SYSTEM, METHOD AND APPARATUS FOR CONTROLLING A SPEED OF A SAILING VESSEL

Abstract

Embodiments of the present invention are directed to system, method and apparatus for controlling the speed of a sailing vessel. The speed of a sailing vessel is controlled by varying a force of a cam follower against a perimeter of a cam mounted to either a rotatable mast, or a rotatable sleeve concentrically mounted to a fixed mast, of the sailing vessel. In some embodiments, an onboard control unit determines conditions such as vessel speed, weather conditions, threats, etc. and automatically causes a sailing vessel to achieve predetermined vessel speeds based on the determined conditions.

Claims

1. A system for controlling a speed of a sailing vessel, comprising: a cam mounted to a portion of a wing of the sailing vessel; an adjustable tensioner assembly, comprising: a base housing; an actuator located within the base housing; and a movable extension arm comprising a first end in contact with the actuator inside the base housing and a second end external to the base housing, comprising a cam follower in contact with the cam; and a control unit configured to adjust a force created by the actuator against the movable extension arm and transfer the force via the movable extension to the cam follower against the cam.

2. The system of claim 1, wherein the actuator comprises a linear actuator controlled directly by the control unit.

3. The system of claim 1, wherein the control unit is configured to control the speed of the sailing vessel by varying the force of the cam follower against the cam via the actuator.

4. The system of claim 1, further comprising: a speed sensor coupled to the control unit configured to determine the speed of the sailing vessel; wherein the control unit is further configured to compare the speed of the sailing vessel with one or more predetermined speeds stored in the memory, and to adjust the force of the actuator against the movable extension arm, and thereby the cam follower against the cam, in accordance with changes in the speed of the sailing vessel.

5. The system of claim 4, wherein a plurality of predetermined, desired vessel speeds are stored in the memory, each vessel speed associated with a particular vessel maneuver, and the control unit is further configured to determine that a first vessel maneuver should be performed, to determine a first vessel speed associated with the first vessel maneuver, determine a current speed of the sailing vessel from the speed sensor, and to cause the actuator to alter the force of the actuator against the movable extension arm, and thereby the force of the cam follower against the cam.

6. The system of claim 5, wherein the control unit is further configured to monitor the speed of the sailing vessel via the speed sensor and to cause the actuator to alter the force of the actuator against the movable extension arm, and thereby the force of the cam follower against the cam, in order to maintain the first predetermined speed.

7. The system of claim 5, wherein the plurality of vessel speeds comprises a first variable vessel speed to achieve a first vessel maneuver, and the control unit is further configured to adjust the speed of the sailing vessel in accordance with the first variable vessel speed by causing the actuator to adjust the force of the actuator against the movable extension arm, and thereby the force of the cam follower against the cam perimeter, over time.

8. The system of claim 7, further comprising a position sensor coupled to the control unit, wherein the first variable vessel speed comprises a first vessel speed and a second vessel speed, and the first vessel maneuver comprises a beaching maneuver, wherein the control unit is configured to: adjust the force of the cam follower against the cam to achieve the first vessel speed; determine a position of the sailing vessel with respect to a beach via the position sensor; and cause the actuator to adjust the force of the cam follower against the cam to achieve the second vessel speed suitable for landing the sailing vessel on the beach when the position of the sailing vessel is at a predetermined distance from the beach.

9. The system of claim 1, further comprising: a wireless receiver coupled to the control unit, configured to wirelessly receive a command to perform a vessel maneuver requiring the sailing vessel to sail at a first speed, and to provide the command to the control unit; wherein the control unit is further configured to alter the speed of the sailing vessel in accordance with the command by causing the actuator to alter the force of the cam follower against the cam perimeter to achieve the first speed.

10. The system of claim 9, wherein the vessel maneuver comprises a dive maneuver where the sailing vessel submerges underwater, the command comprises instructions that causes the sailing vessel to submerge underwater, the first speed comprises a dive speed associated with the dive maneuver and the control unit is configured to cause the actuator to decrease the force of the cam follower against the cam upon receipt of the command, thereby reducing the speed of the sailing vessel to less than the dive speed.

11. A method, performed by an onboard control unit of a sailing vessel, for controlling a speed of the sailing vessel, comprising: determining a current speed of the sailing vessel; determining that a predefined event has occurred; determining a predefined vessel maneuver associated with the predefined event; determining a predefined vessel speed associated with the predefined vessel maneuver; and in response to determining that the predefined event has occurred, causing an actuator of an adjustable tensioner assembly to adjust a force of a cam follower of the adjustable tensioner assembly against a cam mounted to a portion of a wing of the sailing vessel in order to achieve the predefined vessel speed associated with the vessel maneuver.

12. The method of claim 11, further comprising: storing a plurality of predetermined vessel speeds in association with a plurality of predetermined vessel maneuvers, respectfully; after determining that the predefined event has occurred, selecting a first predetermined vessel maneuver to be performed in response to the predefined event; determining a first predetermined vessel speed associated with the first predetermined vessel maneuver; and adjusting the speed of the sailing vessel to the first predetermined vessel speed by causing the actuator to adjust the force of the cam follower against the cam to achieve the first predetermined vessel speed.

13. The method of claim 11, further comprising: continuously comparing the current vessel speed with the predefined vessel speed, and causing the actuator to adjust the force of the cam follower against the cam in accordance with changes in the current speed of the sailing vessel in order to maintain the predefined vessel speed.

14. The method of claim 11, further comprising: comparing the current vessel speed to one or more predetermined speeds stored in the memory; and causing the actuator to adjust the force of the cam follower against the cam to achieve one of the one or more predetermined speeds.

15. The method of claim 12, wherein the plurality of predetermined vessel speeds comprise a first variable vessel speed in association with a second predetermined vessel maneuver, the method further comprising: adjusting the current speed of the sailing vessel in accordance with the first variable vessel speed by causing the actuator to adjust the force of the cam follower against the cam over time, thereby causing a change in the current speed of the sailing vessel over time in accordance with the first variable vessel speed.

16. The method of claim 11, wherein the predefined event comprises a proximity of the sailing vessel to a beach, wherein the predetermined vessel maneuver associated with proximity to a beach comprises a beaching maneuver, whereby adjusting the speed of the sailing vessel to match the predefined vessel speed comprises: determining a first vessel speed and a second vessel speed associated with the beaching maneuver; determining that the sailing vessel is within a first predetermined distance to the beach; causing the actuator to adjust the force of the cam follower against the cam to achieve the first vessel speed when the sailing vessel is within the first predetermined distance to the beach; determining that the sailing vessel is within a second predetermined distance from the beach, closer than the first predetermined distance; and causing the actuator to adjust the force of the cam follower against the cam to achieve the second vessel speed suitable for landing the sailing vessel on the beach.

17. The method of claim 11, wherein the predefined event comprises wirelessly receiving a command to perform a first predefined vessel maneuver, the method further comprising: wirelessly receiving the command; determining a first predetermined vessel speed associated with the first predefined vessel maneuver identified by the command; and causing the actuator to alter the current vessel speed in accordance with the first predetermined vessel speed by causing the actuator to alter the force of the cam follower against the cam to achieve the first predetermined vessel speed.

18. The method of claim 17, further comprising: after achieving the first predetermined vessel speed, causing the sailing vessel to perform the first predefined vessel maneuver in accordance with the command.

19. The method of claim 18, wherein the predefined vessel maneuver comprises a dive maneuver, and altering the current vessel speed in accordance with the first predetermined vessel speed comprises causing the actuator to reduce the force of the cam follower against the cam to achieve the first predetermined vessel speed or less.

20. The method of claim 11, wherein the predefined event comprises detection of a threat to the sailing vessel, the method further comprising: determining the threat to the sailing vessel; determining that a predefined vessel maneuver comprises a dive maneuver to be performed upon determination of the threat; determining a first predetermined vessel speed associated with the dive maneuver; adjusting the speed of the sailing vessel to the first predetermined vessel speed by causing the actuator to adjust the force of the cam follower against the cam; determining when the speed of the sailing vessel is less than or equal to the first predetermined vessel speed; and after achieving the predetermined vessel speed or less, causing the sailing vessel to submerge beneath a water surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The features, advantages, and objects of the present invention will become more apparent from the detailed description as set forth below, when taken in conjunction with the drawings in which like referenced characters identify correspondingly throughout, and wherein:

[0010] FIG. 1 is a perspective view of one embodiment of a submerged sailing vessel, utilizing an automatic, passive, wing-control mechanism;

[0011] FIG. 2 is a close-up, perspective view of a wing as part of the submerged sailing vessel as shown in FIG. 1;

[0012] FIG. 3 is a perspective view of the automatic, passive, wing-control mechanism as shown in FIGS. 1 and 2, viewed at an opposing angle from the view as shown in FIG. 2;

[0013] FIG. 4 is a side view of the automatic, passive, wing-control mechanism as shown in FIGS. 1-3 in use with the wing as shown in FIG. 1;

[0014] FIG. 5 is a top view of the automatic, passive, wing-control mechanism as shown in FIGS. 1-4 located on a deck, with a flange hidden from view in order to better illustrate the relationship between a cam and an opposing end of a tension bar;

[0015] FIG. 6 is a bottom view of one embodiment of the cam as shown in FIG. 5;

[0016] FIG. 7 is a graph, illustrating a radius of half of a dwell profile and a nose profile as a function of an angle from a centerline of the cam as shown in FIGS. 5 and 6;

[0017] FIG. 8 is a graph, illustrating a counter-torque produced by the cam as shown in FIGS. 5 and 6;

[0018] FIG. 9 is a top, plan view of one embodiment of an adjustable tensioner assembly in use with mast 110 of a sailing vessel;

[0019] FIG. 10 is a top, plan view of one embodiment of a system for controlling a speed of a sailing vessel, in use with a mast of a sailing vessel;

[0020] FIG. 11 is a top, plan view of another embodiment of a system for controlling a speed of a sailing vessel, in use with a mast of a sailing vessel;

[0021] FIG. 12 is a top, plan view of yet another embodiment of a system for controlling a speed of a sailing vessel, in use with a mast of a sailing vessel;

[0022] FIG. 13 is a side view of yet still another embodiment of a system for controlling a speed of a sailing vessel, in use with a mast of a sailing vessel;

[0023] FIG. 14 is a side view of yet another embodiment of a system for controlling a speed of a sailing vessel, in use with a mast of a sailing vessel;

[0024] FIGS. 15A, 15B and 15C show three different views of another embodiment of the invention, showing a mast mounted through an elevational cam and a system for controlling a speed of a sailing vessel;

[0025] FIGS. 16A, 16B and 16C show 3 different views of yet another embodiment of the invention, similar to the embodiment shown in FIGS. 15A-C;

[0026] FIG. 17 is a top, plan view of yet another system for controlling the speed of a sailing vessel;

[0027] FIG. 18 is a functional block diagram of one embodiment of a control unit for controlling a speed of a sailing vessel; and

[0028] FIGS. 19A, 19B, and 19C represent a flow diagram illustrating one embodiment of a method for controlling the speed of a sailing vessel.

[0029] It should be understood that the components shown in the figures may not be scaled to size to each other.

DETAILED DESCRIPTION

[0030] Embodiments of the present invention describe systems, methods and apparatus for controlling a speed of a sailing vessel using an automatic wing sail mechanism. In one embodiment, a cam is mounted to a mast of a sailing vessel, and an adjustable tensioner assembly tensioner, comprising a cam follower, which applies a variable force against a cam perimeter. The cam perimeter is shaped to automatically position the mast and associated sail(s) to a desired heading with respect to the apparent wind, for example, 20 degrees. This typically results in achieving a maximum speed of the sailing vessel. The adjustable tensioner assembly is typically set to a desired, initial setting that causes the cam follower to apply a desired force against the cam perimeter. During sailing, as the wind and/or the sailing vessel changes direction, the force applied by the cam follower against the cam perimeter automatically changes, due to the shape of the cam perimeter and the variable force applied by the cam follower against the cam perimeter. The adjustable tensioner assembly may be manually adjusted to achieve a greater, or smaller, force of the cam follower against the cam perimeter. For example, in strong winds, the adjustable tensioner assembly may be manually adjusted to increase the force of the cam follower against the cam perimeter. The increased force inhibits rotation of the mast away from the desired heading. Conversely, in light winds, the adjustable tensioner assembly may be manually adjusted to achieve a smaller force of the cam follower against the cam perimeter. This allows the mast to rotate more freely to achieve the desired heading.

[0031] In another embodiment, a control unit may be used to control the speed of a sailing vessel. The control unit is used alternatively or in addition to manual adjustment of the adjustable tensioner assembly. In this embodiment, the control unit may control the speed of the sailing vessel either by receiving direct commands to achieve a certain speed from remote locations when the sailing vessel is within communication range of a remote location, by receiving commands to perform certain actions (such as to sail at full speed, to submerge, to beach, etc.) or by autonomously determining a desired speed of the sailing vessel depending on conditions sensed by the control unit. For example, while sailing at full speed, the control unit may determine that a storm is approaching and, in response, reduce the speed of the sailing vessel to a desired speed, or to a complete stop. Then, the control unit may cause the sailing vessel to submerge.

[0032] FIG. 1 is a perspective view of one embodiment of a submerged sailing vessel 100, utilizing an automatic, passive, wing-control mechanism 102, herein referred to as mechanism 102. Submerged sailing vessel 100 is a semi-submerged vessel that utilizes wind energy to propel an underwater hull 104 through the water. A detailed description of such a submerged sailing vessel is found in U.S. Pat. No. 10,029,773 entitled, Submerged Sailing Vessel, assigned to the assignee of the present application and incorporated by reference in its entirety herein. A keel 106 extends upward from hull 104 and is attached to wing 108, which is rotatable about mast 110. Wing 108 is shown without a sail, in order to illustrate a series of oblong, ribs 112, parallel and spaced apart from each other and coupled to one another via a leading strut 114 and a trailing strut 116. A hole through each rib 112 allows mast 110 to extend through all of the ribs, so that the ribs, and thus wing 108 are rotatable around mast 110. The perimeter of ribs 112 define a wing shape that is aerodynamically efficient to provide propulsion to hull 104. In one embodiment, the ribs 112 may comprise photovoltaic panels or cells to generate energy for use aboard hull 104. A detailed description of a submerged sailing vessel utilizing such ribs is described in U.S. patent application Ser. No. 16/117,452, entitled Solar Wing System and Apparatus, assigned to the assignee of the present application and incorporated by reference in its entirety herein.

[0033] Submerged sailing vessel 100 may additionally comprise ballast 118 coupled to hull 104 via strut 120 for providing lateral stability to submerged sailing vessel 100, to combat rotational forces caused by the wind as it acts on wing 108. Submerged sailing vessel 100 may additionally comprise thruster 122 to propel submerged sailing vessel 100 in addition to the propulsion provided by wing 108.

[0034] Mast 110 is fixedly mounted to mechanism 102, more particularly shown in FIG. 2. FIG. 2 is a close-up, perspective view of the wing 108 and keel 106 detailing mechanism 102. The lowest-most rib 112, shown in FIG. 1, is not shown in FIG. 2, in order to better view the components of mechanism 102.

[0035] Mechanism 102 comprises a cam 200 and a tensioner 202. Each of these components are located on a surface of deck 204 in this embodiment. However, in other embodiments, mechanism 102 could be located underneath deck 204. While deck 204 is shown in FIG. 2 as a small, rigid platform to support wing 108, in other embodiments, it could comprise a deck of a typical sailboat, catamaran, a paddle board, or some other sailing vessel.

[0036] In one embodiment, cam 200 comprises a sleeve 206 extending perpendicularly from flange 216 that acts as a retainer for mast 108. Flange 216 offers support for a lower-most rib 112 (not shown). In other embodiments, flange 216 is not used, for example, in an embodiment where mechanism 102 is used with a wing comprising a standard mast and sail. In some embodiments, deck 204 comprises a mast mount underneath cam 200, where mast 110 may extend to an underside of deck 204. The mast mount may comprise, simply, a through or partial hole formed into deck 204, or it could comprise a mechanism, such as one or more roller bearings formed into a partial or through hole, a sleeve, etc. In one embodiment, mast 110 is generally free to rotate within the mast hole, but in a fixed relationship to cam 200.

[0037] In one embodiment, cam 200 is rotatable with respect to deck 204, but fixedly attached to mast 110, such that when mast 110 rotates, cam 200 rotates as well. In another embodiment, mast 110 is fixed and does not rotate, wherein cam 200 is mounted to a rotatable sleeve or similar structure concentrically mounted around mast 110, as explained in further detail later herein. Tensioner 202 is used to apply a predetermined force against a surface of cam 200, which helps to generate a counter-torque by mechanism 102 that acts on mast 110 or the sleeve as wing 108 acted on by the wind. When wing 108 is in between approximately +/20 degrees of the apparent wind, no counter-torque is generated by cam 200, and wing 108 is free to move into a position of either +20 degrees or 20 degrees with respect to the apparent wind. Cam 200 is shaped such that as the wind blows wing 108 past either the +20 or 20 degree mark, cam 200 is rotated along with mast 110 or the sleeve causing cam 200 to generate a counter-torque against a torque on mast 110 or the sleeve from the wind acting on wing 108, by the interaction of the force of tensioner 202 against cam 200 at any particular rotational angle of cam 200. The counter-torque is generally constant as cam 200 is rotated further in one direction or the other. The result is that wing 108 remains in an optimal orientation with respect to the apparent wind to propel vessel 100 at a maximum speed.

[0038] Tensioner 202, in the embodiment shown in FIG. 2, comprises a longitudinal tension bar 208 comprising a collar 210 at one end that is rotatably coupled to post 212 extending from deck 204. An opposing end of tension bar 208 (not shown in FIG. 2) is forced against cam 200 with a predetermined force created by mechanical energy storage means 214, such as one or more coil springs, elastic bands, gas struts, or some other mechanical device that applies a tension to tension bar 208, or otherwise provides a spring force against tension bar 208 in a direction that forces the opposing end of tension bar 208 against cam 200. In another embodiment, mechanical energy storage means 214 could comprise a torsion spring applied to the inside of collar 210. In other embodiments, tensioner 202 could comprise a spring-loaded plunger mounted perpendicularly to cam 200 such that the plunger is forced towards cam 200 linearly at a force determined by a spring force of the spring. In one embodiment, tension bar 208 is approximately 188 millimeters long, while a maximum diameter of cam 200 is approximately 83 millimeters, in an embodiment where vessel 100 is relatively small, such as less than 6 feet in length.

[0039] FIG. 3 is a perspective view of mechanism 102 located on deck 204, viewed at an opposing angle from the view shown in FIG. 2. In this view, the opposing end 300 is of tension bar 208 is forced against a cam wall 302 of cam 200, the perimeter of cam wall 302 referred to herein as a cam profile. In one embodiment, opposing end 300 comprises a roller bearing, or some other friction-reducing mechanism, such as a ball bearing or a low-friction material such as polytetrafluoroethylene, commonly known as Teflon. Mast 110 is fixed with respect to rib 112 (acting as a portion of a frame of wing 108) while cam 200 is fixedly mounted to sleeve 206 and sleeve 206 is concentrically mounted over mast 110 as shown, i.e., cam 200 is rotated by sleeve 206 as wing 108 is rotated by the wind. In this embodiment, mast 110 is shown extending through cam 200 and deck 204, protruding from an underside of deck 204.

[0040] FIG. 4 is a side view of mechanism 102 in use with wing 108, where wing 108 comprises the structure shown in FIG. 1. It should be understood that the wing could, alternatively, comprise a standard, prior-art mast having a boom and one or more sails attached. Flange 216 is shown as part of sleeve 206 and cam 200 is affixed to flange 216, while mast 110 is fixed and not free to rotate. Flange 216 is shown fixedly attached to an underside of rib 112 so that cam 200 is rotated as wing 108 rotates about mast 110 when a wind acts on wing 108. It should be understood that in some embodiments, sleeve 206 is not used, and mast 110 extends through a retainer formed longitudinally through cam 200 and secured therein by one or more standard retainers, such as bolts, rivets or screws. In one embodiment, the retainer comprises, simply, a through hole, while in other embodiments, the retainer comprises a sleeve.

[0041] FIG. 5 is a top view of mechanism 102 located on deck 204, with flange 216 hidden from view in order to better illustrate the relationship between cam 200 and, more specifically, cam wall 302 and opposing end 300 of tension bar 208. As described earlier, opposing end 300 of tension bar 208, shown as comprising a roller bearing, is forced against cam wall 302 via mechanical energy storage means 214. The cam wall or profile 302 is configured to create a constant or near-constant counter-torque against mast 110 or sleeve 206, as the case may be, as wing 108 is rotated by the wind, thereby rotating cam 200 in relation to opposing end 300. Cam profile 302 comprises a nose portion and a dwell portion, described later herein. Cam 200 further comprises a mast retaining hole 500, shown as a hole formed longitudinally through cam 200, sized and shaped to receive mast 110 and configured to fixedly secure mast 110 therein. Ring bearing 502 may be included, defining a bottom surface of cam 200, which allows cam 200 to rest on top of deck 204 and rotate with very little friction.

[0042] FIG. 6 is a bottom view of one embodiment of cam 200. As before, in this embodiment, cam 200 comprises mast retaining hole 500, ring bearing 502, flange 216, and a cam profile 302 defined by a dwell portion 600, formed between point 602 to 604 along the cam profile, and a nose portion 606 extending from point 602 counter-clockwise around the cam profile to point 606. Nose portion 606 may be referred to as comprising two, symmetrical half profiles, i.e., a left nose profile 608 extending from point 602 to nose tip 612, and a right nose profile 610 extending from point 604 to nose tip 612. Dwell portion 600 may be defined by a dwell angle 622 formed from center point 620 to each of points 602 and 604, representing a no-go point of sail, as will be explained later herein. A plurality of holes 614 may be formed through cam 200 in order to make cam 200 lighter and to reduce material cost.

[0043] Dwell portion 600 is defined as having a constant radius 618 from a center point 620 of mast retaining hole 502. As such, cam 200 does not generate a counter-torque against mast 110 when opposing end 300 of tension bar 208 is in contact with cam wall 302 as cam 200 is rotated against opposing end 300 along dwell portion 600. Tension bar 208 is in contact with dwell portion 600 when wing 108 of vessel 100 is oriented at an angle in a no-go point of sail, i.e., a range of directions or angles into which a sailing vessel cannot sail. Sailing vessels cannot sail directly into the wind, nor on a course that is too close to an apparent wind. In the no-go zone, a vessel's wing ceases to produce enough drive to maintain forward momentum and, therefore, the vessel slows down towards a stop and steering becomes progressively less effective at controlling a direction of travel. The span of the no-go zone varies among sailing vessels, depending on the design of the vessel, its rig, and its sails, as well as on the wind strength and the sailing conditions (i.e., presence of currents, waves, etc.). The no-go zone may be from 18 to 50 degrees either side of the wind, or a 36 to 100 degree area centered on the apparent wind direction.

[0044] Nose portion 606 is defined as having a radius that varies from center point 620 to produce a counter-torque equal and opposite to a torque created by mast 110 as wind acts on wing 108. The magnitude of the counter-torque is dependent on the amount of force applied by tensioner 202 and the slope of the nose profile 608 at a contact point between the nose profile and opposing end 300. In one embodiment, two constants P2 and P3 are defined and used to determine a radius of nose profile 608 with respect to an angle from a centerline 624 of cam 200. In one embodiment, the radius at each angle between 0 and 180 degrees is determined, representing left nose profile 608 or right nose profile 610. The radius at each angle may be calculated as P3 multiplied by the particular angle under consideration, plus P2, plus the radius calculated at a previous angle, for any angle greater than an angle at which point 602 or 604 is located from centerline 624. For example, if P3 is chosen to be 0.000216440264194842 and P2 is chosen to be 0.192417834295711, and the radius of dwell portion 600 is chosen to be 15 millimeters, then the radius will be 15.56297 millimeters at an angle 23 degrees from centerline 624, on either the left nose profile 608 or the right nose profile 610. Once the radius has been defined for both nose profiles, a counter-torque value can be calculated at each angle using the spring constant of the selected mechanical energy storage means 214, an angle at which tension bar 208 rests against the nose profile, and a length of tension bar 208. P2 and P3 are chosen such that a counter-torque between successive angles is minimized.

[0045] FIG. 7 is a graph, illustrating the radius of half of dwell profile 600 and one of the nose profiles as a function of an angle from centerline 624. As expected, the radius between 0 and 20 degrees (representing point 602 or 604) is constant, at 15 millimeters. 20 degrees is selected to represent a minimum angle at which vessel 100 can sail into an apparent wind before entering a no-go point of sail. The radius then increases linearly, reaching a radius of approximately 42.3 millimeters at 180 degrees.

[0046] FIG. 8 is a graph, illustrating a counter-torque produced by cam 200 against either mast 110 or sleeve 206, as the case may be, as cam 200 is rotated by wing 108 in a single direction (i.e., clockwise) as the wind acts on wing 108. As shown, the counter-torque is zero when wing 108 is within the no-go point of sail, between 0 and 20 degrees, and then jumps to a value of about 0.43 Newton-meters at 21 degrees, increasing to about 0.5 Newton-meters at about 80 degrees, and remaining at about 0.5 Newton-meters for the remainder of the curve. The counter-torque is calculated using the force of opposing end 300 against cam 200 at each angle and multiplying by the cam radius at each angle. A plurality of differential counter-torque values may be calculated by subtracting successive counter-torque values from each other, and then squaring each differential counter-torque value to determine an error curve that indicates how close the counter-torque curve is to being constant. P2 and P3 may be adjusted in order to arrive at an error curve that most closely resembles a constant counter-torque.

[0047] A spreadsheet may be constructed in order to determine the nose and dwell profiles, to calculate various metrics such as a radius of the nose and dwell profiles at each angle of rotation of cam 200 in relation to centerline 624. A representative portion of such a spreadsheet is shown below:

TABLE-US-00001 Moment R* Slope err const Arm Spring (Counter- Mom Angle R dR sindalpha (deg) RS RS err{circumflex over ()}2 Angle Force Torque) Err{circumflex over ()}2 30 16.86 0.185925 0.29440 32.273 544.42 0.70177 0.4924 18.64 49.747 2.545E06 2.829E06 31 17.05 0.185708 0.29764 31.961 545.08 0.66347 0.4402 18.83 49.807 2.414E06 2.683E06 32 17.24 0.185492 0.30088 31.653 545.71 0.62642 0.3924 19.02 49.866 2.289E06 2.545E06

[0048] Where: [0049] Angle=the angle of cam 200 with respect to centerline 624 [0050] R=the radius of dwell portion 600, left nose profile 608 or right nose profile 610, depending on the Angle. Calcuated as P3 multiplied by the Angle, plus P2 plus the previous Angle [0051] dR=the derivative of the Radius, i.e., the difference between successive Radius values [0052] R*SindAlpha=the Radius multiplied by the sine of dR [0053] Slope=the slope of the cam profile at each Angle, calculated as the arctangent of R*SindAlpha and dR, in degrees [0054] RS=the Radius multiplied by the Slope [0055] err const RS=the difference between successive RS values [0056] err{circumflex over ()}2=the square of the err const RS [0057] ArmAng=the angle of tension bar 208 with respect to the horizontal, calculated as the arctangent of the length of tension bar 208 and the Radius, in degrees [0058] Spring Force=force created by mechanical energy storage means 214 against dwell/nose profile at each particular ArmAng [0059] Moment (counter-torque)=Counter-torque produced against mast 110 as mast 110 [0060] rotates cam 200 at each angle relative to centerline 624, calculated by multiplying the Spring Force by the sine of the Slope (in radians), and then multiplying by the Angle divided by 1000. [0061] Momerr{circumflex over ()}2=is the difference between successive Moments, squared

[0062] The following variables are entered into the spreadsheet: [0063] P2/P3 [0064] A torque/force of mechanical energy storage means 214 [0065] A length of tension bar 208

[0066] A mechanical energy storage means 214 start angle

[0067] The spreadsheet varies the parameters P2 and P3 (which determine the progression of the cam slope) to try to minimize the Momerr{circumflex over ()}2. In other words, the terms (P2, P3) are adjusted to produce the least change in the cam torque over the whole angle range (except the 0-20 degree constant segment).

[0068] The size and shape of the various components that make up mechanism 102, i.e., cam 200, tensioner bar 208, and mechanical energy storage means 214 all contribute to the counter-torque. Thus, the size and shape of the components are selected in order to achieve a desired counter-torque to keep wing 108 orientated to a desired point of sail, such as between 20 and 22 degrees on either side of the apparent wind. The torque produced by mast 110 is related to the size and shape of wing 108. Generally, as the size of wing 108 increases, the counter-torque necessary to oppose the torque increases. To increase the counter-torque, nose profile 608 and 610 may require a steeper profile, a shorter tension bar 208, and/or a greater spring force of mechanical energy storage means 214 than what is shown in FIG. 6. Similarly, to decrease the counter-torque, nose profile 608 and 610 may comprise a gentler profile, a longer tension bar 208, and/or a weaker spring force of mechanical energy storage means 214 than what is shown in FIG. 6.

[0069] FIG. 9 is a top, plan view of one embodiment of adjustable tensioner assembly 900 in use with, in one embodiment, a sleeve 206 is rotatably coupled to mast 110 of a sailing vessel. In other embodiments, sleeve 206 is not used, in an embodiment where mast 100 is rotatable with respect to deck 204. Refence to either embodiment is show hereafter as sleeve 206/mast 110. Sleeve 206 is the same or similar to sleeve 206 as shown in FIG. 2 and described earlier herein and is typically part of wing 108 (i.e. part of rib 112 as shown in FIG. 4) or coupled thereto (also shown in FIG. 4), rotating along with wing 108 about mast 110. In some embodiments, sleeve 206 may comprise a friction-reduction means (not shown) located on an interior surface of sleeve 206 for reducing friction between sleeve 206 and mast 110. Such friction-reduction means may comprise a number of ball bearings, grease, low-friction material such as Teflon, etc. While the following description discusses the use of sleeve 206 as a means for allowing wing 108 to rotate around mast 110, in other embodiments, alternative mechanical structures could be used instead, such as a series of rings or bands concentrically surrounding portions of mast 110, a portion of a frame of wing 108, etc.

[0070] Sleeve 206 is shown in FIG. 9 concentrically surrounding a portion of mast 110. For clarity, wing 108 is not shown. In this embodiment, sleeve 206 is placed through hole 500 of cam 200, best shown in FIG. 4, so that cam 200, and therefore wing 108, rotates about mast 110 after sleeve 206 has been placed into mast 110. In another embodiment, cam 200 is part of either sleeve 206 or flange 216. In embodiments where sleeve 206 is not used, i.e., in embodiments where mast 110 is freely rotatable, cam 200 is mounted to mast 110 such that cam 200 rotates along with mast 110.

[0071] Adjustable tensioner assembly 900 is shown, comprising a housing 901, an adjustable force mechanism 902, an adjustment mechanism 904, retractable arm 906, and a cam follower 908. Retractable arm 906 is coupled at one end to adjustable force mechanism 902 while the opposing end comprises follower 908 in contact with a perimeter wall of cam 200. Adjustable force mechanism 902 is shown in this embodiment as a coil spring however, in other embodiments, adjustable force mechanism 902 may comprise one or more elastic bands, hydraulic struts, pneumatic struts or some other mechanical or electro-mechanical device that is capable of applying a force to retractable arm 906. In other embodiments, adjustable force mechanism 902 may comprise a combination of elements, such as a coil spring with one and coupled to an internal piston or plunger that is, in turn, coupled to retractable arm 906. In one embodiment, adjustable tensioner assembly 900 is approximately 188 millimeters long, while a maximum diameter of cam 200 is approximately 83 millimeters, in an embodiment where vessel 100 is relatively small, such as less than 6 feet in length.

[0072] The force applied by adjustable force mechanism 902 to retractable arm 906 is dependent, in this embodiment, on an amount of compression of adjustable force mechanism 902. Compression of adjustable force mechanism 902 may be adjusted using adjustment mechanism 904, comprising, in this example, a threaded post 910 threaded onto a threaded hole 912 in an end portion 914 of housing 901. Threaded post 910 is coupled to one end of adjustable force mechanism 902, while the other end is coupled to a knob 916. Knob 916 is used to manually adjust the tension of adjustable force mechanism 902 as post 910 moves with respect to housing 901 as knob 916 is turned by a person onboard the sailing vessel.

[0073] Although not shown, housing 901 is coupled to a fixed portion of the sailing vessel in order to hold adjustable tensioner assembly 900 securely in place. Housing 901 may be secured using bolts, rivets, straps, welding, or any other suitable mechanical means well-known in the art.

[0074] The amount of force that cam follower 908 exerts against the perimeter wall cam 200 depends in part on the spring force of adjustable force mechanism 902, and an amount that adjustable force mechanism 902 is compressed, in embodiments that use a spring. In other embodiments, the amount of force that cam follower 908 exerts against the perimeter wall of cam 200 may depend on a force exerted by a hydraulic/pneumatic cylinder or a position of an electro-mechanical actuator inside housing 901. Typically, adjustable force mechanism 902 is preloaded (i.e., exerts a predetermined force) to achieve a desired force of cam follower 908 against the perimeter wall of cam 200 when cam 200 is at a particular, relative position with respect to follower 908, such as in the position shown in FIG. 9.

[0075] In embodiments where adjustable force mechanism 902 comprises a spring, the spring may be selected based on its size and spring force such that the spring is capable of applying a predetermined maximum force of follower 908 against the perimeter wall cam 200. The desired maximum force is selected based on one or more factors, such as the size of the sailing vessel, the size of the sail, an expected range of wind speeds, etc.

[0076] With little or no wind, or when the sailing vessel is aimed towards the oncoming wind, follower 908 is forced against dwell portion 600 of cam 200, and wing 108 is free to rotate one way or the other until follower 908 rests against one of two dimples 602 and 604 of cam 200, formed about +/20 degrees from a centerline of the cam 200 as shown in FIG. 6. Generally, a radius of dwell portion 600 is constant, thereby allowing either mast 110 or sleeve 206, as the case may be, to rotate unrestricted between approximately +/20 degrees to the heading of the vessel and settle into one of the two dimples. Sleeve 206/mast 110 will remain in this position until the wind changes direction or as the wind increases, causing sleeve 206/mast 110 and cam 200 rotate together past one of the dimples. As cam 200 is rotated past one of the dimples, the cam profile steepens, forcing retractable arm 906 further into housing 901 and thereby increasing the force produced by adjustable force mechanism 902 against retractable arm 906 and, thus, follower 908 against the perimeter wall of cam 200. For example, in an embodiment where adjustable force mechanism 902 comprises a spring, the spring is further compressed by retractable arm 908 as cam 200 rotates past either of the dimples. The result is a counter-torque applied to cam 200 which opposes the torque applied by the wind against the sail. The counter-torque increases as the cam is rotated further away from either one of the dimples until 180 degrees from center, where it transitions to the other half of cam 200, where cam 200 will continue rotating until either follower 908 again rests in one of the dimples or the wind force and the counter-torque are equal and opposite. The result is that the sail remains in an optimal orientation with respect to the apparent wind to propel the sailing vessel at a maximum speed.

[0077] In the embodiment as shown in FIG. 9, the force that the spring exerts against retractable arm 906 may be adjusted using adjustment mechanism 904. As threaded post 910 travels further inside housing 901 by turning knob 916 in one direction, the spring is further compressed, resulting in a greater force applied to retractable arm 906 and, thus, a greater force applied by follower 908 against a perimeter wall of cam 200. This makes rotation of mast 110 or sleeve 206, as the case may be, more difficult, i.e., by the wind. Conversely, as threaded post 910 retracts from inside housing 901 as knob 916 is turned in an opposite direction, compression of the spring is reduced and, thus, less force is applied by the spring against retractable arm 906 and, thus, less force applied by follower 908 against the perimeter wall of cam 200.

[0078] A major advantage of adjustable force mechanism 902, as well as other related embodiments described herein, is that once an initial preload is created manually, or automatically via a computerized control unit, no further adjustments are typically necessary to maintain a relative angle of attack between the wind and wing 108 as changes in the angle of the wind or heading of the sailing vessel occur.

[0079] FIG. 10 is a top, plan view of one embodiment of a system for controlling a speed of a sailing vessel, shown as system 1000 in use with a sleeve 206, cam 200 and mast 100 of a sailing vessel. The view is similar to FIG. 9, showing cam 200 mounted onto sleeve 206 and adjustable tensioner assembly 1000 applying a force against a perimeter of cam 200 via a follower 1002. However, in this embodiment, follower 1002 is coupled to one end of a leaf spring 1004, and the other end is rotatably coupled to a driven pivot point 1006 attached to the sailing vessel. The force of follower 1002 acting on a perimeter of cam 200 is dependent in part on a stiffness of leaf spring 1004 and is selected similar to selection of a spring as described earlier above. The force of follower 1002 acting on a perimeter of cam 200 may be adjusted by rotating the pivot point either manually with a wrench, for example, or with an electro-mechanical actuator, such as an electronic motor, thus bending leaf spring 1004 a greater amount or a lesser amount. Increasing the bend of leaf spring 1004 creates more force by follower 1002 against the perimeter wall of cam 200, while decreasing the bend of leaf spring 1004 creates less force by follower 1002 against the perimeter wall of cam 200.

[0080] FIG. 11 is a top, plan view of another embodiment of a system for controlling a speed of a sailing vessel, shown as system 1100 in use with sleeve 206, cam 200 and mast 108 of a sailing vessel. The view is similar to FIG. 10, showing cam 200 mounted onto sleeve 206 and adjustable tensioner assembly 1100 applying a force against a perimeter of cam 200 via a follower 1002 mounted to one end of a leaf spring 1004. However, in this embodiment, the other end of the leaf spring is coupled to a free pivot point 1102 mounted to a fixed portion of the sailing vessel, which allows that end to rotate freely with respect to free pivot point 1102. The force of follower 1002 acting on a perimeter of cam 200 may be adjusted using one or more arms 1104 adjusted by mechanical adjustment means 1106, respectively, such as a bolt, screw, knob, lever, gear or some other manual mechanical adjustment mechanism. In FIG. 11, two of such arms 1104 and mechanical adjustment means 1106 are shown, one end of each of the arms 1104 coupled to a tension follower 1108 located at a juncture of the arms 1104 as shown, and the other end of each of the arms coupled to each actuator 1106, respectively. As one or both mechanical adjustment means are manually manipulated, follower 1008 presses against and/or moves along the surface of the leaf spring, causing a greater or lesser amount of bending of leaf spring 1004, and thus the force applied by follower 1002 against the perimeter wall of cam 200. For example, if both arms 1104 are adjusted so that the end of each mechanical adjustment means are moved towards leaf spring 1004, the force of follower 1002 against cam 200 is increased. If both arms 1104 are adjusted in an opposite direction, tension follower 1108 slides closer or further from the pivot point, changing a spring rate of leaf spring 1004 (i.e., how much force leaf spring 1004 exerts when it is deformed a certain amount), but not the preload force of follower 1002 against cam 200. This is also the case in FIG. 12 at 908, FIG. 13 at 908 and FIG. 14 at 908.

[0081] FIG. 12 is a top, plan view of yet another embodiment of a system for controlling a speed of a sailing vessel, shown as system 1200 in use with a sleeve 206, cam 200 and mast 110 of a sailing vessel. System 1200 is similar to the system shown in FIG. 11, except that leaf spring 1004 is replaced by a rigid longitudinal member 1202. As in FIG. 11, FIG. 12 shows cam 200 mounted onto sleeve 206 and follower 1002 applying a force against a perimeter wall of cam 200. However, in this embodiment, the follower is attached to one end of rigid longitudinal member 1202, and the other end of rigid longitudinal member 1202 is rotatably coupled to free pivot point 1102 attached to a fixed portion of the sailing vessel. In this embodiment, follower 1002 is forced against a perimeter wall of cam 200 by a pulling force exerted by adjustable tensioner assembly 1204, which is similar to adjustable tensioner assembly 900 is shown in FIG. 9, with the exception that the coil spring is replaced by an extension arm spring 1206, which resists elongation. Similar to adjustable tensioner assembly 900, the pulling force applied by adjustable tensioner assembly 1204 against rigid longitudinal assembly 1202 may be adjusted manually by turning knob 916, which causes threaded post 910 to move towards and away extension arm spring 1206. Of course, in other embodiments, extension arm spring 1206 may be replaced by some other mechanical component, such as a pneumatic/hydraulic piston, one or more elastic bands, etc. Rigid longitudinal member 1202 may be pre-loaded by a desired amount by force by rotating knob 916 to a point where extension arm spring 1206 is extended an amount that causes the pulling force on rigid longitudinal member 1202 to the desired force. As the pulling force created by adjustable tensioner assembly 1204 changes, the force of follower 1002 against cam 200 is increased. As the location of follower 908's contact point on rigid longitudinal structure 1202 is adjusted (i.e., its radius), the spring rate is changed, but not necessarily the spring preload force

[0082] FIG. 13 is a side view of yet still another embodiment of a system for controlling a speed of a sailing vessel, shown as system 1300 in use with a sleeve 206, cam 200 and mast 110 of a sailing vessel. As before, cam 200 is mounted to sleeve 206. However, in this embodiment, a follower 1302 is coupled at one end of one or more follower arms 1304, respectively, each of which is/are rotatably coupled at a second, opposing end to a pivot point 1306 attached to the sailing vessel, respectively. While FIG. 13 shows an embodiment where system 1300 is above a deck 1308 of the sailing vessel, and cam 200 is attached to sleeve 206 at a point above deck 1308, in other embodiments, the one or more follower arms 1304 could be secured below deck to a fixed point of the sailing vessel, protruding through one or more slots in deck 1308 and attached to the follower, wherein cam 200 is located just above or below deck 1308. The force exerted by follower 1302 against a perimeter wall 1310 of cam 200 is adjusted by adjustable tensioner assembly 1312, similar or identical to adjustable tensioner assembly 900 as shown in FIG. 1, which pushes against one or both of the follower arms 1304. Follower 908 of adjustable tensioner assembly 1312 enables adjustable tensioner assembly 1312 to be adjusted along a length of a follower arm 1304, thus altering the spring rate, spring preload or both, as described earlier herein. The force exerted by follower 1302 against perimeter wall 1310 of cam 200 may be varied as described above with respect to adjustable tensioner assembly 900 of FIG. 9.

[0083] FIG. 14 is a side view of yet another embodiment of a system for controlling a speed of a sailing vessel, shown as system 1400 in use with a cam and a mast (not shown in this view for clarity) of a sailing vessel. In this embodiment, cam 200 is partially or completely hollow and a similar cam profile is present on an interior wall 1402 of cam 200 as the external cam profile as shown in FIG. 6. In this embodiment, adjustable tensioner assembly 1204 is the same or similar to adjustable tensioner assembly 1204 shown in FIG. 12, i.e., one that exerts a pulling force. Follower 1302 is forced against an inside perimeter wall 1402 of cam 200 by one or more follower arms 1304 which is/are rotatably coupled to one or more fixed points 1306 of the sailing vessel, respectively. The force exerted by follower 1302 against inside perimeter wall 1402 of cam 200 is adjusted by adjustable tensioner assembly 1204 similar to that described in relation to FIG. 12.

[0084] FIGS. 15A, 15B and 15C show three different views of another embodiment of the invention, showing sleeve 206/mast 110 mounted through an elevational cam 1502 and a system for controlling a speed of a sailing vessel 1500. In this embodiment, cam 1502 comprises a profile that varies in elevation as cam 1502 is rotated by sleeve 206/mast 110. A rigid longitudinal member 1504 comprises a first end rotatably attached to a fixed portion 1506 of the sailing vessel and a second, opposing end comprising a follower 1002, similar or the same as follower 1002 as described with respect to FIG. 10. While adjustable tensioner assembly 1204 is shown in FIGS. 15B and 15C with the first end attached to a point along rigid longitudinal member 1504, in other embodiments, adjustable tensioner assembly 1204 and rigid member 1504 may be replaced by adjustable tensioner assembly 900, mounted such that it is substantially perpendicular to a deck of the sailing vessel and perpendicular to the horizontal plane of cam 1502. Follower 1002 is forced against a track 1510 of cam 1502. As cam 1502 is rotated along with sleeve 206/mast 110 as the wind acts on wing 108, the force applied by follower 1002 against race 1510 increases as the elevation of race 1510 increases. This increasing force inhibits further rotation of sleeve 206/mast 110, forcing sleeve 206/mast 110 to resist a torque caused by the wind against wing 108. With little or no wind, or when the sailing vessel is aimed towards the oncoming wind, follower 1002 is forced to a flat portion 1512 of race 1510, which allows follower 1002 to roll relatively unimpeded until the elevation of race 1510 begins to increase at an angle of approximately +/20 degrees from the heading.

[0085] FIG. 15A is a top, plan view of mast 110 and cam 1502, illustrating the circular shape of cam 1502 with race 1510 along its perimeter where follower 1002 tracks. The thickness of race 1510 may vary in elevation in a similar way that the radius of cam 200, described in other embodiments, varies.

[0086] FIG. 15B is a front, plan view of cam 1502, mast 110, rigid arm 1504 adjustable tensioner assembly 1204. Rigid arm 1504 is pivotally secured to a pivot point 1506, secured to a fixed portion of the sailing vessel (i.e., to a deck or wall of the sailing vessel, to a raised object secured to the deck, etc.). The opposing end of rigid arm 1504 comprises follower 1002, which rolls in race 1510 of cam 1502 as wing 108 is rotated by the wind. Follower 1002 applies a downward force on race 1510 as a result of adjustable tensioner assembly 1204 pulling the rigid arm 1504 and, thus, follower 1002, downwards, towards race 1510. The force exerted by adjustable tensioner assembly 1204 may be adjusted manually as described earlier herein. As sleeve 206/wing 108 is rotated by the wind, the downward force exerted by the follower against race 1510 increases due to displacement of follower 1002 and, thus, rigid arm 1504, which in turn causes adjustable tensioner assembly 1204 to exert more force against rigid arm 1504. This is best shown in FIG. 15C. The pitch of race 1510 may be formed so that it varies linearly or non-linearly.

[0087] FIGS. 16A, 16B and 16C show 3 different views of yet another embodiment of the invention, similar to the embodiment shown in FIGS. 15A-C. In this embodiment, cam 1602 is similar to cam 1502, except that it comprises two, opposing profiles, each with its own race 1610A and 1610B, as well as an additional rigid arm 1504 and an additional adjustable tensioner assembly 1204 used in association with race 1610B. Each follower of a respective rigid arm 1504 follows a respective race, either 1610A or 1610B, respectively, as cam 1602 is rotated along with sleeve 206/wing 108 as the wind acts on wing 108. The housing of each adjustable tensioner assembly 1204 may be coupled to a stationary object, such as a deck, wall or some other feature of a sailing vessel. Alternatively, the adjustable tensioner assemblies may be coupled to each other.

[0088] FIG. 16A is a top, plan view of mast 110 and cam 1602, illustrating the circular shape of cam 1602 (as opposed to the oblong shape of cam 200), with upper race 1610A shown along its perimeter where upper follower 1002 tracks. FIG. 16B is a front, plan view of cam 1602, mast 110, adjustable tensioner assemblies 1204 and rigid arms 1504. One end of each adjustable tensioner assembly 1204 comprises a respective follower 1002, which rolls in a respective race 1610A or 1610B of cam 1602 sleeve 206/mast 110 is rotated when wind acts on wing 108. Each follower 1002 applies an opposing force against a respective race 1610 as a result of the force applied to each respective rigid arm 1504 by a respective adjustable tensioner assembly 1204. The force exerted by each adjustable tensioner assembly 1204 may be manually adjusted as described earlier herein. As sleeve 206/mast 110 is rotated by wind acting on wing 108, the force of each follower 1002 against a respective race 1610 increases, due to vertical displacement of each follower 1002, caused by the increasing pitch of each respective race 1610. This is best shown in FIG. 16C. The pitch of each race 1610 may be formed so that it varies linearly or non-linearly and, typically, the pitch of each race 1610 is the same.

[0089] FIG. 17 is a top, plan view of a system 1700 for controlling the speed of a sailing vessel. Some of the elements of system 1700 use the same or similar components described earlier herein in other embodiments, and so the same reference numeral will be used to show such elements in FIG. 17.

[0090] In the embodiment as shown in FIG. 17, a follower 908 is coupled to an automated adjustable tensioner 1702 which is, in turn, coupled to an unmovable surface 1704, such as a deck of a sailing vessel, a wall of the sailing vessel, etc. Although FIG. 17 illustrates a particular embodiment of an adjustable tensioner similar to the arrangement shown in FIG. 9, automated adjustable tensioner 1702 as shown in FIG. 17 may be used in any of the adjustable force mechanisms or adjustable tensioner assemblies shown in FIGS. 9-16 herein.

[0091] Automated adjustable tensioner 1702 comprises a base housing 1706, a slidable extension arm 1708 protruding from one end of base housing 1706 and follower 908 coupled to one end of slidable extension arm 1708. The other end of slidable extension arm 1708 is located inside housing 1706 where it is coupled to an actuator 1710 in one embodiment, while in another embodiment, a force gauge 1720 is inserted between the end of slidable extension arm 1708 and actuator 1710 as shown. The actuator 1710 is guided inside a fixed extension 918 of base housing 1706, typically comprising means 920 for allowing slidable extension arm 906 to slide smoothly within fixed extension 918. Actuator 1710 is configured to apply a force against slidable extension arm 906 that is variable by a control unit 1712, typically via a pump, motor or some other electrical, mechanical or electro-mechanical device, herein referred to as pump 1714. Control unit 1712 may vary the force produced by actuator 1710 against slidable extension arm 906 and thereby against cam 200 in order to achieve desired speeds of a sailing vessel during operation. For example, control unit 1712 may determine that a submersible sailing vessel should submerge in response to detecting an approaching storm. Control unit 1712 may then cause actuator 1710 to reduce the force that actuator 1710 exerts against slidable extension arm 906 and, therefore, the force of follower 908 against a perimeter wall of cam 200. This, in turn, reduces a counter-torque created by follower 908 acting on cam 200, making wing rotation easier by the wind. Reducing the counter-torque allows sleeve 206/wing 110 to rotate more freely and, thus, cause the sailing vessel to slow or to even stop, even in a moderate wind.

[0092] Conversely, control unit 1712 may determine that a submersible sailing vessel should sail at maximum speed when control unit 1712 determines that a sailing vessel has just left port. In this case, control unit 1712 may automatically cause actuator 1710 to increase the force that actuator 1710 exerts against slidable extension arm 906. This, in turn, increases a counter-torque created by follower 908 acting on cam 200, making wing rotation more difficult by the wind. Increasing the counter-torque against the cam inhibits rotation of the mast and, thus, the wing is more likely to rest at a position where the nose of the cam rests at one of the two dimples along the perimeter of the cam. This typically causes an increase in the angle of attack of the wing to the wind, i.e., the sail is pointed at a nonzero angle relative to the wind and is acting substantially like a wing, relying on lift to propel the vessel forward on any course as close to the wind as the sail can provide lift. This action of the wing may allow the sailing craft to travel at maximum speed or even diagonally upwind, sideways to the wind direction, or downwind.

[0093] Control unit 1712 may determine certain operating metrics of a sailing vessel, such as a vessel's current speed (as determined by a traditional speed sensor or GPS receiver coupled to control unit 1712), location (as determined by a GPS unit, for example), heel, (as determined by an inclinometer) heading (as determined by a digital compass or GPS unit), wind speed and direction (as determined by a wind transducer), etc. Control unit 1712 may also determine other conditions associated with the sailing vessel, such as wave heights, water currents, or events, such as when a storm is approaching, when an enemy vessel is within a predetermined distance from the sailing vessel, when the sailing vessel will soon be beaching or docking, when the sailing vessel is leaving port, etc., using one or more sensors, including one or more digital cameras, or from receiving a weather report or weather forecasts via wireless receiver 1718. It should be understood that while system 1700 is shown in FIG. 17 comprising a single sensor 1716 coupled to control unit 1712, sensor 1716 represent one or more of the sensors described above.

[0094] Control unit 1712 may determine a speed of the sailing vessel using input from sensor 1716 using conventional means, such as determining an apparent wind speed relative to the sailing vessel, determining a rate of water displacement, or calculating speed using one or more positioning methods, such as GPS. Control unit 1712 receives the speed information from sensor 1716 and may compare it to a desired speed of the sailing vessel. One or more desired speeds may be fixed and programmed into control unit 1712 prior to launch of the sailing vessel, such as a desired speed related to events such as submerging, beaching, docking, leaving port, etc., respectively. In this embodiment, control unit 1712 causes the force created by actuator to vary as control unit 1712 determines the various operating metrics, conditions or events associated with the sailing vessel. For example, control unit 1712 may be programmed to determine when the sailing vessel is sailing in rough seas, high winds or inclement weather and, in response, may automatically reduce the speed of the sailing vessel to a slower speed. In another embodiment, control unit 1712 may be configured to detect approaching vessels or aircraft and, in response, reduce the speed of the sailing vessel to a minimal speed or zero prior to control unit 1712 causing the sailing vessel to submerge beneath the surface of the water.

[0095] In some embodiments, a wireless receiver 1718 is included as part of system 1700, coupled to control unit 1712, for receiving remote commands and information related to the sailing vessel. For example, receiver 1718 may receive satellite messages with commands for the sailing vessel to perform certain vessel maneuvers at certain times and/or locations, such as submerging, sailing at maximum speed, stopping, beaching, etc. Receiver 1718 may also receive other information related to the sailing vessel, such as the vessel's location, speed, heading, current/forecasted weather information, information regarding the presence of other vessels in proximity to the sailing vessel, etc.

[0096] Automated adjustable tensioner 1702 comprises actuator 1710, such as a pneumatic or hydraulic piston, a gas or liquid-based strut, a linear actuator, or the like, typically located inside housing, capable of exerting a force against extension arm. The force exerted by actuator 1710 is controlled directly, or indirectly, by control unit 1712. In some embodiments, one or more springs may be used in combination with actuator 1710.

[0097] In one embodiment, system 1702 additionally comprises an electronic force gauge 1720 that measures a force applied by follower against cam and provides a digital representation of the force to control unit 1712. The measured force may be used by control unit 1712 to control the amount of force being exerted by actuator at any given time.

[0098] FIG. 18 is a functional block diagram of one embodiment of control unit 1712, configured for controlling the speed of a sailing vessel. FIG. 18 shows processor 1800, memory 1802, optional communication interface 1804, control interface 1806, optional receiver 1808 and optional user interface 1810. It should be understood that not all of the functional blocks shown in FIG. 18 are required for operation of control unit 1712, that the functional blocks may be connected to one another in a variety of ways, and that not all functional blocks are necessary for operation of the control unit 1712 are shown (such as a power supply), for purposes of clarity.

[0099] Processor 1800 is configured to provide general operation of control unit 1712 by executing processor-executable instructions stored in memory 1802, for example, executable code. Processor 1800 typically comprises one or more programmable microprocessors, microcomputers, microcontrollers, custom ASICs, System-on-Chips (SoCs), System-in-Packaging (SiP), or the like. Processor 1800 may be selected based on a variety of factors, including power-consumption, size, and cost.

[0100] Memory 1802 is coupled to processor 1800, comprising one or more information storage devices, such as RAM, ROM, flash memory, or some other type of electronic, optical, or mechanical memory device(s). Memory 1802 is used to store processor-executable instructions for operation of control unit 1712 as well as any information used by processor 1800, such as a history of operational metrics related to a sailing vessel, a number of vessel maneuvers and desired speeds associated with each, a number of desired forces associated with each of the vessel maneuvers, etc. It should be understood that memory 1802 is non-transitory, i.e., it excludes propagating signals, and that memory 1802 could be incorporated into processor 1800, for example, when processor 1800 is an SoC. It should also be understood that once the processor-executable instructions are loaded into memory 1802 and executed by processor 1800, control unit 1712 may become a specialized control unit 1712 for controlling the speed of a sailing vessel.

[0101] Optional communication interface 1804 is used in embodiments where system 1700 comprises a wireless receiver or transceiver separate from control unit 1712. In these embodiments, communication interface 1804 is coupled to processor 1800 and to wireless receiver 1808, communication interface 1804 comprising circuitry to receive communication signals from wireless receiver 1808.

[0102] Control interface 1806 is coupled to processor 1800 comprising interface circuitry for sending control signals to pump 17 which, in turn, causes a change in the force exerted by follower against cam. In one embodiment, control interface 1806 is coupled directly to actuator, which directly causes actuator to change in the force exerted by follower against cam. Such interface circuitry is well-known in the art.

[0103] Optional wireless receiver 1808 is coupled to processor 1800, configured to receive wireless commands and information from a remote location, such as a ship, aircraft or terrestrial base. Wireless receiver 1808 is used in embodiments where control unit 1712 lacks such wireless receiving capabilities. Wireless receiver 1718 comprises circuitry to receive wireless signals from one or more wireless networks, such as a cellular or satellite communication network. Such receiver circuitry is well-known in the art.

[0104] Optional user interface 1810 is coupled to processor 1800, comprising circuitry configured to receive user input via one or more pushbuttons, knobs, touchscreens, etc. and to provide user output via one or more display screens, speakers, touchscreens, etc. Such user interface circuitry is well-known in the art.

[0105] FIGS. 19A, 19B, and 19C represent a flow diagram illustrating one embodiment of a method for controlling the speed of a sailing vessel. In this example, it will be assumed that control unit 1712 does not comprise wireless receiver 1808 and that in embodiments that utilize remote commands and/or information, such commands and/or information is received by wireless receiver 1718 and provided to processor 1800 via communication interface 1804. Also in this example, it will be assumed that pump 1714 is used to control actuator 1710, and that actuator 1710 is not capable of being controlled directly by control unit 1712. It should be understood that in some embodiments, not all of the method steps shown in FIGS. 1900A-1900B are performed and that the order in which the steps are performed may be different in other embodiments.

[0106] At step 1900, control unit 1712 is programmed with one or more vessel maneuvers, each associated with a desired vessel speed, in some embodiments, a pressure or other setting associated with pump 1714 to achieve each of the desired vessel speeds, and/or a force of follower 908 against cam 200 in order to achieve each desired vessel speed. Other information may be programmed into control unit 1712 and stored in memory 1802, such as a default pressure or pump setting that achieves a desired, default force of follower 908 against cam 200, mapping information identifying a current location of the sailing vessel, actual or potential destinations, ports, docks, beaches, bays, etc. (landmarks), communication information, etc.

[0107] Control unit 1712 may additionally be programmed with event data in association with the predetermined vessel speeds and/or forces and/or vessel maneuvers. Such events may comprise determining when the sailing vessel is, or is about to, leave port, dock, or beach, or determining when high winds or rough seas are present, when a storm is approaching, when a marine animal is in proximity to the sailing vessel, when the sailing vessel should submerge, either partially or completely, beneath the water surface, etc. Thus, an event such as storm approaching may be associated with a vessel maneuver of diving and a desired speed of the sailing vessel just before diving.

[0108] At step 1902, processor 1800 may send a control signal to pump 1714 via control interface 1810 that causes pump 1714 to activate and cause actuator 1710 to apply a default, preload force to follower 908 against cam 200. The default force may be chosen to reduce or prevent a wing of a sailing vessel from moving as wind acts on the wing, or it may allow sleeve 206/mast 110 of the sailing vessel to rotate freely so that wind acting on a wing of the sailing vessel results in little or no movement of the sailing vessel.

[0109] At step 1904, processor 1800 may determine certain operating metrics of the sailing vessel, such as a heading, speed and a location of the sailing vessel, as well as other information useful to control unit 1712, such as wind speed and direction, wave height, current weather conditions, etc., using either signals received from sensor(s) 1716 or from wireless communications received by wireless receiver 1718 from a remote entity.

[0110] At step 1906, processor 1800 may receive an instruction from a remote entity via wireless receiver 1718 to begin autonomous sailing to a particular destination.

[0111] At step 1908, in response to receiving the instruction, processor 1800 may determine a predefined, desired vessel speed associated with maneuvering the sailing vessel away from a landmark by retrieving a desired vessel speed from memory 1802 in association with leaving a landmark. Typically, the desired vessel speed associated with leaving a landmark is just a few knots, for example, between 3 and 8 knots, suitable for sailing or motoring in a protected area such as a marina, bay, cove, etc.

[0112] At step 1910, processor 1800 may generate and send a control signal to pump 1714, causing pump 1714 to activate, thereby pumping gas or liquid into/from actuator 1710. Pumping gas or liquid into actuator 1710 causes actuator 1710 to expand, thus increasing or decreasing the force of actuator 1710 against slidable extension arm 906 and, thus, follower 908 against cam 200. As a result of the increased force and, thus increased counter-torque, the mast is more likely to hold a fixed position and less free to rotate when a wind acts on the wing sail. This tends to cause the sailing vessel to sail faster, as the wing is more likely to be close hauled with respect to the wind. Conversely, withdrawing gas or liquid from actuator 1710 causes actuator 1710 to retract, thus decreasing the force of actuator 1710 against slidable extension arm 906 and, thus, follower 908 against cam 200. As a result of the decreased force and, thus decreased counter-torque, the mast is less likely to hold a fixed position and freer to rotate when a wind acts on the wing sail. Typically, this causes the sailing vessel to slow or even stop, due to luffing that may result from allowing the mast and wing sail to rotate more freely. Thus, adjusting the force created by actuator 1710 and applied by cam follower 908 against cam 200 can affect the speed of the sailing vessel.

[0113] At step 1912, processor 1800 monitors sensor 1716 to determine a current speed of the sailing vessel.

[0114] At step 1914, processor 1800 may determine that the speed of the sailing vessel substantially matches the predetermined, desired vessel speed for leaving a landmark.

[0115] At step 1916, processor 1800, in response to determining that the speed of the sailing vessel substantially matches predetermined, desired vessel speed, processor 1800 generates and sends another control signal to pump 1714, causing pump 1714 to cease operation, thereby maintaining a current force of actuator 1710 against slidable extension arm 906.

[0116] In step 1918, processor 1800 may determine that the sailing vessel has cleared a low-speed area, such as a marina, cove or bay and, in response, may automatically increase the speed of the sailing vessel to a predetermined speed associated with sailing in open water, as stored in memory 1802.

[0117] At step 1920, processor 1800 generates and sends pump 1714 a control signal, causing pump 1714 to begin pumping additional gas or fluid into actuator 1710 in order to increase the force applied by actuator 1710 against slidable extension arm 906, which may increase the speed of the sailing vessel.

[0118] At step 1922, processor 1800 may identify when the sailing vessel has reached the predetermined speed associated with sailing associated with sailing in open water and in response, shut down pump 1714 in order to maintain a force created by actuator 1710. Processor 1800 may repeat the process of determining a current speed of the sailing vessel and causing pump 1714 to adjust a force created by actuator 1710 in order to maintain a particular desired speed.

[0119] At step 1924, processor 1800 may determine that an event has occurred or will likely occur, such as a threat to the sailing vessel is present or may become present, such as determining that a threat to the sailing vessel is present or about to occur. For example, processor 1800 may detect that a storm is approaching based on readings from sensor(s) 1716 that a current wave height and/or wind speed exceeds a predetermined wave height and/or wind speed based on readings from sensor(s) 1716 or from receiving a weather report or weather forecast via wireless receiver 1718, that a photo or video taken by sensor(s) 1716 indicate dark clouds on the horizon, that a large marine animal is within a predetermined distance of the sailing vessel, such as between 0-100 feet, etc. Other events comprise detection of another vessel or aircraft within a predetermined distance of the sailing vessel, such as between 0-10 miles.

[0120] At step 1926, processor 1800 may determine a particular vessel maneuver in accordance with the particular event that was detected. For example, when the event comprises a threat, processor 1800 may determine that a dive maneuver should be performed, along with a desired vessel speed associated with a dive maneuver, as recorded in memory 1802. As another example, when the event comprises a beaching event, processor 1800 may determine that a beaching maneuver should be performed, along with one or more desired vessel speeds associated with a beaching maneuver.

[0121] At step 1928, in response to detecting the threat, processor 1800 may generate and send one or more control signals to pump 1714 to decrease the force that actuator 1710 causes to follower 908 against cam 200, in order to slow, or stop, the sailing vessel in preparation for a dive maneuver. A dive maneuver comprises a maneuver where the sailing vessel either partially or completely submerges beneath the water surface. During a dive maneuver, it is usually desirable to slow the speed of the sailing vessel to approximately 5 knots or less. The one or more control signals typically cause pump 1714 to withdraw gas or fluid from actuator 1710. This, in turn, allows sleeve 206/mast 110 of the sailing vessel to rotate more freely, as the force of follower 908 against cam 200 is reduced, thus reducing the counter-torque applied to wing 108. When wing 108 is more freely able to rotate about mast 110 due to the reduced counter-torque, sailing becomes more inefficient due to slack in the wing, thus slowing or even stopping the sailing vessel.

[0122] At step 1930, processor 1800 monitors sensor 1716 to determine when the speed of the sailing vessel is equal to or less than the vessel speed stored in association with a vessel maneuver associated with the detected event, in this case, an example, desired speed of less than 5 knots associated with a dive event.

[0123] At 1932, processor 1800 may cause the sailing vessel to perform the dive maneuver, by, for example, flooding one or more hulls and/or ballast tanks attached to the hull(s) of the sailing vessel, as explained in U.S. Pat. No. 10,029,773, assigned to the assignee of this application and incorporated by reference herein.

[0124] At step 1934, processor 1800 may determine that a beaching or docking event has or will occur, i.e., that the sailing vessel is about to land on a particular beach or dock at a particular dock. Detection of a beaching or docketing event may be determined by evaluating signals from sensor(s) 1716, indicating that the vessel is in proximity to a destination beach or dock destination, or it may be determined by receiving a command from wireless receiver 1718 to beach or dock the sailing vessel. A beaching maneuver may be used to land the sailing vessel on a beach for purposes of refueling, loading/unloading, repairs, etc., and may comprise two or more desired vessel speeds-a first vessel speed for approaching a beach at a moderate speed in order for the sailing vessel to at least partially land on a beach and a second vessel speed less than the first vessel speed, for slowing the sailing vessel once it has or is about to make contact with a beach, allowing the momentum of the sailing vessel to carry itself on to the beach without causing damage to the sailing vessel.

[0125] The docking maneuver is similar to the beaching maneuver, however, the speed of the sailing vessel during this maneuver may be different than the speed of the sailing vessel during the beaching maneuver. For example, processor 1800 may decrease the speed of the sailing vessel as the sailing vessel approaches a dock.

[0126] At step 1936, as a result of determining that an event is occurring, or will occur, processor 1800 may determine a vessel maneuver based on the detected event. In this example, processor 1800 determines that a beaching maneuver should be performed based on a determination that a beaching event should be performed.

[0127] At step 1938, during a beaching maneuver, processor 1800 generates and sends one or more control signals to pump 1714 to cause actuator 1710 to adjust the force of follower 908 against cam 200 in order to achieve a first predetermined speed associated with approaching a beach during a beaching maneuver as stored in memory 1802. For example, the first predetermined speed associated with a beaching maneuver may be between 5 and 15 knots. As previously described, processor 1800 may adjust the force as the sailing vessel approaches the beach by monitoring sensor(s) 1716 to determine a current speed of the sailing vessel and adjust the force exerted by follower 908 against cam 200 accordingly.

[0128] At step 1940, just before the sailing vessel makes contact with the beach, or just after, as determined by processor 1800 via signals from a position sensor 1716 and/or a shock sensor 1716, for example, processor 1800 may slow the speed of the sailing vessel to a second, predetermined vessel speed associated with a beaching maneuver. For example, processor 1800 may send a control signal to pump 1714, causing the force exerted by actuator 1710 and, therefore, follower 908 against cam 200, to be reduced, thereby allowing the wing to luff. The sailing vessel may then continue landing on the beach using its momentum from approaching the beach at the first predetermined vessel speed associated with a beaching maneuver.

[0129] At step 1942, processor 1800 may determine that the sailing vessel should dock, i.e., a docking event, based on the vessel's proximity to a dock via signals from sensor 1716, in this case, a location sensor.

[0130] At step 1944, processor 1800 determines that a docking maneuver should be performed based on determining that a docking event is about to occur.

[0131] At step 1946, in response to determining that a docking maneuver should be performed, processor 1800 may generate and send one or more control signals to pump 1714 to adjust the force of actuator 1710 and, thus, follower 908 against cam 200, in order to achieve variable vessel speeds associated with the docking maneuver as stored in memory 1802. For example, it may be desirable, in most docking situations, to reduce the speed of a sailing vessel as it approaches a dock. For example, when the sailing vessel is 20 feet away from the location of a dock, processor 1800 may slow the sailing vessel to a speed of between 3 and 6 knots, and then continuously reduce the speed of the sailing vessel until it reaches a predetermined, minimum speed for docking, such as 0 knots once the sailing vessel is close to the dock. Processor 1800 achieves these speeds by sending control signals to pump 1714 that causes actuator 1710 to adjust the force of follower 908 against cam 200 as the sailing vessel approaches the dock. During this time, processor 1800 may monitor sensor(s) 1716 to determine a current speed of the sailing vessel and adjust the force exerted by follower 908 against cam 200 as necessary in order to achieve the desired, variable speed.

[0132] At step 1948, processor 1800 may determine that the sailing vessel has docked by monitoring sensor(s) 1716. For example, processor 1800 may determine that the sailing vessel has experienced a deceleration and/or is no longer moving and/or that the location of the sailing vessel matches the location of a dock.

[0133] At step 1950, processor 1800, in response to determining that the sailing vessel has docked, may generate and send a control signal to pump 1714 that causes actuator 1710 to decrease the force of follower 908 against cam 200 such that wing 108 may freely rotate with the wind. This prevents the wing from applying a force against the sailing vessel as the wind acts on the wing that might otherwise cause the sailing vessel to move from its docked position, possibly causing damage to the sailing vessel.

[0134] While the foregoing disclosure shows illustrative embodiments of the invention, it should be noted that various changes and modifications could be made herein without departing from the scope of the invention as defined by the appended claims. Furthermore, although elements of the invention may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.