plurality of (four, in this example) indicators iD1, iN, iU1, iU2, and iU3, respectively corresponding to the plurality of trim positions D1, N, U1, U2, and U3 are aligned vertically so as to correspond to the vertical relationship of the trim positions. Also, an icon 58 indicating the bow-up attitude is provided in a vicinity of the indicator iU3 corresponding to the third trim up position U3.

[0070] FIGS. 7A and 7B are diagrams that describe a trim position control by the SCU 32 in outline. FIG. 7A shows an outline of the control when an automatic restore control described below is disabled or uninstalled and FIG. 7B shows an outline of the control when the automatic restore control is enabled.

[0071] After the engine 10 is started, the SCU 32 is put in an ordinary mode. Here, the ordinary mode refers to a state in which only the ordinary positions, that is, the trim down position D1, the neutral trim position N, the first trim up position U1, and the second trim up position U2 are allowed. The SCU 32 is put in a bow-up mode under a fixed condition. Here, the bow-up mode is a state in which the trim position is allowed to be set to the bow-up position, that is, the third trim up position U3. That is, with this example embodiment, rather than indicating control modes of the SCU 32, it is more accurate to say that the ordinary mode and the bow-up mode indicate state divisions in terms of control.

[0072] Immediately after the start of the engine 10, the SCU 32 controls the trim position to the neutral trim position N and, until a predetermined prohibit-at-start time (for example, 6 seconds) elapses, prohibits the setting of the third trim up position U3 and does not transition to the bow-up mode. Thus, the ordinary mode can be maintained until respective portions of the engine 10 can be lubricated sufficiently.

[0073] In the ordinary mode, the SCU 32 performs a control to trim down or trim up within the range of the ordinary positions (the range from the trim down position D1 to the second trim up position U2) according to operation of the trim switch 41. That is, with respect to a single operation of the trim up switch 41u (hereinafter referred to at times as a trim up operation), the SCU 32 executes a control to move the trim position to a position one step higher. Similarly, with respect to a single operation of the trim down switch 41d (hereinafter referred to at times as a trim down operation), the SCU 32 executes a control to move the trim position to a position one step lower.

[0074] When, in the ordinary mode, the trim position is the second trim up position U2, whether or not transition conditions to the bow-up mode are satisfied is checked. The transition conditions include that the trim up operation is performed. Also, the transition conditions include that the prohibit-at-start time has elapsed. The transition conditions further include that a resume prohibit time to be described below has elapsed. The transition conditions also include that an alert related to the engine 10 is not generated, in other words, an abnormality is not occurring in the engine 10, etc. When these transition conditions are satisfied, the SCU 32 transitions to the bow-up mode and controls the trim position to the third trim up position U3 (the bow-up position).

[0075] In the bow-up mode, the SCU 32 determines whether or not the watercraft hull 2 (the hull) is in the bow-up attitude. Specifically, the SCU 32 determines that the watercraft hull 2 (the hull) is in the bow-up attitude when the trim position is the third trim up position U3 (the bow-up position) and the engine rotation speed (corresponding to the output of the propulsion device) is not less than a bow-up start rotation speed (for example, 5000 rpm), which is a predetermined determination threshold.

[0076] When the SCU 32 determines that the watercraft hull 2 (the hull) is in the bow-up attitude, it measures a duration of the bow-up attitude. Hereinafter, a state of the watercraft 1 when the watercraft hull 2 (the hull) is in the bow-up attitude is referred to at times as a bow-up state, etc. When the duration of the bow-up state reaches a predetermined time limit (for example, 120 seconds), the SCU 32 executes a forced trim down control to control the trim position to a predetermined target trim position. The predetermined target trim position is one of the ordinary positions, that is, any of the trim down position D1, the neutral trim position N, the first trim up position U1, and the second trim up position U2. For example, the target trim position of the forced trim down control is preferably set to the second trim up position U2 that is smallest in difference with respect to the third trim up position U3. By such a forced trim down control, the time during which the watercraft hull 2 (the hull) is maintained in the bow-up attitude can be kept within the time limit and influence due to the bow-up attitude can thus be alleviated. Specifically, loads on the engine 10, for example, loads on the lubricating system and the cooling system of the engine 10 can be alleviated.

[0077] After executing the forced trim down control, the SCU 32 prohibits a change of the trim position to the third trim up position U3 (the bow-up position) for the predetermined resume prohibit time (for example, 5 seconds). That is, until the resume prohibit time elapses, the user cannot raise the trim position to the third trim up position U3 even by operating the trim switch 41, just a trim position change within the range between the trim down position D1 to the second trim up position U2 is allowed, and the trim position is maintained at any of the ordinary positions. The resume prohibit time is preferably set to a length that enables the lubrication and/or cooling of the respective portions of the engine 10 to recover sufficiently. The influence due to the bow-up attitude can thus be alleviated and the loads on the engine 10 can be alleviated.

[0078] After the elapse of the resume prohibit time, the SCU 32 may perform the automatic restore control of automatically restoring the trim position to the third trim up position U3 (the bow-up position). An outline of control when this automatic restore control is not performed is shown in FIG. 7A and an outline of control when the automatic restore control is performed is shown in FIG. 7B.

[0079] First, the case in which the automatic restore control is not performed shall be described with reference to FIG. 7A.

[0080] When the duration of the bow-up state reaches the predetermined time limit (for example, 120 seconds), the SCU 32 executes the forced trim down control to transition to the ordinary mode. The SCU 32 also transitions to the ordinary mode when the trim down operation is performed in the bow-up mode.

[0081] The watercraft 1 may be brought into an attitude other than the bow-up attitude before the duration of the bow-up state reaches the predetermined time limit (for example, 120 seconds) in the bow-up mode. A specific case is when the user operates the accelerator lever 7 and lowers the output (the rotation speed) of the engine 10. In this case, the SCU 32 interrupts the measurement of the duration of the bow-up state. When, after the interruption of the measurement, the bow-up state is restored within a predetermined hold time (for example, within 5 seconds), the SCU 32 resumes the measurement of the duration of the bow-up state. That is, even when the determination of the bow-up state is canceled temporarily due to a temporary deceleration operation, the measurement of the duration of the bow-up state is put on hold within the hold time and thereafter, the measurement of the duration is resumed when the bow-up state is restored. Thus, when the user attempts continuation or intermittence of the bow-up state beyond the time limit by the deceleration operation of a short period within the hold time, the measurement of the duration of the bow-up state is not initialized. Thus, the duration of the bow-up state can be limited reliably and the loads on the engine 10, etc., can be alleviated reliably.

[0082] On the other hand, when the bow-up state is not restored even past the predetermined hold time, the SCU 32 ends the measurement of the duration of the bow-up state and discards the measurement value. During this time, the SCU 32 stays in the bow-up mode and unless the user performs the trim down operation, the trim position is kept at the third trim up position U3 (the bow-up position). The bow-up state is therefore not limited more than necessary.

[0083] The bow-up state may be canceled by the trim down operation by the user before the duration of the bow-up state reaches the predetermined time limit (for example, 120 seconds). In this case, the trim position is set to any of the ordinary positions (any of the trim down position D1 to the second trim up position U2) and the SCU 32 transitions to the ordinary mode. The SCU 32 then interrupts the measurement of the duration of the bow-up state. When after interruption of the measurement, the attitude of the watercraft 1 is restored to the bow-up attitude within the predetermined hold time (for example, within 5 seconds), the SCU 32 resumes the measurement of the duration of the bow-up attitude. That is, when the trim position becomes the third trim up position U3 due to the trim up operation by the user and the engine rotation speed becomes not less than the bow-up start rotation speed (for example, 5000 rpm), the SCU 32 determines that the bow-up state is restored and resumes measurement of the duration. That is, even when the determination of the bow-up state is canceled temporarily by a temporary trim down operation, the measurement of the duration of the bow-up state is put on hold within the hold time and thereafter, the measurement of the duration is resumed when the bow-up state is restored. Thus, when the user attempts continuation or intermittence of the bow-up state beyond the time limit by setting the trim position to one of the ordinary positions for just a short period within the hold time, the measurement of the duration of the bow-up state is not initialized. Thus, the duration of the bow-up state can be limited reliably and the loads on the engine 10, etc., can be alleviated reliably.

[0084] On the other hand, when the attitude of the watercraft 1 is not restored to the bow-up attitude even past the predetermined hold time described above, the SCU 32 ends the measurement of the duration of the bow-up state and discards the measurement value. The bow-up state is therefore not limited more than necessary.

[0085] Next, the case in which the automatic restore control is performed shall be described with reference to FIG. 7B.

[0086] The SCU 32 maintains the bow-up mode even when the duration of the bow-up state reaches the predetermined time limit (for example, 120 seconds) and the forced trim down control is executed.

[0087] As mentioned above, in the bow-up mode, the determination of the bow-up state may be canceled before the duration of the bow-up state reaches the predetermined time limit due to the deceleration operation by the user. The actions in this case are the same as in the case of FIG. 7A.

[0088] Also, the watercraft 1 may be brought into an attitude other than the bow-up attitude by the trim down operation by the user before the duration of the bow-up state reaches the predetermined time limit. In this case, the trim position becomes one of the ordinary positions (any of the trim down position D1 to the second trim up position U2) and the SCU 32 transitions to the ordinary mode. The actions in this case are also the same as in the case of FIG. 7A.

[0089] When the duration of the bow-up state reaches the predetermined time limit (for example, 120 seconds) and the trim position is changed to one of the ordinary positions (for example, the second trim up position U2) by the forced trim down control, the SCU 32 maintains the bow-up mode. The SCU 32 then prohibits the change of the trim position to the third trim up position U3 (the bow-up position) for the predetermined resume prohibit time (for example, 5 seconds). That is, even when the user operates the trim switch 41, the trim position cannot be raised to the third trim up position U3 and the trim position is maintained in the range of the ordinary positions. When the target trim position of the forced trim down control is a position lower than the second trim up position U2, the trim up operation up to the second trim up position U2 is allowed and the bow-up mode is maintained. On the other hand, when the trim down operation is performed in the bow-up mode, the SCU 32 transitions to the ordinary mode.

[0090] On the other hand, when the bow-up mode is maintained until the resume prohibit time elapses, the SCU 32 executes the automatic restore control of automatically restoring the trim position to the third trim up position U3 (the bow-up position). The trim position to attain the bow-up attitude is thus set automatically without requiring operation of the trim up switch 41u by the user. The user can thus operate the accelerator lever 7 and make the engine rotation speed not less than the bow-up rotation speed to make the watercraft 1 travel with the watercraft hull 2 (the hull) being in the bow-up attitude.

[0091] As mentioned above, the resume prohibit time is preferably set to the length that enables the lubrication and/or cooling of the respective portions of the engine 10 to recover sufficiently. The influence due to the bow-up attitude can thus be alleviated and the loads on the engine 10 can be alleviated even when performing the automatic restore control.

[0092] Features in common to the case in which the automatic restore control is performed and the case in which it is not performed shall be described again further.

[0093] The SCU 32 changes the trim position at a first speed when changing trim position according to the operation of the trim switch 41. On the other hand, when changing the trim position independently of operation of the trim switch 41, the SCU 32 changes the trim position at a second speed slower than the first speed. Specifically, this corresponds to when trim down from the third trim up position U3 to the target trim position (for example, the second trim up position U2) is performed automatically by the forced trim down control described above and when trim up to the third trim up position U3 (the bow-up position) is performed automatically by the automatic restore control. For example, when the trim actuator 20 includes an electric motor, the SCU 32 can adjust the speed of changing the trim position by changing a drive duty of the electric motor. Specifically, the trim position can be changed at the first speed by setting the drive duty of the trim actuator 20 to 100%. Also, the trim position can be changed at the second speed slower than the first speed by setting the drive duty of the trim actuator 20, for example, to 50%.

[0094] By slowing the speed of trim position change when changing the trim position automatically independently of trim operation by the user, the trim position can be changed gradually and a satisfactory maneuvering feeling can thus be obtained.

[0095] The SCU 32 acquires information related to alerts (information related to abnormality determinations and/or warning determinations) related to the engine 10. When an alert related to the engine 10 is generated, the SCU 32 prohibits transition from the ordinary mode to the bow-up mode (an example of the transition conditions mentioned above). Also, when an alert related to the engine 10 is generated in the bow-up mode, the SCU 32 discontinues the bow-up mode and executes a forced trim down control to transition to the ordinary mode. As a specific example of this forced trim down control, the same control as that performed when the duration of the bow-up state reaches the predetermined time limit is preferable. The alerts related to the engine 10 preferably include at least one among an abnormality determination information about the engine 10, an overheat warning determination information about the engine 10, or an oil pressure warning determination information about the engine 10. The SCU 32 acquires information related to alerts such as the above by executing an abnormality determination process and a warning determination process based on information from the various sensors provided in the watercraft 1. The abnormality determination process and/or the warning determination process may be performed by the ECU 31 and the SCU 32 may acquire information on the process results from the ECU 31.

[0096] FIG. 8 is a flowchart that shows a specific example of processes that the SCU 32 executes repeatedly at a predetermined control cycle (for example, 50 milliseconds) to perform the actions described with reference to FIGS. 7A and 7B.

[0097] The process executed by the SCU 32 includes an initial process S100, an execution permission determination process S200, an execution determination process S300, a cancel process S400, etc. The initial process S100 is an initialization process performed immediately after the start of the engine 10. The execution permission determination process S200 includes a process to determine permission to transition to the bow-up mode. The execution determination process S300 is a process of changing the trim position or changing the mode according to the mode and the trim position of a previous cycle. The cancel process S400 is a process related to cancellation of the bow-up state.

[0098] Specific examples of the respective processes shall be described below and timers, flags, and switches (switches in the program) used in these processes shall be described in outline below.

[0099] A cancel timer is a timer to measure the duration of the bow-up state. When it is determined that the bow-up state has been entered, a cancel wait time (for example, 120 seconds) corresponding to the predetermined time limit is set and decremented to 0 by the SCU 32. The decrementing may be interrupted and may be resumed after the interruption.

[0100] A resume prohibit timer is a timer to measure resume prohibit wait times, specifically, the prohibit-at-start time (for example, 6 seconds) and the resume prohibit time (for example, 5 seconds). When the engine 10 is started, the prohibit-at-start time is set, and is decremented to 0 by the SCU 32. Also, when the cancel timer is decremented and becomes 0, the resume prohibit time is set, and is decremented to 0 by the SCU 32. In this example embodiment, the decrementing of the resume prohibit timer is never interrupted.

[0101] A reset timer is a timer to measure the hold time (for example, 5 seconds). When the decrementing of the cancel timer is interrupted, the hold time is set in the reset timer, and is decremented to 0 by the SCU 32. Until the reset timer becomes 0, the measurement value of the cancel timer is kept and the measurement by the cancel timer is held in the interrupted state. When the reset timer becomes 0, the measurement value of the cancel timer is discarded and the measurement by the cancel timer is discontinued. When the bow-up state is resumed and the measurement by the cancel timer is resumed before the reset timer becomes 0, the value of the reset timer is discarded.

[0102] A resume enable flag is a flag expressing whether or not the value of the resume prohibit timer is 0 and is set to ON (=1) when the value of the resume prohibit timer is 0 and set to OFF (=0) when the value is not 0.

[0103] A normal flag is a flag expressing whether or not there is an abnormality concerning the system that includes the engine 10, etc., and set to ON (=1) when there is no abnormality and set to OFF (=0) when there is an abnormality.

[0104] An engine running flag is a flag expressing whether or not the engine 10 is running and is set to ON (=1) when the engine 10 is running and set to OFF (=0) when the engine 10 is stopped.

[0105] A permit flag is a flag expressing whether or not the transition conditions for transition from the ordinary mode to the bow-up mode are satisfied and is set to ON (=1) when the transition conditions are satisfied and set to OFF (=0) when the conditions are not satisfied.

[0106] An automatic restore switch is a switch inside the program to switch between enabling and disabling the automatic restore control and is set to ON (=1) when the automatic restore control is enabled and set to OFF (=0) when the control is disabled.

[0107] FIG. 9 is a flowchart that describes an example of the initial process S100.

[0108] When the power of the SCU 32 is turned on, the initial process S100 is executed. The SCU 32 judges whether or not the initialization is in progress (step S101). This judgment is positive until the engine 10 is started and becomes negative when the engine 10 is started. While the initialization is in progress (step S101: YES), the SCU 32 sets the prohibit-at-start time (for example, 6 seconds) in the resume prohibit timer (step S102), resets the cancel timer to 0 (step S103), and sets the reset timer to the hold time (initial value; for example, 5 seconds) (step S104). Further, the SCU 32 issues a trim drive command commanding the trim position to be an initial position (for example, the neutral trim position N) (step S105). The trim actuator 20 is thus driven and the trim position becomes the neutral trim position N. Also, the SCU 32 sets the mode to the ordinary mode (step S106). When the initialization is not in progress (step S101: NO), these processes (steps S120 to S106) are skipped.

[0109] FIGS. 10A, 10B, and 10C are flowcharts that describe a specific example of the execution permission determination process S200.

[0110] The SCU 32 performs a decrement process of the resume prohibit timer (step S201). Once the resume prohibit timer is set, it is decremented until the value thereof becomes 0. The resume prohibit timer is decremented by the period of the control cycle (for example, 50 milliseconds) at a time and thus becomes 0 when the time set in the resume prohibit timer elapses.

[0111] The SCU 32 judges whether or not the resume prohibit timer is 0 (step S202) and sets the resume enable flag to ON (=1) when the resume prohibit timer is 0 (step S203) and sets the resume enable flag to OFF (=0) when the resume prohibit timer is not 0 (step S204).

[0112] When the resume enable flag is set to ON (=1), the SCU 32 sets the cancel wait time (for example, 120 seconds) as an initial value in the cancel timer (step S205; initialization of the cancel timer). Also, the SCU 32 sets the hold time (a reset wait time; for example, 5 seconds) as an initial value in the reset timer (step S206; initialization of the reset timer). When the resume prohibit timer is not 0 (step S202: NO) and the resume enable flag is set to OFF (=0), these initialization processes (steps S205 and S206) are omitted.

[0113] The SCU 32 judges whether or not the trim position is the third trim up position U3 (the bow-up position) (step S207) and, when this judgment is positive, further judges whether or not the engine rotation speed is less than the bow-up start rotation speed (for example, 5000 rpm) (step S208). When the trim position is not the third trim up position U3 (step S207: NO) or when the engine rotation speed is less than the bow-up start rotation speed (step S208: YES), the SCU 32 judges that the watercraft 1 is not in the bow-up state. A decrement process of the reset timer is then performed (step S209). This decrementing is executed with 0 as a lower limit. The reset timer is decremented by the period of the control cycle (for example, 50 milliseconds) at a time and thus becomes 0 when the measurement of the hold time (for example, 5 seconds) set in the reset timer ends.

[0114] The SCU 32 judges whether or not the reset timer is more than 0 (step S210) and, when the reset timer >0, keeps the cancel timer at the value of the previous cycle (previous value) (step S211). When the reset timer=0, the cancel wait time (for example, 120 seconds) is set in the cancel timer (step S212; initialization of the cancel timer). When the trim position is the third trim up position U3 (the bow-up position) (step S207: YES) and the engine rotation speed is not less than the bow-up start rotation speed (step S208: NO), the SCU 32 judges that the watercraft 1 is in the bow-up state. In this case, the SCU 32 sets the hold time (for example, 5 seconds) in the reset timer (step S213; initialization of the reset timer).

[0115] Next, the SCU 32 performs the abnormality determination of the engine 10 and the system in the watercraft 1. Specifically, the SCU 32 confirms that the communication network N1 (CAN: control area network) configured in the watercraft 1 is normal (step S214), that the trim drive system is normal (step S215), that a check engine command is not issued (step S216), that an overheat (O/H) warning is not issued (step S217), and that an oil pressure warning is not issued (step S218) and sets the normal flag to ON (=1) (step S219). When any of the above cannot be confirmed, the SCU 32 judges that an abnormality is occurring and sets the normal flag to OFF (=0) (step S220).

[0116] Also, the SCU 32 checks the engine rotation speed and judges whether or not the engine 10 is running (step S221). When the engine 10 is running, the engine running flag is set to ON (=1) (step S222) and when the engine 10 is not running, the engine running flag is set to OFF (=0) (step S223).

[0117] The SCU 32 then determines whether or not the bow-up mode is permissible (step S224). Specifically, the SCU 32 judges whether or not the resume enable flag is ON (the resume prohibit timer is 0), the normal flag is ON (there is no abnormality in the engine 10, etc.), the engine running flag is ON (the engine is running), and the shift mode is the F-mode (the shift mode in which the forward propulsive force can be generated). When this judgment is positive, the SCU 32 sets the permit flag to ON (=1) (step S225) and permits the transition to the bow-up mode. When any of the items judged in step S224 is no, the SCU 32 sets the permit flag to OFF (=0) (step S226) and prohibits the transition to the bow-up mode.

[0118] Next, the SCU 32 checks whether or not the shift mode is the F-mode and whether or not the engine running flag is OFF (=0) (step S227). When either of these applies (step S227: YES), the SCU 32 sets the trim drive speed (the speed of trim position change) to the first speed (sets the drive duty of the trim actuator 20 to 100%) (step S228). Further, the SCU 32 issues the trim drive command commanding the trim position to be the neutral trim position N (step S229) and further sets the mode to the ordinary mode (step S230). Thus, during a shift operation and during engine stoppage, the trim position changes at the first speed in accordance with the trim operation by the user thereafter. When the shift mode is the F-mode and the engine 10 is running (step S227: NO), the processes of steps S228 to S230 are omitted.

[0119] FIG. 11 is a flowchart that describes an example of the execution determination process S300.

[0120] The SCU 32 judges whether the mode of the previous control cycle (the previous cycle mode) is the bow-up mode or the ordinary mode (step S301). When the mode of the previous control cycle is the ordinary mode, the SCU 32 judges whether the trim up operation (operation of the trim up switch 41u) has been performed (step S302). When the trim up operation has been performed, the SCU 32 judges whether the trim position of the previous cycle (that is, the current trim position) is the second trim up position U2 (the trim position one stage below the bow-up position) (step S303). When this judgment is positive, the SCU 32 further judges whether or not the permit flag is ON (=1) (step S304). Then, when the permit flag is ON (=1), the trim drive command commanding the trim position to be the third trim up position U3 (the bow-up position) is issued (step S305). The trim position is thus changed to the third trim up position U3. Also, the SCU 32 transitions the mode to the bow-up mode (step S306). When the permit flag is OFF (=0) (step S304: NO), the trim drive command is not issued, and the mode stays in the ordinary mode.

[0121] When the trim position of the previous cycle (that is, the current trim position) is not the second trim up position U2 (step S303: NO), the SCU 32 issues the trim drive command commanding the trim position that is one stage above the trim position of the previous cycle (that is, the current trim position) (step S307). The trim position is thus changed to be one stage higher. The mode stays in the ordinary mode.

[0122] When the trim down operation (the operation of the trim down switch 41d) is performed (step S308: YES), the SCU 32 issues the trim drive command commanding the trim position that is one stage below the trim position of the previous cycle (that is, the current trim position) (step S309). The trim position is thus changed to one stage below. However, when the trim position of the previous cycle (that is, the current trim position) is the lowest trim position, that is, the trim down position D1, the trim position of the previous cycle (that is, the current trim position) is maintained.

[0123] When the mode of the previous cycle is the bow-up mode (step S301), the SCU 32 judges whether or not the trim position of the previous cycle (that is, the current trim position) is the third trim up position U3 (the bow-up position) (step S310). When the trim position of the previous cycle is not the third trim up position U3, that is, when the trim position is not the bow-up position despite being in the bow-up mode, the SCU 32 judges whether or not the automatic restore switch is ON (=1), that is, whether or not the automatic restore control is enabled (step S311). When the automatic restore switch is ON (=1), the automatic restore control is executed (steps S312 to S314). That is, the SCU 32 judges whether or not the permit flag is ON (=1) (step S312). When the permit flag is ON (=1), the SCU 32 sets the trim drive speed to the second speed (step S313) and issues the trim drive command commanding the trim position to be the third trim up position U3 (the bow-up position) (step S314). The trim position is thus changed to the third trim up position U3 at the second speed (with the drive duty of the trim actuator 20 set to 50%). The mode in this process is maintained in the bow-up mode.

[0124] When the permit flag is OFF (=0) (step S312: NO), the trim drive command is not issued, and the trim position is not changed. The mode stays in the bow-up mode.

[0125] When the automatic restore flag is OFF (=0) (step S311: NO) the above processes (steps S312 to S314) are omitted, and the SCU 32 transitions the mode to the ordinary mode (step S315).

[0126] When, in the bow-up mode (step S301), the trim position is the third trim up position U3 (the bow-up position), the processes of steps S311 to S315 are all omitted.

[0127] FIGS. 12A and 12B are flowcharts that describe an example of the cancel process S400.

[0128] The SCU 32 determines whether the mode is the bow-up mode or the ordinary mode (step S401) and does not perform the following processes when the mode is the ordinary mode. When the mode is the bow-up mode, the SCU 32 checks whether or not the normal flag is ON (=1) (step S402). When the normal flag is OFF (=0), the SCU 32 checks whether the trim position of the previous cycle (that is, the current trim position) is the third trim up position U3 (the bow-up position) (step S403) and, when the trim position of the previous cycle is the third trim up position U3, executes the forced trim down control (steps S404 and S405) and transitions the mode to the ordinary mode (step S406). Specifically, the SCU 32 sets the trim drive speed to the second speed (drive duty: 50%) (step S404) and issues the trim drive command designating the target trim position (for example, the second trim up position U2) (step S405). The trim position thus changes toward the target trim position at the second speed. When the trim position of the previous cycle (that is, the current trim position) is not the third trim up position U3 (the bow-up position) (step S403: NO), the SCU 32 transitions the mode to the ordinary mode (step S406) without performing the forced trim down control (steps S404 and S405).

[0129] Thus, when an abnormality occurs in the bow-up mode and the normal flag becomes OFF (=0) (see steps S214 to S220 of FIG. 10B), the trim position is returned to one of the ordinary positions by the forced trim down control (steps S404 and S405). The bow-up state is thus canceled.

[0130] When the normal flag is ON (=1) (step S402: YES), the SCU 32 checks whether the trim position of the previous cycle (that is, the current trim position) is the third trim up position U3 (the bow-up position) (step S407) and, when the trim position of the previous cycle is the third trim up position U3, further checks whether the trim down operation has been performed (step S408). The third trim up position U3 is the highest trim position and therefore the trim up operation will be an ineffective operation. When the trim down operation has not been performed (step S408: NO), the SCU 32 judges whether or not the engine rotation speed is not less than the bow-up start rotation speed (step S409). When the engine rotation speed is not less than the bow-up rotation speed, the SCU 32 judges that the watercraft 1 is in the bow-up state and performs the decrement process, that is, the decrementing of the cancel timer (step S410). The decrementing is executed with 0 as a lower limit.

[0131] The cancel timer is decremented by the period of the control cycle (for example, 50 milliseconds) at a time and thus becomes 0 when the cancel wait time (for example, 120 seconds) set in the cancel timer is measured. The SCU 32 judges whether or not the cancel timer is 0 (step S411) and when the cancel timer is 0, executes the forced trim down control (steps S412 and S413). Specifically, the SCU 32 sets the trim drive speed to the second speed (drive duty: 50%) (step S412) and issues the trim drive command designating the target trim position (for example, the second trim up position U2) (step S413). The trim position thus changes toward the target trim position at the second speed. When the cancel timer is not 0 (step S411: NO), the forced trim down control (steps S412 and S413) is not executed and the watercraft 1 can continue to travel in the bow-up state.

[0132] When the bow-up state is thus continued and the cancel timer finally becomes 0, the forced trim down control (steps S412 and S413) is executed and the trim position is forcibly changed to one of the ordinary positions. The bow-up state is thus canceled.

[0133] When the trim down operation is performed (step S408: YES), the SCU 32 sets the trim drive speed to the first speed (drive duty: 100%) (step S414) and issues the trim drive command commanding the trim position to be the second trim up position U2 (step S415). The trim position is thus changed to the second trim up position U2. The SCU 32 further transitions the mode to the ordinary mode (step S416).

[0134] When the automatic restore control is enabled, despite being in the bow-up mode, the trim position may be other than the third trim up position U3 (step S407: NO) due to the forced trim down control (steps S412 and S413). The trim position at this point is the target trim position of the forced trim down control or a position that is within the range lower than the third trim up position U3 (the bow-up position) but higher than the target trim position. When the trim position of the previous cycle (that is, the current trim position) is a position lower than the second trim up position U2 (the position one stage below the bow-up position) (step S417), the SCU 32 accepts the trim up operation (step S418). In this case, the SCU 32 sets the trim drive speed to the first speed (drive duty: 100%) (step S419) and issues the trim drive command designating the trim position one stage above the current trim position (step S420). The trim position is thus changed to one stage above.

[0135] Also, when the trim position of the previous cycle (that is, the current trim position) is other than the trim down position D1 (the position of the lowest stage), the SCU 32 accepts the trim down operation (step S421). In this case, the SCU 32 sets the trim drive speed to the first speed (drive duty: 100%) (step S422) and issues the trim drive command designating the trim position one stage below the current trim position (step S423). The trim position is thus changed to one stage below. After these trim up/down actions, the SCU 32 transitions the mode to the ordinary mode (step S416).

[0136] When the trim up operation or the trim down operation is not performed and the automatic restore control is disabled, the ordinary mode is entered in step S315 of FIG. 11. Also, when the automatic restore control is enabled, the actions will be in accordance with the ON/OFF of the permit flag (step S312). When the trim position of the previous cycle (that is, the current trim position) is the second trim up position U2 (the position one stage below the bow-up position) and the trim up operation is performed (NO in both steps S417 and S421 of FIG. 12B), the actions will be the same as when the trim up operation/trim down operation are not performed.

[0137] FIGS. 13 to 15 are time charts that describe action examples.

[0138] FIG. 13 shows an action example when transition to the bow-up mode is performed by a trim up operation by the user. A case in which there is no abnormality related to the engine 10, etc., so that the normal flag is ON (=1), the engine 10 is running so that the engine flag is ON (=1), the mode is the ordinary mode, the permit flag is OFF (=0), and the resume prohibit timer is 0 shall be assumed.

[0139] Each time the user performs the trim up operation (the operation of the trim up switch 41u), the trim position is raised one stage at a time at the first speed (drive duty: 100%). In the example of FIG. 13, the trim up operation is performed twice from the first trim up position U1. That is, at a time t1, the trim up operation of the first time is performed and the trim position thus changes stepwise from the first trim up position U1 to the second trim up position U2 one stage above. Then, at a time t2, the trim up operation of the second time is performed and the trim position thus changes stepwise from the second trim up position U2 to the third trim up position U3 (the bow-up position) one stage above. Also, the mode transitions from the ordinary mode to the bow-up mode.

[0140] FIG. 14 shows an action example when the resume prohibit timer is not 0. Immediately after the start of the engine 10, the prohibit-at-start time (for example, 6 seconds) is set as the resume prohibit wait time in the resume prohibit timer and decremented on each control cycle.

[0141] The trim up operation in a period before the resume prohibit timer reaches 0 is allowed with the second trim up position U2 as an upper limit, and trim up to third trim up position U3 cannot be performed. In the example of FIG. 14, at a time t11, the trim up operation of the first time is performed and the trim position thus changes stepwise from the first trim up position U1 to the second trim up position U2 one stage above. However, when the trim up operation of the second time is performed at a time t12, the resume prohibit timer is not 0 and therefore, the trim position is kept at the second trim up position U2 and the trim up operation is disabled. The mode is maintained accordingly at the ordinary mode.

[0142] The actions are the same when the forced trim down control causes the transition from the bow-up mode to the ordinary mode and the resume prohibit time (for example, 5 seconds) is set as the resume prohibit wait time in the resume prohibit timer.

[0143] FIG. 15 shows an action example related to automatic cancellation of the bow-up mode. However, this action example assumes that the automatic restore switch is ON (=1) and the automatic restore control is enabled.

[0144] When the trim position is the third trim up position U3 (the bow-up position), the user can put the watercraft 1 in the bow-up attitude (see FIG. 4) by operating the accelerator lever 7 and increasing the engine rotation speed. Specifically, when the engine rotation speed exceeds the bow-up start rotation speed (time t21), the SCU 32 judges that the bow-up state is entered, sets the cancel wait time (for example, 120 seconds) in the cancel timer, and starts decrementing it. Also, the SCU 32 sets the hold time (for example, 5 seconds) in the reset timer.

[0145] In the bow-up state, the attitude of the engine 10 is more steeply inclined than during ordinary traveling and therefore, sustaining the bow-up state for a long period of time can burden the protection of the engine 10 and particularly the lubricant system and the cooling system. Therefore, a notification urging the trim down operation is preferably made to the user. For example, the SCU 32 may, upon making the judgment of being in the bow-up state, provide a command to the display 40 and display a message 91 urging the trim down operation (for example, display a popup) as shown in the display example of FIG. 16. In addition to such a displayed message 91 or in place of the displayed message 91, a notification urging the trim down operation may be made to the user by sound (for example, an intermittent buzzer sound).

[0146] FIG. 15 is referenced again. When the cancel timer ends the measurement of the cancel wait time (for example, 120 seconds) and the value thereof becomes 0 (time t22), the SCU 32 executes the forced trim down control. The trim position thus changes from the third trim up position U3 (the bow-up position) to the target trim position of the forced trim down control (here, the second trim up position U2) at the second speed, that is, a comparatively slow speed. The automatic restore control is enabled and therefore, the SCU 32 maintains the mode in the bow-up mode.

[0147] When the trim position is automatically changed, for example, to the second trim up position U2 by the forced trim down control, the watercraft 1 changes in attitude from the bow-up attitude to the ordinary traveling attitude (see FIG. 1). Since the change in attitude occurs independently of operation by the user, the user is preferably notified that the forced trim down control will be executed and/or is being executed. For example, when the cancel timer becomes 0, the SCU 32 may provide a command to the display 40 and display a message 92 expressing that an automatic change to an ordinary trim position will be performed (for example, display a popup) as shown in the display example of FIG. 17. In addition to such a displayed message 92 or in place of the displayed message 92, a notification concerning the automatic change to the trim position may be made to the user by sound (for example, an intermittent buzzer sound). Here, in FIG. 17, a message example where the target trim position of the forced trim down control is the neutral trim position N is shown.

[0148] FIG. 15 is referred to again. When the cancel timer becomes 0, the resume prohibit time (for example, 5 seconds) is set in the resume prohibit timer and the decrementing thereof is started. Until the resume prohibit timer becomes 0, the actions will be similar to those in the case of FIG. 14, and even when the trim up operation is performed, setting to the third trim up position U3 (the bow-up position) cannot be performed. However, since the automatic restore control is enabled, the mode stays in the bow-up mode.

[0149] On the other hand, the trim down operation is permitted even before the resume prohibit timer becomes 0. When the trim down operation is performed, the SCU 32 transitions the mode to the ordinary mode and changes the trim position according to the operation. The measurement of the resume prohibit time by the resume prohibit timer is continued. The actions until the resume prohibit timer becomes 0 are the same as in the case of FIG. 14.

[0150] Since the trim up operation of raising the trim position to the third trim up position U3 is disabled until the resume prohibit timer becomes 0, the user is preferably notified that this is so. For example, while the resume prohibit timer is decrementing, the SCU 32 may provide a command to the display 40 and display a message, expressing that the bow-up mode is prohibited, and/or a wait time, until bow-up mode resumption (remaining time of the resume prohibit timer), (for example, display a popup). In addition to such a displayed message, etc., or in place of such a displayed message, etc., that the bow-up mode is prohibited and/or the wait time until bow-up mode resumption may be notified to the user by sound (for example, an intermittent buzzer sound).

[0151] When the resume prohibit timer becomes 0 (time t23), the SCU 32 executes the automatic restore control. That is, the SCU 32 changes the trim position automatically to the third trim up position U3 (the bow-up position). A change speed (a drive speed) of the trim position in this process is set to the second speed (drive duty: 50%).

[0152] When the user maintains the engine rotation speed at not less than the bow-up rotation speed by the accelerator operation, the watercraft 1 can be put in the bow-up attitude when the trim position is changed to the third trim up position U3 (the bow-up position) by the automatic restore control. The SCU 32 makes the judgment of being in the bow-up state by the trim position being the third trim up position U3 (the bow-up position) and the engine rotation speed being not less than the bow-up rotation speed. The SCU 32 thus sets the cancel wait time (for example, 120 seconds) in the cancel timer and starts decrementing it.

[0153] When the engine rotation speed is made less than the bow-up rotation speed by the accelerator operation by the user before the cancel timer becomes 0 (time t24), the SCU 32 judges that the bow-up state has been canceled. At this point, the SCU 32, while interrupting the decrementing of the cancel timer and keeping the value thereof, starts the decrementing of the reset timer. When the engine rotation speed becomes not less than the bow-up rotation speed by the accelerator operation by the user before the hold time (for example, 5 seconds) set in the reset timer elapses (time t25), the SCU 32 judges that the bow-up state has been entered. Accordingly, the SCU 32 resumes the interrupted decrementing of the cancel timer. Also, the SCU 32 sets the hold time (for example, 5 seconds) in the reset timer and initializes the reset timer.

[0154] When the cancel timer becomes 0 while still in the bow-up state (time t26), the SCU 32 executes the forced trim down control. Also, the SCU 32 sets the resume prohibit time (for example, 5 seconds) in the resume prohibit timer and starts decrementing it.

[0155] When the engine rotation speed is maintained less than the bow-up rotation speed even from the time t24 onward and the reset timer becomes 0, the SCU 32 discards the value of the cancel timer that was kept, sets it to 0, and discontinues the time measurement by the cancel timer. Therefore, when the bow-up state is entered thereafter, the cancel wait time (for example, 120 seconds) is set in the cancel timer and the time measurement thereof is performed.

[0156] While example embodiments of the present invention have thus been described, the present invention may be embodied in some other ways.

[0157] For example, although in an example embodiment described above, the speed of trim position change in changing the trim position in the forced trim down control and the automatic restore control is set to the comparatively slow second speed, the trim position may be changed at the same first speed as when the user performs the trim operation. Also, although with an example embodiment described above, the case in which the target trim position in the forced trim down control is the second trim up position U2 was mainly described, another trim position in the range of the ordinary positions may be set as the target trim position. For example, the neutral trim position N may be set as the target trim position. When changing the trim position from the third trim up position U3 to the neutral trim position N by the forced trim down control, although movement of the trim position to the neutral trim position N at the first speed (direct drive) may be performed, it is more preferable to perform movement of the trim position at the second speed (slow drive). Or, movement to the second trim up position U2 at the first speed and maintaining of the second trim up position U2 for just a predetermined time followed by movement to the first trim up position U1 at the first speed and maintaining of the first trim up position U1 for just a predetermined time followed by movement to the neutral trim position N at the first speed may be performed. That is, the trim position may be moved from the third trim up position U3 to the neutral trim position N by step drive.

[0158] Also, in an example embodiment described above, the waterjet propulsion watercraft is used by way of example, but the present invention may be applied to other planing watercraft such as outboard watercraft and to watercraft other than planing watercrafts. The drive source of the propulsion device is not necessarily required to be the engine, but may be an electric motor.

[0159] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.