Patent Description:
The steering system of a typical personal watercraft (PWC) provides little feedback to a driver when performing a turn. This lack of feedback may be interpreted by the driver as a lack of control, which can lead to dangerous conditions such as unintended sharp cornering, swerving, and collisions.

<CIT> discloses a personal watercraft comprising:.

In one example, a personal watercraft includes a jet powered propulsion system, a steering system coupled to the jet powered propulsion system that includes a handle for adjusting an angle of the jet powered propulsion system relative a longitudinal axis of the personal watercraft, and a driving control system coupled to the steering system. The driving control system includes an electrically actuated device coupled to the steering system for applying torque to the steering system, at least one sensor positioned adjacent the steering system that generates operational data of the personal watercraft, and at least one controller coupled to the electrically actuated device and the at least one sensor. The at least one controller is configured to, responsive to a rotation of the handle; to determine an angle and a speed of the rotation of the handle based on the operational data, to determine a first torque to apply to the steering system based on the angle and the speed of the rotation of the handle; and to operate the electrically actuated device to apply the first torque to the steering system during the rotation of the handle in a direction that is opposite the rotation of the handle for providing enhanced steering control of the personal watercraft, with the first torque being applied only by the electrically actuated device.

In a further example, a method for enhancing steering control of a jet powered personal watercraft including a jet powered propulsion system, a steering system coupled to the jet powered propulsion system that includes a handle for adjusting the angle of the jet powered propulsion system relative to a longitudinal axis of the jet powered personal watercraft, an electrically actuated device coupled to the steering system for applying torque to the steering system, and at least one sensor positioned adjacent the steering system that generates operational data of the jet powered personal watercraft, includes receiving a rotation of the handle; responsive to the rotation of the handle, determining an angle and a speed of the rotation of the handle based on the operational data; and determining a torque to apply to the steering system for the jet powered personal watercraft based on the angle and the speed of the rotation of the handle. The method further includes operating the electrically actuated device to apply the determined torque to the steering system during the rotation of the handle in a direction that is opposite the rotation of the handle for providing enhanced steering control of the jet powered personal watercraft, with the determined torque being applied only by the electrically actuated device.

Personal watercrafts (PWCs) have unique steering dynamics and a distinct driving feel owed to their small size and specific type of propulsion and steering system (e.g., water turbine interacting with steering nozzle). The typical handle of a PWC has less than a ninety-degree lock-to-lock range, such as a seventy- or eighty-degree lock-to-lock range, which offers very quick but low-resolution steering control. Conversely, small boats and automobiles often include a steering wheel having a multi-turn (e.g., three turns) lock-to-lock range, and offer high resolution steering control at the expense of increased driver involvement to generate high steering rates. Relative to small boats and automobiles, PWCs are thus typically able to be turned via very light steering effort and generate tremendous cornering forces at high speeds.

The steering system of a typical PWC provides little or no steering feedback to a driver of the forces exchanged between the watercraft and its environment, such as during a turn. Specifically, a driver of the PWC usually receives little or no resistive steering feedback from the load applied to the watercraft by environmental conditions (e.g., winds, waves), and receives little or no resistive steering feedback from the load the watercraft applies to its surrounding environment. The steering feedback provided to a driver of a typical PWC does not significantly increase with speed. Conversely, the rudder of a small boat and the drivetrain of an automobile each provides a relatively high resistive steering force that is proportional to the speed and steering angle of the vehicle. A driver of a small boat or automobile thus receives greater steering feedback than a driver of a typical PWC.

An unexperienced driver of a typical PWC, who may be used to the driving feel and steering dynamics of an automobile, may associate the lack of feedback and ease of steering with a lack of control. Feeling a lack of control can lead the driver to perform dangerous maneuvers, such as excessive steering operations at high speeds, which can potentially eject an unexpecting driver or passenger from the PWC. Moreover, the ease at which the typical PWC is turned may enable environmental elements, such as waves, wakes, and swells, to cause the PWC to constantly veer off course. Unlike with a small boat or automobile, the loads between a typical PWC and its environment are often not sufficient to provide self-centering of the PWC. The driver of a typical PWC may thus need to perform several steering corrections while the PWC is operated to maintain a particular heading.

PWCs configured to overcome these and other issues are described herein. In one example, a PWC may include a driving control system coupled to a steering system of the PWC. The driving control system may include an electrically actuated device (EAD) and an electronic control unit (ECU) coupled thereto. The EAD may be an electric power steering (EPS) system configured to apply a torque to the steering system of the PWC based on electrical signals received from the ECU.

During operation of the PWC, the driving control system may be configured to implement an active damper regulated based on various operational parameters monitored by the ECU. Specifically, the ECU may be configured to operate the EAD to apply additional resistance to the steering system of the PWC based on the monitored parameters. In this way, a driver may need to provide increased steering effort to turn the PWC, which may better inform the driver of potential forces that can be generated by the PWC responsive to a steering action. The driving feel of the PWC will thus be closer to that of a small boat or automobile, which may be more intuitive and comfortable for the driver, and may correspondingly lead to greater confidence, better steering control, and avoidance of potentially dangerous maneuvers.

<FIG> illustrates a PWC <NUM> with a driving control system <NUM> for providing enhanced steering control. The driving control system <NUM> may be coupled to and configured to interact with a steering system <NUM> of the PWC <NUM>. The steering system <NUM> may be coupled to and configured to interact with a jet-powered propulsion system <NUM> of the PWC <NUM>. The jet-powered propulsion system <NUM> may operate to propel the PWC <NUM> in a forward direction. The steering system <NUM> may operate to adjust the angle of the jet-powered propulsion system <NUM> relative to a longitudinal axis of the PWC <NUM>, and may thereby steer the PWC <NUM> in a given direction.

More particularly, the jet-powered propulsion system <NUM> may include an engine <NUM>, a turbine <NUM>, a nozzle <NUM>, and a throttle <NUM>. The throttle <NUM> may be connected to a handle <NUM> of the PWC <NUM>, and may be coupled to the turbine <NUM>, such as via the engine <NUM>. A driver may interact with the throttle <NUM> to cause the engine <NUM> to rotate the turbine <NUM>. The speed of the PWC <NUM> may correspond to the rotational speed of the turbine <NUM>, which may correspond to the extent of activation of the throttle <NUM> by the driver. For example, the throttle <NUM> may form a rotatable grip secured to the handle <NUM> of the PWC <NUM>. The greater the rotation of the throttle <NUM>, the faster the engine <NUM> may rotate the turbine <NUM>, and the faster the turbine <NUM> may propel the PWC <NUM> in the forward direction.

In particular, rotation of the turbine <NUM> may drive water into an input end of the nozzle <NUM>. The nozzle <NUM> may be configured to responsively form a hydraulic jet stream that is expressed away from the PWC <NUM> through an output end of the nozzle <NUM>. The jet stream may function to propel the PWC <NUM> in the opposite direction of the jet stream. For example, when the nozzle <NUM> expresses a jet stream in a direction parallel and/or collinear to the longitudinal axis of the PWC <NUM> (i.e., the axis extending through the stern and the bow of the PWC <NUM>), the jet stream may propel the PWC <NUM> in a straight forward direction.

The steering system <NUM> may include the handle <NUM>, a steering column <NUM>, a gearbox <NUM>, and a main push-pull cable <NUM>. Rotation of the handle <NUM> left and right may cause the PWC <NUM> to turn left and right respectively. Specifically, the handle <NUM> may be coupled to the gearbox <NUM> via the steering column <NUM>. Rotation of the handle <NUM> by a user may cause a corresponding rotation of the steering column <NUM>, which in turn may be received by the gearbox <NUM>. The gearbox <NUM> may be coupled to the nozzle <NUM> via the main push-pull cable <NUM>, and may be configured to translate a rotation of the steering column <NUM>, such as via one or more gears, into a push or pull force onto the end of the main push-pull cable <NUM> connected to the gearbox <NUM>. Responsive to the push or pull force being applied onto the connected end of the main push-pull cable <NUM>, the other end of the main push-pull cable <NUM> may exert a respective push or pull force on the input end of the nozzle <NUM>, thereby causing the output end of the nozzle <NUM> to pivot with respect to the longitudinal axis of the PWC <NUM>. In alternative examples, rather than the gearbox <NUM>, the PWC <NUM> may include a different mechanism, such as an armlink or an electronic actuator, between the steering column <NUM> and the main push-pull cable <NUM> that is configured to translate a rotation of the handle <NUM> and steering column <NUM> into the push or pull force onto the connected end of the main push-pull cable <NUM> and/or the nozzle <NUM>.

Setting the nozzle <NUM> at a non-parallel angle to the longitudinal axis of the PWC <NUM>, which may correspondingly set the jet stream at a non-parallel angle to the longitudinal axis, may cause the PWC <NUM> to turn in a direction corresponding to the direction of the jet stream. Specifically, as the output end of the nozzle <NUM> pivots away from the longitudinal axis of the PWC <NUM> responsive to a rotation of the handle <NUM> to perform a turn, the jet stream formed by the nozzle <NUM> may cause the hull of the PWC <NUM> to lean in towards the turn. The hull's geometry, which may include ridges or other fixed control surfaces, may correspondingly interact with the water on the inside of the turn. This interaction may effect turning of the PWC <NUM> under the power of the jet stream.

For example, a clockwise rotation of the handle <NUM> may cause a corresponding clockwise rotation of the steering column <NUM>. The gearbox <NUM> may be configured to translate the clockwise rotation of the steering column <NUM> into a pull force on the main push-pull cable <NUM>, which may responsively exert a pull force on the nozzle <NUM>. This pull force may cause the output end of the nozzle <NUM> to pivot right (or counter-clockwise), thereby causing the jet stream to push the back end of the PWC <NUM> left and effect a right turn of the PWC <NUM>. Similarly, a counter-clockwise rotation of the handle <NUM> may cause a corresponding counter-clockwise rotation of the steering column <NUM>. The gearbox <NUM> may be configured to translate this counter-clockwise rotation into a push force on the main push-pull cable <NUM>, which may responsively exert a push force on the nozzle <NUM>. This push force may cause the output end of the nozzle <NUM> to pivot left, thereby causing the jet stream to push the back end of the PWC <NUM> right and effect a left turn of the PWC <NUM>.

As described above, the driving control system <NUM> may be coupled to the steering system <NUM> of the PWC <NUM>, and may be configured to provide enhanced steering control of the PWC <NUM>. The driving control system <NUM> may include an electrically actuated device (EAD) <NUM>, an electronic control unit (ECU) <NUM>, a navigation system <NUM>, one or more sensors <NUM>, and a human machine interface (HMI) <NUM>.

The EAD <NUM> may be coupled to the steering column <NUM>, and may function as an electric power steering (EPS) system for the PWC <NUM>. To this end, the EAD <NUM> may include a motor <NUM>, such as an electric motor, configured to apply torque to the steering column <NUM> in the clockwise and counter-clockwise directions, such as based on control signals received from the ECU <NUM>. For example, the EAD <NUM> may include one or more arms coupled to the steering column <NUM> and rotatable by the motor <NUM>, or may include a sleeve rotatable by the motor <NUM> through which the steering column <NUM> extends and is coupled to.

The ECU <NUM> (also referred to herein as a "controller") may be configured to communicate with other components of the PWC <NUM>, or more particularly of the driving control system <NUM>, directly and/or over one or more wired or wireless networks, such as a control area network (CAN). During operation of the PWC <NUM>, the ECU <NUM> may be configured to control the EAD <NUM> based on data received from the navigation system <NUM>, the sensors <NUM>, and/or the HMI <NUM>.

The navigation system <NUM> may include a global positioning system (GPS) module <NUM> and/or an inertial navigation system (INS) module <NUM>. The GPS module <NUM> and the INS module <NUM> may each be configured to determine and communicate to the ECU <NUM> data indicating the current position, heading, and velocity of the PWC <NUM>.

The GPS module <NUM> may be configured to generate geographic data indicating a current position of the PWC <NUM> by communicating with one or more orbiting satellites <NUM> via a GPS antenna <NUM> of the GPS module <NUM>. Each position generated by the GPS module <NUM> may include the longitude and latitude coordinates of the PWC <NUM> at a given time. The GPS module <NUM> or ECU <NUM> may further be configured to generate geographic data indicating a current heading of the PWC <NUM> by comparing two or more positions determined by the GPS module <NUM> over a set time period relative to direction of movement. The GPS module <NUM> or ECU <NUM> may also be configured to generate operational data indicating a current velocity of the PWC <NUM> by comparing two or more positions determined by the GPS module <NUM> over a set time period relative to time.

The INS module <NUM> may include an accelerometer, gyroscope, and/or magnetometer configured to calculate and generate data indicating the current position, orientation (e.g., heading) and velocity of the PWC <NUM>. Specifically, based on a known geographic position of the PWC <NUM> at a given time, which may be determined using the GPS module <NUM> as described above, and on a known orientation and velocity of the PWC <NUM>, which may be determined using the data generated by the GPS module <NUM> as described above and/or data generated by the INS module <NUM>, the INS module <NUM> or the ECU <NUM> may be configured to determine an updated geographic position, heading, and velocity of the PWC <NUM> based on the data generated by the INS module <NUM> alone. In other words, the INS module <NUM> or ECU <NUM> may be configured to determine how the PWC <NUM> is moved relative to the previously known geographic position, heading, and/or velocity based on the data generated by the INS module <NUM> to determine an updated position, heading, and velocity of the PWC <NUM> at a given time.

The INS module <NUM> may enable the ECU <NUM> to determine the current geographic position, heading, and velocity of the PWC <NUM> when the GPS module <NUM> is unable to communicate with and receive data from the GPS satellite <NUM>. Moreover, the ECU <NUM> may be configured to save power by primarily utilizing the INS module <NUM> as the primary source of geographic data, and utilizing data from the GPS module <NUM> to periodically calibrate the INS module <NUM> with the current geographic position, heading, and/or velocity of the PWC <NUM> as determined via data received from the GPS satellite <NUM>. In other words, the ECU <NUM> may be configured to generate data indicating the current position, heading, and/or velocity of the PWC <NUM> by being configured to calibrate the INS module <NUM> using the GPS module <NUM>, operate the INS module <NUM> to generate this data for a predefined time period, recalibrate the INS module <NUM> using the GPS module <NUM> responsive to expiration of the time period, and so on.

The sensors <NUM> may be configured to generate operational data indicating the current operational state of the PWC <NUM>. For example, the sensors <NUM> may include a tachometer configured to generate data indicating the rotational speed of the engine <NUM> and/or turbine <NUM>, a torque request sensor configured to generate data indicating the amount of torque being requested by the driver from the engine <NUM> and/or turbine <NUM> via the throttle <NUM> (e.g., the extent to which the driver is activating the throttle <NUM>), and a speedometer configured to generate data indicating the current speed of the PWC <NUM>. At least one of the sensors <NUM> may be positioned adjacent the steering system <NUM> to generate operational data indicative of a status of the steering system <NUM>. For instance, the sensors <NUM> may include a steering angle sensor configured to generate data indicating a current angle of the handle <NUM>, such as relative to a center position of the handle <NUM>, and a torque sensor configured to generate data indicating the amount and direction of torque on the steering column <NUM>. The ECU <NUM> may be configured to utilize the operational data generated by the sensors <NUM> to control the EAD <NUM>. The GPS module <NUM> and INS module <NUM> may also be considered as sensors of the PWC <NUM> that generate operational data, such as data indicating the velocity of the PWC <NUM>.

The HMI <NUM> may be positioned adjacent the handle <NUM>, and may facilitate user interaction with the other components of the PWC <NUM>, such as those of the driving control system <NUM>. For example, the HMI <NUM> may enable user interaction with the ECU <NUM> and the navigation system <NUM> described above. The HMI <NUM> may include one or more video and alphanumeric displays, a speaker system, and any other suitable audio and visual indicators capable of providing data from the PWC <NUM> components to a user. The HMI <NUM> may also include a microphone, physical controls, and any other suitable devices capable of receiving input from a user to invoke functions of the PWC <NUM> components. The physical controls may include an alphanumeric keyboard, a pointing device (e.g., mouse), keypads, pushbuttons, and control knobs. A display of the HMI <NUM> may be an integrated touch screen display that includes a touch screen mechanism for receiving user input.

Referring to <FIG>, the ECU <NUM> may include a processor <NUM>, memory <NUM>, non-volatile storage <NUM>, and an input/output (I/O) interface <NUM>. The processor <NUM> may include one or more devices selected from microprocessors, micro-controllers, digital signal processors, microcomputers, central processing units, field programmable gate arrays, programmable logic devices, state machines, logic circuits, analog circuits, digital circuits, or any other devices that manipulate signals (analog or digital) based on operational instructions read from the non-volatile storage <NUM> and stored in the memory <NUM>. The memory <NUM> may include a single memory device or a plurality of memory devices including, but not limited, to read-only memory (ROM), random access memory (RAM), volatile memory, non-volatile memory, static random access memory (SRAM), dynamic random access memory (DRAM), flash memory, cache memory, or any other device capable of storing information. The non-volatile storage <NUM> may include one or more persistent data storage devices such as a hard drive, optical drive, tape drive, non-volatile solid-state device, or any other device capable of persistently storing information.

The processor <NUM> may be configured to read into memory <NUM> and execute computer-executable instructions residing in the non-volatile storage <NUM>. The computer-executable instructions may embody software, such as an active steering application <NUM>, and may be compiled or interpreted from a variety of programming languages and/or technologies, including, without limitation, and either alone or in combination, Java, C, C++, C#, Objective C, Fortran, Pascal, Java Script, Python, Perl, and PL/SQL.

The active steering application <NUM> may be configured to implement the functions, features, modules, processes, and methods of the ECU <NUM> described herein. In particular, the computer-executable instructions embodying the active steering application <NUM> may be configured, upon execution by the processor <NUM>, to cause the processor <NUM> to implement the functions, features, modules, processes, and methods of the ECU <NUM> described herein. For instance, the active steering application <NUM> of the ECU <NUM> may be configured to monitor the operating condition of the PWC <NUM>, such as based on operational data received from the navigation system <NUM> and/or the sensors <NUM>. Responsive to the operational data indicating a user torque applied to the steering system <NUM>, such as via the handle <NUM>, the active steering application <NUM> may be configured to determine an additional torque to apply to the steering system <NUM> based on the operational data, and to operate the EAD <NUM> to apply the torque to the steering system <NUM>. As described in more detail below, application of the additional torque to the steering system <NUM> may function to provide an active damper, self-centering feature, and other enhanced steering functions to the driver.

The non-volatile storage <NUM> may also include data supporting the functions, features, modules, processes, and methods of the ECU <NUM> described herein. The software of the ECU <NUM>, such as the active steering application <NUM>, may be configured to access this data during execution to determine how to provide various forms of enhanced steering control. For instance, the non-volatile storage <NUM> of the ECU <NUM> may include steering control data <NUM>. As described in more detail below, the steering control data <NUM> may define one or more lookup tables that associate PWC operational conditions, such as indicated by the data generated by the navigation system <NUM> and/or sensors <NUM>, with a torque to apply to the steering system <NUM>.

The ECU <NUM> may be operatively coupled to one or more external resources <NUM> via the I/O interface <NUM>. The I/O interface <NUM> may include one or more wireless interfaces such as Wi-Fi and Bluetooth, and may include one or more wired interfaces such as Ethernet and CAN. The external resources <NUM> may include one or more other components of the PWC <NUM>. For example, the external resources <NUM> may include the EAD <NUM>, the GPS module <NUM>, the INS module <NUM>, the sensors <NUM>, and the HMI <NUM>.

While an exemplary PWC <NUM> is illustrated in <FIG> and <FIG>, the example is not intended to be limiting. Indeed, the PWC <NUM> may have more or fewer components, and alternative components and/or implementations may be used. For instance, two or more of the above-described components of the driving control system <NUM>, such as two or more of the EAD <NUM>, ECU <NUM>, sensors <NUM>, or navigation system <NUM>, may be combined into a signal unit or device adapted to be secured to the steering column <NUM> of the steering system <NUM>. As an example, <FIG> illustrates a driving control device <NUM> adapted to be secured to the steering column <NUM> of the steering system <NUM>. The driving control device <NUM> may include the components of the driving control system <NUM>, such as the EAD <NUM>, ECU <NUM>, and one more of the sensors <NUM> (e.g., the torque sensor and steering angle sensor).

<FIG> illustrates a method <NUM> for providing enhanced steering control for the PWC <NUM> in the form of an active damper, and <FIG> illustrates a processing architecture <NUM> for implementing the active damper. The active damper may function to increase feedback felt by a driver when turning the PWC <NUM> via the handle <NUM>. Such feedback may inspire the driver of the PWC <NUM> with greater confidence and steering control, leading to avoidance of potentially dangerous maneuvers, such as sharp and excessive steering operations as described above. The ECU <NUM> may be configured to implement the method <NUM> and processing architecture <NUM>, such as upon execution of the active steering application <NUM>. For instance, the processing architecture <NUM> may include an active damper control module <NUM>, which may be implemented by the ECU <NUM> upon execution of the computer-executable instructions embodying the active steering application <NUM>. The active damper control module <NUM> may then be configured to perform the method <NUM>. The following description of implementation of the active damper thus includes reference to both <FIG> and <FIG>.

In block <NUM>, a determination may be made of whether user torque <NUM> is being applied to the steering system <NUM>, such as via rotation of the handle <NUM>. As described above, the sensors <NUM> may include a steering angle sensor and a steering torque sensor. These sensors may be integrated with EAD <NUM>, or may be external of the EAD <NUM> and otherwise mounted to the steering system <NUM> of the PWC <NUM> (e.g., mounted to the handle <NUM>, steering column <NUM>, or nozzle <NUM>). Responsive to an input of user torque <NUM> to the handle <NUM> to perform a turn, the steering angle sensor may generate operational data indicating the changing angle of the steering system <NUM>, or more particularly of the handle <NUM>, and the steering torque sensor may generate operational data indicating the torque on the steering system <NUM>. Responsive to the steering angle sensor generating operational data indicating that the handle <NUM> is being rotated, such as to a degree greater than a predefined threshold and/or at a speed greater than a predefined threshold, and/or to the steering torque sensor generating operational data indicating that the steering system <NUM> has a torque greater than a predefined threshold, the ECU <NUM> may be configured to determine that user torque <NUM> is being applied to the steering system <NUM>.

In block <NUM>, responsive to application of user torque <NUM> to the steering system <NUM>, an angle and speed of the steering system <NUM>, such as an angle and speed of rotation of the handle <NUM>, or angle and speed of movement of the nozzle <NUM>, is determined. In particular, the ECU <NUM> is configured, such as via implementation of the active damper control module <NUM>, to determine steering angle/speed data <NUM> indicating the angle and speed of the steering system <NUM> based on the operational data generated by the steering angle sensor. The operational data generated by the steering angle sensor indicate an angle of the steering system <NUM>, or more particularly of the handle <NUM>. The operational data generated by the steering angle sensor may also indicate a speed of rotation of the handle <NUM> by indicating the changing angle of the handle <NUM> over time.

In block <NUM>, a target torque for the steering system <NUM> may be determined, such as based on the operational data generated by the sensors <NUM> and/or navigation system <NUM> of the PWC <NUM>. In particular, the active damper control module <NUM> may receive the steering angle/speed data <NUM> determined based on the operational data generated from the steering angle sensor. The active damper control module <NUM> may also receive additional operational data from the sensors <NUM> and/or navigation system <NUM>, such as engine RPM data <NUM> indicating an RPM value of the engine <NUM>, engine torque request data <NUM> indicating an engine torque request value corresponding to the extent of user activation of the throttle <NUM>, and vehicle speed data <NUM> indicating the speed of the PWC <NUM>. The active damper control module <NUM> may be configured to determine target torque data <NUM> based on the angle and speed of the steering system <NUM> indicated in the steering angle/speed data <NUM>, and/or based on one or more of the values determined from the additional data described above. The target torque data <NUM> may indicate an amount of torque desired to be present on the steering system <NUM> during a turn to simulate a steering feedback-based driving feel to the user. In other words, the target torque data <NUM> may indicate an amount of torque that should exist on the steering system <NUM> so that the driver feels a resistive force when making a turn.

The active damper control module <NUM> may be configured to determine the target torque data <NUM> based on the steering control data <NUM>. The steering control data <NUM> of the ECU <NUM> includes a lookup table that associates one or more operational parameters (e.g., engine RPM value, engine torque request value, vehicle speed value, steering angle, and/or steering speed) with a target torque for the steering system <NUM>, which may then be indicated by the target torque data <NUM>. Alternatively, the active damper control module <NUM> may be configured to determine the target torque data <NUM> by applying one or more of these data items to a formula, which may likewise be stored in the ECU <NUM>.

In block <NUM>, the current torque on the steering system <NUM> may be determined. In particular, the ECU <NUM> may be configured to determine steering torque data <NUM> indicating the current torque on the steering system <NUM> based on operational data generated by the sensors <NUM>, such as the torque sensor.

In block <NUM>, the target torque and the current torque on the steering system <NUM> may be compared to determine an error therebetween. Specifically, the active damper control module <NUM> may be configured to perform a comparison <NUM> between the target torque data <NUM> and the steering torque data <NUM> to calculate an error between the current torque on the steering system <NUM> and the target torque for the steering system <NUM>. The active damper control module <NUM> may be configured to apply the resulting error to a control algorithm <NUM>.

In block <NUM>, an EAD torque <NUM> to apply to the steering system <NUM> may be determined based on the comparison. Specifically, the control algorithm <NUM>, which may include a proportional-integral-derivative (PID) algorithm, may be configured to determine an EAD torque <NUM> that reduces or eliminates the error. For instance, the control algorithm <NUM> may determine, as the EAD torque <NUM>, a resistive torque that has a magnitude equal to the error and is in a direction that is opposite the rotation of the handle <NUM>.

In block <NUM>, the EAD <NUM> may be operated to apply the EAD torque <NUM> to the steering system <NUM>. For instance, the ECU <NUM> may be configured to generate a command signal for the EAD <NUM> that, upon receipt by the EAD <NUM>, causes the EAD <NUM> to apply the EAD torque <NUM> onto the steering system <NUM>, such as via the steering column <NUM>. More particularly, the steering control data <NUM> may define a lookup table associating each of various electrical current levels with a torque level applied to the steering system <NUM>, or more particularly to the steering column <NUM>, by the EAD <NUM> responsive to application of the electrical current level to the motor <NUM>. The ECU <NUM> may thus be configured to cause an electrical current level associated with the EAD torque <NUM> in the steering control data <NUM> to be supplied to the motor <NUM>.

As previously described, the EAD torque <NUM> may be a resistive torque that is applied in a direction opposite the rotation of the handle <NUM>. The applied torque may thus make the handle <NUM> more difficult to turn, and may thereby provide feedback to the driver. The amount of feedback may correspond to current operational parameters of the PWC <NUM>, such as one or more of the angle the steering system <NUM>, which may be represented by the angle of the handle <NUM>, the speed of the steering system <NUM>, which may be represented by the rotation speed of the handle <NUM>, the engine RPM value, the engine torque request value, and the speed of the PWC <NUM>.

In some examples, rather than determining and comparing the target torque data <NUM> with the steering torque data <NUM>, the active damper control module <NUM> may be configured to determine the EAD torque <NUM> based on operational data consisting only of the angle and speed of rotation of the steering system <NUM> (e.g., the steering angle/speed data <NUM>). In other words, determining steering torque target data <NUM> and the comparison <NUM> may be omitted. In this case, the steering control data <NUM> may include a lookup table that associates each of various angle and speed combinations with a value of the EAD torque <NUM>, or more particularly with an electrical current level to apply to the motor <NUM> of the EAD <NUM> to cause the EAD <NUM> to apply that value for the EAD torque <NUM>. Accordingly, the active damper control module <NUM> may be configured to determine the EAD torque <NUM>, or more particularly the electrical current level for causing the EAD <NUM> to provide the EAD torque <NUM>, by querying the steering control data <NUM> based only on the angle and speed of rotation of the steering system <NUM>, thus reducing processing time for implementation the active damper.

As illustrated in both <FIG> and <FIG>, the ECU <NUM> may be configured to implement a feedback loop that adjusts the EAD torque <NUM> applied to the steering system <NUM> by the EAD <NUM> to provide a driver with appropriate steering feedback during various parts of a turn. Specifically, the ECU <NUM> may be configured to adjust the applied EAD torque <NUM> based at least on updates to the steering angle/speed data <NUM> over time. For instance, referring to <FIG>, the method <NUM> may loop back to monitoring for user torque on the steering system <NUM>, determining an angle and speed of the steering system <NUM> caused by the user torque, and so on. Referring to <FIG>, the processing architecture <NUM> may include a loop that, in each iteration, determines updated steering angle/speed data <NUM>, and/or updated target torque data <NUM> and steering torque data <NUM>, and determines an updated EAD torque <NUM> based thereon.

<FIG> illustrates a method <NUM> for providing enhanced steering control in the form of a self-centering steering system, and <FIG> illustrates a processing architecture <NUM> for implementing the self-centering steering system. The steering dynamics of a typical PWC may make control of the PWC difficult at low vessel speeds relative to the water and/or in non-calm water conditions (e.g., wind, current, waves, swell). Specifically, because little or no resistive mechanical load is placed on the steering system of the typical PWC when the steering system, or more particularly the handle, is turned to a given angle, the steering system may stay at that angle, or may unreliably return to center at very low speed. The method <NUM> and processing architecture <NUM> may be configured to provide self-centering characteristics similar to those of an automobile by determining a centering torque that, when applied to the steering system <NUM>, causes the steering system <NUM> to automatically self-center the steering system <NUM> absent sufficient user torque, thereby reducing course wandering at low vehicle speeds and making driving the PWC <NUM> more intuitive.

The ECU <NUM> may be configured to implement the method <NUM> and the processing architecture <NUM>, such as upon execution of the active steering application <NUM>. For instance, the processing architecture <NUM> may include a self-centering module <NUM>, which may be implemented by the ECU <NUM> upon execution of the computer-executable instructions embodying the active steering application <NUM>. The self-centering module <NUM> may then be configured to perform the method <NUM>. The following description of implementation of the self-centering system thus includes reference to both <FIG> and <FIG>.

In block <NUM> of the method <NUM>, torque may be received by the steering system <NUM> that causes the steering system <NUM> to become off-center. The applied torque may be user torque <NUM> applied by rotating the handle <NUM>. Alternatively, the applied torque may be caused by an environmental factor of the PWC <NUM>, such as a wave or wind interacting with the PWC <NUM>.

In block <NUM>, a determination may be made of whether a user is providing torque to the steering system <NUM>, such as via rotation of the handle <NUM>, to turn the PWC <NUM>. In this case, the self-centering functionality may not be desired, and the active damper described above may be implemented. The ECU <NUM> may be configured to determine whether the user is providing torque to turn the PWC <NUM> based on operational data generated by the steering angle sensor and the torque sensor. Specifically, responsive to the steering angle sensor generating operational data indicating that the handle <NUM> is being rotated, such as to a degree greater than a predefined threshold and/or at a speed greater than a predefined threshold, and/or to the steering torque sensor generating operational data indicating that the steering system <NUM> has a torque greater than a predefined threshold, the ECU <NUM> may be configured to determine that a user is providing torque to turn the PWC <NUM> ("Yes" branch of block <NUM>). Otherwise, the ECU <NUM> may be configured to determine that the user is not trying to turn the PWC <NUM> ("No" branch of block <NUM>).

In block <NUM>, a current angle of the steering system <NUM> may be determined. The steering angle sensor of the sensors <NUM> may generate operational data indicative of the angle of the steering system <NUM>, or more particularly of the handle <NUM>, resulting from the torque in block <NUM>. The ECU <NUM> may thus be configured to generate steering angle data <NUM> indicating the current steering angle of the steering system <NUM> based on the data generated by the steering angle sensor.

In block <NUM>, a target steering angle for returning the steering system <NUM> to a center position may be determined, such as based on the operational data generated by the sensors <NUM>. The target steering angle may represent an angle for the steering system <NUM>, or more particularly for the handle <NUM>, that, given the operational data generated by the sensors <NUM>, results in the jet stream being parallel and/or collinear with the longitudinal axis of the PWC <NUM>. When the PWC <NUM> is new and the steering system <NUM> is properly calibrated, the target steering angle may be zero. Over time, however, the components of the steering system <NUM> may become misaligned and/or stretched such that zero no longer coincides with the jet stream being parallel and/or collinear with the longitudinal axis of the PWC <NUM>. In this case, the self-centering module <NUM> may be configured to determine the non-zero steering center based on the operational data generated by the sensors <NUM>, such as the engine RPM data <NUM>, engine torque request data <NUM>, and/or the vehicle speed data <NUM>. In particular, during operation of the PWC <NUM>, the self-centering module <NUM> may be configured to log correlations between the angle of the handle <NUM> and the jet stream, such as via a sensor <NUM> configured to measure an angle of the nozzle <NUM>, during different operating conditions. The self-centering module <NUM> may then be configured to generate steering center data <NUM> indicating the target steering angle based on the received operational data and the log.

In block <NUM>, the current steering angle and the target steering angle may be compared to determine an error therebetween. Specifically, the self-centering module <NUM> may be configured to perform a comparison <NUM> between the steering angle data <NUM> and the steering center data <NUM> to determine the error. The self-centering module <NUM> may be configured to apply the resulting error to a control algorithm <NUM>.

In block <NUM>, an EAD torque <NUM> for reducing or eliminating the error may be determined. In particular, the control algorithm <NUM>, which may include a PID algorithm, may be configured to determine the EAD torque <NUM> that should be applied to the steering column <NUM> by the EAD <NUM> to reduce or eliminate the error, and thereby cause the steering system <NUM> to center when little or no torque is applied by the driver. Specifically, the steering control data <NUM> may include a lookup table that associates each of various angle errors with a value for the EAD torque <NUM>, or more particularly with an electrical current level to apply to the motor <NUM> of the EAD <NUM> to cause the EAD <NUM> to apply that value for the EAD torque <NUM>. The self-centering module <NUM> may thus be configured to query the steering control data <NUM> based on the angle error to determine the EAD torque <NUM>.

In block <NUM>, the EAD <NUM> may be operated to apply the EAD torque <NUM> to the steering system <NUM>. For instance, the ECU <NUM> may be configured to generate a command signal for the EAD <NUM> that, upon receipt by the EAD <NUM>, causes the EAD <NUM> to apply the EAD torque <NUM> onto the steering system <NUM>, such as via the steering column <NUM>. More particularly, the ECU <NUM> may be configured to cause an electrical current level to be supplied to the motor <NUM> that in turn causes the motor <NUM> to apply the EAD torque <NUM> to the steering system <NUM>. The EAD torque <NUM> may cause the steering system <NUM> to return to a center position.

As illustrated in both <FIG> and <FIG>, the ECU <NUM> may be configured to implement a feedback loop that adjusts the centering torque applied to the steering system <NUM> by the EAD <NUM> to provide proper self-centering functionality. Specifically, the ECU <NUM> may be configured to adjust the applied centering torque based on updates to the current steering angle of the steering system <NUM> and/or to the target steering angle derived from the operational data over time. For instance, referring to <FIG>, the method <NUM> may loop back to determining whether user torque is being applied to the steering system <NUM>, and so on. Referring to <FIG>, the processing architecture <NUM> may include a loop that, in each iteration, determines updated steering angle data <NUM> and/or steering center data <NUM>, and determines updated EAD torque <NUM> based thereon.

As previously described, the PWC <NUM> may be steerable by activating the throttle <NUM> to form a jet stream, and thereafter rotating the handle <NUM> to angle the jet stream in a direction corresponding to the desired heading. Responsive to a rotation of the handle <NUM> by a user, the ECU <NUM> may be configured, such as via the active damper control module <NUM> and/or the self-centering module <NUM>, to apply a resistive force onto the steering system <NUM> to provide a more intuitive and comfortable experience for the driver. When a collision of the PWC <NUM> is imminent, however, a driver may impulsively release the throttle <NUM>, which may eliminate the jet stream steering forces and correspondingly render the handle <NUM> unable to affect a turn away from the collision. The ECU <NUM> may be configured to alert the driver to this lack of steering control when the throttle <NUM> is released by being configured to disable the EAD <NUM> from applying torque onto the steering system <NUM> responsive to a user throttle release event. Disabling the EAD <NUM> in this manner may remove all artificial resistive torque applied by the EAD <NUM> from the steering system <NUM>, which may be perceived by the driver through an increased ease in rotating the handle <NUM>, and may correspondingly remind the driver to reengage the throttle <NUM> to steer away from the collision.

<FIG> illustrates a method <NUM> for providing the lack of steering control warning described above. The ECU <NUM>, such as via the active steering application <NUM>, may be configured to implement the method <NUM>.

In block <NUM>, a determination may be made of whether the driver is actuating the throttle <NUM>. As previously described, the sensors <NUM> may be configured to generate operational data indicating an extent to which the throttle <NUM> is being actuated by a driver. The ECU <NUM> may thus be configured to determine whether the throttle <NUM> is being actuated based on the operational data. Responsive to a throttle release event ("No" branch of block <NUM>), in block <NUM>, the EAD <NUM> may be disabled from providing any resistive torque onto the steering system <NUM>. In other words, the ECU <NUM> may be configured to disable the active damper control module <NUM>, the self-centering module <NUM>, and any other enhanced steering control features described herein. In this way, the driver may feel little or no resistance when rotating the handle <NUM> in the absence of throttle, thereby avoiding the driver having a false sense of control. As a result, if a driver releases the throttle <NUM> while steering to avoid a collision, he or she will immediately sense a drop in the resistive torque applied to the steering system <NUM>. This drop in resistive torque may help remind the driver to apply the throttle <NUM> to regain steering control of the PWC <NUM>.

Responsive to the EAD <NUM> being disabled, in block <NUM>, a determination may be made of whether the throttle <NUM> is reengaged. The ECU <NUM> may be configured to similarly make this determination based on the operational data generated by the sensors <NUM>. Responsive to the throttle being reengaged ("Yes" branch of block <NUM>), in block <NUM>, the EAD <NUM> may be enabled to apply resistive torque onto the steering system <NUM>. Specifically, the ECU <NUM> may be configured to enable the other enhanced steering control features described herein. The method <NUM> may then loop back to the determination of block <NUM>.

The dynamics of the steering system of a typical PWC may enable the PWC to be easily affected by environmental elements, especially when the PWC is traveling at low speeds relative to the water and/or in non-calm water conditions. For example, when little or no throttle is being applied by a driver, a strong wave or current may cause the typical PWC to veer off course. The driving control system <NUM> may thus be configured to implement enhanced steering control in the form of an autopilot system that is configured to provide course corrections, such as when environmental conditions cause the PWC <NUM> to veer off course from a set heading or destination.

<FIG> illustrates a method <NUM> for implementing an autopilot system, and <FIG> illustrates a processing architecture <NUM> for implementing the autopilot system. The method <NUM> and the processing architecture <NUM> may each include a control loop configured to continuously monitor a position and orientation of the PWC <NUM> relative to a navigation target, and to identify situations in which the PWC <NUM> veers off course. In such situations, the method <NUM> and processing architecture <NUM> may be configured to apply a corrective torque to the steering system <NUM> that causes the PWC <NUM> to move back on course.

The ECU <NUM> may be configured to implement the method <NUM> and the processing architecture <NUM>, such as via execution of the active steering application <NUM>. For instance, the processing architecture <NUM> may include an autopilot module <NUM>, which may be implemented by the ECU <NUM> upon execution of the computer-executable instructions embodying the active steering application <NUM>. The autopilot module <NUM> may then be configured to perform the method <NUM>. The following description of implementation of the autopilot system thus includes reference to both <FIG> and <FIG>.

In block <NUM> of the method <NUM>, a navigation target <NUM> may be received, such as by the autopilot module <NUM>. The navigation target <NUM> may define a position (e.g., destination target) or heading lock set by a driver. Specifically, the driver may interact with the HMI <NUM> to set a position or heading lock, which may then be received by the autopilot module <NUM>. As described in more detail below, the autopilot module <NUM> may be configured to determine a torque to apply the steering system <NUM> via the EAD <NUM> based on the navigation target. In block <NUM>, geographic data <NUM> may be received, such as by the autopilot module <NUM>, from the navigation system <NUM>. The autopilot module <NUM> may then be configured to perform a comparison <NUM> based on the navigation target <NUM> and the geographic data <NUM>, and identify an error <NUM> therebetween.

To this end, the autopilot module <NUM> may be configured to perform blocks <NUM> through blocks <NUM> of the method <NUM>. In block <NUM>, a current heading of the PWC <NUM> may be determined based on the geographic data <NUM>. As previously described in reference to the navigation system <NUM>, the geographic data <NUM> may indicate a current position and heading of the PWC <NUM>. In block <NUM>, a target heading for the PWC <NUM> may be determined based on the navigation target <NUM>. In particular, if the navigation target <NUM> includes a heading lock, then the autopilot module <NUM> may be configured to set the target heading as the heading lock. If the navigation target <NUM> includes a position (e.g., destination) lock, then the autopilot module <NUM> may be configured to determine the target heading based on the location of the PWC <NUM> relative to the destination. Specifically, the autopilot module <NUM> may include map data, and may be configured to determine a target heading for the PWC <NUM> that leads the PWC <NUM> to the set destination based on the map data. In block <NUM>, the current heading of the PWC <NUM> may be compared to the target heading of the PWC <NUM> to determine an error <NUM> therebetween. The error <NUM> may indicate if and how far the PWC <NUM> has veered off course from the navigation target.

In block <NUM>, an EAD torque <NUM> to apply to the steering system <NUM> to course correct the PWC <NUM> may be determined based on the comparison. In particular, the autopilot module <NUM> may be configured to apply the determined error <NUM> to a control algorithm <NUM> implemented by the autopilot module <NUM>, which may include a PID algorithm. The control algorithm <NUM> may be configured to calculate a correction that minimizes the error <NUM>. Specifically, the control algorithm <NUM> may be configured to determine a target angle for the steering system <NUM> to adjust the PWC <NUM> from the current heading to the target heading, and thereby reduce the error <NUM>, such as based on the steering control data <NUM>, which may define a lookup table associating each of various errors <NUM> with a different target angle for the steering system <NUM>. The control algorithm <NUM> may then be configured to determine an EAD torque <NUM> that indicates an amount and direction of torque to apply to the steering column <NUM> by the EAD <NUM> to reduce the error <NUM>, and thereby put the PWC <NUM> back on course. The control algorithm <NUM> may be configured to determine the EAD torque <NUM> based on the steering control data <NUM>, which may define a lookup table that associates each of various target angles of the steering system <NUM> with a value for the EAD torque <NUM>, or more particularly with an electrical current level to apply to the motor <NUM> of the EAD <NUM> to cause the EAD <NUM> to apply that value for the EAD torque <NUM> to the steering system <NUM>.

In block <NUM>, the EAD <NUM> may be operated to apply the EAD torque <NUM> to the steering system <NUM>. Specifically, responsive to generating the EAD torque <NUM>, the autopilot module <NUM> may be configured to communicate a command signal to the EAD <NUM> that, upon receipt by the EAD <NUM>, causes the EAD <NUM> to apply the EAD torque <NUM>. More particularly, the ECU <NUM> may be configured to cause an electrical current level to be supplied to the motor <NUM> that in turn causes the motor <NUM> to apply the EAD torque <NUM> to the steering system <NUM>. Application of the EAD torque <NUM> onto the steering system <NUM> by the EAD <NUM> may cause a course correcting turn of the PWC <NUM> in accordance with the navigation target <NUM>.

As illustrated in the method <NUM> of <FIG> and the processing architecture <NUM> of <FIG>, the ECU <NUM> may be configured to repeat performance of a control loop that adjusts the EAD torque <NUM> applied to the steering system <NUM> to provide course correction based on updated geographic data <NUM> of the PWC <NUM> and the navigation target <NUM>. As a result, the method <NUM> and the processing architecture <NUM> may provide drivers with improved steering control by reducing their involvement in course correction and reducing steering overshoots, which can be a frequent consequence of the lack of resistive steering and of the low-resolution steering of a typical PWC. In some examples, the ECU <NUM> may be configured to deactivate the autopilot module <NUM>, and thus deactivate the autopilot functionality, responsive to receiving a deactivation input from the driver via the HMI <NUM>, and/or responsive to rotation of the handle <NUM> and/or an activation of the throttle <NUM> greater than a respective threshold, which may be detected by the ECU <NUM> based on the operational data generated by the sensors <NUM>.

Referring to <FIG> and <FIG>, as the nozzle <NUM> pivots away from the longitudinal axis of the PWC <NUM> responsive to a rotation of the handle <NUM> to perform a turn, the jet stream formed by the nozzle <NUM> may cause a hull <NUM> of the PWC <NUM> to lean in towards the turn. The hull's <NUM> geometry, which may include ridges or other fixed control surfaces, may interact with the water on the inside the turn, and may be shaped to effect turning of the PWC <NUM> under the power of the jet stream. To further enhance the turning ability of the PWC <NUM>, the steering system <NUM> of the PWC <NUM> may include control surfaces <NUM> positioned at opposed ends of an aft portion of the PWC <NUM> on each side of the nozzle <NUM>. These control surfaces <NUM> may likewise be configured to interact with the water responsive to a rotation of the handle <NUM> to facilitate a turn. The control surfaces <NUM> may be shaped to affect a faster turn, thereby improving reactivity of the PWC <NUM> to steering input, especially at higher speeds.

As shown in <FIG> and <FIG>, the control surfaces <NUM> may be mechanically coupled to the handle <NUM> via the steering column <NUM>, gearbox <NUM>, and supplemental push-pull cables <NUM>. Responsive to a rotation of the handle <NUM> to effect a turn of the PWC <NUM>, the gearbox <NUM> may be configured, such as based on the rotation of the steering column <NUM> caused by the rotation of the handle <NUM>, to cause the control surface <NUM> on the inside of the turn to lower into the water, such as by applying a force on the supplemental push-pull cable <NUM> coupled to the control surface <NUM> on the inside of the turn. Responsive to the handle <NUM> returning to a center position, the gearbox <NUM> may be configured to cause the control surface <NUM> on the inside of the turn to raise from the water, such as by applying an opposite force on the supplemental push-pull cable <NUM> coupled to the control surface <NUM> on the inside of the turn.

For instance, responsive to a rotation of the handle <NUM> to the right from a center position, the gearbox <NUM> may be configured to apply a push force onto the supplemental push-pull cable 554B, which may responsively apply a push force onto a proximal end of the control surface 552B, and thereby pivot a distal end of the control surface 552B into the water. Similarly, responsive to a rotation of the handle <NUM> to the left from the center position, the gearbox <NUM> may be configured to apply a push force onto the supplemental push-pull cable 554A, which may responsively apply a push force onto a proximal end of the control surface 552A, and thereby pivot a distal end of the control surface 552A into the water. During high speeds, the control surfaces <NUM> may cause the PWC <NUM> to lean faster and sooner towards a turn, which improves the contact between the hull <NUM> and the water on inside of the turn, and causes the PWC <NUM> to start turning sooner. Responsive to the handle <NUM> being returned to the center position from the right or left, the gearbox <NUM> may be configured to apply a pull force on the supplemental push-pull cable 554B or the supplemental push-pull cable 554A respectively, which may then apply a pull force to and correspondingly lift the control surface 552B or the control surface 552A respectively.

The operation of the control surfaces <NUM> via the supplemental push-pull cables <NUM> may increase resistive load on the steering system <NUM>, or more particularly the steering column <NUM> and the handle <NUM>, during a turn. To avoid driver fatigue resulting from this additional resistive load, responsive to a driver beginning a turn that causes a control surface <NUM> to be lowered into the water, the EAD <NUM> may be configured to apply torque to the steering column <NUM> in the same direction as the driver's torque applied via the handle <NUM>. In this way, the EAD <NUM> may assist the driver in overcoming the resistive force caused by the control surfaces <NUM>.

The control surfaces <NUM>, which may have a fin-like structure, may also improve maneuverability of the PWC <NUM> in the absence of thrust being provided by an active jet stream. Specifically, while rotating the handle <NUM> in the absence of activation of the throttle <NUM> may cause the nozzle <NUM> to pivot relative to the longitude axis of the PWC <NUM>, because no jet stream is being produced by the nozzle <NUM>, the hull <NUM> may not lean into the water to effect the turn. Each of the control surfaces <NUM>, however, may function as a rudder when inserted into the water. For example, the control surface 552A may be structured and angled to bias the PWC <NUM> left when lowered into the water, and the control surface 552B may be structured and angled to bias the PWC <NUM> right when lowered into the water. The control surfaces <NUM> may thus improve maneuverability of the PWC <NUM> by enabling the PWC <NUM> to be biased (or steered) left and right in the absence of an active jet stream.

Referring to <FIG>, rather than being mechanically coupled to the handle <NUM>, the control surfaces <NUM> may be electrically coupled to the handle <NUM>, such as via the ECU <NUM>. Specifically, referring to <FIG>, each of the control surfaces <NUM> may be mechanically coupled to a respective actuator <NUM>. Each actuator <NUM> may be electrically coupled to and configured to receive command signals from the ECU <NUM>, such as wirelessly or via a respective electrical wire <NUM>. Responsive to receiving a command signal from the ECU <NUM>, each actuator <NUM> may be configured to lower or raise the respective control surface <NUM> coupled to the actuator <NUM> into and out of the water as appropriate.

As shown in the illustrated examples, the actuators <NUM> may be positioned in the aft of the PWC <NUM> near the control surfaces <NUM>. Alternatively, the actuators <NUM> may be located elsewhere in and/or be integrated with another component of the PWC <NUM>, such as the gearbox <NUM> or EAD <NUM>, and may be mechanically coupled to the control surfaces <NUM> using the push-pull cables <NUM> as described above.

<FIG> illustrates a method <NUM> for actuating the control surfaces <NUM> to enhance steering of the PWC <NUM>, as described above. The ECU <NUM> may be configured to perform the method <NUM>, such as via execution of the computer-executable instructions embodying the active steering application <NUM>.

In block <NUM>, a determination may be made of whether the handle <NUM> has been rotated to perform a turn. For example, the ECU <NUM> may be configured to monitor for a rotation of the handle <NUM>, such as based on operational data received from the sensors <NUM> indicating a rotation of the handle <NUM> (e.g., data generated by a steering angle sensor).

Responsive to identifying a rotation ("Yes" branch of block <NUM>), in block <NUM>, a determination may made of whether one or more conditions exist to support actuation of the control surfaces <NUM>. The ECU <NUM> may be configured to identify whether these one or more conditions exist from the operational data generated by the sensors <NUM>. For instance, the ECU <NUM> may be configured to determine whether the speed of the PWC <NUM> is greater than a threshold speed based on the operational data, which may increase the effectiveness of the control surfaces <NUM>. In addition or alternatively, the ECU <NUM> may be configured to determine whether the extent of the driver's actuation of the throttle <NUM> is greater than or equal to a threshold throttle level based on the operational data.

Responsive to determining that the one or more conditions do not exist ("No" branch of block <NUM>), in block <NUM>, actuation of the control surfaces <NUM> may be deactivated. For instance, when the coupling between the handle <NUM> and the control surfaces <NUM> is electrical, the ECU <NUM> may be configured to raise the control surfaces <NUM> (if lowered) via control signals to the actuators <NUM>, and to prevent actuation of the control surfaces <NUM> by not transmitting command signals to the actuators <NUM> coupled to the control surfaces <NUM>. When the coupling between the handle <NUM> and control surfaces <NUM> is purely mechanical, the ECU <NUM> may similarly be configured to raise the control surfaces <NUM> (if lowered) by applying a force, such as a pull force, onto the supplemental push-pull cables <NUM>, and to prevent actuation of the control surfaces <NUM> by disconnecting the mechanical coupling. For instance, the gearbox <NUM> may include at least one motor that is configured, based on command signals received from the ECU <NUM>, to effect raising the control surfaces <NUM> (if lowered) via interaction with the supplemental push-pull cables <NUM>, and to mechanically disengage the steering column <NUM> from the supplemental push-pull cables <NUM>. Hence, responsive to determining that the one or more conditions do not presently exist ("No" branch of block <NUM>), in block <NUM>, the ECU <NUM> may be configured to transmit a signal to the one or more motors that causes the motor to raise the control surfaces <NUM> and mechanically disengage the steering column <NUM> from the supplemental push-pull cables <NUM>.

Responsive to determining that the one or more conditions do exist ("Yes" branch of block <NUM>), in block <NUM>, the control surfaces <NUM> may be activated. For instance, responsive to determining that the one or more conditions do presently exist, the ECU <NUM> may be configured to permit the transmission of control signals to the actuators <NUM> (if the control surfaces <NUM> are electrically coupled to the handle <NUM>), or may be configured to transmit a signal to the mechanical coupling motor that causes the motor to mechanically couple the control surfaces <NUM> to the handle <NUM> (if the control surfaces <NUM> are configured to be mechanically coupled to the handle <NUM>).

In block <NUM>, a determination may be made of the direction of the rotation of the handle <NUM>. For instance, the ECU <NUM> may be configured to determine whether the handle <NUM> is rotated left or right based on the angle of the handle <NUM> indicated by the operational data generated by the steering angle sensor of the PWC <NUM>. Responsive to determining that the handle <NUM> is rotated left ("Left" branch of block <NUM>), in block <NUM>, the right control surface 552B may be raised (if not already raised), and in block <NUM>, the left control surface 552A may be lowered (if not already lowered). Alternatively, responsive to determining that the handle <NUM> is rotated right ("right" branch of block <NUM>), in block <NUM>, the left control surface 552A may be raised (if not already raised), and in block <NUM>, the right control surface 552B may be lowered (if not already lowered).

Thus, the PWC <NUM>, or more particularly, the ECU <NUM>, may be configured to lower the control surface 552A into water responsive to a rotation of the handle <NUM> in one direction and to a determination that one or more conditions exists, such as the speed of the PWC <NUM> being greater than a predefined threshold speed. The ECU <NUM> may similarly be configured to lower the control surface 552B into the water responsive to a rotation of the handle <NUM> in another direction opposite the one direction and to a determination that the one or more conditions exist. In alternative examples, block <NUM> may be omitted such that the ECU <NUM> is configured to lower and raise the control surfaces <NUM> responsive to rotation of the handle <NUM> alone. In addition, if the control surfaces <NUM> are mechanically coupled to the handle <NUM>, the determination of block <NUM> may be performed by the gearbox <NUM> rather than the ECU <NUM> by virtue of the gearbox <NUM> being configured to mechanically translate left and right rotations of the handle <NUM> to forces that raise and lower the control surfaces <NUM> appropriately as described above.

When the control surfaces <NUM> are mechanically coupled to the handle <NUM> via the supplemental push-pull cables <NUM>, lowering any one of the control surfaces <NUM> may increase the resistive load on the steering column <NUM> and the handle <NUM> during a turn. Thus, in block <NUM>, the EAD <NUM> may be operated to apply assistive torque to the steering system <NUM>, or more particularly to the steering column <NUM>, to prevent driver fatigue resulting from this additional resistive load. Specifically, the ECU <NUM> may be configured to operate the EAD <NUM> to apply torque to the steering system <NUM> in a direction corresponding to the rotation of the handle <NUM>. In other words, the ECU <NUM> may be configured to apply a torque to the steering system <NUM> in one direction responsive to a rotation of the handle <NUM> in the one direction, and to apply the torque to the steering system <NUM> in another direction opposite the one direction responsive to the rotation of the handle <NUM> in the another direction. In this way, the EAD <NUM> may assist the driver in overcoming the resistive force caused by the control surfaces <NUM>.

Providing an electrical rather than a mechanical coupling between the handle <NUM> and the control surfaces <NUM> may lessen the resistive load applied to the handle <NUM> by the control surfaces <NUM>, which may avoid the need for the EAD <NUM> to apply torque to the steering column <NUM> that assists the driver in rotating the handle <NUM>. However, installation of an actuator <NUM> on the PWC <NUM> for each control surface <NUM> may increase the weight of the PWC <NUM>, which may adversely affect its overall speed and maneuverability capabilities.

In some examples, rather than the control surfaces <NUM> being automatically actuated on turns, the control surfaces <NUM> may be manually actuated by a user during turns, such as via user interaction with the HMI <NUM>. For example, a driver may interact with the HMI <NUM> to input an actuation signal for one of the control surfaces <NUM> to the ECU <NUM>, which in turn may transmit a command signal to the actuator <NUM> coupled to the control surface <NUM> to cause the control surface <NUM> to lower into and raise from the water.

Responsive to lowering one of the control surfaces <NUM> into the water to better effect a turn (block <NUM> or block <NUM>), and possibly to operating the EAD <NUM> to apply assistive torque on the steering system <NUM> (block <NUM>), the method <NUM> may return to block <NUM> to determine whether the handle <NUM> continues to be rotated, and so on. If the handle <NUM> is returned to center position ("No" branch of block <NUM>), or one of the one or more conditions of block <NUM> ceases to exist ("No" branch of block <NUM>), then in block <NUM>, the control surfaces <NUM> may be deactivated as described above. The method <NUM> may then return to block <NUM>.

PWCs including enhanced steering control are described herein. In one example, a PWC may include a driving control system coupled to a steering system of the PWC and configured to apply a torque to the steering system based on electrical signals received from an ECU. During operation of the PWC, the driving control system may be configured to implement enhanced steering functions, such as an active damper, regulated based on various operational parameters monitored by the ECU. The enhanced steering functions may install greater confidence in the driver, provide better steering control, and avoid potentially dangerous maneuvers.

In general, the routines executed to implement the embodiments of the invention, whether implemented as part of an operating system or a specific application, component, program, object, module or sequence of instructions, or even a subset thereof, may be referred to herein as "computer program code," or simply "program code. " Program code typically comprises computer readable instructions that are resident at various times in various memory and storage devices in a computer and that, when read and executed by one or more processors in a computer, cause that computer to perform the operations necessary to execute operations and/or elements embodying the various aspects of the embodiments of the invention. Computer readable program instructions for carrying out operations of the embodiments of the invention may be, for example, assembly language or either source code or object code written in any combination of one or more programming languages.

Various program code described herein may be identified based upon the application within that it is implemented in specific embodiments of the invention. However, it should be appreciated that any particular program nomenclature that follows is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature. Furthermore, given the generally endless number of manners in which computer programs may be organized into routines, procedures, methods, modules, objects, and the like, as well as the various manners in which program functionality may be allocated among various software layers that are resident within a typical computer (e.g., operating systems, libraries, API's, applications, applets, etc.), it should be appreciated that the embodiments of the invention are not limited to the specific organization and allocation of program functionality described herein.

The program code embodied in any of the applications/modules described herein is capable of being individually or collectively distributed as a program product in a variety of different forms. In particular, the program code may be distributed using a computer readable storage medium having computer readable program instructions thereon for causing a processor to carry out aspects of the embodiments of the invention.

Computer readable storage media, which is inherently non-transitory, may include volatile and non-volatile, and removable and non-removable tangible media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. Computer readable storage media may further include RAM, ROM, erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other solid state memory technology, portable compact disc read-only memory (CD-ROM), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and which can be read by a computer. A computer readable storage medium should not be construed as transitory signals per se (e.g., radio waves or other propagating electromagnetic waves, electromagnetic waves propagating through a transmission media such as a waveguide, or electrical signals transmitted through a wire). Computer readable program instructions may be downloaded to a computer, another type of programmable data processing apparatus, or another device from a computer readable storage medium or to an external computer or external storage device via a network.

Computer readable program instructions stored in a computer readable medium may be used to direct a computer, other types of programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions that implement the functions, acts, and/or operations specified in the flowcharts, sequence diagrams, and/or block diagrams. The computer program instructions may be provided to one or more processors of a general purpose computer, a special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the one or more processors, cause a series of computations to be performed to implement the functions, acts, and/or operations specified in the flowcharts, sequence diagrams, and/or block diagrams.

In certain alternative embodiments, the functions, acts, and/or operations specified in the flowcharts, sequence diagrams, and/or block diagrams may be re-ordered, processed serially, and/or processed concurrently consistent with the scope of the general inventive concept as defined by the claims. Moreover, any of the flowcharts, sequence diagrams, and/or block diagrams may include more or fewer blocks than those illustrated consistent with the scope of the general inventive concept as defined by the claims.

Claim 1:
A personal watercraft (<NUM>) comprising:
a jet powered propulsion system (<NUM>);
a steering system (<NUM>) coupled to the jet powered propulsion system (<NUM>) and including a handle (<NUM>) for adjusting an angle of the jet powered propulsion system (<NUM>) relative a longitudinal axis of the personal watercraft; and
a driving control system (<NUM>) coupled to the steering system (<NUM>), the driving control system (<NUM>) comprising:
an electrically actuated device (<NUM>) coupled to the steering system (<NUM>) for applying torque to the steering system (<NUM>);
at least one sensor (<NUM>) positioned adjacent the steering system (<NUM>) that generates operational data of the personal watercraft; and
at least one controller (<NUM>) coupled to the electrically actuated device (<NUM>) and the at least one sensor (<NUM>), the at least one controller (<NUM>) configured to:
responsive to a rotation of the handle (<NUM>), determine an angle and a speed of the rotation of the handle (<NUM>) based on the operational data;
determine a first torque to apply to the steering system (<NUM>) based on the angle and the speed of the rotation of the handle (<NUM>); and
operate the electrically actuated device (<NUM>) to apply the first torque to the steering system (<NUM>) during the rotation of the handle (<NUM>) in a direction that is opposite the rotation of the handle (<NUM>) for providing enhanced steering control of the personal watercraft, with the first torque being applied only by the electrically actuated device (<NUM>).