Thruster system for marine vessels

A boat comprises a hull, a primary steering mechanism carried by the hull, a control station located on the hull, a helm located at the control station, and a thruster system carried by the hull. The primary steering mechanism, such as a rudder, is operable via the helm with a helm input being derived from operation of the primary steering mechanism thereby. The thruster system includes at least one thruster mounted to the hull, distinct from the primary steering mechanism, and a controller. The controller receives the helm input and is configured with program instructions to operate the at least one thruster responsive to the helm input to supplement a corresponding movement of the hull. The controller can also automatically operate the thruster responsive to direction, speed and ballast inputs.

FIELD OF THE INVENTION

The present invention relates to boats and other marine vessels with one or more maneuvering thrusters, and more particularly, to systems and methods for controlling the operation of such thrusters.

BACKGROUND OF THE INVENTION

Maneuvering thrusters are well known for facilitating the handling of vessels, particularly at lower speeds and/or in situations with limited space available. There are many placements and designs of such thrusters, with placement adjacent the bow and/or stern being the most common. Thrusters can be retractable into the hull or mounted in fixed locations. Likewise, thrusters can be trainable in different directions or directed along a fixed axis. Thrusters are often controlled via a joystick or other input device located near the helm of the vessel.

Thrusters are especially beneficial on vessels primarily steered with a rudder; which most often are vessels with one or more propeller shafts driven by inboard motors or turbines. At lower speeds, the effectiveness of a rudder as a control surface decreases with decreased water flow across the rudder. This can be particularly the case when the vessel is making sternway. Despite the benefits afforded by thrusters to these and other vessels, further improvements are possible.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention to provide an improved thruster system for marine vessels and related methods.

According to an embodiment of the present invention, a boat comprises a hull, a primary steering mechanism carried by the hull, a control station located on the hull, a helm located at the control station, and a thruster system carried by the hull. The primary steering mechanism, such as a rudder, is operable via the helm with a helm input being derived from operation of the primary steering mechanism thereby. The thruster system includes at least one thruster mounted to the hull, distinct from the primary steering mechanism, and a controller. The controller receives the helm input and is configured with program instructions to operate the at least one thruster responsive to the helm input to supplement a corresponding movement of the hull.

According to an aspect of the present invention, the controller is further configured to distinguish between forward and aft operation based on a direction input when operating the at least one thruster responsive to the helm input.

According to another aspect of the present invention, the controller is further configured to operate the at least one thruster responsive to a vehicle speed input indicative of boat speed.

According to a further aspect of the present invention, a ballasting system is carried by the hull, and the controller is further configured to operate the at least one thruster responsive to a ballast input indicative of a ballast level in the ballasting system.

According to an additional aspect of the present invention, the thruster system further includes a user interface device, the user interface device operable to allow a user to disable automatic control of the at least one thruster by the controller and to select manual control of the at least one thruster via a manual control input.

According to another aspect of the present invention, the at least one thruster includes a stern thruster mounted athwartship at a stern of the hull, such that operation of the stern thruster in opposite directions will urge the stern to port and starboard, respectively. The boat further includes a first exhaust port positioned to vent engine exhaust below a hull waterline at the stern, and a second exhaust port positioned to vent engine exhaust above a hull waterline. A crossover device configured to automatically switch an exhaust vent path between the first and second exhaust ports such that thruster cavitation during operation thereof is prevented.

These and other objects, aspects and advantages of the present invention will be better appreciated in view of the drawings and following detailed description of preferred embodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

According to an embodiment of the present invention, referring toFIGS. 1 and 2, a boat10is equipped with a thruster system12. The thruster system12includes at least one thruster14operable to impart a degree of lateral motion to a portion of the boat10. A controller16directs operation of the thruster14, preferably via a proportional drive20allowing variable speed operation. The controller16is configured to operate the thruster14automatically in response to helm input.

In a preferred embodiment, the boat10includes a rudder22controlled by a helm24located at a control station26. The rudder22is positioned aft of a propeller30driven by shaft32via an inboard motor. Advantageously, the helm input used by the controller16for automatic operation of the thruster is derived via monitoring of the rudder22position. Other helm inputs could be used, however. For instance, position of the helm24, itself, could be detected. Additionally, the thruster system12could be used to supplement steering in boats with a primary steering mechanism other than a rudder, such as in boats with outboard motors or jet drives, airboats, etc., although superior low speed maneuvering is typically inherent in such vessels.

In the depicted embodiment, the thruster14is a stern thruster fixedly mounted to the stern34of the hull36of the boat10at a point below the waterline and oriented athwartship, such that operation in opposite directions will urge the stern34to port and starboard, respectively. Alternately, or in addition to, a stern thruster14, other thrusters (such as a bow thruster14A) could be used. In general, the controller16is configured to automatically operate any thrusters14(14A) in response to the helm input such that a movement of the hull corresponding to the detected helm input is supplemented. For example, in the boat10equipped with the stern thruster14, if the boat10is making headway and the helm24is turned to port, the controller16will operate the stern thruster14to urge the stern34to starboard.

To this end, the controller16is advantageously further configured to distinguish between forward and aft operation when automatically operating the thruster14(14A) using a direction input. For instance, the controller16receives a direction input derived from throttle position (i.e., forward and reverse). Consistent with the principles described above, when the direction input indicates movement astern (in the boat10equipped with the stern thruster14), if the helm24is turned to port, the controller16will operate the stern thruster14to urge the stern34to port. Such control can be based simply on receipt of a helm input to port or starboard above a predetermined input threshold. In addition to a direction of the helm input, a magnitude of the helm input above the threshold could be employed, as will be described in greater detail below.

At higher speeds it may not be desirable to operate the thruster14(14A), or it may be desirable to operate the thruster at a lower speed. Accordingly, the controller16is further configured to automatically operate the thruster14(14A) responsive to a speed input. The speed input is derived for a global positioning system (GPS) determined speed, a water speed sensor, an engine speed or the like. Above a predetermined upper speed threshold, the controller16is preferably configured not to automatically operate the thruster14(14A). Other, lower speed thresholds could be used to automatically increase thruster14(14A) output as speed decreases and/or thruster speed control could be varied in inverse proportion with vessel speed up to the upper speed threshold.

Some vessels, such as watersports boats, are equipped with ballasting systems. In such vessels, the controller16is preferably configured to automatically operate the thruster14(14A) responsive to a ballast input. For example, with ballast level detected above a predetermined level threshold, the controller16automatically increases thruster speed to compensate for the effect of the additional ballast.

In addition to controlling thruster speed based on a vessel speed input and a ballast input, the controller16can be further configured to vary thruster speed based on the magnitude of the helm input. For example, if the helm input in a given direction (i.e., port or starboard) is greater than a predetermined threshold, the controller will automatically increase thruster14(14A) speed. Multiple thresholds could be employed or speed could be varied continuously over a range of helm input up to a predetermined maximum speed (which could be dependent on vessel speed, ballast level, etc.). Alternately, the controller16could simply operate the thruster at a single predetermined speed once helm input in a given direction is detected beyond a minimum threshold, regardless of the magnitude of input past that point.

The system12preferably further includes a user interface device40, such as a touch screen and/or multi-function controller. Via the user interface device40, an operator of the boat10can opt to enable or disable automatic control of the thruster14(14A) via the controller16. Advantageously, the operator can also set the thruster14for manual control responsive to a manual control input. The manual control input can be derived via any desired input device, such as a joystick, multi-function controller, touch screen icons, etc. When operated manually, the manual control inputs can be processed via the controller16or transmitted directly to the proportional drive20(or other drive) of the thruster14(14A).

Via the user interface device40, the operator is preferably also able to vary operational settings of the controller16when operating the thruster14(14A) automatically. For example, a user setting input can be used to select a speed or speed range at which the controller16operates the thruster14(14A). Additionally, threshold values applicable to helm, direction, speed and/or ballast inputs could be varied via the user setting input.

Some boats10are equipped with an exhaust port42that vents engine exhaust below the waterline at the stern34. With a stern drive thruster14, such exhaust can result in cavitation of the thruster. Such cavitation may be avoided by cowling the thruster and/or vectoring engine exhaust away therefrom. Alternately, a second exhaust44can employed for use during thruster14operation—for example an exhaust44venting above the waterline. A crossover device50is configured to automatically switch between the exhausts42,44. The switching can be directed by the controller16based on thruster operation or be effected automatically (e.g., based on differing backpressure at different engine speeds).

It will be appreciated that the thruster system12of the present invention affords intuitive thruster control in a manner that reduces demands on the marine vessel operator. In addition to eliminating the need for separate, manual control inputs to actuate a thruster, the system automatically takes into account other potentially relevant factors impacting thruster operation and vessel handling.

Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within and of the claims appended hereto.