Patent Description:
A marine vessel maneuvering system that controls a propulsive force and steering based on a user's operation is known in general. Such a marine vessel maneuvering system is disclosed in <CIT>, for example.

<CIT> discloses a marine propulsion unit that propels a hull. The marine propulsion unit disclosed in <CIT> includes a propeller driven by a motor, a steering shaft, a motor controller, and a steering mechanism. The marine propulsion unit disclosed in <CIT> is attached to the hull. A remote control and a steering wheel are provided on the hull. In the marine propulsion unit disclosed in <CIT>, rotational driving of the propeller is controlled by the motor controller based on a user's operation on the remote controller such that the magnitude of a propulsive force to propel the hull is adjusted. Furthermore, the steering shaft is rotated by the steering mechanism based on a user's operation on the steering wheel such that the direction of the propulsive force is adjusted.

Although not disclosed in <CIT>, in a conventional marine propulsion unit including a propeller driven by a motor as disclosed in <CIT>, when a marine vessel is turned or laterally moved, for example, both the magnitude of a propulsive force and a steering angle are adjusted based on a user's operation on an operator when the operator is moved from a neutral position by the user's operation on the operator. Then, when the operator is returned to the neutral position, the steering angle is returned to a reference position (a position at which the direction of the propulsive force is parallel to the forward-rearward direction of the hull) with generation of the propulsive force by the motor stopped. In such a case, a steering mechanism is driven without generation of a propulsive force and generation of a water flow, and thus the driving noise of the steering mechanism is noticeable unlike a case in which the steering mechanism is driven with generation of a water flow. When the operator is returned to the neutral position, the driving noise of the steering mechanism is noticeable even when the steering angle is returned to the reference position without completely stopping generation of the propulsive force by the motor and with generation of a relatively small propulsive force. When the propeller is driven by an engine, relatively loud operating noise is continuously generated by idling even with generation of the propulsive force stopped, and thus the driving noise of the steering mechanism is unlikely to be noticeable. On the other hand, when the propeller is driven by the motor, driving of the motor is stopped with generation of a propulsive force stopped, and thus the driving noise of the steering mechanism is particularly likely to be noticeable. Therefore, there is a desire to significantly reduce or prevent a decrease in quietness due to the noticeable driving noise of the steering mechanism.

It is an object of the present invention to provide a marine vessel maneuvering system and a control method of a marine vessel that significantly reduce or prevent a decrease in quietness due to the noticeable driving noise of a steering mechanism. According to the present invention, said object is solved by a marine vessel maneuvering system and a control method of a marine vessel having the features of independent claims <NUM> and <NUM>. Preferred embodiments are laid down in the dependent claims.

A marine vessel maneuvering system according to a preferred embodiment includes a propulsive force generator configured to generate a propulsive force to propel a marine vessel, a steering mechanism configured to steer the propulsive force generator, and a controller configured or programmed to control the propulsive force of the propulsive force generator and steering by the steering mechanism based on a user's operation on an operator configured to maneuver the marine vessel. The controller is configured or programmed to control a steering speed to a first steering speed when the operator is moved from a neutral position, and to control the steering speed to a second steering speed that is lower than the first steering speed when the operator is returned to the neutral position.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is configured or programmed to control the steering speed to the first steering speed when the operator is moved from the neutral position, and to control the steering speed to the second steering speed that is lower than the first steering speed when the operator is returned to the neutral position. Accordingly, when the operator is returned to the neutral position, the steering speed at which the steering angle is returned to the reference position becomes relatively low. Therefore, when the steering angle is returned to the reference position, the driving speed of the steering mechanism is decreased such that the driving noise of the steering mechanism becomes relatively small. Consequently, a decrease in quietness due to the noticeable driving noise of the steering mechanism is significantly reduced or prevented. This advantageous effect is particularly effective when a propulsive force generator driven by a motor is provided in which the driving noise of a steering mechanism is likely to be noticeable. Furthermore, the consumption of components of the steering mechanism is significantly reduced or prevented by a decrease in the driving speed of the steering mechanism at which the steering angle is returned to the reference position, and thus the life of the components of the steering mechanism is improved.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is preferably configured or programmed to control the steering speed to the second steering speed with generation of the propulsive force of the propulsive force generator stopped when the operator is returned to the neutral position. Accordingly, the steering speed at which the steering angle is returned to the reference position with generation of the propulsive force stopped becomes relatively low. Consequently, a propulsive force is not generated, and a water flow is not generated. Thus, the steering speed becomes relatively low in a state in which the driving noise of the steering mechanism is likely to be noticeable, and thus the noticeable driving noise of the steering mechanism due to driving of the steering mechanism is effectively significantly reduced or prevented.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is preferably configured or programmed to control the steering speed to the second steering speed by adjusting a steering angle command value or a speed command value output to the steering mechanism when the operator is returned to the neutral position. Accordingly, the steering angle command value as the target value of the steering angle is continuously adjusted such that the steering speed is indirectly adjusted, and the speed command value as the speed of steering is adjusted such that the steering speed is directly adjusted. Thus, the steering speed at which the steering angle is returned to the reference position is easily controlled to the second steering speed.

In such a case, the controller is preferably configured or programmed to determine whether or not an actual steering angle that changes following the steering angle command value has reached the steering angle command value when the operator is returned to the neutral position, and to control the steering speed to the second steering speed when determining that the actual steering angle has reached the steering angle command value. Accordingly, when the steering angle is returned to the reference position, the steering speed is controlled to the second steering speed after the actual steering angle reaches the steering angle command value, and thus the steering angle command value is appropriately controlled such that the steering speed becomes the second steering speed.

In a marine vessel maneuvering system including the controller configured or programmed to control the steering speed to the second steering speed by adjusting the steering command value or the speed command value, the controller is preferably configured or programmed to control the steering speed to the second steering speed by adjusting the steering angle command value at predetermined intervals. Accordingly, the steering angle command value as the target value of the steering angle is adjusted at the predetermined intervals, and thus the steering speed at which the steering angle is returned to the reference position is more easily controlled to the second steering speed.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is preferably configured or programmed to control the steering speed to the second steering speed when the operator including at least one of a joystick, a steering wheel, or a remote control configured to maneuver the marine vessel is returned to the neutral position. Accordingly, in the marine vessel maneuvering system in which the marine vessel is maneuvered based on a user's operation on at least one of the joystick, the steering wheel, or the remote control, the steering speed at which the steering angle is returned to the reference position is relatively reduced such that a decrease in quietness is significantly reduced or prevented.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is preferably configured or programmed to control the steering speed to the second steering speed based on the operator being returned to the neutral position after an operation is performed to perform at least one of turning, lateral movement, or rotation of the marine vessel. Accordingly, the steering speed at which the steering angle is returned to the reference position after the marine vessel is turned, laterally moved, or rotated becomes relatively low. Consequently, when the operator is returned to the neutral position after the marine vessel is turned, laterally moved, or rotated, a propulsive force is not generated, and a water flow is not generated. Thus, the steering speed becomes relatively low in a state in which the driving noise of the steering mechanism is likely to be noticeable, and thus the noticeable driving noise of the steering mechanism due to driving of the steering mechanism is effectively significantly reduced or prevented.

In a marine vessel maneuvering system according to a preferred embodiment, the second steering speed is preferably set to one half or less of the first steering speed. Accordingly, the steering speed at which the steering angle is returned to the reference position is sufficiently decreased such that the noticeable driving noise of the steering mechanism is significantly reduced or prevented.

In such a case, the first steering speed is preferably set to a maximum settable steering speed, and the second steering speed is preferably set to one half or less of the first steering speed. Accordingly, the operator is operated such that the steering speed at which the steering angle is returned to the reference position is sufficiently decreased such that the noticeable driving noise of the steering mechanism is significantly reduced or prevented without decreasing the steering speed occurring when the operator is moved from the neutral position.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is preferably configured or programmed to control the steering speed to a constant second steering speed when the operator is returned to the neutral position. Accordingly, as compared with a case in which the second steering speed is changed, a control process for the steering speed at which the steering angle is returned to the reference position is simplified.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is preferably configured or programmed to control the steering mechanism to change the steering speed from the second steering speed to the first steering speed when the operator is moved from the neutral position while the steering mechanism is steering the propulsive force generator at the second steering speed. Accordingly, even when a subsequent operation is performed on the operator while the steering angle is being returned to the reference position with the steering speed decreased from the first steering speed to the second steering speed, steering by the steering mechanism is immediately controlled with the steering speed returned from the second steering speed to the first steering speed based on the subsequent operation on the operator.

In a marine vessel maneuvering system according to a preferred embodiment, the steering mechanism preferably includes a motor, a steering shaft configured to perform the steering, and a plurality of gears configured to transmit a rotational force of the motor to the steering shaft, and the controller is preferably configured or programmed to control the steering mechanism to change the steering between being performed at the first steering speed and being performed at the second steering speed by adjusting a current supplied to the motor. Accordingly, the current supplied to the motor is adjusted such that the steering speed is easily controlled to the first steering speed and the second steering speed via the plurality of gears and the steering shaft. Furthermore, the consumption of the motor, the gears, and the steering shaft is significantly reduced or prevented by a decrease in the driving speed of the steering mechanism at which the steering angle is returned to the reference position. Therefore, the life of the motor, the gears, and the steering shaft is improved.

In such a case, the motor of the steering mechanism preferably includes a DC motor with a brush. Accordingly, the consumption of the brush of the DC motor with a brush is significantly reduced or prevented by a decrease in the driving speed of the steering mechanism at which the steering angle is returned to the reference position, and thus the life of the motor is effectively improved.

In a marine vessel maneuvering system according to a preferred embodiment, the controller is preferably configured or programmed to perform a feedback control on the steering by the steering mechanism by a PI control. Accordingly, the accuracy of a control of steering by the steering mechanism is improved, and thus the accuracy of a control to change the steering speed to the second steering speed is improved.

In a marine vessel maneuvering system according to a preferred embodiment, the propulsive force generator and the steering mechanism preferably include a plurality of sets of propulsive force generators and steering mechanisms, and the controller is preferably configured or programmed to control steering speeds of the steering mechanisms to the second steering speed when the operator is returned to the neutral position. Accordingly, even when a plurality of sets of propulsive force generators and steering mechanism are provided, the steering speeds of all of a plurality of steering mechanisms are controlled to the second steering speed, and thus the steering speed at which the steering angle is returned to the reference position becomes relatively low without shifting the timing of returning the steering angle to the reference position among the plurality of steering mechanisms.

A marine vessel maneuvering system according to a preferred embodiment is preferably used for the marine vessel. Accordingly, in the marine vessel, a decrease in quietness due to the noticeable driving noise of a steering mechanism is significantly reduced or prevented.

A control method of a marine vessel according to a preferred embodiment includes controlling a steering speed to a first steering speed when an operator is moved from a neutral position, and controlling the steering speed to a second steering speed that is lower than the first steering speed when the operator is returned to the neutral position.

In a control method of a marine vessel according to a preferred embodiment, the steering speed is controlled to the first steering speed when the operator is moved from the neutral position, and the steering speed is controlled to the second steering speed that is lower than the first steering speed when the operator is returned to the neutral position. Accordingly, the steering speed at which a steering angle is returned to a reference position becomes relatively low, similarly to the marine vessel maneuvering system according to preferred embodiments of the present invention described above. Consequently, a decrease in quietness due to the noticeable driving noise of a steering mechanism is significantly reduced or prevented, similarly to the marine vessel maneuvering system according to preferred embodiments of the present invention described above. This advantageous effect is particularly effective when a propulsive force generator driven by a motor is provided in which the driving noise of a steering mechanism is likely to be noticeable, similarly to the marine vessel maneuvering system according to preferred embodiments of the present invention described above. Furthermore, the life of components of the steering mechanism is improved, similarly to the marine vessel maneuvering system according to preferred embodiments of the present invention described above.

The above and other elements, features, steps, characteristics and advantages of preferred embodiments will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

Preferred embodiments are hereinafter described with reference to the drawings.

The structure of a marine vessel maneuvering system <NUM> and the structure of a marine vessel <NUM> according to preferred embodiments are now described with reference to <FIG>. The marine vessel maneuvering system <NUM> is a system to maneuver the marine vessel <NUM>. That is, the marine vessel maneuvering system <NUM> is a system used for the marine vessel <NUM>. The marine vessel maneuvering system <NUM> is provided in the marine vessel <NUM>.

As shown in <FIG>, the marine vessel <NUM> (marine vessel maneuvering system <NUM> (see <FIG>)) includes a hull <NUM> and marine propulsion units <NUM>. The marine propulsion units <NUM> are attached to the rear of the hull <NUM>. That is, the marine propulsion units <NUM> are outboard motors. The marine vessel <NUM> is used for sightseeing in a canal and a lake, for example. The marine vessel <NUM> is a relatively small marine vessel. Arrow FWD and arrow BWD in <FIG> represent the front side and the rear side of the marine vessel <NUM>, respectively.

As shown in <FIG>, each of the marine propulsion units <NUM> (marine vessel maneuvering system <NUM> (see <FIG>)) includes a propulsive force generator <NUM> to generate a propulsive force to propel the marine vessel <NUM> and a steering mechanism <NUM> to steer the propulsive force generator <NUM>.

The propulsive force generator <NUM> includes a propeller <NUM>. As shown in <FIG>, the propulsive force generator <NUM> includes a motor <NUM>. As the motor <NUM> is rotated, the propeller <NUM> (see <FIG>) rotates such that the propulsive force generator <NUM> generates a propulsive force. That is, the propulsive force generator <NUM> is an electric propulsive force generator (electric propulsion device) driven by the motor <NUM>.

As shown in <FIG>, the steering mechanism <NUM> changes the orientation of the propulsive force generator <NUM> with respect to the marine propulsion unit <NUM> (marine vessel <NUM>). <FIG> show a state in which the steering mechanism <NUM> is located at a reference position P10 (a position at which the direction of the propulsive force is parallel to the forward-rearward direction of the marine vessel <NUM>), a state in which the steering mechanism <NUM> is steered in the starboard direction from the reference position P10 such that the marine vessel <NUM> changes its course in the portside direction, and a state in which the steering mechanism <NUM> is steered in the portside direction from the reference position P10 such that the marine vessel <NUM> changes its course in the starboard direction, respectively.

Specifically, as shown in <FIG>, the steering mechanism <NUM> includes a motor <NUM>, a steering shaft <NUM> to perform steering (change the direction of the propulsive force), and a plurality of gears <NUM> to transmit the rotational force of the motor <NUM> to the steering shaft <NUM>. The steering shaft <NUM> is a shaft fixed to the propulsive force generator <NUM>. The motor <NUM> is a DC motor with a brush. The plurality of gears <NUM> include a spur gear 23a, a spur gear 23b, a spur gear 23c, a spur gear 23d, a worm gear 23e, and a worm wheel 23f.

The spur gear 23a is fixed to a rotation shaft of the motor <NUM> so as to rotate coaxially with the rotation shaft of the motor <NUM>. The spur gear 23b meshes with the spur gear 23a. The spur gear 23c is fixed to the spur gear 23b so as to rotate coaxially with the spur gear 23b. The spur gear 23d meshes with the spur gear 23c. The worm gear 23e is fixed to the spur gear 23d so as to rotate together with the spur gear 23d. The worm wheel 23f meshes with the worm gear 23e. The worm wheel 23f is fixed to the steering shaft <NUM> so as to rotate coaxially with the steering shaft <NUM> about a steering center axis A1. The steering mechanism <NUM> rotates the steering shaft <NUM> with rotation of the motor <NUM> to steer the propulsive force generator <NUM> (change the direction of the propulsive force generator <NUM>). In the steering mechanism <NUM>, rotation of the motor <NUM> is decelerated by the plurality of gears <NUM> (at a reduction ratio of about <NUM>/<NUM>, for example) and transmitted to the steering shaft <NUM>.

Thus, as shown in <FIG>, the steering mechanism <NUM> changes (steers) the direction of the propulsive force (thick arrow) of the marine vessel <NUM>. <FIG> shows a state in which the steering mechanism <NUM> is located at the reference position P10 (a position at which the direction of the propulsive force is parallel to the forward-rearward direction of the marine vessel <NUM>), and a state in which the orientation of the steering mechanism <NUM> is changed by a steering angle θ from the reference position P10 with chain lines and solid lines, respectively.

A plurality of (two) marine propulsion units <NUM> are provided for one marine vessel <NUM>. That is, in the marine vessel maneuvering system <NUM>, a plurality of sets (two sets) of propulsive force generators <NUM> and steering mechanisms <NUM> are provided.

As shown in <FIG>, the hull <NUM> (marine vessel maneuvering system <NUM>) includes an operator <NUM> to maneuver the marine vessel <NUM>. The operator <NUM> receives a user's (a user of the marine vessel <NUM>) operation. The operator <NUM> includes a remote control <NUM>, a steering wheel <NUM>, and a joystick <NUM>.

The remote control <NUM> includes a lever to adjust the propulsive force, and the lever is operated such that the propulsive force generator <NUM> (the magnitude of the propulsive force of the propulsive force generator <NUM>) is controlled. The steering wheel <NUM> is rotatable, and the steering mechanism <NUM> (steering by the steering mechanism <NUM>) is controlled according to the amount of rotation of the steering wheel <NUM>.

As shown in <FIG>, the joystick <NUM> includes a base 33a and a lever 33b. The lever 33b is attached so as to be tiltable and rotatable with respect to the base 33a. When the lever 33b is tilted, the propulsive force generator <NUM> (the magnitude of the propulsive force of the propulsive force generator <NUM>) and the steering mechanism <NUM> (steering by the steering mechanism <NUM>) are controlled according to the amount and direction of tilting of the lever 33b. When the lever 33b is rotated, the propulsive force generator <NUM> (the magnitude of the propulsive force of the propulsive force generator <NUM>) and the steering mechanism <NUM> (steering by the steering mechanism <NUM>) are controlled according to the amount of rotation of the lever 33b. The lever 33b is urged by an urging member such as a spring so as to automatically return to a neutral position P20 (a position at which the lever 33b is upright) when not touched by the user.

As shown in <FIG>, the hull <NUM> (marine vessel maneuvering system <NUM>) includes a first controller <NUM>, a second controller <NUM>, and a control switch <NUM>. The first controller <NUM>, the second controller <NUM>, and the control switch <NUM> are circuit boards including a central processing unit (CPU), a read-only memory (ROM), a random access memory (RAM), etc., for example. The second controller <NUM> is an example of a "controller".

The first controller <NUM> controls the propulsive force of the propulsive force generator <NUM> and steering by the steering mechanism <NUM> based on user's operations on the steering wheel <NUM> and the remote control <NUM>. The second controller <NUM> controls the propulsive force of the propulsive force generator <NUM> and steering by the steering mechanism <NUM> based on a user's operation on the joystick <NUM>.

The first controller <NUM> and the second controller <NUM> performs a feedback control on the propulsive force of the propulsive force generator <NUM> and steering by the steering mechanism <NUM> by a PI control. Specifically, the propulsive force generator <NUM> includes a propulsive force controller <NUM> and a rotation speed sensor <NUM>. The propulsive force controller <NUM> includes a motor driver and an inverter, for example. The rotation speed sensor <NUM> detects the rotation speed of the motor <NUM>. The first controller <NUM> and the second controller <NUM> control the rotation speed of the motor <NUM> via the propulsive force controller <NUM> such that the rotation speed of the motor <NUM> detected by the rotation speed sensor <NUM> becomes a target value.

The steering mechanism <NUM> includes a steering controller <NUM> and a steering angle sensor <NUM>. The steering controller <NUM> includes a motor driver, for example. The steering angle sensor <NUM> detects the rotation angle of the steering shaft <NUM> (see <FIG>). As shown in <FIG>, the steering mechanism <NUM> includes a sensor gear <NUM>. The sensor gear <NUM> includes a spur gear 26a and a spur gear 26b. The spur gear 26a is fixed to the worm wheel 23f so as to rotate coaxially with the worm wheel 23f. The spur gear 26b meshes with the spur gear 26a and rotates about a steering angle sensor axis A2. Although not shown in <FIG>, the steering angle sensor <NUM> is provided adjacent to or in the vicinity of the spur gear 26b to detect the amount of rotation of the spur gear 26b. The steering angle sensor <NUM> is an optical sensor or a magnetic sensor, for example. As shown in <FIG>, the first controller <NUM> and the second controller <NUM> control the rotation speed of the motor <NUM> via the steering controller <NUM> such that the rotation angle of the steering shaft <NUM> detected by the steering angle sensor <NUM> becomes a target value.

The control switch <NUM> switches between a state in which the first controller <NUM> controls the propulsive force of the propulsive force generator <NUM> and steering by the steering mechanism <NUM> and a state in which the second controller <NUM> controls the propulsive force of the propulsive force generator <NUM> and steering by the steering mechanism <NUM>. As shown in <FIG>, a joystick mode switch 33c is provided on the base 33a of the joystick <NUM>. The joystick mode switch 33c is pressed such that the control switch <NUM> switches between a state in which the marine vessel maneuvering system <NUM> receives an operation on the joystick <NUM> (joystick mode) and a state in which the marine vessel maneuvering system <NUM> does not receive an operation on the joystick <NUM>.

According to preferred embodiments, as shown in <FIG>, the second controller <NUM> (see <FIG>) controls a steering speed V (see <FIG>) to a first steering speed V1 when the joystick <NUM> is moved from the neutral position P20, and controls the steering speed V to a second steering speed V2 that is lower than the first steering speed V1 when the joystick <NUM> is returned to the neutral position P20. Specifically, the second controller <NUM> controls the steering speed V to the second steering speed V2 with generation of the propulsive force of the propulsive force generator <NUM> stopped when the joystick <NUM> is returned to the neutral position P20. The second controller <NUM> controls the steering speed V to the second steering speed V2 based on the joystick <NUM> being returned to the neutral position P20 after an operation is performed to turn or laterally move the marine vessel <NUM>.

Specifically, when the marine vessel <NUM> is turned or laterally moved, the second controller <NUM> (see <FIG>) controls both the propulsive force and the steering based on an operation on the joystick <NUM> when the joystick <NUM> is moved from the neutral position P20 by a user's operation on the joystick <NUM>. That is, the second controller <NUM> controls the steering mechanism <NUM> to steer the propulsive force generator <NUM> at the first steering speed V1 with the propeller <NUM> of the propulsive force generator <NUM> rotated. According to preferred embodiments, the first steering speed V1 is set to a maximum steering speed V that is settable in the marine vessel maneuvering system <NUM>.

Then, when the user releases the joystick <NUM> such that the joystick <NUM> is returned to the neutral position P20, the second controller <NUM> (see <FIG>) controls the steering mechanism <NUM> to steer the propulsive force generator <NUM> at the second steering speed V2 such that the steering angle θ (see <FIG>) is returned to the reference position P10 (see <FIG>) with generation of the propulsive force stopped. That is, the second controller <NUM> controls the steering mechanism <NUM> to steer the propulsive force generator <NUM> at the second steering speed V2 with rotation of the propeller <NUM> of the propulsive force generator <NUM> stopped. According to preferred embodiments, as shown in <FIG>, the second steering speed V2 is set to one half or less of the first steering speed V1 (which is the maximum steering speed V that is settable in the marine vessel maneuvering system <NUM>). <FIG> shows a case in which the first steering speed V1 is half of the second steering speed V2. The second steering speed V2 is a constant steering speed V. That is, according to preferred embodiments, the second controller <NUM> controls the steering speed V to the constant second steering speed V2 when the operator <NUM> is returned to the neutral position P20.

According to preferred embodiments, as shown in <FIG>, the second controller <NUM> controls the steering mechanism <NUM> to change steering between being performed at the first steering speed V1 (see <FIG>) and being performed at the second steering speed V2 (see <FIG>) by adjusting a current supplied to the motor <NUM>. Specifically, the second controller <NUM> controls the steering controller <NUM> to adjust power supplied to the motor <NUM> of the steering mechanism <NUM> so as to adjust the amount of rotation of the motor <NUM>. Thus, the amount of rotation of the motor <NUM> is adjusted such that the rotation angle (steering speed V) of the steering shaft <NUM> of the steering mechanism <NUM> per unit time is adjusted.

According to preferred embodiments, the second controller <NUM> controls the steering speed V to the second steering speed V2 (see <FIG>) by adjusting a steering angle command value α (see <FIG>) output to the steering mechanism <NUM> when the joystick <NUM> is returned to the neutral position P20 (see <FIG>). Specifically, the second controller <NUM> controls the steering speed V to the second steering speed V2 by adjusting the steering angle command value α at predetermined intervals. More specifically, the second controller <NUM> adjusts and outputs the steering angle command value α as the target value of the steering angle θ (see <FIG>) every time a predetermined time period (the control cycle of a PI control, for example) elapses to adjust the steering angle every predetermined time period. That is, the steering speed V is indirectly adjusted. The second controller <NUM> controls the steering speed V to the second steering speed V2 by filtering the steering angle command value α such that the steering angle becomes smaller than when the steering speed V is controlled to the first steering speed V1 before the predetermined time period elapses and outputting the filtered steering angle command value α to the steering mechanism <NUM>.

According to preferred embodiments, the second controller <NUM> determines whether or not an actual steering angle β that changes following the steering angle command value α has reached the steering angle command value α when the joystick <NUM> is returned to the neutral position P20, and controls the steering speed V to the second steering speed V2 when determining that the actual steering angle β has reached the steering angle command value α. Specifically, due to a change in the actual steering angle β following the steering angle command value α, the actual steering angle β may be larger than the steering angle command value α (the actual steering angle β may not reach the steering angle command value α) immediately after the joystick <NUM> is returned to the neutral position P20. Then, after a predetermined time period (several hundred milliseconds, for example) elapses after the joystick <NUM> is returned to the neutral position P20, the actual steering angle β becomes smaller than the steering angle command value α (the steering angle command value α reaches the actual steering angle β). Then, the second controller <NUM> controls the steering mechanism <NUM> such that the steering speed V becomes the second steering speed V2 (transmits the filtered steering angle command value to the steering mechanism <NUM>) at the timing at which the actual steering angle β becomes smaller than the steering angle command value α (the steering angle command value α reaches the actual steering angle β). Immediately after the joystick <NUM> is returned to the neutral position P20, the steering speed V is controlled to the first steering speed V1 until the actual steering angle β reaches the steering angle command value α.

According to preferred embodiments, the second controller <NUM> controls the steering mechanism <NUM> to change the steering speed V from the second steering speed V2 to the first steering speed V1 when the joystick <NUM> is moved from the neutral position P20 while the steering mechanism <NUM> is steering the propulsive force generator <NUM> at the second steering speed V2. Specifically, when a subsequent operation is performed on the joystick <NUM> (the joystick <NUM> is moved from the neutral position P20) while the steering angle θ is being returned to the reference position P10 based on the joystick <NUM> being moved from the neutral position P20, the second controller <NUM> controls the steering mechanism <NUM> such that the steering to return the steering angle θ to the reference position P10 is interrupted, and steering based on the subsequent operation is immediately performed (at the first steering speed V1).

As described above, the plurality of sets (two sets) of propulsive force generators <NUM> and steering mechanisms <NUM> are provided. Therefore, the second controller <NUM> controls the steering speeds V of the plurality of sets (two sets) of steering mechanisms <NUM> to the second steering speed V2 when the operator <NUM> (joystick <NUM>) is returned to the neutral position P20.

A control flow of steering by the joystick <NUM> in the marine vessel maneuvering system <NUM> is now described with reference to <FIG>. A control shown in <FIG> is performed by the second controller <NUM>.

First, in step S1, the second controller <NUM> determines whether or not the marine vessel maneuvering system <NUM> is in the joystick mode (a state in which an operation on the joystick <NUM> is received). When determining in step S1 that the marine vessel maneuvering system <NUM> is in the joystick mode, the second controller <NUM> advances to step S2. When determining in step S1 that the marine vessel maneuvering system <NUM> is not in the joystick mode, the second controller <NUM> advances to step S3.

In step S2, the second controller <NUM> receives the steering angle command value α (the unfiltered steering angle command value α or the filtered steering angle command value α) from the joystick <NUM>. Then, the second controller <NUM> advances to step S4.

In step S3, the second controller <NUM> receives the steering angle command value α (the unfiltered steering angle command value α or the filtered steering angle command value α) from the joystick <NUM> as in step S2. Then, the second controller <NUM> advances to step S5.

In step S4, the second controller <NUM> determines whether or not the marine propulsion unit <NUM> is attached to the hull <NUM>. When determining in step S4 that the marine propulsion unit <NUM> is attached to the hull <NUM>, the second controller <NUM> advances to step S6. When determining in step S4 that the marine propulsion unit <NUM> is not attached to the hull <NUM>, the second controller <NUM> advances to step S5.

In step S5, the second controller <NUM> transmits the steering angle command value α (the unfiltered steering angle command value α or the filtered steering angle command value α) to the marine propulsion unit <NUM> (steering mechanism <NUM>). That is, step S5 is a step to control the steering speed V to the first steering speed V1. Then, the second controller <NUM> returns to step S1.

In step S6, the second controller <NUM> determines whether or not the joystick <NUM> is at the neutral position P20. When determining in step S6 that the joystick <NUM> is at the neutral position P20, the second controller <NUM> advances to step S7. That is, when the joystick <NUM> is returned to the neutral position P20, the second controller <NUM> advances to step S7 (and thus step <NUM> and step <NUM>). When determining in step S6 that the joystick <NUM> is not at the neutral position P20, the second controller <NUM> advances to step S5. That is, when the joystick <NUM> is moved from the neutral position P20, the second controller <NUM> advances to step S5.

In step S7, the second controller <NUM> determines whether or not the steering angle command value α is smaller than the actual steering angle β (whether or not the actual steering angle β that changes following the steering angle command value α has reached the steering angle command value α).

When determining in step S7 that the steering angle command value α is smaller than the actual steering angle β (the actual steering angle β has reached the steering angle command value α), the second controller <NUM> advances to step S8. When determining in step S7 that the steering angle command value α is not smaller than the actual steering angle β (the actual steering angle β has not reached the steering angle command value α), the second controller <NUM> advances to step S5.

In step S8, the second controller <NUM> determines whether or not the previously transmitted value (previously transmitted steering angle command value α) is filtered (whether or not the steering speed V is controlled to the second steering speed V2). When determining in step S8 that the previously transmitted value (previously transmitted steering angle command value α) is filtered (the steering speed V is controlled to the second steering speed V2), the second controller <NUM> advances to step S9. When determining in step S8 that the previously transmitted value (previously transmitted steering angle command value α) is not filtered (the steering speed V is not controlled to the second steering speed V2 (i.e., the steering speed V is controlled to the first steering speed V1)), the second controller <NUM> advances to step S10.

In step S9, the second controller <NUM> transmits the filtered steering angle command value α to the marine propulsion unit <NUM> (steering mechanism <NUM>). Then, the second controller <NUM> returns to step S1. That is, step S9 is a step to control the steering speed V to the second steering speed V2 that is lower than the first steering speed V1.

In step S10, the second controller <NUM> filters the steering angle command value α and transmits it to the marine propulsion unit <NUM> (steering mechanism <NUM>) (transmits a filtered initial steering angle command value). That is, step S10 is a step to control the steering speed V to the second steering speed V2 that is lower than the first steering speed V1. Then, the second controller <NUM> returns to step S1.

The control flow described above may be configured as follows. For example, when determining in step S1 that the marine vessel maneuvering system <NUM> is not in the joystick mode, the second controller <NUM> may return to step S1 without advancing to step S3. When determining in step S4 that the marine propulsion unit <NUM> is not attached to the hull <NUM>, the second controller <NUM> may return to step S1 without advancing to step S5.

According to the various preferred embodiments described above, the following advantageous effects are achieved.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to control the steering speed V to the first steering speed V1 when the joystick <NUM> is moved from the neutral position P20, and control the steering speed V to the second steering speed V2 that is lower than the first steering speed V1 when the operator <NUM> is returned to the neutral position P20. Accordingly, when the joystick <NUM> is returned to the neutral position P20, the steering speed V at which the steering angle θ is returned to the reference position P10 becomes relatively low. Therefore, when the steering angle θ is returned to the reference position P10, the driving speed of the steering mechanism <NUM> is decreased such that the driving noise of the steering mechanism <NUM> becomes relatively small. Consequently, a decrease in quietness due to the noticeable driving noise of the steering mechanism <NUM> is significantly reduced or prevented. According to preferred embodiments, the propulsive force generator <NUM> is an electric propulsive force generator driven by the motor <NUM>. Thus, the driving noise of the steering mechanism <NUM> is particularly likely to be noticeable, and thus a decrease in quietness due to the noticeable driving noise of the steering mechanism <NUM> is effectively significantly reduced or prevented. Furthermore, the consumption of components of the steering mechanism <NUM> is significantly reduced or prevented by a decrease in the driving speed of the steering mechanism <NUM> at which the steering angle θ is returned to the reference position P10, and thus the life of the components of the steering mechanism <NUM> is improved.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to control the steering speed V to the second steering speed V2 with generation of the propulsive force of the propulsive force generator <NUM> stopped when the joystick <NUM> is returned to the neutral position P20. Accordingly, the steering speed V at which the steering angle θ is returned to the reference position P10 with generation of the propulsive force stopped becomes relatively low. Consequently, a propulsive force is not generated, and a water flow is not generated. Thus, the steering speed V becomes relatively low in a state in which the driving noise of the steering mechanism <NUM> is likely to be noticeable, and thus the noticeable driving noise of the steering mechanism <NUM> due to driving of the steering mechanism <NUM> is effectively significantly reduced or prevented.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to control the steering speed V to the second steering speed V2 by adjusting the steering angle command value α output to the steering mechanism <NUM> when the joystick <NUM> is returned to the neutral position P20. Accordingly, the steering angle command value α as the target value of the steering angle θ is continuously adjusted such that the steering speed V is indirectly adjusted, and thus the steering speed V at which the steering angle θ is returned to the reference position P10 is easily controlled to the second steering speed V2.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to determine whether or not the actual steering angle β that changes following the steering angle command value α has reached the steering angle command value α when the joystick <NUM> is returned to the neutral position P20, and control the steering speed V to the second steering speed V2 when determining that the actual steering angle β has reached the steering angle command value α. Accordingly, when the steering angle θ is returned to the reference position P10, the steering speed V is controlled to the second steering speed V2 after the actual steering angle β reaches the steering angle command value α, and thus the steering angle command value α is appropriately controlled such that the steering speed V becomes the second steering speed V2.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to control the steering speed V to the second steering speed V2 by adjusting the steering angle command value α at the predetermined intervals. Accordingly, the steering angle command value α as the target value of the steering angle θ is adjusted at the predetermined intervals, and thus the steering speed V at which the steering angle θ is returned to the reference position P10 is more easily controlled to the second steering speed V2.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to control the steering speed V to the second steering speed V2 based on the joystick <NUM> being returned to the neutral position P20 after an operation is performed to turn or laterally move the marine vessel <NUM>. Accordingly, the steering speed V at which the steering angle θ is returned to the reference position P10 after the marine vessel <NUM> is turned or laterally moved becomes relatively low. Consequently, when the joystick <NUM> is returned to the neutral position P20 after the marine vessel <NUM> is turned or laterally moved, a propulsive force is not generated, and a water flow is not generated. Thus, the steering speed V becomes relatively low in a state in which the driving noise of the steering mechanism <NUM> is likely to be noticeable, and thus the noticeable driving noise of the steering mechanism <NUM> due to driving of the steering mechanism <NUM> is effectively significantly reduced or prevented.

According to a preferred embodiment, the second steering speed V2 is set to one half or less of the first steering speed V1. Accordingly, the steering speed V at which the steering angle θ is returned to the reference position P10 is sufficiently decreased such that the noticeable driving noise of the steering mechanism <NUM> is significantly reduced or prevented.

According to a preferred embodiment, the first steering speed V1 is set to the maximum settable steering speed V, and the second steering speed V2 is set to one half or less of the first steering speed V1. Accordingly, the joystick <NUM> is operated such that the steering speed V at which the steering angle θ is returned to the reference position P10 is sufficiently decreased such that the noticeable driving noise of the steering mechanism <NUM> is significantly reduced or prevented without decreasing the steering speed V occurring when the operator <NUM> is moved from the neutral position P20.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to control the steering speed V to the constant second steering speed V2 when the joystick <NUM> is returned to the neutral position P20. Accordingly, as compared with a case in which the second steering speed V2 is changed, a control process for the steering speed V at which the steering angle θ is returned to the reference position P10 is simplified.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to control the steering mechanism <NUM> to change the steering speed V from the second steering speed V2 to the first steering speed V1 when the joystick <NUM> is moved from the neutral position P20 while the steering mechanism <NUM> is steering the propulsive force generator <NUM> at the second steering speed V2. Accordingly, even when a subsequent operation is performed on the joystick <NUM> while the steering angle θ is being returned to the reference position P10 with the steering speed V decreased from the first steering speed V1 to the second steering speed V2, steering by the steering mechanism <NUM> is immediately controlled with the steering speed V returned from the second steering speed V2 to the first steering speed V1 based on the subsequent operation on the joystick <NUM>.

According to a preferred embodiment, the steering mechanism <NUM> includes the motor <NUM>, the steering shaft <NUM> to perform steering, and the plurality of gears <NUM> to transmit the rotational force of the motor <NUM> to the steering shaft <NUM>. Furthermore, the second controller <NUM> is configured or programmed to control the steering mechanism <NUM> to change steering between being performed at the first steering speed V1 and being performed at the second steering speed V2 by adjusting a current supplied to the motor <NUM>. Accordingly, the current supplied to the motor <NUM> is adjusted such that the steering speed V is easily controlled to the first steering speed V1 and the second steering speed V2 via the plurality of gears <NUM> and the steering shaft <NUM>. Furthermore, the consumption of the motor <NUM>, the gears <NUM>, and the steering shaft <NUM> is significantly reduced or prevented by a decrease in the driving speed of the steering mechanism <NUM> at which the steering angle θ is returned to the reference position P10. Therefore, the life of the motor <NUM>, the gears <NUM>, and the steering shaft <NUM> is improved.

According to a preferred embodiment, the motor <NUM> of the steering mechanism <NUM> is a DC motor with a brush. Accordingly, the consumption of the brush of the DC motor with a brush is significantly reduced or prevented by a decrease in the driving speed of the steering mechanism <NUM> at which the steering angle θ is returned to the reference position P10, and thus the life of the motor <NUM> is effectively improved.

According to a preferred embodiment, the second controller <NUM> is configured or programmed to perform a feedback control on steering by the steering mechanism <NUM> by a PI control. Accordingly, the accuracy of a control of steering by the steering mechanism <NUM> is improved, and thus the accuracy of a control to change the steering speed V to the second steering speed V2 is improved.

According to a preferred embodiment, the plurality of sets (two sets) of propulsive force generators <NUM> and steering mechanisms <NUM> are provided. Furthermore, the second controller <NUM> is configured or programmed to control the steering speeds V of the plurality of (two) steering mechanisms <NUM> to the second steering speed V2 when the joystick <NUM> is returned to the neutral position P20. Accordingly, even when a plurality of sets (two sets) of propulsive force generators <NUM> and steering mechanism <NUM> are provided, the steering speeds V of all of the plurality of steering mechanisms <NUM> are controlled to the second steering speed V2, and thus the steering speed V at which the steering angle θ is returned to the reference position P10 becomes relatively low without shifting the timing of returning the steering angle θ to the reference position P10 among the plurality of steering mechanisms <NUM>.

According to a preferred embodiment, the marine vessel maneuvering system <NUM> is used for the marine vessel <NUM>. Accordingly, in the marine vessel <NUM>, a decrease in quietness due to the noticeable driving noise of the steering mechanism <NUM> is significantly reduced or prevented.

The preferred embodiments described above are illustrative for present teaching but the present teaching also relates to modifications of the preferred embodiments.

For example, while the plurality of sets (two sets) of propulsive force generators <NUM> and steering mechanisms <NUM> are preferably provided in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, three or more sets of propulsive force generators and steering mechanisms may alternatively be provided, or only one set of a propulsive force generator and a steering mechanism may alternatively be provided.

While the second controller <NUM> (controller) preferably performs a feedback control on steering by the steering mechanism <NUM> by a PI control in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may alternatively perform a feedback control on steering by the steering mechanism by a PD control or a PID control.

While the motor <NUM> of the steering mechanism <NUM> is preferably a DC motor with a brush in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the motor of the steering mechanism may alternatively be a DC motor without a brush, or may be a motor other than a DC motor, such as an AC motor or a stepping motor.

While the second controller <NUM> (controller) preferably controls the steering mechanism <NUM> by adjusting a current supplied to the motor <NUM> in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may alternatively control the steering mechanism by adjusting an oil pressure.

While the second controller <NUM> (controller) preferably controls the steering mechanism <NUM> to change the steering speed V from the second steering speed V2 to the first steering speed V1 when the joystick <NUM> (operator) is moved from the neutral position P20 while the steering mechanism <NUM> is steering the propulsive force generator <NUM> at the second steering speed V2 in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may alternatively control the steering mechanism to not change the steering speed from the second steering speed to the first steering speed when the operator is moved from the neutral position while the steering mechanism is steering the propulsive force generator <NUM> at the second steering speed.

While the second controller <NUM> (controller) preferably controls the steering speed V to the constant second steering speed V2 when the joystick <NUM> (operator) is returned to the neutral position P20 in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may alternatively control the steering speed to a changing second steering speed when the operator is returned to the neutral position.

While the first steering speed V1 is preferably set to the maximum settable steering speed V in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the first steering speed may alternatively be set to a value that is smaller than the maximum settable steering speed.

While the second steering speed V2 is preferably set to one half or less of the first steering speed V1 in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the second steering speed may alternatively be set to a value that is larger than one half of the first steering speed.

While the second controller <NUM> (controller) preferably controls the steering speed V to the second steering speed V2 based on the joystick <NUM> (operator) being returned to the neutral position P20 after an operation is performed to turn or laterally move the marine vessel <NUM> in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may not control the steering speed to the second steering speed based on the operator being returned to the neutral position after an operation is performed to turn the marine vessel. Alternatively, the controller may not control the steering speed to the second steering speed based on the operator being returned to the neutral position after an operation is performed to laterally move the marine vessel. Alternatively, the controller may control the steering speed to the second steering speed based on the operator being returned to the neutral position after a maneuvering operation (such as rotation) other than turning and lateral movement of the marine vessel is performed.

While the second controller <NUM> (controller) preferably controls the steering speed V to the second steering speed V2 when the operator <NUM> is returned to the neutral position P20 based on a user's operation on the joystick <NUM> to steer the marine vessel <NUM> in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may alternatively control the steering speed to the second steering speed when the operator is returned to the neutral position based on a user's operation on the steering wheel or the remote control to steer the marine vessel.

While the second controller <NUM> (controller) preferably controls the steering speed V to the second steering speed V2 by adjusting the steering angle command value α output to the steering mechanism <NUM> when the joystick <NUM> (operator) is returned to the neutral position P20 in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may alternatively control the steering speed to the second steering speed by adjusting a speed command value output to the steering mechanism when the operator is returned to the neutral position. In such a case, the steering speed is directly adjusted by adjusting the speed command value, and thus the steering speed at which the steering angle is returned to the reference position is easily controlled to the second steering speed.

While the second controller <NUM> (controller) preferably controls the steering speed V to the second steering speed V2 with generation of the propulsive force of the propulsive force generator <NUM> stopped when the joystick <NUM> (operator) is returned to the neutral position P20 in the preferred embodiments described above, the present teaching is not restricted to this. In the present teaching, the controller may alternatively control the steering speed to the second steering speed without (completely) stopping generation of the propulsive force of the propulsive force generator when the operator is returned to the neutral position.

Claim 1:
A marine vessel maneuvering system (<NUM>) for a marine vessel (<NUM>) comprising:
a propulsive force generator (<NUM>) configured to generate a propulsive force to propel the marine vessel (<NUM>);
a steering mechanism (<NUM>) configured to steer the propulsive force generator (<NUM>); and
a controller (<NUM>) configured or programmed to control the propulsive force of the propulsive force generator (<NUM>) and steering by the steering mechanism (<NUM>) based on a user's operation on an operator (<NUM>) configured to maneuver the marine vessel (<NUM>), wherein
the controller (<NUM>) is configured or programmed to control a steering speed (V), when controlling a changing of an orientation of the propulsive force generator (<NUM>) with respect in the marine vessel (<NUM>) by the steering mechanism (<NUM>) from a reference position (P10) at which the direction of the propulsive force is parallel to a forward-rearward direction of the marine vessel (<NUM>), to a first steering speed (V1) when the operator (<NUM>) is moved from a neutral position (P20), characterised in that the controller (<NUM>) is
configured or programmed to control the steering speed (V) to a second steering speed (V2) that is lower than the first steering speed (V1) when the operator (<NUM>) is returned to the neutral position (P20) to return a steering angle (θ) to the reference position (P10).