Motor control device of electrically-driven propeller

Abstract

To provide a motor control device of an electrically-driven propeller capable of increasing the opportunity or time to perform a motor regenerative operation and suppressing adverse effect on a motor and the like when a ship jumps.SOLUTION: A motor control device 21 is a device to control a motor 8 of an electrically-driven outboard engine 6. The motor control device 21 comprises: a driving control part 25 for performing driving control of the motor 8 and rotating a propeller 7 of the electrically-driven outboard engine 6; a jump determination part 27 for determining whether or not a ship 1 has jumped; and a regenerative control part 26 for performing regenerative control of the motor 8 when the ship 1 jumps based on a determination result by the jump determination part 27.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a motor control device that controls a motor of an electric propulsion device. [Background technology]

[0002] There are known marine propulsion devices that use a motor (electric motor) as a power source to rotate a propeller (see, for example, Japanese Patent Application Laid-Open Publication No. 2007-125909). Here, the electric propulsion device refers to such an electric marine propulsion device.

[0003] Recently, following in the footsteps of the electrification of automobiles, the electrification of marine propulsion units has been promoted, and it is expected that electric propulsion units will become more widespread in the future. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-125909 Summary of the Invention [Problem to be solved by the invention]

[0005] When the vehicle decelerates, the motor mounted on the vehicle functions as a generator and performs a regenerative operation to convert the vehicle's kinetic energy into electrical energy. The electrical energy obtained by the motor's regenerative operation can be stored in a power storage device such as a battery or capacitor and then used to drive the motor, thereby extending the vehicle's cruising range.

[0006] In automobiles, starting and stopping are repeated frequently during travel, leading to frequent deceleration. Furthermore, automobiles spend a lot of time decelerating because the running resistance of the vehicle is low. For example, it takes a long time for the automobile to stop after the driver releases the accelerator. For these reasons, electric and hybrid automobiles can ensure ample opportunities or time for the motor to perform regenerative operation.

[0007] In contrast, a boat starts and stops less frequently than a car, so deceleration is less frequent. Furthermore, a boat experiences greater water resistance while sailing, so the time spent decelerating is shorter. For example, when a boat operator returns the lever of a boat propulsion remote control device from the forward position to the neutral position, the boat stops in a short time. For these reasons, it is difficult to ensure sufficient opportunities or time for the motor to perform regenerative operation in an electric propulsion unit.

[0008] Meanwhile, while a ship is sailing, it may run up on a wave and jump above the water surface. If the ship is equipped with an electric propulsion unit and is sailing using the propulsive force generated by the electric propulsion unit, when the ship jumps, the propeller of the electric propulsion unit rises above the water surface. When the propeller of the electric propulsion unit rises above the water surface, the water resistance acting on the propeller disappears, and the rotation speed of the motor that rotates the propeller in the electric propulsion unit suddenly increases, causing the motor to rotate at an excessively high speed.

[0009] Excessively high-speed rotation of the motor may adversely affect the motor itself, and may also adversely affect the bearings supporting the propeller shaft, or the gear mechanism, if any, between the motor and the propeller shaft. For example, excessively high-speed rotation of the motor may shorten the lifespan of the motor, bearings, gear mechanism, etc.

[0010] The present invention has been made in consideration of problems such as those described above, and an object of the present invention is to provide a motor control device for an electric propulsion unit that can increase the opportunities or time for the motor to perform regenerative operation and can suppress adverse effects on the motor, etc. when the ship jumps. [Means for solving the problem]

[0011] In order to solve the above problems, the present invention provides a motor control device for an electric propulsion unit that controls the motor of an electric propulsion unit having a propeller and a motor that rotates the propeller, and is characterized by comprising a drive control unit that controls the drive of the motor and rotates the propeller, a jump judgment unit that judges whether a ship equipped with the electric propulsion unit has jumped, and a regeneration control unit that performs regenerative control of the motor when the ship has jumped as a result of the judgment of the jump judgment unit. [Effects of the Invention]

[0012] According to the present invention, when the vessel jumps, regenerative control of the motor is performed, thereby increasing the opportunities or time for the motor to perform regenerative operation. Furthermore, according to the present invention, when the vessel jumps, regenerative control of the motor is performed, thereby applying regenerative braking to the motor and suppressing an increase in the motor rotation speed. Therefore, it is possible to suppress adverse effects on the motor, etc., caused by the motor rotating at excessively high speed. [Brief explanation of the drawings]

[0013] [Figure 1] 1A is an external view showing a vessel equipped with a vessel propulsion system including a motor control device according to an embodiment of the present invention, and FIG. 1B is an explanatory diagram showing the vessel in a jumping state. [Figure 2] 1 is a block diagram showing a marine vessel propulsion system including a motor control device according to an embodiment of the present invention; [Figure 3] FIG. 1 is an explanatory diagram showing a remote control device. [Figure 4]3 is a flowchart illustrating a motor control process in the motor control device according to the embodiment of the present invention. [Figure 5] 4 is a flowchart showing a water landing determination process in the motor control device according to the embodiment of the present invention. [Figure 6] 3 is a flowchart showing a regenerative control process in the motor control device according to the embodiment of the present invention. [Figure 7] 1 is a timing chart showing an example of changes in the required drive torque, required regenerative torque, upward or downward acceleration of the vessel, vessel speed, motor rotation speed, etc. when a motor control process is performed in a motor control device according to an embodiment of the present invention and a vessel traveling forward jumps. [Figure 8] FIG. 10 is a timing chart showing another example of changes in the required drive torque, required regenerative torque, upward or downward acceleration of the vessel, vessel speed, motor rotation speed, etc. when motor control processing is performed in a motor control device according to an embodiment of the present invention and a vessel traveling forward jumps. DETAILED DESCRIPTION OF THE INVENTION

[0014] A motor control device for an electric propulsion unit according to an embodiment of the present invention is a device for controlling the motor of an electric propulsion unit having a propeller and a motor for rotating the propeller. In the motor control device of this embodiment, the motor is, for example, an AC synchronous motor, and torque-based control, for example, is used for higher-level control of the motor, and vector control, for example, is used for lower-level control of the motor. The motor control device of this embodiment also includes a drive control unit, a jump determination unit, and a regeneration control unit.

[0015] The drive control unit controls the drive of the motor to rotate the propeller. Specifically, a vessel equipped with an electric propulsion unit is provided with an operating device (e.g., a remote control device) that allows the vessel operator to operate the electric propulsion unit. The operating device has, for example, an operating lever. The vessel operator tilts the operating lever forward to move the vessel forward, tilts the operating lever backward to move the vessel backward, and returns the operating lever to the neutral position to stop the vessel. The operating device outputs, for example, an operating signal that indicates the tilt direction and tilt angle (operation amount) of the operating lever. The drive control unit controls the drive of the motor based on the operating signal. When the vessel operator tilts the operating lever forward or backward, the drive control unit drives the motor so that the motor's rotor rotates in a direction corresponding to the tilt direction of the operating lever indicated by the operating signal, and so that the motor generates a drive torque corresponding to the tilt angle of the operating lever indicated by the operating signal. This rotates the propeller, generating a propulsive force that moves the vessel forward or backward. The direction of the thrust at that time depends on the tilt direction of the control lever, and the magnitude of the thrust at that time depends on the tilt angle of the control lever. For example, when the operator tilts the control lever significantly forward, the boat moves forward at high speed and enters a sailing state.

[0016] The jump determination unit determines whether a vessel equipped with an electric propulsion unit has jumped. A vessel jumping here refers to the vessel moving upward while sailing and the propeller of the electric propulsion unit emerging from the water. A vessel may jump by running onto a wave while sailing, and the frequency of vessel jumping increases when the vessel is sailing at high speed, for example, when the vessel is planing. Whether a vessel has jumped can be determined, for example, based on the rotation speed of the motor. That is, the drive control unit constantly recognizes the angle or angular velocity of the motor's rotor while controlling the drive of the motor, and performs control to synchronize the rotation of the rotating magnetic field with the rotation of the rotor based on the rotor angle or angular velocity. When the vessel jumps and the propeller of the electric propulsion unit emerges from the water while sailing under the drive control of the motor by the drive control unit, the water resistance acting on the propeller disappears, and the load on the motor suddenly decreases. For example, if the load on the motor suddenly decreases while the motor is rotating and generating a certain drive torque, the angular velocity of the motor's rotor suddenly increases. The drive control unit detects this increase in the rotor's angular velocity and increases the rotational angular velocity of the rotating magnetic field to follow this increase in the rotor's angular velocity. As a result, the motor's rotation speed suddenly increases. In this way, when the ship jumps, the motor's rotation speed suddenly increases, so it is possible to determine whether the ship has jumped based on the motor's rotation speed.

[0017] The regenerative control unit performs regenerative control of the motor when the boat jumps as a result of the judgment by the jump judgment unit. That is, when the boat jumps, motor control is switched from drive control by the drive control unit to regenerative control by the regenerative control unit. After motor control is switched to regenerative control, the propeller and motor rotor continue to rotate due to inertial force. Regenerative control causes the motor to perform regenerative operation and function as a generator. As a result, the kinetic energy of the rotor's rotation is converted into electrical energy.

[0018] By controlling the motor for regeneration when the vessel jumps, the opportunities or time for the motor to perform regenerative operation can be increased. The electrical energy obtained by the motor's regenerative operation can be stored in a storage device such as a battery or capacitor and used to drive the motor thereafter, thereby extending the vessel's cruising range.

[0019] In addition, the regenerative operation of the motor applies regenerative braking to the motor. When the ship jumps, the motor's rotation speed increases suddenly, but the regenerative braking reduces the rate at which the motor's rotation speed increases. This prevents the motor from rotating at excessively high speeds, and prevents the motor and other components from being adversely affected by excessively high speeds. [Example]

[0020] (ship) FIG. 1(A) shows a boat 1 provided with a boat propulsion system 5 including a motor control device 21 according to an embodiment of the present invention.

[0021] The vessel 1 is, for example, a small vessel as shown in Fig. 1(A), and specifically, is a leisure boat, fishing boat, sports boat, cruiser, fishing boat, etc. Note that the present invention is not limited to such small vessels, but can also be applied to medium-sized or large vessels.

[0022] An electric outboard motor 6 is provided at the rear of the hull 2 ​​of the boat 1. The electric outboard motor 6 is one form of electric propulsion unit. The motor control device 21 of this embodiment is a device that controls the motor 8 of the electric outboard motor 6, but the motor control device of the present invention can also be applied to control the motors of other types of electric propulsion units, such as electric inboard / outboard motors and electric inboard motors.

[0023] (Marine Propulsion Systems) FIG. 2 shows the configuration of a boat propulsion system 5. The boat propulsion system 5 is a system that propels the boat 1 and is provided on the boat 1. As shown in FIG. 2, the boat propulsion system 5 includes an electric outboard motor 6, a remote control device (remote control) 31, a boat speed sensor 33, and an acceleration sensor 34. The electric outboard motor 6 also includes a propeller 7, a motor 8, a battery 10, a rotation detection unit 11, and a motor control device 21. The battery 10 may be provided external to the electric outboard motor 6, for example, in the hull 2 ​​of the boat 1. The motor control device 21 may also be provided external to the electric outboard motor 6, for example, in the hull 2 ​​of the boat 1.

[0024] The propeller 7 is a device that generates a propulsive force for the vessel 1 by rotating. The motor 8 is a power source that rotates the propeller 7. For example, the motor 8 is an AC motor, and more specifically, a three-phase synchronous motor. Although not shown in detail, a power transmission mechanism 9 (for example, a drive shaft, a gear mechanism, a propeller shaft, etc.) that transmits the power of the motor 8 to the propeller 7 is provided between the motor 8 and the propeller 7. The battery 10 is a secondary battery that supplies the motor 8 with power for driving the motor.

[0025] The rotation detection unit 11 is a device that detects the angle or angular velocity of the rotor of the motor 8 and the number of rotations n of the motor 8. The rotation detection unit 11 outputs a detection signal indicating the angle or angular velocity of the rotor of the motor 8 to the lower-level control unit 22. The rotation detection unit 11 also outputs a detection signal indicating the number of rotations n of the motor 8 to the upper-level control unit 23. Note that, for example, a configuration may be adopted in which a rotation detection unit that detects only the angle of the rotor of the motor 8 is provided, the lower-level control unit 22 calculates the angular velocity of the motor 8 based on the detection signal from the rotation detection unit, and the upper-level control unit 23 calculates the number of rotations of the motor 8 based on the detection signal from the rotation detection unit.

[0026] The remote control 31 is a device for operating the electric outboard motor 6. As shown in Fig. 3, the remote control 31 has an operation lever 32 that allows the operator to input operations. As shown in Fig. 2, the remote control 31 outputs an operation signal p that indicates the tilt direction and tilt angle (operation amount) of the operation lever 32 to the higher-level control unit 23.

[0027] The boat speed sensor 33 is a device that detects the speed (boat speed s) of the boat 1. The boat speed sensor 33 outputs a detection signal indicating the boat speed s to the upper control unit 23.

[0028] The acceleration sensor 34 is a device that detects the acceleration of the vessel 1. The acceleration sensor 34 can detect the upward acceleration and downward acceleration of the vessel 1. The acceleration sensor 34 outputs a detection signal indicating the upward or downward acceleration a of the vessel 1 to the upper control unit 23. In this embodiment, when the acceleration a has a positive value, the acceleration a indicates the upward acceleration of the vessel 1, and when the acceleration a has a negative value, the acceleration a indicates the downward acceleration of the vessel 1.

[0029] (Motor control device) The motor control device 21 is a device that controls the motor 8. In this embodiment, the motor control device 21 employs torque-based control as the upper control method for the motor 8, and vector control as the lower control method for the motor 8. As shown in FIG. 2, the motor control device 21 has a lower control unit 22 and an upper control unit 23. The motor control device 21 is configured such that the upper control unit 23 controls the lower control unit 22, and the lower control unit 22 controls the motor 8 according to the control of the upper control unit 23. The upper control unit 23 has an arithmetic processing unit, a storage device, etc. The lower control unit 22 has a vector control circuit, a PWM (Pulse Width Modulation) inverter circuit, etc.

[0030] The host control unit 23 functions as a control switching command unit 24, a drive control unit 25, a regeneration control unit 26, and a jump determination unit 27, for example, by executing a computer program stored in a storage device that the host control unit 23 has.

[0031] The control switching command unit 24 switches the control of the lower control unit 22. Specifically, when the drive control unit 25 performs drive control of the motor 8, the control switching command unit 24 outputs a drive control command signal c1 to the lower control unit 22. As a result, the state of the lower control unit 22 changes to a state in which it performs drive control of the motor 8 in cooperation with the drive control unit 25 of the upper control unit 23. Furthermore, when the regenerative control unit 26 performs regenerative control of the motor 8, the control switching command unit 24 outputs a regenerative control command signal c2 to the lower control unit 22. As a result, the state of the lower control unit 22 changes to a state in which it performs regenerative control of the motor 8 in cooperation with the regenerative control unit 26 of the upper control unit 23.

[0032] The drive control unit 25 controls the drive of the motor 8. Specifically, the drive control unit 25 outputs a command signal indicating a rotation direction command j and a required drive torque d to the subordinate control unit 22. The subordinate control unit 22 drives the motor 8 based on the command signal and the angle or angular velocity of the rotor of the motor 8 output from the rotation detection unit 11. Specifically, the subordinate control unit 22 drives the motor 8 so that the rotation direction of the rotor of the motor 8 is the rotation direction indicated by the rotation direction command j and the drive torque generated by the motor 8 is a drive torque corresponding to the required drive torque d. The drive torque generated by the motor 8 increases as the required drive torque d increases.

[0033] When the regenerative control process described later is not being performed, the drive control unit 25 normally controls the drive of the motor 8 in accordance with the operation of the operation lever 32 of the remote control 31. Specifically, the drive control unit 25 determines a rotation direction instruction j and a required drive torque d in accordance with the operation of the operation lever 32 of the remote control 31. That is, in FIG. 3 , when the vessel helmsman moves the vessel 1 forward, he tilts the operation lever 32 forward to the forward position. When the vessel helmsman moves the vessel 1 backward, he tilts the operation lever 32 backward to the reverse position. When the vessel helmsman moves the vessel 1 to a stop, he sets the operation lever 32 to the neutral position. As shown in FIG. 2 , the remote control 31 outputs an operation signal p indicating the tilt direction and tilt angle (operation amount) of the operation lever 32 to the upper control unit 23. The drive control unit 25 determines the rotation direction instruction j based on the tilt direction of the operation lever 32 indicated by the operation signal p. Specifically, when the tilt direction of the operating lever 32 indicated by the operation signal p is forward, the drive control unit 25 sets the rotation direction instruction j to an instruction to change the rotation direction of the motor 8 in one direction, and when the tilt direction of the operating lever 32 indicated by the operation signal p is backward, the drive control unit 25 sets the rotation direction instruction j to an instruction to change the rotation direction of the motor 8 in the other direction. In addition, the drive control unit 25 determines the required drive torque d based on the tilt angle of the operating lever 32 indicated by the operation signal p. The larger the tilt angle of the operating lever 32 indicated by the operation signal p, the larger the required drive torque d is.

[0034] The lower-level control unit 22 controls the motor 8 based on the command signal indicating the rotation direction command j and the required drive torque d determined in this manner, and the angle or angular velocity of the rotor of the motor 8 output from the rotation detection unit 11, so that the rotor of the motor 8 rotates in a direction corresponding to the tilt direction of the control lever 32, and the drive torque generated by the motor 8 corresponds to the tilt angle of the control lever 32. As a result, when the vessel operator tilts the control lever 32 forward to the forward position, the propeller rotates in the forward direction, generating a propulsive force that moves the vessel 1 forward; the greater the forward tilt angle of the control lever 32, the greater the propulsive force that moves the vessel 1 forward. When the vessel operator tilts the control lever 32 backward to the reverse position, the propeller rotates in the reverse direction, generating a propulsive force that moves the vessel 1 astern; the greater the rearward tilt angle of the control lever 32, the greater the propulsive force that moves the vessel 1 astern.

[0035] Furthermore, in a regenerative control process described below, the drive control unit 25 performs drive control of the motor 8 independent of the operation of the operating lever 32 of the remote control 31. Specifically, in the regenerative control process, the drive control unit 25 sets the required drive torque d to 0 regardless of the tilt angle of the operating lever 32 immediately before the start of regenerative control of the motor, and after the end of regenerative control of the motor, gradually increases the required drive torque d from 0 regardless of the tilt angle of the operating lever 32. These will be described in detail later.

[0036] The regenerative control unit 26 performs regenerative control of the motor 8. Specifically, the regenerative control unit 26 determines a required regenerative torque g and outputs a command signal indicating the required regenerative torque g to the subordinate control unit 22. Based on the command signal, the subordinate control unit 22 controls the induced current flowing through the stator coil of the motor 8 so that the regenerative torque generated in the motor 8 corresponds to the required regenerative torque g. The regenerative torque is torque in the opposite direction to the rotation direction of the rotor at that time, and is generated by the regenerative operation of the motor 8. In a regenerative control process described later, the regenerative control unit 26 determines the required regenerative torque g (required regenerative torque initial value Gs) based on the rotation speed increase rate r per unit time of the motor 8 when the boat 1 starts jumping, and then gradually reduces the required regenerative torque g. This will be described in detail later.

[0037] The jump determination unit 27 determines whether the boat 1 has jumped. Specifically, the jump determination unit 27 determines whether the boat 1 has started to jump. A jump of the boat 1 means that the boat 1 moves upward while traveling and the propeller 7 of the electric outboard motor 6 comes out of the water. The boat 1 may jump by running over a wave while traveling, and the boat 1 jumps more frequently when traveling at high speed, for example, when the boat 1 is planing. FIG. 1(B) shows an example of the boat 1 jumping. Note that W in FIG. 1(B) indicates the water surface. When the jump determination unit 27 determines that the boat 1 has started to jump, a regenerative control process is started, and in the regenerative control process, regenerative control of the motor 8 and the like are performed. These will be described in detail later. The jump determination unit 27 also determines whether the boat 1 has landed on water after jumping.

[0038] (Motor control processing, jump start judgment processing) Fig. 4 shows the motor control process in the motor control device 21. As shown in Fig. 4, the motor control process includes a jump start determination process (steps ST1 to ST5), a drive control process in response to the operation of the control lever (step ST6), a water landing determination process (step ST7), and a regeneration control process (step ST8).

[0039] FIG. 5 shows the water landing determination process. FIG. 6 shows the regeneration control process. FIG. 7 shows an example of changes in the required drive torque d, the required regenerative torque g, the upward or downward acceleration a of the vessel 1, the vessel speed s, the rotation speed n of the motor 8, etc. when the motor control process shown in FIG. 4 is performed and the vessel 1 traveling forward jumps. FIG. 8 shows another example of changes in the required drive torque d, the required regenerative torque g, the upward or downward acceleration a of the vessel 1, the vessel speed s, the rotation speed n of the motor 8, etc. when the motor control process shown in FIG. 4 is performed and the vessel 1 traveling forward jumps. Note that in FIGS. 7 and 8, the downward direction is the increasing direction for the graph of required regenerative torque g, and the upward direction is the increasing direction for the other graphs. Also, in the graphs of upward or downward acceleration a in FIGS. 7 and 8, values ​​above 0 represent the upward acceleration a of the vessel 1, and values ​​below 0 represent the downward acceleration a of the vessel 1 (as described above, the upward acceleration a is a positive value and the downward acceleration a is a negative value). 7 and 8, a graph showing the change in the waterline of the vessel 1 is added at the top of each figure to show the timing and behavior of the jump of the vessel 1.

[0040] 4 is repeatedly executed during operation of the vessel propulsion system 5. When the vessel propulsion system 5 starts operating (for example, immediately before the start of the motor control process), the subordinate control unit 22 enters an initial state. The initial state of the subordinate control unit 22 is a state in which it controls the drive of the motor 8 in cooperation with the drive control unit 25 of the superior control unit 23.

[0041] In the motor control process shown in Fig. 4, first, the jump determination unit 27 performs a jump start determination process (steps ST1 to ST5). The jump start determination process is a process for determining whether or not the boat 1 has started a jump. In this embodiment, the jump determination unit 27 determines whether or not the boat 1 has started a jump based on the upward acceleration a of the boat 1, the boat speed s of the boat 1, the required drive torque d, the rate of increase r of the rotation speed per unit time of the motor 8, and the rotation speed n of the motor 8.

[0042] In the jump start determination process, the jump determination unit 27 first recognizes the current upward acceleration a of the boat 1 based on the detection signal output from the acceleration sensor 34, and determines whether the acceleration a is equal to or greater than a predetermined upward acceleration reference value Ath1 (step ST1). If the current upward acceleration a of the boat 1 is equal to or greater than the upward acceleration reference value Ath1, the jump determination unit 27 recognizes the current boat speed s of the boat 1 based on the detection signal output from the boat speed sensor 33, and determines whether the boat speed s is equal to or greater than a predetermined boat speed reference value Sth (step ST2). If the current boat speed s of the boat 1 is equal to or greater than the boat speed reference value Sth, the jump determination unit 27 determines whether the required drive torque d currently being output by the drive control unit 25 to the subordinate control unit 22 is equal to or greater than a predetermined required drive torque reference value Dth (step ST3). If the current required drive torque d is equal to or greater than the required drive torque reference value Dth, the jump determination unit 27 calculates the current rotation speed increase rate r per unit time of the motor 8 based on the detection signal output from the rotation detection unit 11, and determines whether the rotation speed increase rate r is equal to or greater than a predetermined rotation speed increase rate reference value Rth (step ST4). If the current rotation speed increase rate r per unit time of the motor 8 is equal to or greater than the rotation speed increase rate reference value Rth, the jump determination unit 27 monitors the rotation speed n of the motor 8 based on the detection signal output from the rotation detection unit 11, and determines whether the rotation speed n of the motor 8 has increased to or greater than a predetermined rotation speed reference value Nth (step ST5).

[0043] In the jump start determination process, the order in which the determination of whether the current acceleration a is equal to or greater than the upward acceleration reference value Ath1, the determination of whether the current boat speed s is equal to or greater than the boat speed reference value Sth, the determination of whether the current required drive torque d is equal to or greater than the required drive torque reference value Dth, and the determination of whether the current rotation speed increase rate r per unit time is equal to or greater than the rotation speed increase rate reference value Rth is performed is not limited to the order shown in Fig. 4. The order in which these determinations are performed can be reversed. However, the determination of whether the current rotation speed increase rate r per unit time is equal to or greater than the rotation speed increase rate reference value Rth should be performed after the determination of whether the current acceleration a is equal to or greater than the upward acceleration reference value Ath1.

[0044] If the current acceleration a is not equal to or greater than the upward acceleration reference value Ath1, the current boat speed s is not equal to or greater than the boat speed reference value Sth, the current required drive torque d is not equal to or greater than the required drive torque reference value Dth, the current rotation speed increase rate r per unit time is not equal to or greater than the rotation speed increase rate reference value Rth, or the rotation speed n has not increased to or greater than the rotation speed reference value Nth, the jump determination unit 27 determines that the boat 1 has not started a jump. If the jump determination unit 27 determines that the boat 1 has not started a jump, the drive control unit 25 executes drive control processing in accordance with the operation of the operating lever 32 (step ST6).

[0045] The drive control process in response to the operation of the operating lever 32 is a process for driving the motor 8 in response to the operation of the operating lever 32. When the drive control process in response to the operation of the operating lever 32 starts, the drive control unit 25 determines a rotation direction instruction j in response to the tilt direction of the operating lever 32 indicated by the operation signal p output from the remote controller 31, and also determines a required drive torque d in response to the tilt angle of the operating lever 32 indicated by the operation signal p, and outputs command signals indicating the rotation direction instruction j and the required drive torque d to the subordinate control unit 22. Thereafter, the process returns to step ST1. Since the motor control process is repeatedly executed while the vessel propulsion system 5 is in operation, the process of step ST6, i.e., the drive control process in response to the operation of the operating lever 32, is repeatedly executed while the vessel 1 has not started jumping. During this time, the drive control unit 25 continuously outputs command signals indicating the rotation direction instruction j and the required drive torque d to the subordinate control unit 22. During this time, when the tilt direction of the operating lever 32 indicated by the operation signal p output from the remote control 31 changes, the drive control unit 25 changes the rotation direction instruction j in accordance with the change in the tilt direction of the operating lever 32, and when the tilt angle of the operating lever 32 indicated by the operation signal p changes, the drive control unit 25 changes the required drive torque d in accordance with the change in the tilt angle of the operating lever 32. The subordinate control unit 22 drives the motor 8 based on the command signal output from the drive control unit 25. As a result, the motor 8 is driven in accordance with the operation of the operating lever 32.

[0046] On the other hand, if the current acceleration a is greater than or equal to the upward acceleration reference value Ath1, the current ship speed s is greater than or equal to the ship speed reference value Sth, the current required drive torque d is greater than or equal to the required drive torque reference value Dth, the current rotation speed increase rate r per unit time is greater than or equal to the rotation speed increase rate reference value Rth, and the rotation speed n has increased to greater than or equal to the rotation speed reference value Nth, the jump judgment unit 27 judges that the ship 1 has started a jump.

[0047] The vessel 1 is more likely to jump when traveling at high speed. Whether the vessel 1 is traveling at high speed and has entered a state in which it is more likely to jump can be estimated based on the vessel speed s of the vessel 1. The vessel speed reference value Sth is a value that indicates the vessel speed of the vessel 1 when the vessel 1 is traveling at high speed and has entered a jump, and is a value that is determined, for example, by prior experiments or simulations. By determining whether the vessel speed s of the vessel 1 is equal to or greater than the vessel speed reference value Sth, it can be estimated whether the vessel 1 is traveling at high speed and has entered a state in which it is more likely to jump.

[0048] Furthermore, when the operator tilts the operating lever 32 of the remote control 31 significantly, the required drive torque d increases, the drive torque of the motor 8 increases, and the propulsive force of the boat 1 increases. As a result, the boat 1 travels at high speed and enters a state in which it is easy to jump. Therefore, whether the boat 1 has entered a state in which it is easy to travel at high speed and jump can be estimated based on the required drive torque d. The required drive torque reference value Dth is a value that indicates the required drive torque when the boat 1 travels at high speed and jumps, and is a value that is determined, for example, by prior experiments or simulations. By determining whether the required drive torque d is equal to or greater than the required drive torque reference value Dth, it can be estimated whether the boat 1 has entered a state in which it is easy to travel at high speed and jump.

[0049] Furthermore, when the vessel 1 starts to jump, the vessel 1 suddenly moves upward by a large amount. Whether the vessel 1 has suddenly moved upward by a large amount can be determined based on the upward acceleration a of the vessel 1. The upward acceleration reference value Ath1 is a value that indicates the upward acceleration of the vessel 1 when the vessel 1 starts to jump, and is a value that is determined, for example, by a prior experiment or simulation. Whether the vessel 1 has started to jump can be inferred by determining whether the upward acceleration a of the vessel 1 is equal to or greater than the upward acceleration reference value Ath1.

[0050] Furthermore, when the vessel 1 begins to jump, the propeller 7 emerges from the water, eliminating the water resistance acting on the propeller 7, causing a sudden, large increase in the rotation speed of the motor 8. This sudden, large increase in the rotation speed of the motor 8 can be determined based on the rotation speed increase rate r per unit time of the motor 8 and the rotation speed n of the motor 8 immediately after the sudden increase. The rotation speed increase rate reference value Rth is a value that indicates the rotation speed increase rate per unit time of the motor 8 when the vessel 1 begins to jump. The rotation speed reference value Nth is a value that indicates the rotation speed of the motor 8 immediately after the vessel 1 begins to jump. These values ​​are determined, for example, through prior experiments or simulations. Whether the vessel 1 has begun to jump can be inferred by determining whether the rotation speed increase rate r per unit time of the motor 8 is equal to or greater than the rotation speed increase rate reference value Rth and whether the rotation speed n of the motor 8 immediately after the sudden increase is equal to or greater than the rotation speed reference value Nth.

[0051] Therefore, by determining that the vessel 1 has started a jump when the current acceleration a is equal to or greater than the upward acceleration reference value Ath1, the current vessel speed s is equal to or greater than the vessel speed reference value Sth, the current required drive torque d is equal to or greater than the required drive torque reference value Dth, the current rotation speed increase rate r per unit time is equal to or greater than the rotation speed increase rate reference value Rth, and the rotation speed n has increased to equal to or greater than the rotation speed reference value Nth, it is possible to determine with high accuracy that the vessel 1 has started a jump.

[0052] The jump start determination process will now be described in detail with reference to Figure 7. At time t1 in Figure 7, the acceleration a is equal to or greater than the upward acceleration reference value Ath1, the vessel speed s is equal to or greater than the vessel speed reference value Sth, the required drive torque d is equal to or greater than the required drive torque reference value Dth, and the rotation speed increase rate r per unit time is equal to or greater than the rotation speed increase rate reference value Rth. Furthermore, at time t2, the rotation speed n increases to or greater than the rotation speed reference value Nth. In this case, at time t2, the jump determination unit 27 determines that the vessel 1 has started a jump.

[0053] 4, when the jump determination unit 27 determines that the vessel 1 has started jumping, a water landing determination process and a regeneration control process are executed (step ST7). The water landing determination process and the regeneration control process are executed in parallel (or in parallel) with each other.

[0054] (Water landing judgment processing) In the water-landing determination process shown in FIG. 5, first, the jump determination unit 27 initializes a water-landing flag. Specifically, the jump determination unit 27 turns off the water-landing flag (step ST11). The water-landing flag is a flag indicating whether the jumped vessel 1 has landed on water, and is rewritably stored in, for example, a storage device included in the upper control unit 23. Next, the jump determination unit 27 determines whether the jumped vessel 1 has landed on water (step ST12). Specifically, the jump determination unit 27 recognizes the current downward acceleration a of the vessel 1 based on the detection signal output from the acceleration sensor 34. If the acceleration a is equal to or less than the downward acceleration reference value Ath2, the jump determination unit 27 determines that the jumped vessel 1 has landed on water, and if the acceleration a is not equal to or less than the downward acceleration reference value Ath2, the jump determination unit 27 determines that the jumped vessel 1 has not landed on water. Then, if the result of this determination indicates that the jumped vessel 1 has landed on water, the jump determination unit 27 turns on the water-landing flag (step ST13) and ends the water-landing determination process.

[0055] (Regenerative control processing) 6, the regeneration control process is configured as follows: first, a process related to drive control of motor 8 is performed (step ST21), then the control of motor 8 is switched (step ST22), then a process related to regeneration control of motor 8 is performed (steps ST23 to ST26), then the control of motor 8 is switched (step ST27), then a process related to drive control of motor 8 is performed (steps ST28 to ST29). The regeneration control process will be described in detail below.

[0056] In the regenerative control process, first, the drive control unit 25 sets the required drive torque d to 0 regardless of the current tilt angle of the operating lever 32 (step ST21).

[0057] Next, the control switching command unit 24 outputs a regenerative control command signal c2 to the lower control unit 22 (step ST22). As a result, the state of the lower control unit 22 changes to a state in which the lower control unit 22 performs regenerative control of the motor 8 in cooperation with the regenerative control unit 26 of the upper control unit 23. That is, the output of the regenerative control command signal c2 interrupts the drive control of the motor 8, and the regenerative control of the motor 8 is started.

[0058] Next, the regeneration control unit 26 determines the required regeneration torque initial value Gs based on the rotation speed increase rate r of the motor 8 when the boat 1 starts to jump (step ST23). The regeneration control unit 26 increases the required regeneration torque initial value Gs as the rotation speed increase rate r of the motor 8 when the boat 1 starts to jump increases.

[0059] Next, the regenerative control unit 26 sets the required regenerative torque g to the required regenerative torque initial value Gs, and outputs a command signal indicating the required regenerative torque g to the lower-level control unit 22 (step ST24). While the regenerative control of the motor 8 is being performed, the regenerative control unit 26 continuously outputs the command signal indicating the required regenerative torque g.

[0060] Next, the regenerative control unit 26 gradually reduces the required regenerative torque g from the required regenerative torque initial value Gs until the rotation speed n of the motor 8 becomes equal to or less than the rotation speed N0 of the motor 8 immediately before the boat 1 starts to jump. Specifically, the regenerative control unit 26 first reduces the required regenerative torque g by a predetermined unit amount (step ST25). Next, the regenerative control unit 26 recognizes the current rotation speed n of the motor 8 based on the detection signal output from the rotation detection unit 11, and determines whether the rotation speed n is equal to or less than the rotation speed N0 of the motor 8 immediately before the boat 1 starts to jump (step ST26). The upper control unit 23 stores and accumulates the rotation speed of the motor 8 over a certain recent period as a rotation speed memory value in a storage device included in the upper control unit 23, and the rotation speed N0 of the motor 8 immediately before the boat 1 starts to jump can be obtained from the rotation speed memory values ​​stored in the storage device. If the current rotation speed n of the motor 8 is not equal to or less than the rotation speed N0 of the motor 8 immediately before the boat 1 started the jump, the process returns to step ST25, and the regeneration control unit 26 again reduces the requested regenerative torque g by the predetermined unit amount. On the other hand, if the current rotation speed n of the motor 8 is equal to or less than the pre-jump rotation speed N0, the process proceeds to step ST27.

[0061] In step ST27, the control switching command unit 24 outputs a drive control command signal c1 to the lower control unit 22. This causes the lower control unit 22 to enter a state where it cooperates with the drive control unit 25 of the upper control unit 23 to control the drive of the motor 8. That is, the output of the drive control command signal c1 ends the regenerative control of the motor 8, and the drive control of the motor 8 is resumed.

[0062] Next, the drive control unit 25 starts outputting a command signal indicating the rotation direction command j and the required drive torque d to the lower-level control unit 22. The drive control unit 25 then gradually increases the required drive torque d from 0 until the boat 1 lands on water after jumping and the boat speed s of the boat 1 starts to increase from a decrease. This process is a drive control process for the motor 8 that is independent of the operation of the control lever 32, and the drive control unit 25 gradually increases the required drive torque d from 0 regardless of the current tilt angle of the control lever 32. Specifically, the drive control unit 25 first increases the required drive torque d by a predetermined unit amount (step ST28). Next, the drive control unit 25 determines whether the water-landing flag is on and whether the boat speed s of the boat 1 has started to increase from a decrease (step ST29). The drive control unit 25 determines whether the water-landing flag is on by referring to the water-landing flag stored in a storage device of the upper-level control unit 23. The drive control unit 25 also recognizes changes in the current boat speed s of the boat 1 based on the detection signal output from the boat speed sensor 33, and thereby determines whether the boat speed s of the boat 1 has changed from decreasing to increasing. The behavior of the boat 1, in which the boat 1 lands on water after jumping and then the boat speed of the boat 1 changes from decreasing to increasing, is the behavior of the boat 1 when the boat 1 finishes the jump and returns to the same state as immediately before the jump. In other words, after starting the jump, the boat 1 lands on water, and temporarily decelerates due to the water resistance applied to the boat 1 as a result of the water landing, and then begins to accelerate due to the thrust generated by the propeller 7, which is submerged, rotating due to the power of the motor 8, and returns to the same state as immediately before the jump.

[0063] If the determination in step ST29 shows that the water landing flag is not on, or if the water landing flag is on but the boat speed s of the boat 1 has not changed from a decrease to an increase, the process returns to step ST28. The drive control unit 25 then increases the required drive torque d by the predetermined unit amount again. On the other hand, if the determination in step ST29 shows that the water landing flag is on and the boat speed s of the boat 1 has changed from a decrease to an increase, the process returns to step ST1 in FIG. 4.

[0064] If the boat 1 starts jumping again at the same time that the processing returns to step ST1, the jump start determination processing will determine that the boat 1 has started jumping immediately after the processing returns to step ST1, and the regeneration control processing will be executed again. However, considering that the processing speed of the upper control unit 23 is significantly faster than the behavior of the boat 1, this is unlikely to occur. Normally, immediately after the processing returns to step ST1, the jump start determination processing will determine that the boat 1 has not started jumping, and the processing will proceed to step ST6, where the drive control processing will be executed in accordance with the operation of the operating lever 32.

[0065] The regenerative control process will now be described in detail with reference to Figure 7. At time t2 in Figure 7, the jump determination unit 27 determines that the boat 1 has started a jump, and in response, the regenerative control process is started and the required drive torque d becomes 0. Then, the state of the lower control unit 22 is switched to a state in which the regenerative control of the motor 8 is performed in cooperation with the regenerative control unit 26 of the upper control unit 23. As a result, the drive control of the motor 8 is interrupted, but the rotor of the motor 8 continues to rotate due to inertial force.

[0066] Furthermore, at time t2, regenerative control of motor 8 is started, and requested regenerative torque g set to requested regenerative torque initial value Gs is output to lower-level control unit 22. When requested regenerative torque g set to requested regenerative torque initial value Gs is output to lower-level control unit 22, the corresponding control of lower-level control unit 22 causes regenerative torque corresponding to requested regenerative torque g set to requested regenerative torque initial value Gs to be generated in motor 8, regenerative braking is applied to motor 8, and an increase in the rotation speed of motor 8 is suppressed.

[0067] In the graph of rotation speed n at the bottom of Figure 7, solid line Ls1 shows the change in rotation speed n when regenerative control processing is being performed, and dashed line Lb1 shows the change in rotation speed n when regenerative control processing is not being performed. When vessel 1 begins jumping, propeller 7 emerges from the water, and water resistance acting on propeller 7 is eliminated, causing motor rotation speed n to rapidly increase from time t1 to time t2. When regenerative control processing is not being performed, as indicated by dashed line Lb1, the rapid increase in rotation speed n of motor 8 continues after time t2, and thereafter, motor rotation speed n reaches an excessively high rotation speed Np. In contrast, when regenerative control processing is being performed, as indicated by solid line Ls1, regenerative braking is applied to motor 8 at time t2, thereby suppressing the increase in motor rotation speed n. As a result, motor rotation speed n does not reach an excessively high rotation speed Np. In this way, when the boat 1 starts to jump, the regenerative control process applies regenerative braking to the motor 8, thereby preventing the motor 8 from rotating at an excessively high speed.

[0068] Furthermore, in the regeneration control process, the regeneration control unit 26 increases the required regenerative torque initial value Gs as the rotation speed increase rate r of the motor 8 at time t1 increases. Therefore, the greater the rotation speed increase rate r of the motor 8 at time t1, the greater the regenerative torque generated in the motor 8 at time t2, and as a result, the greater the braking force due to the regenerative braking applied to the motor 8. This makes it possible to reliably prevent the rotation speed of the motor 8 from increasing excessively, even if the rotation speed increase rate r of the motor 8 is large when the vessel 1 starts to jump.

[0069] Furthermore, from time t2 to time t3 in FIG. 7 , the regenerative torque required g is gradually reduced by the processing of the regenerative control unit 26. Therefore, from time t2 to time t3, the regenerative torque generated by the motor 8 is gradually reduced. As a result, from time t2 to time t3, the rotation speed n of the motor 8 is gradually reduced slowly from time t2 to time t3, as indicated by the solid line Ls1 in the graph of the rotation speed n. By slowly reducing the rotation speed n of the motor 8 from time t2, two effects are obtained. The first effect is that when the regenerative control process ends after the jumped boat 1 lands on water and the drive control process corresponding to the operation of the operating lever 32 is resumed, a sudden and significant change in the rotation speed n of the motor 8 can be suppressed, thereby suppressing large vibrations in the boat 1. The second effect is that the amount of regenerative power obtained by the regenerative operation of the motor 8 can be increased from the time the boat 1 starts jumping until it lands on water.

[0070] To explain the first effect, drive control processing in response to the operation of the operating lever 32 is performed until immediately before the boat 1 starts to jump. Then, after the boat 1 starts to jump, the drive control processing in response to the operation of the operating lever 32 is interrupted and regenerative control processing is performed. Then, after the boat 1 has landed on water after jumping, the regenerative control processing ends and the drive control processing in response to the operation of the operating lever 32 is resumed. Furthermore, in the drive control processing in response to the operation of the operating lever 32, the required drive torque d is determined in response to the operation of the operating lever 32 by the boat operator (the tilt angle of the operating lever 32), which determines the drive torque generated by the motor 8, determines the rotation speed n of the motor 8, and determines the magnitude of the propulsive force of the boat 1. Therefore, if the operator does not operate the operating lever 32 (the inclination angle of the operating lever 32 has not changed) between immediately before the drive control processing in response to the operation of the operating lever 32 is interrupted due to the start of a jump of the vessel 1 and immediately after the drive control processing in response to the operation of the operating lever 32 is resumed, when the drive control processing in response to the operation of the operating lever 32 is resumed, the drive control of the motor 8 by the drive control unit 25 will cause the required drive torque d, drive torque of the motor 8, rotation speed n of the motor 8, and propulsion force of the vessel 1 to return to the required drive torque d, drive torque, rotation speed n, and propulsion force that were present immediately before the drive control processing in response to the operation of the operating lever 32 was interrupted due to the start of a jump of the vessel 1. Therefore, if the rotation speed n of the motor 8 is close to the rotation speed n immediately before the drive control process in response to the operation of the operating lever 32 is interrupted due to the start of the jump of the boat 1 when the boat 1 lands on the water and the regenerative control process is then completed, when the drive control process in response to the operation of the operating lever 32 is resumed, the rotation speed n of the motor 8 will not change suddenly or significantly, thereby preventing large vibrations from occurring in the boat 1.

[0071] If the required regenerative torque g is not gradually reduced from time t2, the required regenerative torque initial value Gs is maintained from time t2, and therefore the rate at which the rotation speed n of the motor 8 gradually reduces increases from time t2, and the rotation speed n of the motor 8 decreases significantly in an extremely short time after time t2. If the rotation speed n of the motor 8 decreases significantly in an extremely short time after time t2, when the boat 1 lands on water after jumping and the regenerative control process ends, the rotation speed n of the motor 8 may be significantly lower than the rotation speed n immediately before the start of the jump of the boat 1 and the drive control process corresponding to the operation of the operating lever 32 is interrupted. In this case, when the regenerative control process ends and the drive control process corresponding to the operation of the operating lever 32 is resumed, the rotation speed n of the motor 8 increases abruptly and significantly, which may cause large vibrations in the boat 1.

[0072] In contrast, in the motor control device 21 of this embodiment, after outputting the required regenerative torque g set to the required regenerative torque initial value Gs at time t2, the required regenerative torque g is gradually reduced from time t2, thereby slowing the rate at which the rotation speed n of the motor 8 gradually decreases from time t2. By slowing the rate at which the rotation speed n of the motor 8 gradually decreases in this manner, it is possible to make the rotation speed n of the motor 8, when the boat 1 has landed on water after jumping and the regenerative control process is then completed, close to the rotation speed n immediately before the drive control process responsive to the operation of the operating lever 32 was interrupted due to the start of the jump of the boat 1. Therefore, it is possible to prevent the rotation speed n of the motor 8 from changing suddenly and significantly when the drive control process responsive to the operation of the operating lever 32 is resumed, thereby suppressing large vibrations in the boat 1.

[0073] The second effect obtained by slowly and gradually decreasing the rotation speed n of the motor 8 from time t2 will be explained. If the required regenerative torque g is not gradually decreased from time t2, the required regenerative torque initial value Gs is maintained from time t2. This may cause the rotation of the motor 8 to slow down or stop in an extremely short time after time t2. When the rotation of the motor 8 is slow, the regenerative power obtained through the regenerative operation of the motor 8 is reduced. Furthermore, if the rotation of the motor 8 stops, the regenerative operation of the motor 8 is no longer performed, and no regenerative power can be obtained. Therefore, if the required regenerative torque g is not gradually decreased from time t2, the amount of regenerative power obtained through the regenerative operation of the motor 8 will be reduced from the time the boat 1 starts jumping until it hits the water. In contrast, in the motor control device 21 of this embodiment, at time t2, the required regenerative torque g set to the required regenerative torque initial value Gs is output, and then the required regenerative torque g is gradually reduced from time t2, thereby slowing the rate at which the rotation speed n of the motor 8 gradually decreases from time t2. This prevents the rotation of the motor 8 from slowing down or stopping during the period from time t2 until the boat 1 hits the water. Therefore, the regenerative operation of the motor 8 can be continued for a long time while the boat 1 is jumping, and the amount of regenerative power obtained by the regenerative operation of the motor 8 can be increased.

[0074] 7, the rotation speed n of the motor 8 is equal to or less than the rotation speed N0 immediately before the boat 1 starts to jump. The regenerative control unit 26 recognizes that the rotation speed n of the motor 8 is equal to or less than the rotation speed N0 immediately before the boat 1 starts to jump, and the state of the subordinate control unit 22 is switched to a state in which the subordinate control unit 22 cooperates with the drive control unit 25 of the superior control unit 23 to control the drive of the motor 8. This ends the regenerative control of the motor 8, and the drive control of the motor 8 is resumed. By terminating the regenerative control of the motor 8 when the rotation speed n of the motor 8 is equal to or less than the rotation speed N0 immediately before the boat 1 starts to jump, the rotation speed n of the motor 8 at the end of the regenerative control process can be made to approach the rotation speed N0 immediately before the boat 1 starts to jump. This makes it possible to suppress sudden and significant changes in the rotation speed n of the motor 8 when the drive control process in response to the operation of the operating lever 32 is resumed, thereby suppressing large vibrations in the boat 1.

[0075] Then, at time t3, the drive control unit 25 executes a drive control process independent of the operation of the operating lever 32, thereby starting a gradual increase of the required drive torque d from 0. Thereafter, at time t4, the boat 1 that jumped lands on water. As a result of the boat 1 that jumped on water, the downward acceleration a of the boat 1 becomes equal to or less than the downward acceleration reference value Ath2. At this time, in the water-landing determination process that is executed in parallel (or in parallel) with the regenerative control process, it is recognized that the boat 1 that jumped on has landed on water based on the downward acceleration a of the boat 1, and the water-landing flag is switched from off to on. Furthermore, as the boat 1 encounters water resistance when the boat 1 lands on water, the boat speed s of the boat 1 decreases from time t4. Thereafter, at time t5, the boat speed s of the boat 1 changes from decreasing to increasing. At this time, in the regenerative control process, the drive control unit 25 recognizes that the water-landing flag is on and that the boat speed s of the boat 1 has changed from decreasing to increasing, and the gradual increase of the required drive torque d is stopped. Then, the regenerative control process ends, and immediately thereafter, the drive control process according to the operation of the operating lever 32 is resumed.

[0076] From time t3, when the regenerative control of the motor 8 ends, until time t5, when the boat 1 lands on water and the boat speed s of the boat 1 starts to increase after decreasing, the drive control unit 25 performs a process of gradually increasing the required drive torque d from 0. This process will be referred to as the "required drive torque gradual increase process." The required drive torque gradual increase process gradually increases the drive torque generated by the motor 8 from time t3 to time t5. This makes it possible to suppress a decrease in boat speed s due to the boat 1 landing on water after jumping, and to suppress vibration of the boat 1 when the boat 1 lands on water after jumping. In the graph of boat speed s second from the bottom in Figure 7, the solid line Ls2 shows the change in boat speed s when the required drive torque gradual increase process is being performed, and the dashed line Lb2 shows the change in boat speed s when the required drive torque gradual increase process is not being performed. When the boat 1 lands on water after jumping, water resistance is applied to the boat 1, causing the boat speed s of the boat 1 to decrease. If the required drive torque gradual increase process is not performed, the drive torque generated by the motor 8 is small when the boat 1 lands on water, and therefore the boat speed s decreases significantly, as shown by the dashed line Lb2. In contrast, if the required drive torque gradual increase process is performed, the drive torque generated by the motor 8 increases when the boat 1 lands on water (or the drive torque has already increased to a certain extent), and therefore the decrease in boat speed s is smaller, as shown by the solid line Ls2. Therefore, by performing the required drive torque gradual increase process, it is possible to suppress vibrations of the boat 1 when the boat 1 lands on water after jumping.

[0077] Furthermore, at time t5, it is recognized that the water landing flag is on and that the vessel speed s of the vessel 1 has changed from decreasing to increasing, and the required drive torque gradual increase processing and the regenerative control processing are terminated, thereby enabling a quick and smooth transition from the regenerative control processing to the drive control processing in response to the operation of the operating lever 32.

[0078] Incidentally, when the boat 1 jumps, there are cases where the rotation speed n of the motor 8 becomes equal to or less than the rotation speed N0 immediately before the jump before the jumped boat 1 hits the water, and cases where the rotation speed n of the motor 8 does not become equal to or less than the rotation speed N0 immediately before the jump before the jumped boat 1 hits the water. Figure 7 shows an example where the rotation speed n of the motor 8 becomes equal to or less than the rotation speed N0 immediately before the jump before the jumped boat 1 hits the water. On the other hand, Figure 8 shows an example where the rotation speed n of the motor 8 does not become equal to or less than the rotation speed N0 immediately before the jump before the jumped boat 1 hits the water.

[0079] In Figure 8, the period from time t11 to just before time t13 is the same as the period from time t1 to just before time t3 in Figure 7. At time t13, the vessel 1 that has jumped lands on water. As a result of the vessel 1 that has jumped on water, the downward acceleration a of the vessel 1 becomes equal to or less than the downward acceleration reference value Ath2. At this time, the water landing determination process that is executed in parallel (or in parallel) with the regeneration control process recognizes that the vessel 1 that has jumped on water, and the water landing flag is switched from OFF to ON. Furthermore, as the vessel 1 encounters water resistance when it lands on water, the vessel speed s of the vessel 1 decreases from time t13. Furthermore, as the propeller 7 encounters water resistance when the vessel 1 lands on water, the rotation speed n of the motor 8 suddenly decreases from time t13. Thereafter, at time t14, the rotation speed n of the motor 8 becomes equal to or less than the rotation speed N0 immediately before the vessel 1 started jumping. The regenerative control unit 26 then recognizes that the rotation speed n of the motor 8 has fallen below the rotation speed N0 immediately before the boat 1 started to jump, and the state of the subordinate control unit 22 is switched to a state in which the subordinate control unit 22 controls the drive of the motor 8 in cooperation with the drive control unit 25 of the superior control unit 23. This ends the regenerative control of the motor 8, and the drive control of the motor 8 is resumed. Then, at time t14, the drive control unit 25 executes a drive control process independent of the operation of the control lever 32, thereby starting to gradually increase the required drive torque d from 0. Thereafter, at time t15, the boat speed s of the boat 1 changes from decreasing to increasing. At this time, in the regenerative control process, the drive control unit 25 recognizes that the water landing flag is on and that the boat speed s of the boat 1 has changed from decreasing to increasing, and stops the gradual increase of the required drive torque d. The regenerative control process then ends, and immediately thereafter, the drive control process in response to the operation of the control lever 32 is resumed.

[0080] In this way, even if the rotation speed n of the motor 8 does not become less than the rotation speed N0 immediately before the jump before the jumped vessel 1 lands on the water, the motor control device 21 achieves the same effect as when the rotation speed n of the motor 8 becomes less than the rotation speed N0 immediately before the jump before the jumped vessel 1 lands on the water.

[0081] As described above, the motor control device 21 according to the embodiment of the present invention performs regenerative control of the motor 8 when the boat 1 jumps. This increases the opportunities or time for the motor 8 to perform regenerative operation. Therefore, the amount of regenerative power obtained by the regenerative operation of the motor 8 can be increased. The regenerative power obtained by the regenerative operation of the motor 8 can be stored in a power storage device such as a battery or capacitor and used to drive the motor 8 thereafter, thereby extending the cruising range of the boat 1.

[0082] Furthermore, regenerative control enables regenerative braking to be applied to the motor 8, thereby suppressing an increase in the rotation speed of the motor 8 when the vessel 1 jumps. This prevents the motor 8 from rotating at an excessively high speed when the vessel 1 jumps, and prevents the motor 8 and other components from being adversely affected by excessively high speed rotation.

[0083] Furthermore, by gradually reducing the regenerative torque generated in the motor 8 through regenerative control, the rotation of the motor 8 can be prevented from slowing down or stopping while the vessel 1 is jumping, and the regenerative operation of the motor 8 can be continued for a long period of time. This makes it possible to increase the amount of regenerative power obtained through the regenerative operation of the motor 8 while preventing the motor from rotating at an excessively high speed.

[0084] In the above embodiment, in the regeneration control process, the required regenerative torque initial value Gs is determined based on the rotation speed increase rate r of the motor 8 when the boat 1 starts jumping. Specifically, the required regenerative torque initial value Gs is increased as the rotation speed increase rate r increases. However, the present invention is not limited to this. The required regenerative torque initial value Gs may be set to a predetermined constant value.

[0085] In the above embodiment, the required regenerative torque g is gradually reduced in the regenerative control process. However, the present invention is not limited to this. For example, after the required regenerative torque g set to the required regenerative torque initial value Gs is output, the required regenerative torque g may be quickly reduced to a predetermined value that is greater than 0 and less than the required regenerative torque initial value Gs, and then the required regenerative torque g may be maintained at the predetermined value until the rotation speed n of the motor 8 becomes equal to or less than the rotation speed N0 of the motor 8 immediately before the boat 1 starts jumping.

[0086] Furthermore, in the above embodiment, the jump determination unit 27 determines that the vessel 1 has started a jump when all of the following conditions are satisfied: (1) the upward acceleration a of the vessel 1 is equal to or greater than a predetermined upward acceleration reference value Ath1; (2) the vessel speed s of the vessel 1 is equal to or greater than a predetermined vessel speed reference value Sth; (3) the required drive torque d is equal to or greater than a predetermined required drive torque reference value Dth; (4) the rotation speed increase rate r per unit time of the motor 8 is equal to or greater than a predetermined rotation speed increase rate reference value Rth; and (5) the rotation speed n of the motor 8 has increased to equal to or greater than a predetermined rotation speed reference value Nth. However, the present invention is not limited to this. It may also be determined that the vessel 1 has started a jump when some of the above five conditions are satisfied. For example, it may be determined that the boat 1 has started a jump when all of the above conditions (1), (4), and (5) are satisfied, or it may be determined that the boat 1 has started a jump when all of the above conditions (2), (4), and (5) are satisfied, or it may be determined that the boat 1 has started a jump when all of the above conditions (3), (4), and (5) are satisfied, or it may be determined that the boat 1 has started a jump when all of the above conditions (4) and (5) are satisfied. Furthermore, when determining whether the boat 1 has started a jump, a detected value or a controlled value that represents the behavior of the boat 1 or the electric outboard motor 6 other than the upward acceleration a of the boat 1, the boat speed s, the required drive torque d, the rate of increase in the rotation speed per unit time r of the motor 8, and the rotation speed n of the motor 8 may be used. For example, when determining whether the boat 1 has started a jump, it may be determined whether the boat 1 is moving forward based on the rotation direction command j (in other words, the condition that the boat 1 is moving forward may be added to the conditions for determining that the boat 1 has started a jump).

[0087] In the above embodiment, the regenerative control of the motor 8 is terminated when the rotation speed n of the motor 8 becomes equal to or less than the rotation speed N0 of the motor 8 immediately before the boat 1 starts to jump. However, the present invention is not limited to this. For example, the regenerative control of the motor 8 may be terminated when it is determined that the boat 1 has landed on water after jumping.

[0088] In the above embodiment, whether or not the boat 1 has landed on water after jumping is determined based on the downward acceleration of the boat 1. However, the present invention is not limited to this. The boat speed or the number of rotations of the motor may also be used to determine whether or not the boat 1 has landed on water after jumping.

[0089] In the above embodiment, the process of gradually increasing the required drive torque is stopped during the regeneration control process when the boat 1 lands on water and the boat speed s subsequently changes from a decrease to an increase. However, the present invention is not limited to this. For example, the process of gradually increasing the required drive torque may be stopped after a predetermined time has elapsed since the boat 1 lands on water.

[0090] Furthermore, the present invention can be modified as appropriate within the scope of the claims and the entire specification without going against the gist or concept of the invention, and motor control devices for electric propulsion devices that involve such modifications are also included in the technical concept of the present invention. [Explanation of symbols]

[0091] 1 ship 6 Electric outboard motor (electric propulsion machine) 7 propellers 8 motors 21 Motor control device 25 Drive control unit 26 Regeneration control unit 27 Jump Judgment Department

Claims

1. 1. A motor control device for an electric propulsion device that controls a motor of an electric propulsion device having a propeller and a motor that rotates the propeller, a drive control unit that controls the drive of the motor to rotate the propeller; a jump determination unit that determines whether the vessel provided with the electric propulsion unit has jumped; a regeneration control unit that performs regenerative control of the motor when the jump determination unit determines that the vessel has jumped.

2. 2. The motor control device for an electric propulsion unit according to claim 1, wherein the regenerative control unit increases the regenerative torque of the motor as the rate of increase in the rotation speed of the motor when the vessel starts to jump increases in the regenerative control of the motor.

3. 2. The motor control device for an electric propulsion unit according to claim 1, wherein the regenerative control unit generates a regenerative torque in the motor when the vessel starts jumping, and then gradually reduces the regenerative torque in the regenerative control of the motor.

4. 2. The motor control device for an electric propulsion unit according to claim 1, wherein the jump determination unit determines that the ship has started a jump when the rotation speed increase rate of the motor is equal to or greater than a predetermined rotation speed increase rate reference value and the rotation speed of the motor increases to or greater than a predetermined rotation speed reference value.

5. 2. The motor control device for an electric propulsion unit according to claim 1, wherein the jump determination unit determines that the vessel has started a jump when the speed of the vessel is equal to or greater than a predetermined vessel speed reference value, the rate of increase in the rotation speed of the motor is equal to or greater than a predetermined rotation speed increase rate reference value, and the rotation speed of the motor increases to equal to or greater than a predetermined rotation speed reference value.

6. the drive control unit drives the motor so that the motor generates a drive torque corresponding to a required drive torque corresponding to an operation amount of an operation device that operates the electric propulsion machine, in drive control of the motor; 2. The motor control device for an electric propulsion unit according to claim 1, wherein the jump determination unit determines that the ship has started a jump when the required drive torque is equal to or greater than a predetermined required drive torque reference value, the rate of increase in the rotation speed of the motor is equal to or greater than a predetermined rotation speed increase rate reference value, and the rotation speed of the motor increases to equal to or greater than a predetermined rotation speed reference value.

7. 2. The motor control device for an electric propulsion unit according to claim 1, wherein the jump determination unit determines that the vessel has started a jump when the upward acceleration of the vessel is equal to or greater than a predetermined upward acceleration reference value, the rate of increase in the rotation speed of the motor is equal to or greater than a predetermined rotation speed increase rate reference value, and the rotation speed of the motor increases to equal to or greater than a predetermined rotation speed reference value.

8. 2. The motor control device for an electric propulsion unit according to claim 1, wherein the regenerative control unit terminates regenerative control of the motor when the rotation speed of the motor, which has increased due to the vessel jumping, decreases to or below the rotation speed immediately before the vessel jumped.

9. The motor control device for an electric propulsion device according to claim 1 , wherein the drive control unit gradually increases the drive torque of the motor after regenerative control of the motor ends.

10. the jump determination unit determines whether the vessel that has jumped has landed on water, 10. The motor control device for an electric propulsion unit according to claim 9, wherein the drive control unit terminates the control for gradually increasing the drive torque of the motor when, as a result of the judgment by the jump judgment unit, the speed of the vessel changes from decreasing to increasing after the vessel has landed on water after jumping.

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