Methods and systems for watercraft control

Abstract

A watercraft comprising a hull, a deck on the hull, a motor disposed in the hull, and a propulsion system operatively connected to the motor. The propulsion system comprises a nozzle operatively connected to a nozzle actuator configured to selectively displace the nozzle in a plurality of positions between a first position and a second position. A gate is operatively connected to a gate actuator configured to selectively displace the gate in a plurality of positions between a stowed position and a deceleration position. An electronic control unit is configured to selectively activate the nozzle actuator and the gate actuator to generate a thrust vector in three-dimensional space. The thrust vector is characterized by an amplitude and components in a longitudinal direction, a lateral direction, and a vertical direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 63 / 749,375, titled WATERCRAFT CONTROL SYSTEM, filed January 24, 2025, which is hereby incorporated by reference in its entirety.FIELD OF DISCLOSURE

[0002] The present disclosure relates to control systems for watercraft, and more particularly to fine to ultra-fine control systems for personal watercraft and marine vehicles that enable precise thrust vector generation in three-dimensional space through coordinated control of nozzle position, gate position, and propulsion system operation.BACKGROUND

[0003] Watercraft such as personal watercraft (PWC), jet boats, pontoons, and other marine vehicles utilize various propulsion systems to navigate bodies of water. Among these, jet propulsion systems have become prevalent in certain watercraft categories due to their compact design and maneuverability characteristics. A typical jet propulsion system comprises a jet pump operatively coupled to an engine, a venturi connected to a rear end region of the jet pump, and a nozzle mounted on the venturi that directs water flow to generate thrust.

[0004] Conventional watercraft may include trim and reverse systems to facilitate controlling the pitch of the vehicle, moving backwards, and decelerating. For instance, a watercraft may comprise a reverse gate movable between a stowed position and a deceleration position, with a reverse gate actuator operatively connected to the reverse gate for moving the gate between these positions. The steering of such vehicles is typically achieved by operatively connecting the nozzle to the helm of the vehicle via one or more cables, so that the nozzle pivots about a height wise axis when the helm is operated.

[0005] In existing watercraft control systems, the reverse gate has generally been used for predefined discrete positions or position ranges. These positions or position ranges typically include a first range of positions for substantial forward acceleration and a second range of positions for braking and moving in the reverse direction. This limited use of the motive facilities of the watercraft has constrained the range of thrust vectors that can be generated, leaving portions of the potential thrust vector domain inaccessible during operation.

[0006] Watercraft maneuvering encompasses a variety of tasks that may benefit from enhanced control over propulsion and deceleration systems. For example, docking maneuvers can be challenging for watercraft users, particularly those with less experience. Low-speed maneuvering in confined spaces, maintaining position in currents or wind, and executing precise directional changes represent additional scenarios where finer control over thrust direction and magnitude may be beneficial.

[0007] Various approaches have been developed to address aspects of watercraft control, including systems for automatic position holding, orientation control, and autonomous navigation. However, opportunities remain for improvements in the precision and range of thrust vector control available to watercraft operators and control systems.SUMMARY

[0008] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0009] According to an aspect of the present disclosure, a watercraft is provided. The watercraft includes a hull. The watercraft includes a deck on the hull. The watercraft includes a motor disposed in the hull. The watercraft includes a propulsion system operatively connected to the motor, wherein the propulsion system comprises a nozzle operatively connected to a nozzle actuator configured to selectively displace the nozzle in a plurality of positions between a first position and a second position. The watercraft includes a gate operatively connected to a gate actuator configured to selectively displace the gate in a plurality of positions between a stowed position and a deceleration position. The watercraft includes an electronic control unit configured to selectively activate the nozzle actuator and the gate actuator to generate a thrust vector in three-dimensional space, the thrust vector characterized by an amplitude and components in a longitudinal direction, a lateral direction, and a vertical direction.

[0010] According to other aspects of the present disclosure, the watercraft may include one or more of the following features. The plurality of positions of the gate may comprise an infinite number of positions between the stowed position and the deceleration position. The plurality of positions of the nozzle may comprise an infinite number of positions between the first position and the second position. The electronic control unit may be configured to selectively activate the nozzle actuator and the gate actuator based on an RPM of the motor. The electronic control unit may calculate the component in the longitudinal direction based on input from the gate actuator. The electronic control unit may calculate the component in the lateral direction based on input from the nozzle actuator. The electronic control unit may calculate the amplitude based at least on an input from the motor. The electronic control unit may calculate the amplitude based on the input from the motor and an input from the gate actuator. The watercraft may have a thrust vector domain, and the electronic control unit may be configured to facilitate propulsion of the watercraft into any part of the thrust vector domain. The propulsion system may comprise a jet propulsion system including a jet pump operatively coupled to the motor. The propulsion system may comprise an electric motor configured to provide thrust vectoring at low speeds.

[0011] According to another aspect of the present disclosure, a control unit for a watercraft is provided. The control unit includes a module configured to receive a plurality of user inputs including at least a steering input and a throttle input. The control unit includes a module configured to determine a target gate angle, a target nozzle angle, and a target rotational speed of a propulsion device based on at least one of the plurality of user inputs. The control unit includes a module configured to generate control signals to a gate actuator and a nozzle actuator to produce a thrust vector having a longitudinal component, a lateral component, and an amplitude, wherein the control unit is configured to facilitate propulsion of the watercraft into a thrust vector domain of the watercraft.

[0012] According to other aspects of the present disclosure, the control unit may include one or more of the following features. The plurality of user inputs may further comprise a speed target, an acceleration target, and a pitch target. The module configured to determine the target gate angle, the target nozzle angle, and the target rotational speed of the propulsion device may be further configured to compute a desired force and a desired direction based on characteristics of the watercraft. The control unit may be selectively automatic and may comprise at least one pre-selected automatic mode. The at least one pre-selected automatic mode may include a quasi-stationary mode and a low-speed stable mode.

[0013] According to another aspect of the present disclosure, a method of controlling a watercraft is provided. The method includes receiving, by an electronic control unit, a plurality of sensor inputs including at least one of a speed input, an acceleration input, and a steering input. The method includes computing, by the electronic control unit, a target reverse gate angle based on at least one of the plurality of sensor inputs. The method includes computing, by the electronic control unit, a target nozzle angle based on at least one of the plurality of sensor inputs. The method includes computing, by the electronic control unit, a target rotational speed of a jet pump based on at least one of the plurality of sensor inputs. The method includes generating, by the electronic control unit, control signals to a gate actuator and a nozzle actuator to produce a thrust vector having a longitudinal component, a lateral component, a vertical component, and an amplitude.

[0014] According to other aspects of the present disclosure, the method may include one or more of the following features. Computing the target reverse gate angle, the target nozzle angle, and the target rotational speed of the jet pump may comprise accessing at least one computer readable map stored in a memory of the electronic control unit. The at least one computer readable map may comprise a first map for determining the target reverse gate angle based on the speed input and the steering input, and a second map for determining the target nozzle angle based on the target reverse gate angle and at least one of the plurality of sensor inputs. The electronic control unit may be configured to facilitate propulsion of the watercraft into any part of a thrust vector domain of the watercraft.

[0015] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.BRIEF DESCRIPTION OF FIGURES

[0016] Non-limiting and non-exhaustive examples are described with reference to the following figures.

[0017] FIG. 1A illustrates an exemplary front perspective view of an exemplary watercraft.

[0018] FIG. 1B illustrates an exemplary rear perspective view of an exemplary watercraft.

[0019] FIG. 1C illustrates an exemplary rear cut-away profile view of the right side of an exemplary watercraft.

[0020] FIG. 1C illustrates an exemplary rear cut-away profile view of the right side of an exemplary prior art watercraft.

[0021] FIG. 1D illustrates an exemplary rear cut-away profile view of the right side of an exemplary watercraft in accordance with the disclosures herein.

[0022] FIG. 2A illustrates a top plan view of a prior art watercraft and prior art watercraft thrust domain.

[0023] FIG. 2B illustrates a top plan view of a watercraft and watercraft thrust domain in accordance with the disclosures herein.

[0024] FIG. 3A illustrates one profile view of an exemplary watercraft control system.

[0025] FIG. 3B illustrates another profile view of an exemplary watercraft control system.

[0026] FIG. 4 illustrates an exemplary diagrammatic lay out of an exemplary watercraft control system.

[0027] FIGS. 4A-D each illustrates an exemplary lay out of exemplary functions of an exemplary watercraft control system.

[0028] In the drawings like characters of reference indicate corresponding parts in the different and interchangeable and interrelated figures. Parts and components of each figure may be substitutes for other components in other figures to achieve the various methods and embodiments disclosed herein. Methods and protocols disclosed in any embodiment may be run in any order so as to affect their disclosed goals and / or enable performance of the systems as described. Additionally, any one embodiment may utilize any method or protocol described and in any portions, sequences, and combinations thereof.

[0029] For purposes of description herein, the terms “forward”, “reverse”, “aft”, “fore”, “port”, “starboard”, “clockwise”, “counter clockwise”, “lateral”, and derivatives thereof, shall relate to the invention as oriented in FIG. 1A, with point “F” being the reference for “forward” on the watercraft 100 illustratively depicted therein. However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

[0030] Further, the axes illustrated in FIGS. 1C-D may be understood as having a “z” axis pointing into or out of the page at an angle orthogonal to both the axis marked “y” and the axis marked “x” for reference purposes.DETAILED DESCRIPTION

[0031] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein.

[0032] The present disclosure relates to control systems for watercraft that enable fine to ultra-fine control over handling characteristics. A watercraft according to the present disclosure may be a personal watercraft (PWC), a marine vehicle such as a boat or pontoon, or another liquid displacement vehicle. The control systems described herein may enable accomplishing complex maneuvers, such as docking, and may improve the user experience of handling such vehicles. In some cases, the control systems may provide enhanced maneuverability by coordinating multiple propulsion and steering components to achieve precise thrust vector control in three-dimensional space.

[0033] Referring to FIG. 1C, a prior art watercraft configuration is illustrated. Prior art watercraft systems may include a jet propulsion system 85 with various components arranged within and around a prior art hull 42. A jet pump 460 may be disposed within the prior art hull 42 and connected to a propulsion assembly. A prior art venturi 49 may be positioned at an upper portion of the assembly, connecting to a prior art nozzle 47 that directs water flow for propulsion. A brake and reverse system 48 may be positioned adjacent to the prior art nozzle 47, enabling control over deceleration and reverse movement of the watercraft.

[0034] With continued reference to FIG. 1C, in prior art configurations, the axial disposition of the prior art nozzle 47 may be controlled by a control cable 41 that connects from a steering system to an orientation housing of the prior art nozzle 47. The control cable 41 may extend along a lower portion of the assembly, providing mechanical linkage for steering control. In some cases, the control cable 41 may be connected directly to the orientation housing of the prior art nozzle 47. In other cases, the control cable 41 may be connected indirectly via one or more additional control cables. Examples of such prior art watercraft configurations are provided in U.S. Patent Nos. US9908601B2, US9376189B1, US10775808B2, US11866134B2, US11611651B2, and US11188080B2.

[0035] Referring to FIG. 2A, a prior art watercraft 80 and a prior art thrust vector domain 200 are illustrated in a top plan view. The prior art watercraft 80 is shown positioned within a plane P representing the water surface when the prior art watercraft 80 and water are at rest. The prior art thrust vector domain 200 may be defined by a perimeter formed by all possible thrust vectors that the prior art watercraft 80 can produce up to a fixed distance from the prior art nozzle 47. The outer perimeter of the prior art thrust vector domain 200 may comprise all possible thrust vectors when thrust is set at a maximum amplitude.

[0036] With continued reference to FIG. 2A, the prior art thrust vector domain 200 is divided into discrete zones labeled A through E. A prior art thrust vector 434 is shown with a prior art longitudinal component 435 extending in a fore-aft direction, a prior art lateral component 436 extending in a port-starboard direction, and a prior art vertical component 437 at point X extending into and out of the figure plane. The prior art watercraft 80 may operate such that the prior art thrust vector 434 can be controlled in three zones within the prior art thrust vector domain 200, specifically zones A, C, and E. Zones B and D of the prior art thrust vector domain 200 may remain inaccessible due to mechanical and ergonomic limitations of prior art thrust control systems.

[0037] With continued reference to FIG. 2A, in a drive mode, the prior art watercraft 80 may have a gate fully open to allow water to flow away from the prior art watercraft 80 to move the vehicle forward. In drive mode, in response to an acceleration user input via a throttle device, the prior art thrust vector 434 may control the flow of water into zone E of the prior art thrust vector domain 200 to propel the prior art watercraft 80.

[0038] In a neutral gear, the prior art watercraft 80 may not have substantial thrust or may direct the prior art thrust vector 434 underneath the prior art watercraft 80, within zone C of the prior art thrust vector domain 200.

[0039] With continued reference to FIG. 2A, the prior art watercraft 80 may direct the prior art thrust vector 434 underneath the prior art watercraft 80 and towards a forward direction to cause the prior art watercraft 80 to brake or move in reverse based on water placed into zone A of the prior art thrust vector domain 200.

[0040] The prior art thrust vector 434 may provide for water thrust from the prior art watercraft 80 in a way that allows the vehicle to operate in portions of the overall strata of zones of the prior art thrust vector domain 200, as illustrated in FIG. 2A by zones A, C, and E. Zones B and D of the prior art thrust vector domain 200 may remain inaccessible due to mechanical and ergonomic limitations of prior art thrust control systems. Watercraft may engage in maneuvers, such as docking, in which control would be beneficial in all zones, including zones B and D.

[0041] Referring to FIG. 1A, an exemplary watercraft 100 is illustrated in a front perspective view. The watercraft 100 may be any suitable water traversing device, including a personal watercraft (PWC), a marine vehicle such as a boat or pontoon, or another liquid displacement vehicle.

[0042] With continued reference to FIG. 1A, the watercraft 100 includes a hull 2 forming a lower portion of the vessel that contacts the water surface. A deck 1 is positioned on the hull 2 and provides an upper surface of the watercraft 100. A seat 6 is mounted on the deck 1 toward a rear portion of the watercraft 100, providing a seating area for an operator.

[0043] The watercraft 100 includes a motor disposed in the hull 2 and below the deck 1. The motor may be operatively connected to a propulsion system for propelling the watercraft 100 through water.

[0044] With continued reference to FIG. 1A, a steering system 5 is located forward of the seat 6 and includes handlebars for directional control of the watercraft 100. A throttle 45 is positioned on the steering system 5 for controlling acceleration of the watercraft 100. A deceleration device 46 is also associated with the steering system 5 for controlling braking or deceleration functions. The throttle 45 and the deceleration device 46 may provide user inputs to a control system for managing propulsion and maneuvering of the watercraft 100.

[0045] As shown in FIG. 1A, the watercraft 100 is positioned relative to a plane P. The plane P represents a thrust vector domain for the watercraft 100 and corresponds to a plane parallel with the water surface when the watercraft 100 and the water surface are both at rest. A forward direction indicator F is shown to establish the orientation of the watercraft 100.

[0046] Referring to FIG. 1B, a rear perspective view of the watercraft 100 is illustrated, showing a jet propulsion system 70 and associated components. The watercraft 100 includes a propulsion system operatively connected to the motor. In some cases, the propulsion system may comprise the jet propulsion system 70 including a jet pump 60 operatively coupled to the motor.

[0047] With continued reference to FIG. 1B, the hull 2 of the watercraft 100 is shown with a rear end region 23 visible. A venturi 9 is connected to the rear end region 23 of the jet pump 60. A nozzle 7 is mounted on the venturi 9 and is configured to direct water flow for propulsion and steering of the watercraft 100.

[0048] As further shown in FIG. 1B, a trim 7A is positioned to provide support about the nozzle 7. The watercraft 100 may comprise the trim 7A for support about the nozzle 7.

[0049] With continued reference to FIG. 1B, a reverse gate 8 is shown adjacent to the nozzle 7 and the venturi 9. The reverse gate 8 is configured to channel propelled water in a desired direction to enable braking, reversing, and trim control of the watercraft 100. The reverse gate 8 may work in conjunction with the trim 7A to enable channeling of the propelled water from front to back of the watercraft 100, including upwardly or downwardly. In some cases, the reverse gate 8 may have a geometry allowing control of the trim of the watercraft 100, notably when the watercraft 100 is accelerating in a substantially forward and optionally lateral direction.

[0050] The rear perspective view of FIG. 1B illustrates the spatial arrangement of the propulsion components relative to the hull 2, showing how the jet propulsion system 70 is integrated into a rear portion of the watercraft 100 to provide maneuvering capabilities.

[0051] In some cases, the watercraft may employ alternative or supplemental propulsion configurations in place of, or in combination with, a jet propulsion system. The propulsion system may include an electric motor configured to provide precise thrust vectoring at low speeds. In certain embodiments, an outboard motor, such as an electric outboard motor, may be utilized to enhance low speed maneuverability, particularly in operating environments requiring fine directional control, including docking, station keeping, or confined area maneuvers. The propulsion configuration may further include a rudder positioned aft of the outboard motor's propeller to generate steering forces. In additional embodiments, a bow mounted lateral thruster may be provided to generate a transverse thrust component at the bow, thereby complementing the stern based thrust vectoring capability. The electric outboard motor, rudder, and bow thruster may each be operatively coupled to an electronic control unit (ECU) and may receive coordinated control signals for adjusting thrust direction, thrust magnitude, and steering response, enabling multi axis maneuverability and enhanced low speed handling performance.

[0052] In some cases, the propulsion system may comprise a redirection of water from a main pump to create side thrusters for thrust vectoring at lower speeds. The side thrusters may receive water flow redirected from the main pump and may direct the water flow laterally to produce lateral thrust components. The side thrusters may be positioned at various locations along the hull to provide lateral maneuvering capability. The electronic control unit may be configured to coordinate operation of the side thrusters with the nozzle actuator and the gate actuator to generate thrust vectors in three-dimensional space. The redirection of water from the main pump to the side thrusters may enable enhanced maneuverability at lower speeds without requiring additional pumping mechanisms.

[0053] In some cases, the watercraft may comprise an auxiliary motor rotatable about a steering axis and configured to generate a vectorable thrust output. The auxiliary motor may be an electric outboard motor mounted at the stern or transom of the watercraft. The auxiliary motor may be configured to rotate about the steering axis to direct thrust in various directions, thereby enabling precise control over thrust direction at low speeds. The auxiliary motor may be operatively coupled to the electronic control unit to receive control signals for adjusting the rotational position of the auxiliary motor about the steering axis. The electronic control unit may generate coordinated control signals to the auxiliary motor to adjust thrust direction and thrust magnitude based on sensor inputs and user commands. In some cases, the auxiliary motor may operate in conjunction with the jet propulsion system to provide enhanced maneuverability. In other cases, the auxiliary motor may operate independently of the jet propulsion system to provide supplemental thrust vectoring capability.

[0054] In some cases, the watercraft may comprise a water redirection subsystem operatively coupled to the jet propulsion system. The water redirection subsystem may be configured to selectively divert a portion of pressurized water from the jet propulsion system to one or more lateral nozzles so as to form side thrusters capable of generating lateral or rotational thrust components. The lateral nozzles may be positioned at various locations along the hull of the watercraft to provide lateral maneuvering capability. In some cases, the lateral nozzles may be positioned near the bow of the watercraft to generate transverse thrust components at the bow. In other cases, the lateral nozzles may be positioned near the stern of the watercraft to complement the stern-based thrust vectoring capability of the nozzle and gate. The water redirection subsystem may comprise one or more valves or diverters configured to selectively route pressurized water from the jet propulsion system to the lateral nozzles. The electronic control unit may be configured to generate control signals to the water redirection subsystem to adjust the amount of water diverted to the lateral nozzles and the direction of thrust produced by the lateral nozzles.

[0055] The electronic control unit may be configured to generate coordinated control signals to the auxiliary motor and the water redirection subsystem to adjust thrust direction and thrust magnitude. The coordinated control signals may enable the auxiliary motor and the side thrusters formed by the lateral nozzles to operate in conjunction with the nozzle actuator and the gate actuator to produce thrust vectors in three-dimensional space. The electronic control unit may receive sensor inputs from the speed sensor, the acceleration sensor, the steering sensor, and the operational characteristic sensors, and may generate the coordinated control signals based on the received sensor inputs. In some cases, the electronic control unit may utilize one or more computer readable maps stored in a memory of the electronic control unit to determine appropriate control signals for the auxiliary motor and the water redirection subsystem based on the sensor inputs.

[0056] The auxiliary motor and the side thrusters may each be operable to provide enhanced thrust vectoring when the watercraft is operating below a predetermined speed threshold. The predetermined speed threshold may be a speed at which the primary jet propulsion system provides reduced steering authority due to lower water flow rates through the nozzle. In some cases, the predetermined speed threshold may be between approximately 3 knots and approximately 10 knots. In other cases, the predetermined speed threshold may be between approximately 5 knots and approximately 8 knots. In some cases, the predetermined speed threshold may be approximately 5 knots. The electronic control unit may be configured to detect when the watercraft is operating below the predetermined speed threshold and may activate the auxiliary motor and the side thrusters to provide enhanced thrust vectoring capability. The enhanced thrust vectoring provided by the auxiliary motor and the side thrusters when operating below the predetermined speed threshold may improve low speed handling, docking control, and fine position maneuverability of the watercraft.

[0057] In some cases, the watercraft may comprise both the auxiliary motor and the water redirection subsystem to provide multiple sources of enhanced thrust vectoring at low speeds. In other cases, the watercraft may comprise only the auxiliary motor or only the water redirection subsystem. The electronic control unit may be configured to coordinate operation of whichever components are present on the watercraft to achieve desired thrust vector characteristics. The combination of the auxiliary motor, the water redirection subsystem, the nozzle actuator, and the gate actuator may enable the watercraft to access a greater portion of the thrust vector domain at low speeds compared to configurations lacking the auxiliary motor and the water redirection subsystem. The enhanced low speed maneuverability provided by the auxiliary motor and the side thrusters may be particularly beneficial during docking maneuvers, station keeping operations, maneuvering in confined spaces, and other situations requiring fine position control.

[0058] Referring to FIG. 1D, a rear cut-away profile view of the right side of the watercraft 100 is illustrated in accordance with the present disclosure. The view shows an internal arrangement of components within the jet propulsion system 70 and associated control mechanisms. The hull 2 forms a lower structural portion of the watercraft 100 visible in the figure. The venturi 9 is connected to a rear end region of the jet pump 60, which is disposed within the hull 2. The nozzle 7 is mounted on the venturi 9 and is configured to direct water flow for propulsion and steering purposes. The reverse gate 8 is positioned adjacent to the nozzle 7 and functions as part of a brake and reverse system to channel propelled water in a desired direction.

[0059] With continued reference to FIG. 1D, the propulsion system comprises the nozzle 7 operatively connected to a nozzle actuator system 55 configured to selectively displace the nozzle 7 in a plurality of positions between a first position and a second position. The first position may be a position whereby the nozzle 7 is most proximal to the hull 2. The second position may be a position whereby the nozzle 7 is most proximal to the deck 1. The nozzle actuator system 55 is shown operatively coupled to the nozzle 7 to control movement of the nozzle 7 in an X-Y plane using linear or other control-system based actuating mechanisms.

[0060] As further shown in FIG. 1D, the nozzle actuator system 55 includes an actuation mechanism 51 and a linkage 52 connecting the actuation mechanism 51 to the nozzle 7 to enable controlled movement of the nozzle 7. The actuation mechanism 51 may comprise a linear actuator or other control-system based actuating mechanism. The linkage 52 provides a mechanical connection between the actuation mechanism 51 and the nozzle 7, allowing for selective displacement of the nozzle 7 in the plurality of positions.

[0061] With continued reference to FIG. 1D, the nozzle actuator system 55 may have any suitable configuration. In some cases, the nozzle actuator system 55 may comprise a screw actuator allowing a range of movement of the nozzle 7 of between 90 degrees and 180 degrees, more specifically about 135 degrees, at a maximum speed of between 120 degrees per second and 180 degrees per second, with a backlash of no more than 1 degree and a precision of at least plus or minus 1 degree. In other cases, the nozzle actuator system 55 may be implemented by a rotary servo motor allowing a range of movement of the nozzle 7 of at least plus or minus 60 degrees, at a maximum speed of between 150 degrees per second and 180 degrees per second, with a precision of at least plus or minus 0.1 degrees.

[0062] The plurality of positions of the nozzle 7 may include at least five unique positions between the first position and the second position. In some cases, the plurality of positions of the nozzle 7 may include at least sixteen unique positions between the first position and the second position. In some cases, the plurality of positions of the nozzle 7 may include at least sixty-four unique positions between the first position and the second position.

[0063] In some cases, the plurality of positions of the nozzle 7 may comprise an infinite number of positions between the first position and the second position. The nozzle actuator system 55 may be configured to position the nozzle 7 at any position along a continuous range between the first position and the second position, rather than being limited to a finite number of discrete positions. The infinite number of positions may enable finer control over the direction of water flow from the nozzle 7, thereby enabling more precise thrust vector control for maneuvering the watercraft 100.

[0064] The nozzle actuator system may comprise a screw actuator. The screw actuator may allow a range of movement of the nozzle of between 90 degrees and 180 degrees. In some cases, the screw actuator may allow a range of movement of the nozzle of about 135 degrees.

[0065] The nozzle actuator system may operate at a maximum speed of between 120 degrees per second and 180 degrees per second. The nozzle actuator system may have a backlash of no more than 1 degree. The nozzle actuator system may have a precision of at least plus or minus 1 degree.

[0066] In some cases, the nozzle actuator system may be implemented by a rotary servo motor. The rotary servo motor may allow a range of movement of the nozzle of at least plus or minus 60 degrees. The rotary servo motor may operate at a maximum speed of between 150 degrees per second and 180 degrees per second. The rotary servo motor may have a precision of at least plus or minus 0.1 degrees.

[0067] A gate may be operatively connected to a gate actuator configured to selectively displace the gate in a plurality of positions between a stowed position and a deceleration position. The gate actuator may be configured to control angular displacement of the gate to enable channeling of propelled water in desired directions. The gate actuator may comprise a screw actuator or other suitable actuating mechanism. In some cases, the gate actuator may comprise a screw actuator allowing a range of movement of the gate of between 100 degrees and 140 degrees, more specifically about 120 degrees, at a maximum speed of between 45 degrees per second and 60 degrees per second, with a backlash of no more than 0.5 degrees and a precision of at least plus or minus 1 degree.

[0068] The gate may have a geometry allowing control of the trim of the watercraft when the watercraft is accelerating in a substantially forward and optionally lateral direction. The geometry of the gate may enable the gate to redirect water flow to adjust the pitch of the watercraft during forward acceleration. In some cases, the gate may be configured to channel propelled water upwardly or downwardly relative to the watercraft to affect trim characteristics.

[0069] The watercraft may further comprise a variable trim system (VTS) to control the trim of the watercraft. The variable trim system may operate in conjunction with the gate to provide enhanced control over the pitch and attitude of the watercraft during various operating conditions. Examples of variable trim systems are provided in U.S. Patent Nos. US9908601B2, US9517826B1, and US9376189B1, the disclosures of such systems in each of these patents being incorporated herein by reference in their entirety.

[0070] The plurality of positions of the gate may include at least five unique positions between the stowed position and the deceleration position. In some cases, the plurality of positions of the gate may include at least sixteen unique positions between the stowed position and the deceleration position. In some cases, the plurality of positions of the gate may include at least sixty-four unique positions between the stowed position and the deceleration position.

[0071] In some cases, the plurality of positions of the gate may comprise an infinite number of positions between the stowed position and the deceleration position. The gate actuator may be configured to position the gate at any position along a continuous range between the stowed position and the deceleration position, rather than being limited to a finite number of discrete positions. The infinite number of positions may enable finer control over the direction of water flow channeled by the gate, thereby enabling more precise thrust vector control for maneuvering the watercraft. The continuous positioning capability of the gate may allow the electronic control unit to generate thrust vectors with greater precision in the longitudinal direction, as the longitudinal component of the thrust vector may be calculated based on input from the gate actuator.

[0072] The gate actuator system may comprise a screw actuator. The screw actuator may allow a range of movement of the reverse gate of between 100 degrees and 140 degrees. In some cases, the screw actuator may allow a range of movement of the reverse gate of about 120 degrees.

[0073] The gate actuator system may operate at a maximum speed of between 45 degrees per second and 60 degrees per second. The gate actuator system may have a backlash of no more than 0.5 degrees. The gate actuator system may have a precision of at least plus or minus 1 degree.

[0074] Referring to FIG. 3A, a profile view of an exemplary watercraft control system is illustrated. The watercraft control system includes several components arranged to enable precise control of watercraft propulsion and maneuvering. The steering system 5 is positioned at an upper left portion of the assembly and includes the deceleration device 46. The steering system 5 may comprise handlebars or other suitable steering input devices for directional control of the watercraft 100.

[0075] With continued reference to FIG. 3A, a steering sensor 21 is located at or near a revolute coupling junction of the steering system 5 to the watercraft 100. The steering sensor 21 may be configured to detect steering inputs from the steering system 5 and to generate signals corresponding to a steering angle or steering position. The steering sensor 21 may be positioned at or near the revolute coupling junction to accurately measure rotational displacement of the steering system 5 relative to the watercraft 100.

[0076] As further shown in FIG. 3A, the watercraft control system includes a network that electronically couples the steering system 5 and the steering sensor 21 to an electronic control unit (ECU) 25. The ECU 25 serves as a central processing unit for the control system. The steering sensor 21 is electronically coupled to the ECU 25 to communicate steering angle information to the ECU 25. The electronic coupling between the steering sensor 21 and the ECU 25 may comprise wired connections, wireless connections, or combinations thereof.

[0077] With continued reference to FIG. 3A, an engine 30 is positioned centrally within the assembly and is operatively connected to the jet propulsion system 70. The engine 30 may be electronically coupled to the ECU 25 to enable the ECU 25 to monitor and control operation of the engine 30. The electronic coupling between the engine 30 and the ECU 25 may enable the ECU 25 to receive input signals from the engine 30, such as rotational speed or RPM data, and to transmit control signals to the engine 30 to adjust engine operation.

[0078] As further shown in FIG. 3A, a gate actuator system 50 is shown within a dashed outline region and is configured for angular displacement of the reverse gate 8 to enable channeling of propelled water in desired directions. The gate actuator system 50 is electronically coupled to the ECU 25 to enable the ECU 25 to control positioning of the reverse gate 8. The electronic coupling between the gate actuator system 50 and the ECU 25 may enable the ECU 25 to transmit control signals to the gate actuator system 50 to selectively displace the reverse gate 8 in the plurality of positions between the stowed position and the deceleration position.

[0079] With continued reference to FIG. 3A, the ECU 25 is electronically coupled to the engine 30 and the gate actuator system 50 to coordinate control of the various propulsion components based on sensor inputs and user commands. The ECU 25 may receive input signals from the steering sensor 21 and may generate control signals to the gate actuator system 50 based at least in part on the steering input signals. The ECU 25 may also receive input signals from the engine 30, such as RPM data, and may utilize the engine input signals in conjunction with the steering input signals to determine appropriate control signals for the gate actuator system 50.

[0080] Referring to FIG. 3B, another profile view of an exemplary watercraft control system is illustrated. The watercraft control system includes the steering system 5 positioned at one end of the assembly. The steering system 5 includes the throttle 45 for user input control. The throttle 45 may be positioned on the steering system 5 to enable an operator to provide acceleration inputs to the watercraft control system. The throttle 45 may generate signals corresponding to a desired acceleration or thrust level for the watercraft.

[0081] With continued reference to FIG. 3B, the steering sensor 21 is operatively connected to the steering system 5 via a linkage. The steering sensor 21 may be configured to detect rotational displacement of the steering system 5 and to generate signals corresponding to a steering angle or steering position. The steering sensor 21 is operatively connected to the ECU 25 to communicate steering angle information to the ECU 25. The ECU 25 serves as the electronic control unit for the watercraft control system and may receive input signals from the steering sensor 21 to determine appropriate control signals for the propulsion components.

[0082] As further shown in FIG. 3B, the ECU 25 is connected to the engine 30, which is centrally positioned within the control system assembly. The engine 30 is operatively coupled to the jet propulsion system 70 located at an opposite end of the assembly from the steering system 5. The ECU 25 may receive input signals from the engine 30, such as rotational speed or RPM data, and may transmit control signals to the engine 30 to adjust engine operation based on user inputs and sensor data.

[0083] With continued reference to FIG. 3B, the jet propulsion system 70 includes the jet pump 60 that is enclosed within a housing indicated by a dashed outline. The jet pump 60 is operatively coupled to the engine 30 to receive mechanical power for generating water thrust. The jet pump 60 may draw water into the jet propulsion system 70 and expel the water through the nozzle 7 to produce thrust for propelling the watercraft.

[0084] As further shown in FIG. 3B, the nozzle actuator system 55 is positioned adjacent to the jet pump 60 and is configured to control the positioning of the nozzle 7. The nozzle 7 is mounted at a rearward end of the jet propulsion system 70 and is displaceable through a plurality of positions to direct water thrust for maneuvering the watercraft. The nozzle actuator system 55 may be electronically coupled to the ECU 25 to enable the ECU 25 to control positioning of the nozzle 7. The electronic coupling between the nozzle actuator system 55 and the ECU 25 may enable the ECU 25 to transmit control signals to the nozzle actuator system 55 to selectively displace the nozzle 7 in the plurality of positions between the first position and the second position.

[0085] With continued reference to FIG. 3B, the arrangement of components demonstrates the integration of the steering system 5, the ECU 25, the engine 30, and the jet propulsion system 70 to enable coordinated control of watercraft propulsion and steering functions. The ECU 25 may receive input signals from the steering sensor 21 and the throttle 45, and may generate control signals to the nozzle actuator system 55 based at least in part on the steering input signals and the throttle input signals. The ECU 25 may also receive input signals from the engine 30 and may utilize the engine input signals in conjunction with the steering input signals and the throttle input signals to determine appropriate control signals for the nozzle actuator system 55.

[0086] The nozzle actuator system 55 may be configured to selectively displace the nozzle 7 to direct water thrust in a lateral direction for steering the watercraft. The ECU 25 may calculate a lateral component of a thrust vector based on input from the nozzle actuator system 55. The lateral component of the thrust vector may correspond to thrust directed in a port-starboard direction relative to the watercraft. The ECU 25 may coordinate operation of the nozzle actuator system 55 with operation of the gate actuator system 50 to generate thrust vectors in three-dimensional space having longitudinal components, lateral components, and vertical components.

[0087] An electronic control unit may be configured to selectively activate a nozzle actuator and a gate actuator to generate a thrust vector in three-dimensional space. The thrust vector may be characterized by an amplitude and components in a longitudinal direction, a lateral direction, and a vertical direction. The electronic control unit may receive input signals from various sensors and may generate control signals to the nozzle actuator and the gate actuator based at least in part on the sensor input signals. The electronic control unit may coordinate operation of the nozzle actuator and the gate actuator to produce thrust vectors having desired longitudinal components, lateral components, vertical components, and amplitudes for maneuvering the watercraft.

[0088] The electronic control unit may be implemented by one or more processing modules comprising a processing unit and a memory that is connected by a communication bus. The memory may include program instructions and data. The processing unit may be adapted to process the data and the program instructions in order to implement the functionality described herein with reference to the watercraft. The processing module may also comprise one or more input / output (I / O) interfaces for receiving or sending data elements to external modules by receiving or generating and transmitting signals. Non-limiting examples of I / O interfaces include I / O interfaces with user interface devices such as throttle input devices, brake input devices, and helm devices, I / O interfaces with the nozzle actuator and the gate actuator, and I / O interfaces with the engine.

[0089] In some cases, the electronic control unit may be implemented by a single, centralized, processing module located in an enclosure between the deck and the hull. The centralized processing module may be positioned vertically above a battery and in front of the engine when viewed from an elevated side view. The centralized implementation may enable the electronic control unit to be positioned in a protected location within the watercraft while maintaining electronic connections to the various sensors, actuators, and other components of the control system. The centralized processing module may receive input signals from the steering sensor, the throttle, the deceleration device, and other sensors, and may generate control signals to the nozzle actuator and the gate actuator based on the received input signals.

[0090] In other cases, the electronic control unit may be implemented by a plurality of processing modules in communication with each other. The plurality of processing modules may comprise a first processing module affixed to the engine for controlling and sensing the engine. The first processing module may be configured to monitor engine parameters such as rotational speed and may transmit engine data to other processing modules of the electronic control unit. The plurality of processing modules may further comprise a second processing module integrated in the gate actuator system. The second processing module may be disposed inside a housing of an actuator of the gate actuator system. The second processing module may be configured to receive control signals from the first processing module or from other processing modules and may generate actuation signals to control positioning of the gate. The plurality of processing modules may further comprise a third processing module integrated in the nozzle actuator system. The third processing module may be disposed inside a housing of an actuator of the nozzle actuator system. The third processing module may be configured to receive control signals from the first processing module or from other processing modules and may generate actuation signals to control positioning of the nozzle. The distributed implementation may enable the electronic control unit to position processing capabilities proximate to the components being controlled, which may reduce signal transmission distances and may enable faster response times for actuator control.

[0091] A control unit for a watercraft may comprise the electronic control unit described herein. The control unit may be configured to receive a plurality of user inputs and to generate control signals to the nozzle actuator and the gate actuator to produce thrust vectors for maneuvering the watercraft. The control unit may be implemented as a centralized processing module or as a plurality of distributed processing modules in communication with each other.

[0092] The ECU 25 may be configured to selectively activate the nozzle actuator system 55 and the gate actuator system 50 to generate a thrust vector 34 in three-dimensional space. The thrust vector 34 may be characterized by an amplitude and components in a longitudinal direction, a lateral direction, and a vertical direction. The thrust vector 34 may comprise a longitudinal component 35 extending in a fore-aft direction relative to the watercraft 100, a lateral component 36 extending in a port-starboard direction relative to the watercraft 100, and a vertical component 37 extending in a height wise direction relative to the watercraft 100. The amplitude of the thrust vector 34 may correspond to a magnitude of the thrust force produced by the propulsion system.

[0093] The ECU 25 may be configured to selectively activate the nozzle actuator system 55 and the gate actuator system 50 based on an RPM of the engine 30. The ECU 25 may receive input signals from the engine 30 corresponding to a rotational speed of the jet pump 60. The ECU 25 may utilize the RPM input from the engine 30 to determine appropriate control signals for the nozzle actuator system 55 and the gate actuator system 50. In some cases, the ECU 25 may adjust the positioning of the nozzle 7 and the reverse gate 8 based on the RPM of the engine 30 to achieve a desired thrust vector 34 for maneuvering the watercraft 100.

[0094] The ECU 25 may calculate the longitudinal component 35 of the thrust vector 34 based on input from the gate actuator system 50. The gate actuator system 50 may provide position feedback signals to the ECU 25 corresponding to an angular position of the reverse gate 8. The ECU 25 may utilize the position feedback signals from the gate actuator system 50 to determine the longitudinal component 35 of the thrust vector 34. The angular position of the reverse gate 8 may affect the direction of water flow channeled by the reverse gate 8, which may in turn affect the longitudinal component 35 of the thrust vector 34. In some cases, the ECU 25 may calculate the longitudinal component 35 based on a relationship between the angular position of the reverse gate 8 and the resulting longitudinal thrust force.

[0095] The ECU 25 may calculate the lateral component 36 of the thrust vector 34 based on input from the nozzle actuator system 55. The nozzle actuator system 55 may provide position feedback signals to the ECU 25 corresponding to an angular position of the nozzle 7. The ECU 25 may utilize the position feedback signals from the nozzle actuator system 55 to determine the lateral component 36 of the thrust vector 34. The angular position of the nozzle 7 may affect the direction of water flow expelled from the nozzle 7, which may in turn affect the lateral component 36 of the thrust vector 34. In some cases, the ECU 25 may calculate the lateral component 36 based on a relationship between the angular position of the nozzle 7 and the resulting lateral thrust force.

[0096] The ECU 25 may calculate the amplitude of the thrust vector 34 based at least on an input from the engine 30. The ECU 25 may receive input signals from the engine 30 corresponding to the rotational speed of the jet pump 60. The rotational speed of the jet pump 60 may affect the volume and velocity of water expelled through the nozzle 7, which may in turn affect the amplitude of the thrust vector 34. In some cases, the ECU 25 may calculate the amplitude based on a relationship between the RPM of the engine 30 and the resulting thrust force magnitude.

[0097] The ECU 25 may calculate the amplitude of the thrust vector 34 based on the input from the engine 30 and an input from the gate actuator system 50. The ECU 25 may utilize both the RPM input from the engine 30 and the position feedback signals from the gate actuator system 50 to determine the amplitude of the thrust vector 34. The angular position of the reverse gate 8 may affect the proportion of water flow that is redirected by the reverse gate 8, which may in turn affect the amplitude of the thrust vector 34. In some cases, the ECU 25 may calculate the amplitude based on a combination of the RPM of the engine 30 and the angular position of the reverse gate 8 to account for the effects of both the water flow rate and the water flow redirection on the resulting thrust force magnitude.

[0098] The watercraft 100 may have a thrust vector domain. The thrust vector domain may be defined by a perimeter, wherein the thrust vector domain is formed by all possible thrust vectors that the watercraft 100 can produce up to a fixed distance from the nozzle 7. The outer perimeter of the thrust vector domain may comprise all possible thrust vectors when thrust is set at a maximum amplitude. A center of the thrust vector domain, or a centroid for polyhedral thrust vector domains, may be at a point downstream of a center of an orifice of the nozzle 7 and upstream of an inner-most wall of the reverse gate 8 when facing the orifice of the nozzle 7. In some cases, the center or centroid may be at a mean distance between the center of the orifice of the nozzle 7 and the inner-most wall of the reverse gate 8. The perimeter may form a three-dimensional surface about the nozzle-gate centroid. The perimeter may have any suitable shape or dimension.

[0099] The ECU 25 may be configured to facilitate propulsion of the watercraft 100 into any part of the thrust vector domain. The ECU 25 may coordinate operation of the nozzle actuator system 55 and the gate actuator system 50 to generate thrust vectors 34 that enable the watercraft 100 to access any region within the thrust vector domain. The ability to facilitate propulsion into any part of the thrust vector domain may enable enhanced maneuverability compared to prior art configurations where certain zones of the prior art thrust vector domain 200 remained inaccessible.

[0100] In some cases, the ECU 25 may be configured to facilitate propulsion of the watercraft 100 into at least 80 percent of the thrust vector domain. The ECU 25 may generate control signals to the nozzle actuator system 55 and the gate actuator system 50 to produce thrust vectors 34 that enable the watercraft 100 to access at least 80 percent of the regions within the thrust vector domain.

[0101] In some cases, the ECU 25 may be configured to facilitate propulsion of the watercraft 100 into at least 90 percent of the thrust vector domain. The ECU 25 may generate control signals to the nozzle actuator system 55 and the gate actuator system 50 to produce thrust vectors 34 that enable the watercraft 100 to access at least 90 percent of the regions within the thrust vector domain.

[0102] In some cases, the ECU 25 may be configured to facilitate propulsion of the watercraft 100 into approximately all of the thrust vector domain. The ECU 25 may generate control signals to the nozzle actuator system 55 and the gate actuator system 50 to produce thrust vectors 34 that enable the watercraft 100 to access substantially all regions within the thrust vector domain.

[0103] A rear end of the perimeter of the thrust vector domain and the nozzle 7 of the watercraft 100 may correspond to a maximum thrust produced by the watercraft 100. The maximum thrust may be between 800 lbs. and 2000 lbs. when measured at the nozzle 7. The rear end of the perimeter may correspond to thrust vectors 34 directed in a rearward direction relative to the watercraft 100 for forward propulsion.

[0104] A front end of the perimeter of the thrust vector domain and the nozzle 7 of the watercraft 100 may correspond to a maximum braking or reversing thrust produced by the watercraft 100. The maximum braking or reversing thrust may be between 400 lbs. and 1000 lbs. when measured at the reverse gate 8. The front end of the perimeter may correspond to thrust vectors 34 directed in a forward direction relative to the watercraft 100 for braking or reverse movement.

[0105] A span of the perimeter of the thrust vector domain in a lateral direction of the watercraft 100 may correspond to a maximum lateral thrust produced by the watercraft 100. The maximum lateral thrust span may be between 600 lbs. and 2000 lbs. when measured at the center or centroid of the thrust vector domain. In some cases, the maximum lateral thrust span may correspond to a maximum thrust of between 300 lbs. and 1000 lbs. when measured at the center or centroid of the thrust vector domain.

[0106] A control unit for the watercraft 100 may be configured to facilitate propulsion of the watercraft 100 into the thrust vector domain of the watercraft 100. The control unit may comprise the ECU 25 and may be configured to generate control signals to the gate actuator system 50 and the nozzle actuator system 55 to produce thrust vectors 34 having longitudinal components 35, lateral components 36, and amplitudes that enable the watercraft 100 to access regions within the thrust vector domain.

[0107] Referring to FIG. 4, an exemplary diagrammatic layout of an exemplary watercraft control system is illustrated. The control system includes the ECU 25 positioned centrally within the system architecture. On an input side, the ECU 25 receives signals from multiple sensors. The ECU 25 may comprise a module configured to receive a plurality of user inputs including at least a steering input and a throttle input.

[0108] With continued reference to FIG. 4, the ECU 25 receives signals from a speed sensor 10, an acceleration sensor 12, the steering sensor 21, and operational characteristic sensors 16. The speed sensor 10 provides velocity data to the ECU 25. The acceleration sensor 12 supplies acceleration measurements to the ECU 25. The steering sensor 21 communicates steering angle information to the ECU 25. The operational characteristic sensors 16, shown with a dashed border indicating optional or additional sensor inputs, provide supplementary data regarding various operational parameters of the watercraft 100. In some cases, the operational characteristic sensors 16 may comprise GPS sensor data. In some cases, the operational characteristic sensors 16 may comprise inertial measurement units data. The operational characteristic sensors 16 may provide data regarding form factor and other characteristics of vehicle dynamics of the watercraft 100.

[0109] As further shown in FIG. 4, on an output side, the ECU 25 generates control signals directed to three outputs including a reverse gate angle 20, a nozzle angle 22, and an RPM of jet pump 24. The reverse gate angle 20 output controls an angular position of the reverse gate 8 for managing deceleration and reverse thrust. The nozzle angle 22 output controls an angular displacement of the nozzle 7 for directional thrust management. The RPM of jet pump 24 output regulates a rotational speed of the jet pump 60 to control thrust amplitude.

[0110] With continued reference to FIG. 4, the ECU 25 processes the input signals from the various sensors and computes appropriate output values for the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24 to achieve desired thrust vector 34 characteristics for watercraft 100 maneuvering and control. The ECU 25 may comprise a module configured to determine a target gate angle, a target nozzle angle, and a target rotational speed of a propulsion device based on at least one of the plurality of user inputs. The ECU 25 may comprise a module configured to generate control signals to the gate actuator system 50 and the nozzle actuator system 55 to produce the thrust vector 34 having the longitudinal component 35, the lateral component 36, and an amplitude.

[0111] The plurality of user inputs received by the ECU 25 may further comprise a speed target, an acceleration target, and a pitch target. The speed sensor 10 may provide input corresponding to a speed target for the watercraft 100. The acceleration sensor 12 may provide input corresponding to an acceleration target for the watercraft 100. In some cases, the operational characteristic sensors 16 may provide input corresponding to a pitch target for the watercraft 100.

[0112] The module configured to determine the target gate angle, the target nozzle angle, and the target rotational speed of the propulsion device may be further configured to compute a desired force and a desired direction based on characteristics of the watercraft 100. The characteristics of the watercraft 100 may comprise form factor data, vehicle dynamics data, GPS sensor data from the operational characteristic sensors 16, and inertial measurement units data from the operational characteristic sensors 16. The ECU 25 may compute the desired force and the desired direction based on the throttle input, the steering input from the steering sensor 21, the GPS sensor data, and the inertial measurement units data.

[0113] A method of controlling the watercraft 100 may comprise receiving, by the ECU 25, a plurality of sensor inputs including at least one of a speed input from the speed sensor 10, an acceleration input from the acceleration sensor 12, and a steering input from the steering sensor 21. The method may comprise computing, by the ECU 25, a target reverse gate angle based on at least one of the plurality of sensor inputs. The method may comprise computing, by the ECU 25, a target nozzle angle based on at least one of the plurality of sensor inputs. The method may comprise computing, by the ECU 25, a target rotational speed of the jet pump 60 based on at least one of the plurality of sensor inputs. The method may comprise generating, by the ECU 25, control signals to the gate actuator system 50 and the nozzle actuator system 55 to produce the thrust vector 34 having the longitudinal component 35, the lateral component 36, the vertical component 37, and an amplitude.

[0114] Referring to FIG. 4A, a first embodiment of the watercraft control system is illustrated. In the first embodiment, a first computer readable map 25A may be stored in a memory of the ECU 25. The first computer readable map 25A may contain a desired force vector comprised of a particular reverse gate angle 20, a particular nozzle angle 22, and a particular RPM of jet pump 24. The first computer readable map 25A may be selectively or automatically executable when readings are made from the requisite sensors.

[0115] With continued reference to FIG. 4A, the first computer readable map 25A is represented as a three-dimensional coordinate system with three axes. The speed sensor 10 axis extends along one edge of the coordinate system. The acceleration sensor 12 axis extends along another edge of the coordinate system. The steering sensor 21 axis extends along a third edge of the coordinate system. Within the three-dimensional space defined by these axes, a first partial force vector 27 is represented as a point. The first partial force vector 27 corresponds to outputs including the reverse gate angle 20 labeled as variable x, the nozzle angle 22 labeled as variable y, and the RPM of jet pump 24 labeled as variable z.

[0116] As further shown in FIG. 4A, the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24 are shown in boxes with arrows pointing to the first partial force vector 27, indicating that these control outputs are determined based on the sensor inputs from the speed sensor 10, the acceleration sensor 12, and the steering sensor 21. The ECU 25 may access the first computer readable map 25A to determine appropriate values for the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24 based on current readings from the speed sensor 10, the acceleration sensor 12, and the steering sensor 21.

[0117] With continued reference to FIG. 4A, inputs from the operational characteristic sensors 16 may be equally applicable to one of the axes shared by the other sensors. In some cases, data from the operational characteristic sensors 16 may be mapped to the same axis as data from the speed sensor 10, the acceleration sensor 12, or the steering sensor 21. In some cases, an axis of the first computer readable map 25A may be comprised of a combination or functional result following from an operation on one or more sensor inputs. For example, an axis may represent a mean of the steering sensor 21 inputs. In another example, an axis may represent a multiplication of vehicle form data from the operational characteristic sensors 16 by an input from the acceleration sensor 12. The first computer readable map 25A may accommodate various combinations of sensor inputs to determine the first partial force vector 27 corresponding to the desired thrust vector 34 for maneuvering the watercraft 100.

[0118] A method of controlling the watercraft 100 may comprise computing the target reverse gate angle, the target nozzle angle, and the target rotational speed of the jet pump 60 by accessing at least one computer readable map stored in the memory of the ECU 25. In the first embodiment, the at least one computer readable map may comprise the first computer readable map 25A. The ECU 25 may receive sensor inputs from the speed sensor 10, the acceleration sensor 12, and the steering sensor 21, and may access the first computer readable map 25A to determine the target reverse gate angle, the target nozzle angle, and the target rotational speed of the jet pump 60 corresponding to the received sensor inputs. The ECU 25 may then generate control signals to the gate actuator system 50 and the nozzle actuator system 55 based on the values retrieved from the first computer readable map 25A.

[0119] Referring to FIG. 4B, a second embodiment of the watercraft control system is illustrated. In the second embodiment, the first computer readable map 25A may be stored in the memory of the ECU 25 and may allow identification of a pre-existing reverse gate angle 20 for the first partial force vector 27 based on one or more of the exemplary inputs from the speed sensor 10, the acceleration sensor 12, the steering sensor 21, and the operational characteristic sensors 16.

[0120] With continued reference to FIG. 4B, the first computer readable map 25A is shown on a left side of the figure and includes axes representing the speed sensor 10, the reverse gate angle 20, the steering sensor 21, and the acceleration sensor 12. The first partial force vector 27 is indicated as a point within the first computer readable map 25A, positioned along the reverse gate angle 20 axis. The first computer readable map 25A enables identification of the pre-existing reverse gate angle 20 for the first partial force vector 27 based on inputs from the speed sensor 10, the acceleration sensor 12, and the steering sensor 21.

[0121] As further shown in FIG. 4B, selection of the reverse gate angle 20 from the first computer readable map 25A leads to a second computer readable map 25B. The second computer readable map 25B is shown on a right side of the figure and includes axes representing the reverse gate angle 20, the nozzle angle 22, the steering sensor 21, and the speed sensor 10. The second computer readable map 25B is comprised of the selected reverse gate angle 20 corresponding to the first partial force vector 27 and, in conjunction with one or more other inputs from the steering sensor 21 and the speed sensor 10, allows for identification of the nozzle angle 22 corresponding to a second partial force vector 28.

[0122] With continued reference to FIG. 4B, the second partial force vector 28 is indicated as a point within the second computer readable map 25B. The ECU 25 may access the first computer readable map 25A to determine the reverse gate angle 20 based on current readings from the speed sensor 10, the acceleration sensor 12, and the steering sensor 21. The ECU 25 may then access the second computer readable map 25B using the determined reverse gate angle 20 along with inputs from the steering sensor 21 and the speed sensor 10 to determine the nozzle angle 22.

[0123] According to the second embodiment, the ECU 25 may combine the first partial force vector 27 and the second partial force vector 28 to result in a final force vector. The final force vector may correspond to the thrust vector 34 having the longitudinal component 35, the lateral component 36, and an amplitude for maneuvering the watercraft 100. The ECU 25 may generate control signals to the gate actuator system 50 based on the reverse gate angle 20 from the first partial force vector 27 and may generate control signals to the nozzle actuator system 55 based on the nozzle angle 22 from the second partial force vector 28.

[0124] With continued reference to FIG. 4B, while the first computer readable map 25A and the second computer readable map 25B are illustrated without showing how the RPM of jet pump 24 may be derived for either the first partial force vector 27 or the second partial force vector 28, the RPM of jet pump 24 may either be computed based on any of the inputs or may be selected from a suitably configured map. The absence of a particular sensor input or control output in the figures does not prevent the use of the same in an appropriately configured map according to the disclosures herein.

[0125] A method of controlling the watercraft 100 may comprise computing the target reverse gate angle, the target nozzle angle, and the target rotational speed of the jet pump 60 by accessing at least one computer readable map stored in the memory of the ECU 25. In the second embodiment, the at least one computer readable map may comprise a first map for determining the target reverse gate angle based on the speed input from the speed sensor 10 and the steering input from the steering sensor 21, and a second map for determining the target nozzle angle based on the target reverse gate angle and at least one of the plurality of sensor inputs. The ECU 25 may receive sensor inputs from the speed sensor 10, the acceleration sensor 12, and the steering sensor 21, and may access the first computer readable map 25A to determine the target reverse gate angle corresponding to the received sensor inputs. The ECU 25 may then access the second computer readable map 25B using the determined target reverse gate angle along with at least one of the plurality of sensor inputs to determine the target nozzle angle. The ECU 25 may then generate control signals to the gate actuator system 50 and the nozzle actuator system 55 based on the values retrieved from the first computer readable map 25A and the second computer readable map 25B.

[0126] Referring to FIG. 4C, a third embodiment of the watercraft control system is illustrated. In the third embodiment, the first computer readable map 25A may be stored in the memory of the ECU 25 and may allow identification of a pre-existing reverse gate angle 20 for the first partial force vector 27 based on one or more of the exemplary inputs from the speed sensor 10, the acceleration sensor 12, the steering sensor 21, and the operational characteristic sensors 16.

[0127] With continued reference to FIG. 4C, the first computer readable map 25A shows a three-dimensional relationship between the speed sensor 10 along one axis, the reverse gate angle 20 along another axis, and inputs from the steering sensor 21 and the acceleration sensor 12. The first partial force vector 27 is identified within the first computer readable map 25A. The ECU 25 may access the first computer readable map 25A to determine the reverse gate angle 20 based on current readings from the speed sensor 10, the acceleration sensor 12, and the steering sensor 21.

[0128] As further shown in FIG. 4C, selection of the reverse gate angle 20 from the first computer readable map 25A leads to the second computer readable map 25B. The second computer readable map 25B depicts a relationship between the reverse gate angle 20 along one axis and the nozzle angle 22 along another axis, with inputs from the steering sensor 21 and the acceleration sensor 12. The second partial force vector 28 is identified within the second computer readable map 25B. The second computer readable map 25B is comprised of the selected reverse gate angle 20 corresponding to the first partial force vector 27 and, in conjunction with one or more other inputs from the steering sensor 21 and the acceleration sensor 12, allows for identification of the nozzle angle 22 corresponding to the second partial force vector 28.

[0129] With continued reference to FIG. 4C, selection of the nozzle angle 22 from the second computer readable map 25B leads to a third computer readable map 25C. The third computer readable map 25C shows a relationship between the reverse gate angle 20 along one axis, the RPM of jet pump 24 along another axis, and the nozzle angle 22 along a third axis, with inputs from the steering sensor 21. A third partial force vector 29 is identified within the third computer readable map 25C. The third computer readable map 25C is comprised of the selected nozzle angle 22 corresponding to the second partial force vector 28 and, in conjunction with one or more other inputs or derived inputs such as the reverse gate angle 20, allows for identification of the RPM of jet pump 24 corresponding to the third partial force vector 29.

[0130] As further shown in FIG. 4C, the three maps 25A, 25B, and 25C are interconnected by dashed lines indicating that the selection of the reverse gate angle 20 from the first computer readable map 25A leads to the second computer readable map 25B, and the selection of the nozzle angle 22 from the second computer readable map 25B leads to the third computer readable map 25C. The ECU 25 may access the first computer readable map 25A to determine the reverse gate angle 20, may then access the second computer readable map 25B using the determined reverse gate angle 20 to determine the nozzle angle 22, and may then access the third computer readable map 25C using the determined nozzle angle 22 and the determined reverse gate angle 20 to determine the RPM of jet pump 24.

[0131] According to the third embodiment, a precise force vector comprised of the first partial force vector 27, the second partial force vector 28, and the third partial force vector 29 may be achieved. The ECU 25 may combine the first partial force vector 27, the second partial force vector 28, and the third partial force vector 29 to result in the thrust vector 34 having the longitudinal component 35, the lateral component 36, the vertical component 37, and an amplitude for maneuvering the watercraft 100. The ECU 25 may generate control signals to the gate actuator system 50 based on the reverse gate angle 20 from the first partial force vector 27, may generate control signals to the nozzle actuator system 55 based on the nozzle angle 22 from the second partial force vector 28, and may generate control signals to the engine 30 based on the RPM of jet pump 24 from the third partial force vector 29.

[0132] With continued reference to FIG. 4C, the sequential access of the first computer readable map 25A, the second computer readable map 25B, and the third computer readable map 25C may enable the ECU 25 to determine appropriate values for the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24 in a cascaded manner. The cascaded approach may allow each subsequent map to utilize outputs from preceding maps as inputs, thereby enabling interdependent determination of the control outputs. The third embodiment may enable the ECU 25 to generate the thrust vector 34 with coordinated control of the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24 based on the plurality of sensor inputs from the speed sensor 10, the acceleration sensor 12, the steering sensor 21, and the operational characteristic sensors 16.

[0133] Referring to FIG. 4D, a fourth embodiment of the watercraft control system is illustrated. In the fourth embodiment, the ECU 25 may utilize multiple dynamic computer readable maps to determine appropriate values for the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24 based on the plurality of sensor inputs.

[0134] With continued reference to FIG. 4D, a first dynamic computer readable map 26A may be stored in the memory of the ECU 25 and may allow identification of a pre-existing reverse gate angle 20 for the first partial force vector 27 based on one or more of the exemplary inputs from the speed sensor 10, the acceleration sensor 12, the steering sensor 21, and the operational characteristic sensors 16. As illustrated, the first dynamic computer readable map 26A may enable identification of the reverse gate angle 20 based on input from the speed sensor 10 and input from the steering sensor 21. The first dynamic computer readable map 26A plots the speed sensor 10 on one axis against the steering sensor 21 on another axis, with the reverse gate angle 20 as the output, and identifies the first partial force vector 27.

[0135] As further shown in FIG. 4D, iteratively or simultaneously with the operation of the first dynamic computer readable map 26A, a second dynamic computer readable map 26B may identify a pre-existing reverse gate angle 20 for the second partial force vector 28 based on the speed sensor 10 input and the acceleration sensor 12 input. The second dynamic computer readable map 26B plots the speed sensor 10 on one axis against the acceleration sensor 12 on another axis, with the reverse gate angle 20 as the output, and identifies the second partial force vector 28.

[0136] With continued reference to FIG. 4D, iteratively or simultaneously with the operation of the first dynamic computer readable map 26A and the second dynamic computer readable map 26B, a third dynamic computer readable map 26C may identify a pre-existing reverse gate angle 20 for the third partial force vector 29 based on the speed sensor 10 input and yaw of the vehicle from the operational characteristic sensors 16. The third dynamic computer readable map 26C plots the speed sensor 10 on one axis against the operational characteristic sensors 16 representing yaw of vehicle on another axis, with the reverse gate angle 20 as the output, and identifies the third partial force vector 29.

[0137] As further shown in FIG. 4D, according to the fourth embodiment, the ECU 25 may plot the reverse gate angle 20 corresponding to several force vectors including the first partial force vector 27, the second partial force vector 28, and the third partial force vector 29 to generate a fourth dynamic computer readable map 26D from which a trend line 33 may be constructed. The fourth dynamic computer readable map 26D combines the sensor readings from the first dynamic computer readable map 26A, the second dynamic computer readable map 26B, and the third dynamic computer readable map 26C, plotting the reverse gate angle 20 against the sensor readings from the first dynamic computer readable map 26A, the second dynamic computer readable map 26B, and the third dynamic computer readable map 26C. The first partial force vector 27, the second partial force vector 28, and the third partial force vector 29 are shown as data points within the fourth dynamic computer readable map 26D. The trend line 33 is constructed through these data points in the fourth dynamic computer readable map 26D.

[0138] With continued reference to FIG. 4D, the trend line 33 analytic for each of the first partial force vector 27, the second partial force vector 28, and the third partial force vector 29 corresponding to the calculated reverse gate angle 20 may enable the identification of any yet calculated watercraft 100 feature. An arrow with the trend line 33 leads from the fourth dynamic computer readable map 26D to a fifth dynamic computer readable map 26E. The fifth dynamic computer readable map 26E allows for functional identification of each nozzle angle 22 input and RPM of jet pump 24 input along the previously created trend line 33 from the fourth dynamic computer readable map 26D. The fifth dynamic computer readable map 26E plots the nozzle angle 22 against the RPM of jet pump 24, showing a curved relationship derived from the trend line 33 analysis.

[0139] In an exemplary aspect of the fourth embodiment, the watercraft control system may generate dynamic maps, such as the fourth dynamic computer readable map 26D and the fifth dynamic computer readable map 26E, that may be later stored, retrieved, updated, overwritten, and optimized based on other sensor input or other target dynamics. The ECU 25 may store the fourth dynamic computer readable map 26D and the fifth dynamic computer readable map 26E in the memory for subsequent retrieval and use. The ECU 25 may update the fourth dynamic computer readable map 26D and the fifth dynamic computer readable map 26E based on new sensor inputs received during operation of the watercraft 100. The ECU 25 may overwrite previous versions of the fourth dynamic computer readable map 26D and the fifth dynamic computer readable map 26E with updated versions that reflect current operating conditions. The ECU 25 may optimize the fourth dynamic computer readable map 26D and the fifth dynamic computer readable map 26E based on target dynamics for the watercraft 100.

[0140] The trend line 33 analysis shown in the fourth dynamic computer readable map 26D may change after each iteration of control system use to better predict the proper correlations between the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24. The ECU 25 may recalculate the trend line 33 based on updated data points from the first partial force vector 27, the second partial force vector 28, and the third partial force vector 29 after each control system iteration. The recalculated trend line 33 may provide improved predictions for the nozzle angle 22 and the RPM of jet pump 24 based on the accumulated operational data.

[0141] While the maps shown in the fourth embodiment are illustrated as two-dimensional maps, the first dynamic computer readable map 26A, the second dynamic computer readable map 26B, the third dynamic computer readable map 26C, the fourth dynamic computer readable map 26D, and the fifth dynamic computer readable map 26E may be implemented as three-dimensional maps for some or all of the various maps. The use of three-dimensional maps may enable the ECU 25 to accommodate additional sensor inputs or control outputs within each map.

[0142] The first dynamic computer readable map 26A, the second dynamic computer readable map 26B, the third dynamic computer readable map 26C, the fourth dynamic computer readable map 26D, and the fifth dynamic computer readable map 26E may be based on target dynamics and vehicle dynamics. The maps may be based on a model of the vehicle on which the maps are employed. The maps may be based on a priori information of force vectors for particular thrusts for particular situations. In some cases, the target reverse gate angle 20, the target nozzle angle 22, and the target RPM of jet pump 24 may be computed without other inputs, such as by starting with a map similar to the fourth dynamic computer readable map 26D as illustratively provided in the fourth embodiment.

[0143] According to a method of controlling the watercraft 100, the ECU 25 may be configured to facilitate propulsion of the watercraft 100 into any part of a thrust vector domain of the watercraft 100. The ECU 25 may utilize the first dynamic computer readable map 26A, the second dynamic computer readable map 26B, the third dynamic computer readable map 26C, the fourth dynamic computer readable map 26D, and the fifth dynamic computer readable map 26E to determine appropriate values for the reverse gate angle 20, the nozzle angle 22, and the RPM of jet pump 24 that enable the watercraft 100 to access any region within the thrust vector domain. The trend line 33 analysis may enable the ECU 25 to interpolate or extrapolate control values for thrust vectors 34 that were not explicitly stored in the maps, thereby enabling the ECU 25 to facilitate propulsion of the watercraft 100 into any part of the thrust vector domain.

[0144] The control unit may be selectively automatic and may comprise at least one pre-selected automatic mode. The control unit may operate in a manual mode in which the control unit generates control signals to the gate actuator and the nozzle actuator based on direct user inputs from the steering input and the throttle input. The control unit may also operate in an automatic mode in which the control unit generates control signals to the gate actuator and the nozzle actuator based on pre-selected parameters and sensor inputs without requiring continuous direct user inputs. The control unit may be configured to switch between the manual mode and the automatic mode based on user selection or based on detected operating conditions of the watercraft.

[0145] The at least one pre-selected automatic mode may include a quasi-stationary mode. In the quasi-stationary mode, the control unit may be configured to maintain the watercraft in a substantially stationary position relative to the water surface. The control unit may receive sensor inputs from the speed sensor, the acceleration sensor, and the operational characteristic sensors, and may generate control signals to the gate actuator and the nozzle actuator to counteract drift forces acting on the watercraft. The quasi-stationary mode may enable the watercraft to remain in a fixed position without requiring continuous user input to the steering input or the throttle input. The control unit may adjust the target gate angle, the target nozzle angle, and the target rotational speed of the propulsion device to produce thrust vectors that counteract wind forces, current forces, and other environmental forces acting on the watercraft. The quasi-stationary mode may be utilized during docking maneuvers, during loading or unloading operations, or during other situations in which maintaining a stationary position is desired.

[0146] The at least one pre-selected automatic mode may include a low-speed stable mode. In the low-speed stable mode, the control unit may be configured to maintain stable handling characteristics of the watercraft at low speeds. The control unit may receive sensor inputs from the speed sensor, the acceleration sensor, the steering sensor, and the operational characteristic sensors, and may generate control signals to the gate actuator and the nozzle actuator to maintain directional stability of the watercraft at low speeds. The low-speed stable mode may enable the watercraft to travel at low speeds with reduced sensitivity to steering inputs and reduced susceptibility to directional disturbances. The control unit may adjust the target gate angle, the target nozzle angle, and the target rotational speed of the propulsion device to produce thrust vectors that maintain a desired heading and speed of the watercraft. The low-speed stable mode may be utilized during maneuvering in confined spaces, during approach to docking areas, or during other situations in which stable low-speed handling is desired.

[0147] In some cases, the control unit may be configured to automatically transition between the quasi-stationary mode and the low-speed stable mode based on detected speed of the watercraft. The control unit may transition from the low-speed stable mode to the quasi-stationary mode when the detected speed of the watercraft falls below a first threshold speed. The control unit may transition from the quasi-stationary mode to the low-speed stable mode when the detected speed of the watercraft rises above a second threshold speed. The first threshold speed and the second threshold speed may be the same value or may be different values to provide hysteresis in the mode transitions.

[0148] In some cases, the control unit may be configured to receive user selection of the at least one pre-selected automatic mode. The user may select the quasi-stationary mode or the low-speed stable mode via a user interface device associated with the watercraft. The user interface device may comprise buttons, switches, or a display screen located on the steering system or on another accessible location of the watercraft. The control unit may activate the selected pre-selected automatic mode in response to the user selection and may deactivate the selected pre-selected automatic mode in response to a subsequent user selection or in response to user input to the steering input or the throttle input that indicates a desire to resume manual control.

[0149] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Claims

1. A watercraft, comprising:a hull;a deck on the hull;a motor disposed in the hull;a propulsion system operatively connected to the motor, wherein the propulsion system comprises a nozzle operatively connected to a nozzle actuator configured to selectively displace the nozzle in a plurality of positions between a first position and a second position;a gate operatively connected to a gate actuator configured to selectively displace the gate in a plurality of positions between a stowed position and a deceleration position; andan electronic control unit configured to selectively activate the nozzle actuator and the gate actuator to generate a thrust vector in three-dimensional space, the thrust vector characterized by an amplitude and components in a longitudinal direction, a lateral direction, and a vertical direction.

2. The watercraft of claim 1, wherein the plurality of positions of the gate comprises an infinite number of positions between the stowed position and the deceleration position.

3. The watercraft of claim 1, wherein the plurality of positions of the nozzle comprises an infinite number of positions between the first position and the second position.

4. The watercraft of claim 1, wherein the electronic control unit is configured to selectively activate the nozzle actuator and the gate actuator based on an RPM of the motor.

5. The watercraft of claim 4, wherein the electronic control unit calculates the component in the longitudinal direction based on input from the gate actuator.

6. The watercraft of claim 5, wherein the electronic control unit calculates the component in the lateral direction based on input from the nozzle actuator.7.​ The watercraft of claim 6, wherein the electronic control unit calculates the amplitude based at least on an input from the motor, or an input from the gate actuator.8.​ The watercraft of claim 1, wherein the watercraft has a thrust vector domain, and wherein the electronic control unit is configured to facilitate propulsion of the watercraft into any part of the thrust vector domain.9.​ The watercraft of claim 1, wherein the propulsion system comprises a jet propulsion system including a jet pump operatively coupled to the motor.10.​ The watercraft of claim 1, wherein the propulsion system comprises an electric motor configured to provide thrust vectoring at low speeds.11.​ The watercraft of claim 1, wherein the watercraft further comprises one or more of: an auxiliary motor rotatable about a steering axis and configured to generate a vectorable thrust output; and a water redirection subsystem operatively coupled to the jet propulsion system and configured to selectively divert a portion of pressurized water from the jet propulsion system to one or more lateral nozzles so as to form side thrusters capable of generating lateral or rotational thrust components,wherein the electronic control unit is configured to generate coordinated control signals to the auxiliary motor and the water redirection subsystem to adjust thrust direction and thrust magnitude, andwherein the auxiliary motor and the side thrusters are each operable to provide enhanced thrust vectoring when the watercraft is operating below a predetermined speed threshold.

12. A control unit for a watercraft, comprising:a module configured to receive a plurality of user inputs including at least a steering input and a throttle input;a module configured to determine a target gate angle, a target nozzle angle, and a target rotational speed of a propulsion device based on at least one of the plurality of user inputs; anda module configured to generate control signals to a gate actuator and a nozzle actuator to produce a thrust vector having a longitudinal component, a lateral component, and an amplitude, wherein the control unit is configured to facilitate propulsion of the watercraft into a thrust vector domain of the watercraft.

13. The control unit of claim 12, wherein the plurality of user inputs further comprises a speed target, an acceleration target, and a pitch target.

14. The control unit of claim 13, wherein the module configured to determine the target gate angle, the target nozzle angle, and the target rotational speed of the propulsion device is further configured to compute a desired force and a desired direction based on characteristics of the watercraft.

15. The control unit of claim 12, wherein the control unit is selectively automatic and comprises at least one pre-selected automatic mode.

16. The control unit of claim 15, wherein the at least one pre-selected automatic mode includes a quasi-stationary mode and a low-speed stable mode.

17. A method of controlling a watercraft, comprising:receiving, by an electronic control unit, a plurality of sensor inputs including at least one of a speed input, an acceleration input, and a steering input;computing, by the electronic control unit, a target reverse gate angle based on at least one of the plurality of sensor inputs;computing, by the electronic control unit, a target nozzle angle based on at least one of the plurality of sensor inputs;computing, by the electronic control unit, a target rotational speed of a jet pump based on at least one of the plurality of sensor inputs; andgenerating, by the electronic control unit, control signals to a gate actuator and a nozzle actuator to produce a thrust vector having a longitudinal component, a lateral component, a vertical component, and an amplitude.

18. The method of claim 17, wherein computing the target reverse gate angle, the target nozzle angle, and the target rotational speed of the jet pump comprises accessing at least one computer readable map stored in a memory of the electronic control unit.

19. The method of claim 18, wherein the at least one computer readable map comprises a first map for determining the target reverse gate angle based on the speed input and the steering input, and a second map for determining the target nozzle angle based on the target reverse gate angle and at least one of the plurality of sensor inputs.

20. The method of claim 17, wherein the electronic control unit is configured to facilitate propulsion of the watercraft into any part of a thrust vector domain of the watercraft.

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