System and method for twisted propellers for enhanced boat steering

Abstract

A steering system for a watercraft having twin propulsion units whose thrust axes are fixed to diverge outward from a longitudinal centerline in plan view. During a turn, a controller differentially commands thrust such that the outboard propulsion unit produces greater thrust than the inboard unit. The outward alignment of the thrust axes yields a net lateral force whose vertical offset from the craft's center of gravity produces a rolling moment that banks the hull inward toward the turn. The system enables banked turns without swiveling drives or rudders and supports zero-radius maneuvers at low speeds. Embodiments include electric propeller pods or water-jet nozzles, planing and hydrofoil craft, and optional feedback to regulate bank angle.

Description

[0001] SYSTEM AND METHOD FOR TWISTED PROPELLERS FOR ENHANCED BOAT STEERING

[0002] Cross Reference to Related Applications

[0003]

[0001] This application claims the benefit of, and priority to U.S. Provisional Application No. 63 / 690,829 filed on September 05 , 2024 and entitled “SYSTEM AND METHOD FOR TWISTED PROPELLERS FOR ENHANCED BOAT STEERING”, the entirety of which is incorporated by reference herein.

[0004] Background

[0005]

[0002] The embodiments described herein relate to marine propulsion and steering systems. In particular, it concerns twin-propulsion watercraft (for example, dual-motor electric boats) with fixed propulsion units mounted at an outward angle to produce improved steering characteristics.

[0006]

[0003] Traditional non-steerable dual-propeller boats suffer from uncomfortable ride characteristics during turns. Typically, such boats execute turns flat, without banking, resulting in a roll away from the turn direction, akin to how a car behaves. This contrasts with the more comfortable rolling "into the turn" experienced with conventional steering outboard motors. This difference leads to a less comfortable and potentially less safe ride, especially at higher speeds or in rough water conditions.

[0007]

[0004] High-speed boats and personal watercraft often experience uncomfortable dynamics during turning maneuvers. In a typical twin-engine boat with non-steerable propellers (for instance, a catamaran or electric craft with two fixed pods and no rudder), turns are executed mostly flat. The hull tends to remain level or even roll outward (away from the turn) due to centrifugal forces, much like a car on a flat road. This is unlike motorcycles or airplanes (and some single-engine outboard boats), which bank inward during a turn, leaning into the curve. In boating, an inward bank is generally more comfortable and safer for passengers, as it counteracts lateral forces.

[0008]

[0005] Conventional solutions for achieving better turning dynamics in boats have relied on mechanical steering of thrust or added control surfaces. For example, boats with outboard motors or stern drives physically swivel the propulsion unit to steer; this inherently causes the boat to lean into a turn (because the thrust vector is redirected). Boats without steerable drives might use rudders or trim tabs to induce some heeling effect. There are also active stabilization systems (e.g., fins or gyroscopic stabilizers) aimed at controlling roll, but these target wave -induced roll and not specifically the banking in turns.

[0006] In recent years, the rise of electric propulsion and simplified boat designs (including hydrofoil craft and jet-drive boats) has led to interest in using differential thrust for steering. Dil'l'crenlial thrust means varying the power between port and starboard propulsion units to effect yaw rotation (turning the boat). While this method can eliminate the need for rudders or pivoting motors, it typically results in very flat turns. A twin-propeller vessel using only throttle differences will turn akin to a tank: it can yaw effectively, even pivot in place, but the lack of inward bank can make high-speed turns uncomfortable and potentially unstable (the outward roll can lead to spray and occupants feeling “thrown” outward).

[0009]

[0007] There is a desire to provide technologies to provide comfort and safety for enhanced boat steering. Furthermore, there is a desire for a technology that combines the simplicity of differential thrust steering with the comfort of banked turning. The goal is to have a twin-engine boat (particularly an electric boat with fixed pods or jets) that can steer by thrust alone yet still lean into the turn as if it were using a conventional steering mechanism. Achieving this would improve ride comfort, safety, and potentially even turning performance (reducing the risk of skidding or ventilation in sharp turns).

[0010] Summary

[0011]

[0008] A system and method using twisted boat propellers for enhanced boat steering and ride comfort. The twisted boat propellers are designed for smoother turns. The system includes two boat propellers that are mounted slightly angled (i.e., toe-out) to create a horizontal thrust component, thus generating a rolling moment during turns. This design allows for differential steering by varying propeller speeds on either side of the boat, while also enabling the boat to bank into the turn compared to conventional steering on outboard motors. Furthermore, this design provides for a more comfortable and safer ride, especially at higher speeds or in rough water condilions. The system also enables a boat to bank into turns by generating a rolling moment via dil'l'crenlial thrust, enhancing comfort and stability especially in high-speed planing or hydrofoil-operating condilions.

[0012]

[0009] The present disclosure provides a system and method for enhanced boat steering using what will be referred to as “Twister” propellers or propulsors. In essence, the disclosure mounts twin propulsion units (such as propellers, impellers or water-jet nozzles) at a fixed outward toe-out angle relative to the centerline of the boat. This slight angular offset of each thrust axis introduces a lateral component to the thrust force. When the propulsion units are operated at differential speeds, the imbalance in lateral thrust generates a net rolling moment on the vessel, causing it to bank inward into a turn.

[0013]

[0010] In a typical embodiment, a boat has two propeller pods or engines affixed near the stern, each canted outward by a few degrees. A control system (e.g., an electronic controller linked to the throttle or steering input) modulates power to each propeller. To initiate a right turn, the system increases thrust on the left propeller and decreases thrust on the right. With toe-out mounting, each propeller’s thrust vector has a forward (longitudinal) component and an outward (lateral) component. The higher forward thrust on the port (left) side relative to the starboard (right) side produces the dominant yawing moment about the vessel’s vertical axis — approximately proportional to the thrust difference and the lateral separation between the propulsors. Simultaneously, the lateral components are unequal: the left unit’s outward (port- directed) lateral force exceeds the right unit’s outward (starboard-directed) lateral force, yielding a net lateral force to port acting below the center of gravity. That lateral force creates a rolling moment that banks the hull to starboard — i.e., into the right-hand turn. The result is a turn with inward lean, achieved without moving rudders or swiveling motors.

[0014] [Oi l] This design allows differential -thrust steering with built-in banking. The boat can execute sharper and more stable turns, with reduced occupant sway and improved high-speed handling. In addition, the di I'l'crenlial thrust approach enables maneuvers like zero-radius turns (spinning on the spot) by driving the propellers in opposite directions or at very different speeds. Such maneuvers are useful for docking or tight space navigation. The slight outward angle of the thrust does not impede this; in fact, it can aid in inilialing a twist of the hull.

[0015]

[0012] The Twister propeller system thus marries the advantages of fixed electric propulsion (simplicity, fewer moving parts, high responsiveness) with the dynamic benefits of a banked turn. It provides a more comfortable and safer ride, especially at higher speeds or in rough water, because the inward roll helps counteract the outward centrifugal force on passengers and hull. Importantly, the system is passive in hardware - the propulsors are fixed in place - relying on intelligent control of thrust for steering, which can reduce mechanical complexity and maintenance compared to hydraulic or electro-mechanical steering systems.

[0016]

[0013] In some embodiments, the boat may also be equipped with a retractable hydrofoil assembly. The disclosure is applicable both when the boat is in displacement or planing mode (hull in the water) and when it is foiling (hull lifted by the foil). In foiling mode, the inward rolling moment generated by the angled propellers can be used in conjunction with foil control surfaces to bank the craft during turns, improving stability and comfort aloft. In planing mode, the effect counters the natural outward roll tendency of flat turns. Thus, the system consistently provides better turning dynamics across different operaring regimes.

[0017]

[0014] Additional features and embodiments include the possibility of varying the toe-out angle (either through design choice or even an adjustable mechanism) to tune the magnitude of the rolling moment, integrating sensors to actively control roll angle (for example, an onboard gyroscope or inclinometer could modulate thrust split to achieve a target bank angle), or combining the system with small trim fins that deploy asymmetrically to augment the roll if needed. The disclosure also anticipates that the concept could be extended to other multi-thrust configurations (such as four-propeller setups or contra-rotating propeller pods) as long as a lateral thrust component is present to induce roll.

[0018] Brief Description of the Drawings

[0019]

[0015] FIG. 1 is a bottom plan view of a boat hull equipped with an exemplary pair of “Twister” propellers according to the disclosure.

[0020]

[0016] FIG. 2 is a schematic rear elevation view of the boat during a turn to the right, demonstrating the induced bank.

[0021]

[0017] FIGURES 3A and 3B are side views of the watercraft illustrating two modes of operation. FIG. 3A shows the boat in a planing mode (or displacement mode) with its hull on the water surface, while FIG. 3B shows the boat in a foiling mode with a hydrofoil deployed lifting the hull. In both sub-figures, the orientation of the propeller thrust vectors and the resulting moments during a turn are depicted. In the foiling mode, the coordination between the thrust-induced roll and the hydrofoil’s lift distribution is highlighted.

[0022]

[0018] FIG. 4 is a block diagram illustrating an example steering control method for the Twister propeller system.

[0023] Detailed Description

[0024]

[0019] In a typical hydrofoil-equipped watercraft, the hydrofoil (or “foil”) is rigidly mounted to the underside of the watercraft. Herein we describe a watercraft with a foil mounted to a moveable assembly (a motor / foil assembly, or MFA), which assembly is configured to retract by moving up towards the underside of the watercraft when extension of the foil is not required, and to deploy by moving downwards away from the underside of the watercraft when extension of the foil is required. The moving may be actuated by actuators or may be effected through forces created by the primary propulsion motor and control surfaces of the watercraft.

[0025]

[0020] The disclosure will now be described in detail with reference to the figures. Identical reference numbers in different figures refer to the same or similar components. It should be understood that the drawings are not necessarily to scale; instead they emphasize the configuration and operation of the disclosure.

[0026] Boat and Propulsion Configuration

[0027]

[0021] FIG. 1 is a bottom plan view of a boat hull equipped with an exemplary pair of “Twister” propellers according to the disclosure. FIG. 1 illustrates the twin propeller units (or propulsion pods) mounted with a toe-out angle relalive to the longitudinal centerline of the hull. Arrows on the figure indicate the thrust directions of each propeller, showing both the primarily forward component and the smaller outward lateral component.

[0028]

[0022] FIG. 1 shows a represenlali ve boat hull 10 equipped with two propulsion units 20L and 20R (left and right, as viewed from the stern). In this embodiment, these are electrically-driven propeller pods mounted under the transom. The key feature is that each propulsion unit is fixed at an outward angle (toe- out) with respect to the boat’s forward centerline 12. In the figure, centerline 12 is a dashed line splitting the hull, and each propeller’s axis 22L, 22R is angled such that they diverge toward the rear. The toe-out angle 0 (theta) can be defined as the angle between the propeller ’ s thrust axis and the longitudinal centerline. Typically, 0 is small - for example, in a range of about 2° to 10° on each side - sufficient to generate lateral thrust but small enough to maintain forward efficiency.

[0029]

[0023] In a preferred design, the propellers 20L / R are counter-rotating (one left-hand, one right-hand rotation) to cancel out torque effects on the boat. They are positioned symmetrically about the centerline, at a spacing similar to conventional twin-engine mounts. The propeller shafts or pod struts are rigidly affixed at the set toe-out angle. This could be achieved via shims on the transom mount or by designing the pod housing with the angle built-in. The mounting should also account for vertical trim; in most cases the propeller shafts remain approximately horizontal (parallel to water surface) so that the angle is primarily in the horizontal plane. However, some embodiments might tilt the units slightly downward to optimize thrust when the boat is on plane or to assist in creating a vertical component of thrust (for additional stability), if desired.

[0030] Differential Thrust Steering and Banking

[0031]

[0024] The fundamental operation of the system is illustrated in FIG. 2. FIG. 2 is a schematic rear elevation view of the boat during a turn to the right, denionslraling the induced bank. According to FIG. 2, the right side of the hull is shown lower in the water (heeled to starboard) and the left side raised, as the boat banks into the turn. FIG. 2 includes an arrow indicating the rolling moment (curved arrow) generated by the differential thrust, as well as the rclali vc longer thrust vector on the left side (high throttle) and shorter on the right (low throttle) in this right-turn scenario.

[0032]

[0025] When the pilot turns the boat to the right, a control system 30 (see FIG. 4 for details on control logic) will increase power to the left propulsion unit 20L and decrease power to the right propulsion unit 20R. The thrust vectors are shown in FIG. 2: a longer thrust arrow 24L on the left side and a shorter arrow 24R on the right side. Because of the outward canting, each thrust vector has a forward component (F_L and F_R) and a lateral outward component (L_L and L_R). In straight driving (no turn), the left and right thrust are equal and the lateral components cancel each other out, so the boat experiences no net sideways force or roll moment (just a slight outward push on each side absorbed by the hull).

[0033]

[0026] However, in the right-turn case, thrust on the left increases and on the right decreases. Consequently, the lateral components satisfy L_L > L_R (each being the outward component of thrust from the toe-out alignment). The difference (L_L - L_R) is a net lateral force to port. That lateral force, applied below the boat’s center of gravity and concentrated on the port side of the hull, creates a rolling moment (indicated by curved arrow 26 in FIG. 2) that rotates the hull with the starboard side down and the port side up (i.e., the boat banks into the right turn). The yawing moment that turns the boat to the right arises primarily from the forward thrust imbalance (F_L > F_R) acting across the lateral separation of the propulsors, while the lateral components contribute mainly to roll.

[0034]

[0027] The magnitude of the roll can be modulated by the degree of thrust difference and the angle 0. For typical small angles, the effect is subtle but noticeable: even a few degrees of inward bank can significantly improve comfort and reduce lateral slippage in a fast turn. The system can be tuned such that at a certain rate of turn (or rudder input equivalent), the boat achieves an optimal bank angle (similar to the “ideal bank” in aircraft where centripetal force aligns with the resultant of weight and lift). For instance, the control system might target a bank angle of say 5° into the turn at cruising speeds. In one formulation, the roll moment M_roll is approximately the difference in lateral thrust components multiplied by the vertical distance to the center of gravity.

[0035] Zero-Radius Turn and Low-Speed Maneuvering

[0036]

[0028] The differential thrust not only turns the boat but can also spin it in place. If one propulsion unit is ihrusling forward and the other in reverse (or one at high forward thrust, the other at idle reverse), the boat will rotate about its vertical center axis without significant forward movement. In such a maneuver (useful for docking), the lateral thrust components from each propeller actually add together as a pure moment (one pushing port side forward, the other pushing starboard side backward, both contributing to clockwise rotation, for example). The outward angles ensure that even in such a twist, there is some upward force component on the outer sides that could help keep the boat level (though at very low speeds the roll effect is minimal due to lack of hydrodynamic lift). Essentially, the toe-out does not impede close-quarters handling and may slightly improve it by widening the thrust base and increasing the turning moment.

[0037] Control System

[0038]

[0029] FIG. 4 is a flowchart or control diagram illustrating an example steering control method for the Twister propeller system. According to FIG. 4, a steering input (e.g., wheel or joystick) is translated by a control module into differential thrust commands for the port and starboard propellers, possibly incorporating feedback from a roll sensor to modulate the thrust split for achieving a desired bank angle.

[0039]

[0030] According to FIG. 4, a suitable control system 30 for the Twister propeller arrangement can be implemented in hardware, software or a combination (such as a microcontroller or an electronic control module interfacing with the motor controllers).

[0040]

[0031] FIG. 4 outlines an example or exemplary logic. The driver’s steering input 32 (which could be a wheel, joystick, or autopilot command) is read by a controller 34. If the input is zero (centered), the system keeps both propellers at equal thrust for straight line travel. If a steering input to the right is detected (e.g., wheel turned right), the controller computes a thrust differential: it may send a signal 36L to increase left propeller speed and a signal 36R to decrease right propeller speed. The amount might be proportional to the steering angle or rate.

[0041]

[0032] Additionally, a roll sensor 38 (such as a gyro or accelerometer measuring heel angle) can feed back into the controller. The system can use this to adjust the thrust split to achieve a desired roll. For example, if the boat is not banking enough for the given turn rate, the controller can further increase the thrust difference (within safe limits) to induce more roll. Conversely, if the boat is banking too much (perhaps a sudden wave or an overreaction), the controller can reduce the thrust difference.

[0042]

[0033] The control strategy can also factor in speed: at very low speeds, large thrust differentials can be applied without concern of excessive roll (since the hull’s hydrodynamic forces are low), whereas at high speeds the system might impose a limit to maintain roll angles within a stable range. The result is an active but straightforward steering system - the user still just “turns the wheel,” but instead of moving a rudder, they are commanding a differential thrust which, thanks to the fixed angles, also commands a lean. This can be made seamless to the operator.

[0034] It should be noted that in simpler embodiments, no special sensors are needed; the natural physics will cause some bank. A basic implementation might simply map wheel angle to a fixed RPM difference between motors. More advanced implementabons incorporate full stability control logic as described above.

[0043] Hydrofoil Integration

[0044]

[0035] FIGURES 3A and 3B are side views of the watercraft illustrating two modes of operation. FIG. 3A shows the boat in a planing mode (or displacement mode) with its hull on the water surface, while FIG. 3B shows the boat in a foiling mode with a hydrofoil deployed liliing the hull. In both sub-figures, the orientation of the propeller thrust vectors and the resulting moments during a turn are depicted. In the foiling mode, the coordination between the thrust-induced roll and the hydrofoil’s lift distribution is highlighted. FIG. 3A and FIG. 3B illustrate the disclosure’s applicability to a boat that can operate both as a planing hull and as a hydrofoil-supported hull. In some innovative electric boats, a retractable hydrofoil assembly 40 is mounted to the hull.

[0045]

[0036] When extended (FIG. 3B), the foil lifts the hull largely out of the water at speed, reducing drag. In such craft, steering is often accomplished by a combination of liliing the foil or using rudder-like flaps on the foil, and / or differential thrust if twin motors are present. The Twister propeller system can enhance a foiling boat by providing a rolling input even when foiling. Normally, a hydrofoil boat needs to bank into turns as well, much like an airplane, to avoid slipping. This is usually achieved by controlling foil angles. With the present system, the propulsion units themselves contribute a roll. The lateral force from the propellers (which are typically submerged along with the foil-supporting struts) will impart a rolling moment to supplement the foil’s action. This can potentially simplify foil control or provide redundancy. For instance, if a foil’s aileron effect isn’t fast enough, the motors’ differential thrust can kick in to help roll the craft.

[0046]

[0037] When the foil is retracted and the boat is in planing mode (FIG. 3A), the hull is in contact with water. Here the Twister system addresses the original problem statement: normally a planing hull without steering outdrives would turn flat. With the angled props, even on plane, the hull will bit inward. Planing hulls can particularly benefit because high-speed turns generate strong outward centrifugal force; an inward bank reduces the strain on passengers and on the boat structure (it mitigates the tendency to slide outward or the feeling of being flung to the side).

[0047]

[0038] The retractable foil assembly 40 itself can be any known mechanism - for example, a motor / foil assembly (MFA) that hinges or translates upward to bring the foil wings out of water when not needed, and lowers them for high-speed operation. The presence of the foil does not change the propeller toe-out configuration; the propulsors can be attached to the foil strut or hull such that their angle relative to the hull’s centerline remains set.

[0048] Design Considerations and Alternatives

[0049]

[0039] The optimal toe -out angle 0 may vary with boat type. A deeper V-hull that naturally causes outward flow might use a slightly different angle than a flat-bottom hull. It’s possible to have a mechanism to adjust 0 - for instance, an adjustable mounting bracket that an operator or builder can set after testing, or even an act i ve system that pivots the pods outwards at speed. However, a fixed angle is preferred for simplicity. The chosen angle is generally a compromise: larger angles produce more lateral force (hence more roll) for a given thrust difference but also reduce forward thrust efficiency when the props are operated equally. In practice, a few degrees toe-out has minimal impact on straight-line performance (the slight outward push is countered by the hull and results in a trivial increase in drag) but is enough to create a noticeable roll when thrust is unbalanced.

[0050]

[0040] The propeller size and thrust line height relative to the center of gravity also affect the rolling moment. If the propellers are lower (deeper in water) and far apart, the moment arm for roll is larger, enhancing the effect. Thus, in designing a boat to use this system, one might mount the motors slightly outboard and low. Conversely, if they are very close together (near center) the lateral forces might just cause roll without much yaw. The disclosure anticipates typical twin configurations which are usually spaced for stability.

[0051] Comparison to Traditional Systems

[0052]

[0041] For clarity, it’s useful to contrast this disclosure with the steering mechanisms mentioned in the Background:

[0053]

[0042] Mechanical / Cable or Hydraulic Steering: Those involve turning the entire drive or a rudder. They create inward bank by directing thrust sideways. The Twister system achieves a similar end (side force + bank) without turning any hardware, using only differential throttle and fixed geometry. This removes the complexity of linkages or hydraulic lines, and eliminates points of failure like jammed rudders. Maintenance is potentially reduced since there are fewer moving parts exposed to water.

[0054]

[0043] Electronic Steering and Vectoring: Modern pods (e.g., Volvo IPS or aircraft-style thrust vectoring) can direct thrust at angles for maneuvering. Those are complex, gimbal-mounted systems. Here, we get a continuous small vectoring effect by static toe-out. While we cannot vector on the fly (beyond what differential RPM does), the simplicity is a trade-off. The disclosure could be seen as a passive vectoring approach optimized for turning scenarios.

[0055]

[0044] Active Stabilization (e.g.,fins or gyros): Those are primarily for countering waves and keeping a boat level. Our system is almost the converse: it intentionally induces a roll when turning. However, it could work in harmony with an active stabilizer - for instance, one could program a fin stabilizer to allow the inward roll when it detects a turn (rather than fighting it). If a competitor had a fin system, they might try to replicate our effect by active control (rolling the boat into a turn), but doing so via fins or moving surfaces is a different mechanism (and would fall outside the scope of a propeller-based patent).

[0056] Detection of Infringement and Safety

[0057]

[0045] A note on detectability - any boat using this system will have a visibly non-parallel engine alignment. One could measure the divergence of the drives (for example, by comparing the distance between the nose cones of twin outboards at front vs back) to see the toe-out, as known from rigging practices. Typically, traditional setups aim for near parallel or slight toe-in. So a pronounced toe-out would be a hallmark of this disclosure in use. From a safety perspective, the angles involved are small and do not compromise normal operation. Even if the control system were to fail or if equal thrust is applied, the boat might have a slight tendency to diverge outward, but this can be corrected easily by minor steering input (or could be countered by a simple linkage tying the motors if it’s an outboard configuration). In practice, most operators would not notice any difference in straight-line tracking.

[0058]

[0046] To further exemplify the disclosure, consider a specific use-case scenario: An electric sport boat 25 feet long, with twin 50 kW pod drives. The drives are mounted 4° toe-out each. At high speed (30 knots), the operator makes a hard right turn. In a conventional setup, if using differential thrust without our disclosure, the boat would yaw right but stay flat; occupants might feel a strong lateral pull. In our setup, as the left pod throttles up and right pod throttles down, the boat immediately starts to lean right. At, say, 20° of wheel input, the boat might achieve a 4-5° bank. The turn feels smoother; water stays more evenly under the hull (reducing spray). The inward roll also helps the hull’s chines bite into the water, potentially reducing slide and turning radius. The operator completes the turn feeling more confident in the boat’s stability. Later, when docking, the operator toggles a “station-keeping” mode: one pod forward, one reverse. The boat neatly spins 180° within its own length, the toe-out angle providing a slight outward push that keeps the hull from wandering off-center. Additional Embodiments and Variations

[0059]

[0047] The above description focuses on a twin-prop monohull boat, but the disclosure could be applied to other configurations:

[0060]

[0048] Multi-hull Vessels: A catamaran or trimaran with twin drives could employ this system. In fact, cats often have wide-set engines - an outward cant might be even more effective at inducing roll on a catamaran (which normally has almost no inward lean in turns). The control logic remains the same.

[0061]

[0049] Alternate Propulsion Types: While propellers are the main example, waterjet propulsion units could be used. For instance, a twin-jet boat could have its jet nozzles fixed at a slight outward angle (or the intake ducts angled outward). By varying thrust between jets, the same effect is achieved. Ducted electric thrusters or even azimuth pods locked in a canted position are variations included in the concept. The claims use the term “propulsion unit” to cover all such possibilities (propellers, impellers, thrusters).

[0062]

[0050] Adjustable or Adaptive Toe Angle: In some advanced designs, one might allow the toe angle to be actively adjusted. For example, small linear actuators could push the rear of each pod slightly outward at high speeds to increase 0 and thus bank angle, then retract for lower speeds or straight running to maximize efficiency. This would introduce moving parts and complexity, usually not preferred, but it is a conceivable variant for fine-tuning performance. The patent claims would cover a fixed angle primarily, but could include language for an adjustable configuration.

[0063]

[0051] Integration with Autopilot and Stability Systems: This system can be integrated into an autonomy or stability control framework. An autopilot that commands a course change can automatically apply differential thrust and achieve coordinated turns. If the boat has an active gyro stabilizer, the control system can instruct it to allow the boat to heel intentionally during a turn (since normally a stabilizer might try to counter any heeling). The interplay of systems can be managed via software.

[0064]

[0052] Sensing Competitor Use: As a sidebar embodiment (not an disclosure per se, but a practical note), one can detect if another vessel is using this system by externally measuring their propulsion alignment. A simple tool (like lasers or calipers between engines) could reveal toe-out. This highlights that infringement would be straightforward to observe.

[0065]

[0053] Economic and Maintenance Benefits: From a commercial standpoint, the Twister propeller system can reduce maintenance (no steering pumps, cables, or linkages to service) and possibly lower manufacturing cost by omitting expensive steering hardware. These advantages may be highlighted in marketing, though they are ancillary to the core mechanical innovation.

[0054] It will be appreciated by persons skilled in the art that the present disclosure is not limited to the specific examples illustrated and described. Various modifications and improvements can be made without departing from the scope of the disclosure. For instance, the exact angle, placement, and number of propulsion units can be adjusted to suit different boat sizes and purposes. The disclosure can be embodied in small personal watercraft as well as larger vessels (e.g., two azimuth thrusters on a yacht could be locked at slight outward angle and controlled in power to achieve similar banking for comfort of passengers). All such variations that employ the essential principle of fixed angled twin thrust with differential control to induce roll are intended to be covered by the claims below.

[0066]

[0055] According to further embodiments of the disclosure, detecting the use of this disclosure by competitors would be apparent on any differential drive system by measuring the toe-out angle of the propeller pods. A further improvement involves designing an advanced steering system that simulates the banking effect using variable-speed propellers and additional control surfaces. Alternative embodiments could include varying the toe-out angle or integrating this concept with other types of propulsion systems to achieve similar results in different types of watercraft.

[0067]

[0056] According to the disclosure, a watercraft steering system is disclosed. The watercraft steering system comprises a hull having a longitudinal centerline and port and starboard sides, a pair of propulsion units mounted to the hull, one on the port side and one on the starboard side, each propulsion unit being fixed at an outward toe angle relative to the centerline such that its thrust axis is canted away from the centerline and a control mechanism configured to independently regulate the output of each propulsion unit. During a turning maneuver the control mechanism increases thrust from the propulsion unit on the side opposite the turn direction relative to the other side, such that a net lateral force component is generated and produces a rolling moment that banks the hull inward toward the turn.

[0068]

[0057] According to the disclosure, the outward toe angle of each propulsion unit of the watercraft steering system is between 1 degree and 15 degrees relative to the centerline. The propulsion units of the watercraft steering system are electric motor-driven propellers mounted in fixed pods below the hull, and the control mechanism comprises an electronic controller that receives a steering input and outputs differential throttle commands to the propellers.

[0069]

[0058] According to the disclosure, the propulsion units of the watercraft steering system are waterjet drives with fixed-direction nozzles angled outward, or other thrust-generating devices oriented to have a horizontal outward component.

[0059] According to the disclosure, the watercraft steering system further comprises a hydrofoil assembly attached to the hull and configured to lift the hull at speed, the control mechanism being adapted to operate the propulsion units to induce inward roll when the hydrofoil is deployed, thereby coordinating with the hydrofoil to bank the watercraft during turns in foiling operation.

[0070]

[0060] According to the disclosure, each propulsion unit of the watercraft steering system is a counterrotating propeller such that one propeller rotates clockwise and the other counter-clockwise, thereby minimizing net torque on the hull while allowing differential thrust steering.

[0071]

[0061] According to the disclosure, the control mechanism of the watercraft steering system is further configured to execute zero-radius turns by driving one propulsion unit in forward thrust and the other in reverse thrust, utilizing the outward toe angles to enhance the turning moment about the hull’s vertical axis.

[0072]

[0062] According to the disclosure, a method of steering a twin-propulsion watercraft having port and starboard propulsion units fixed in an outwardly angled orientation is disclosed. The method comprises the steps of commanding an increase in thrust on the port propulsion unit relative to the starboard unit to initiate a starboard (right) turn, or commanding an increase in thrust on the starboard unit relali ve to the port unit to initiate a port (left) turn, generating, by virtue of the outwardly angled orienlalion of the propulsion units, a lateral force component as a result of said thrust difference, and rolling the watercraft’s hull inward toward the turn in response to the lateral force component, such that the watercraft banks into the turn without any steering surface or steerable drive deployment.

[0073]

[0063] According to the disclosure, the method of steering further comprises sensing an actual roll angle of the hull and adjusting the thrust difference to achieve a target roll angle commensurate with a turning rate, thereby providing active roll stabilization into turns.

[0074]

[0064] According to the disclosure, at low speeds the commanding step includes reversing one of the propulsion units and driving the other forward to spin the watercraft in place, utilizing the fixed angled orienlalion of the propulsion units to maintain stability during the pivot.

[0075]

[0065] According to the disclosure, a watercraft is disclosed. The watercraft comprises a hull, a port and starboard propulsion means for propelling the hull, said propulsion means being oriented such that their thrust vectors diverge outward toward the bow of the hull at a fixed angle, a means for differentially controlling the propulsion means in response to a steering input, wherein the outward divergence of the thrust vectors causes a net heeling moment that rolls the hull inward when the propulsion means are operated at unequal thrust, thereby mimicking a banked turn.

[0076]

[0066] According to the disclosure, the term “propulsion means” is intended to encompass propellers, impellers, thrusters or equivalent structures that produce thrust for the watercraft.

[0077]

[0067] According to the disclosure, the outward toe angle of each propulsion unit of the watercraft is between 1 degree and 15 degrees relative to the centerline. The propulsion units of the watercraft are electric motor-driven propellers mounted in fixed pods below the hull, and the control mechanism comprises an electronic controller that receives a steering input and outputs differential throttle commands to the propellers.

[0078]

[0068] According to the disclosure, the propulsion units of the watercraft are water jet drives with fixed- direction nozzles angled outward, or other thrust-generating devices oriented to have a horizontal outward component.

[0079]

[0069] According to the disclosure, the watercraft further comprises a hydrofoil assembly attached to the hull and configured to lift the hull at speed, the control mechanism being adapted to operate the propulsion units to induce inward roll when the hydrofoil is deployed, thereby coordinating with the hydrofoil to bank the watercraft during turns in foiling operation.

[0080]

[0070] According to the disclosure, each propulsion unit of the watercraft is a counter-rotating propeller such that one propeller rotates clockwise and the other counter-clockwise, thereby minimizing net torque on the hull while allowing dil erenlial thrust steering.

[0081]

[0071] According to the disclosure, the control mechanism of the watercraft is further configured to execute zero-radius turns by driving one propulsion unit in forward thrust and the other in reverse thrust, utilizing the outward toe angles to enhance the turning moment about the hull’s vertical axis.

[0082]

[0072] Iniplenienlalions disclosed herein provide systems, methods and apparatus for generating or augmenting training data sets for machine learning training. The functions described herein may be stored as one or more instructions on a processor-readable or computer-readable medium. The term “computer- readable medium” refers to any available medium that can be accessed by a computer or processor. By way of example, and not limitation, such a medium may comprise RAM, ROM, EEPROM, flash memory, CD- ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. It should be noted that a computer-readable medium may be tangible and non-transitory. As used herein, the term “code” may refer to software, instructions, code or data that is / are executable by a computing device or processor. A “module” can be considered as a processor executing computer-readable code.

[0083]

[0073] A processor as described herein can be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor can be a microprocessor, but in the alternative, the processor can be a controller, or microcontroller, combinations of the same, or the like. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Although described herein primarily with respect to digital technology, a processor may also include primarily analog components. For example, any of the signal processing algorithms described herein may be implemented in analog circuitry. In some embodiments, a processor can be a graphics processing unit (GPU). The parallel processing capabilities of GPUs can reduce the amount of time for training and using neural networks (and other machine learning models) compared to central processing units (CPUs). In some embodiments, a processor can be an ASIC including dedicated machine learning circuitry custom-build for one or both of model training and model inference.

[0084]

[0074] The disclosed or illustrated tasks can be distributed across multiple processors or computing devices of a computer system, including computing devices that are geographically distributed. The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and / or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0085]

[0075] As used herein, the term “plurality” denotes two or more. For example, a plurality of components indicates two or more components. The term “determining” encompasses a wide variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory) and the like. Also, “determining” can include resolving, selecting, choosing, establishing and the like.

[0076] The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.” While the foregoing written description of the system enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The system should therefore not be limited by the above-described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the system. Thus, the present disclosure is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

ClaimsWhat is claimed:

1. A watercraft steering system, comprising: a hull having a longitudinal centerline and port and starboard sides; a pair of propulsion units mounted to the hull, one on the port side and one on the starboard sides, each having a thrust axis fixed to diverge outward from the longitudinal centerline in plan view, the thrust axes lying substantially in a horizontal plane; and a control mechanism configured to independently regulate the output of each propulsion unit, wherein, during a turn, the control mechanism increases thrust from the propulsion unit on the outboard side of the turn relative to the inboard side such that the resultant lateral force component and its vertical offset from a center of gravity produce a rolling moment that banks the hull inward toward the turn. wherein during a turning maneuver the control mechanism increases thrust from the propulsion unit on the side opposite the turn direction relative to the other side, such that a net lateral force component is generated and produces a rolling moment that banks the hull inward toward the turn.

2. The watercraft steering system of claim 1, wherein the outward toe angle of each propulsion unit is between 1 degree and 15 degrees relative to the centerline.

3. The watercraft steering system of claim 1, wherein the propulsion units are electric motor-driven propellers mounted in fixed pods below the hull, and the control mechanism comprises an electronic controller that receives a steering input and outputs differential throttle commands to the propellers.

4. The watercraft steering system of claim 1, wherein the propulsion units are waterjet drives with fixed- direction nozzles angled outward, or other thrust-generating devices oriented to have a horizontal outward component.

5. The watercraft steering system of claim 1, further comprising a hydrofoil assembly attached to the hull and configured to lift the hull at speed, the control mechanism being adapted to operate the propulsion units to induce inward roll when the hydrofoil is deployed, thereby coordinating with the hydrofoil to bank the watercraft during turns in foiling operation.

6. The watercraft steering system of claim 1, wherein each propulsion unit is a counter-rotating propeller such that one propeller rotates clockwise and the other counter-clockwise, thereby minimizing net torque on the hull while allowing di H ere filial thrust steering.

7. The watercraft steering system of claim 1, wherein the control mechanism is further configured to execute zero-radius turns by driving one propulsion unit in forward thrust and the other in reverse thrust, utilizing the outward toe angles to enhance the turning moment about the hull’s vertical axis.

8. A method of steering a twin-propulsion watercraft having port and starboard propulsion units fixed in an outwardly angled orientation, the method comprising: commanding an increase in thrust on the port propulsion unit relative to the starboard unit to initiate a starboard turn, or commanding an increase in thrust on the starboard unit relative to the port unit to initiate a port turn; generating, by virtue of the outwardly angled orientation of the propulsion units, a lateral force component as a result of said thrust difference; and rolling the watercraft’s hull inward toward the turn in response to the lateral force component, such that the watercraft banks into the turn without any steering surface or steerable drive deployment.

9. The method of steering of claim 8, further comprising sensing an actual roll angle of the hull and adjusting the thrust difference to achieve a target roll angle commensurate with a turning rate, thereby providing active roll stabilization into turns.

10. The method of steering of claim 8, wherein at low speeds the commanding step includes reversing one of the propulsion units and driving the other forward to spin the watercraft in place, utilizing the fixed angled orientation of the propulsion units to maintain stability during the pivot.

11. A watercraft, comprising: a hull; a port and starboard propulsion units whose thrust vectors diverge outward from the longitudinal centerline in plan view; anda controller configured to differentially command the propulsion units in response to a steering input so that unequal thrust induces an inward banking roll during a turn.

12. The watercraft of claim 11, wherein the outward toe angle of each propulsion unit is between 1 degree and 15 degrees relative to the centerline.

13. The watercraft of claim 11, wherein the propulsion units are electric motor-driven propellers mounted in fixed pods below the hull, and the control mechanism comprises an electronic controller that receives a steering input and outputs differential throttle commands to the propellers.

14. The watercraft of claim 11 , wherein the propulsion units are water jet drives with fixed-direction nozzles angled outward, or other thrust-generating devices oriented to have a horizontal outward component.

15. The watercraft of claim 11, further comprising a hydrofoil assembly attached to the hull and configured to lift the hull at speed, the control mechanism being adapted to operate the propulsion units to induce inward roll when the hydrofoil is deployed, thereby coordinating with the hydrofoil to bank the watercraft during turns in foiling operation.

16. The watercraft of claim 11, wherein each propulsion unit is a counter-rotating propeller such that one propeller rotates clockwise and the other counter-clockwise, thereby minimizing net torque on the hull while allowing differential thrust steering.

17. The watercraft of claim 11, wherein the control mechanism is further configured to execute zeroradius turns by driving one propulsion unit in forward thrust and the other in reverse thrust, utilizing the outward toe angles to enhance the turning moment about the hull’s vertical axis.

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