U.S. patent application number 17/578906 was filed with the patent office on 2022-07-21 for kite power with directional control for marine vessels.
The applicant listed for this patent is Gregory Hall, Robert Richardson. Invention is credited to Gregory Hall, Robert Richardson.
Application Number | 20220227468 17/578906 |
Document ID | / |
Family ID | 1000006150892 |
Filed Date | 2022-07-21 |
United States Patent
Application |
20220227468 |
Kind Code |
A1 |
Richardson; Robert ; et
al. |
July 21, 2022 |
KITE POWER WITH DIRECTIONAL CONTROL FOR MARINE VESSELS
Abstract
The disclosure provides methods and devices for enabling a
Vessel propelled by a Kite or similar devices, e.g., a balloon, to
adjust its direction of travel to either side of the true wind
direction without the aid of rudder(s), tiller(s), or similar
devices. The subject invention applies to wind-powered Vessels as
well as hybrid vessels and vessels utilizing propeller-driven
propulsion, jot propulsion and others in addition to wind
power.
Inventors: |
Richardson; Robert;
(Shingleton, CA) ; Hall; Gregory; (Belmont,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Richardson; Robert
Hall; Gregory |
Shingleton
Belmont |
CA
MA |
US
US |
|
|
Family ID: |
1000006150892 |
Appl. No.: |
17/578906 |
Filed: |
January 19, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
63138858 |
Jan 19, 2021 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B63H 8/16 20200201 |
International
Class: |
B63H 8/16 20060101
B63H008/16 |
Claims
1. A method of improving the performance of a vessel, comprising:
a) attaching one or more cables from the vessel to a kite or
similar device; b) deploying the kite or similar device into wind;
c) transferring energy from the wind into an external force vector
applied through the one or more cables; and d) selectively locating
an overall force vector at a variable location with respect to the
vessel, wherein the force vector imparts either a forward
propulsive force or a forward propulsive force and a variable
turning moment.
2. The method of claim 1, wherein when the external force vector
crosses the vessel's center of turning, there is only a forward
propulsive force and no turning moment.
3. The method of claim 1, wherein when the external force vector or
an extension of the external force vector crosses the vessel's
longitudinal axis in front of the vessel's center of turning, the
turning moment is in a clockwise direction.
4. The method of claim 1, wherein when the external force vector or
an extension of the external force vector crosses the vessel's
longitudinal axis behind the vessel's center of turning, the
turning moment is in a counterclockwise direction.
5. The method of claim 3, wherein the magnitude of turning moment
is varied by adjusting the radial distance from the center of
turning to the external force vector.
6. The method of claim 4, wherein the magnitude of turning moment
is varied by adjusting the radial distance from the center of
turning to the external force vector.
7. The method of claim 1, wherein the external force vector is
variably located with respect to the vessel by connecting cables
from the kite or similar device to a carriage that is constrained
by a track.
8. The method of claim 7, wherein the track is a linear and
longitudinally mounted track.
9. The method of claim 7. wherein the track is a linear and
transversely mounted track.
10. The method of claim 7, wherein the track is located on or
around a perimeter of the vessel.
11. The method of claim 1, wherein the external force vector is
variably located with respect to the vessel by connecting cables
from the kite or similar device to a connection point and varying
the length of two or more vessel-mounted cables of variable length
that define the location of the connection point to the external
force vector.
12. The method of claim 1, wherein vessel efficiency is improved by
eliminating drag associated with use of a rudder or tiller.
13. The method of claim 1, Wherein location of the external force
on the vessel is automatically and dynamically varied to maintain a
specified vessel course.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35
U.S.C. 119(e) to U.S. Provisional Patent Application Ser. No.
63/138,858, titled: KITE POWER WITH DIRECTIONAL CONTROL FOR MARINE
VESSELS, filed on Jan. 19, 2021, the disclosure of which is hereby
incorporated by reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] The disclosure generally relates to marine vessels, and more
particularly to optimizing kite power with, directional controls
for marine vessels.
BACKGROUND OF THE INVENTION
[0003] Air moving with respect to the vessel's position (Wind) has
been used as a method of vessel (boat/ship) locomotion (hereinafter
referred to as Sailing or Sail) for more than 5,000 years. Sailing
technology reportedly originated in or around Mesopotamia or Egypt
and is now used around the world. From then until now, the sailing
vessels have varied in many ways for example, size, materials of
construction and number of hulls. Collectively they are all
referred to as Vessels in this document.
SUMMARY OF THE INVENTION
[0004] The disclosure provides methods and devices for enabling a
Vessel propelled by a Kite or similar devices, e.g., a balloon, to
adjust its direction of travel to either side of the true wind
direction without the aid of rudder(s), tillers, or similar
devices. The subject invention applies to wind-powered Vessels as
well as hybrid vessels and vessels utilizing propeller-driven
propulsion, jet propulsion and others in addition to wind power. In
some embodiments vessel direction of travel can vary to either side
of the true wind direction by up to about 90 degrees. A direction
of travel is obtained within about +90 /-90-degree deviation from
the true wind direction by moving the point of attachment between
the Vessel and the surface area(s) intended to interact with Wind.
The method reported in this document is uniquely different from
essentially every other Sailing Vessel because it does not require
the use of a pole or poles affixed to the Vessel on one end, with
the other end projected into the sky (Masts) as a means of
supporting the surface area intended to interact with the wind
(Kite).
[0005] Kite propulsion for marine vessels has been explored and
published elsewhere. All prior art involves attaching the Kite to
the bow/front of the Vessel. The subject invention differs from
prior Kite-propelled Vessels by applying the Kite force to the
Vessel in a manner that more effectively transfers the force
supplied by the interaction between the Kite and wind to the Vessel
as will be described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The disclosure, in accordance with one or more various
embodiments, is described in detail with reference to the following
figures. The drawings are provided for purposes of illustration
only and merely depict exemplary embodiments of the disclosure.
These drawings are provided to facilitate the reader's
understanding of the disclosure and should not be considered
limiting of the breadth, scope, or applicability of the disclosure.
It should be noted that for clarity and ease of illustration these
drawings are not necessarily made to scale.
[0007] FIG. 1 illustrates an embodiment of a System Control
Diagram;
[0008] FIG. 2A illustrates an embodiment of a Manual Carriage
positioning device;
[0009] FIG. 2B illustrates an embodiment of a Cable-driven
carriage;
[0010] FIG. 2C illustrates an embodiment of a Hydraulic actuator
driven carriage;
[0011] FIG. 2D illustrates an embodiment of a Chain-driven
carriage;
[0012] FIG. 3 illustrates an embodiment of the Mechanics of Kites
attached to the bow of a vessel;
[0013] FIG. 4 illustrates an embodiment of Cancelling lateral
effects of Kite force that is not from in front of the vessel;
[0014] FIGS. 5A & 5B illustrates an embodiment of the Turning
effect caused by longitudinal movement of Kite point of attachment
with track mounted at the longitudinal center line of the vessel
that intersects the Center of Turning;
[0015] FIGS. 6A & 6B illustrates an embodiment of the Turning
effect caused by transverse movement of Kite point of attachment
that intersects Center of Turning;
[0016] FIG. 7A & 7B illustrates an embodiment of the Turning
effect caused by Kite connection to Vessel at transverse point of
attachment that is stern of the Center of Turning;
[0017] FIGS. 8A & 8B illustrates an embodiment of Turning
effect caused by variation in angle, .THETA. with Kite connection
to Vessel at a transverse point of attachment that is stern of the
Center of Turning;
[0018] FIGS. 9A & 9B illustrates an embodiment of Turning
effect caused by movement of transverse track position along Vessel
Y axis;
[0019] FIGS. 10A & 10B illustrates an embodiment of
Transversely mounted track in front of the Center of Turning;
[0020] FIGS. 11A & 11B illustrates an embodiment of
Side-mounted track;
[0021] FIG. 12 illustrates an embodiment of Manual transfer of Kite
cable from side to side;
[0022] FIG. 13 illustrates an embodiment of Continuous side-mounted
track;
[0023] FIG. 14 illustrates an embodiment of Kite powered jibe turn
with continuous side mounted track;
[0024] FIG. 15 illustrates an embodiment of Perimeter cable-driven
carriage;
[0025] FIG. 16 illustrates an embodiment of Hull tilt moment
counteracted by Kite steering moment;
[0026] FIG. 17A illustrates an embodiment of Kite cable and sensor
array with pilot Kite;
[0027] FIG. 17B illustrates an embodiment of Exemplary wind
sensor;
[0028] FIG. 17C illustrates an embodiment of Differential
pressure-based wind speed sensor assembly;
[0029] FIG. 17D illustrates an embodiment of a Cable mounted sensor
with power generation;
[0030] FIG. 18 illustrates an embodiment of Tripoidal shaped Kite
cable collection device & area changing system;
[0031] FIG. 19 illustrates an embodiment of Example of concept for
Cable storage device;
[0032] FIG. 20 illustrates an embodiment of Examples of Kite
designs;
[0033] FIG. 21 illustrates an embodiment of an Exemplary 4-cable
Kite;
[0034] FIG. 22 illustrates an embodiment of Adjusting Kite area by
reducing the size of Wind scoop;
[0035] FIG. 23 illustrates an embodiment of Adjusting Kite power by
changing wind flap opening;
[0036] FIG. 24 illustrates an embodiment of a Carriage with
motor-driven Kite cable spools; and
[0037] FIG. 25 illustrates an embodiment of a Vessel-mounted Kite
cable spools for 4-cable Kite.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0038] The following description is presented to enable a person of
ordinary skill in the art to make and use embodiments described
herein. Descriptions of specific devices, techniques, and
applications are provided only as examples. Various modifications
to the examples described herein will be readily apparent to those
of ordinary skill in the art, and the general principles defined
herein may be applied to other examples and applications without
departing from the spirit and scope of the disclosure. Thus, the
disclosure is not intended to be limited to the examples described
herein and shown but is to be accorded the scope consistent with
the claims.
[0039] The word "exemplary" is used herein to mean "serving as an
example illustration," Any aspect or design described herein as
"exemplary" is not necessarily to be construed as preferred or
advantageous over other aspects or designs.
[0040] Reference will now be made in detail to aspects of the
subject technology, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to
like elements throughout.
Method of Vessel Locomotion
[0041] The disclosed methodology affixes one or more Kites intended
to interact with wind in such a way as to transfer force via one or
more cables to a Vessel. The cable(s) connect the Kite to the
vessel at one effective location on the Vessel, generating a Kite
force vector. With single Kite cable applications, the Kite force
vector is in the direction of the kite cable. In multi-kite cable
applications, the Kite force vector is in the direction of the sum
of each of the individual kite cable vectors. The attachment
location of the Kite force vector to the vessel is movable with
respect to the Vessel coordinate frame. In one embodiment, the
cable connection is located on a mobile carriage with one or more
degrees of freedom relative to the Vessel frame of reference
(Carriage).
[0042] In some embodiments, a single stable Kite is connected to
the Vessel via a single cable or rope and is intrinsically stable
in flight without the need to adjust cables/ropes affixed to
additional points on the Kite. In other embodiments, a Kite is
controlled by 2 or 3 or 4 or more cables that can manipulate the
orientation, altitude, and power of the Kite. In some embodiments,
2 or more control cables are housed within a common sheath to
facilitate cable management at the Carriage. In some embodiments,
two or more cables are directed through a common eyelet on the
Carriage to precisely locate the application of force. In other
embodiments, cables are attached to one or more carriages that are
independently mobile and collectively form the Kite force vector
attachment point. In all embodiments, the Carriage locates the
center of force from the Kite to a specific location with respect
to the vessel frame of reference.
[0043] in some embodiments, an unstable Kite is utilized with a
single cable. This can result in a Kite traversing the sky in a
figure-8 pattern. As the Kite travels in this pattern, the Kite
force vector acting on the Vessel changes direction. In one
embodiment, an automated control system adjusts carriage location
to compensate for variation in the Kite force direction to maintain
a desired Vessel course.
[0044] A Kite control system requires information on the Kite
orientation, altitude, and stability in order to adjust and
optimize the Kite power. Kite orientation can be discerned by one
or more sensors (e.g., accelerometers) mounted on the Kite,
measurement of tension in one or more Kite cables, and measurement
of. Kite control cable length. Kite altitude can be discerned based
on one or a combination of Kite cable length (e.g., amount
unspooled), Kite cable angle, line-mounted altitude sensors,
Kite-mounted altitude sensors, optical measurement of the distance
between photo targets on the kite from a mounted camera, laser,
radar, or similar technology, and Kite-mounted GPS. Kite power can
be discerned by tension sensors in the cable, tension, sensors in
the Kite, load sensors in the Carriage, and/or load sensors in the
track to vessel connection.
[0045] The connection between the Kite(s) and Vessel is via one or
more cables, ropes, or similar devices hereinafter as Cables. In
one embodiment, one end of the cable/rope is affixed to the Kite
and the other is affixed to a movable piece of hardware (Carriage)
that is mechanically connected to a track in such a way that the
Carriage is restrained from leaving the surface of the track, is
limited to motion along the length of the track and can be
restrained at a designated point. The track is typically connected
to a fixed location on the vessel, however in some embodiments the
track can move as well. The combination of Carriage and Track
assembly is referred to as the Track Assembly.
[0046] In another embodiment one end of a Cable is affixed to the
Kite and the other is affixed to a piece of hardware hereinafter
referred to as Coupling that is mechanically connected to two or
more Cables that are affixed to the Vessel. The position of the
Coupling with respect to the Vessel is moved by adjusting the
lengths of one or more of the Cables that connect it to the
Vessel.
[0047] Increasing the height of Kite attachment above the water
line induces list in the Vessel towards the Kite, which could
indirectly induce Vessel turning away from the Kite due to reaction
forces with the water.
[0048] Every Vessel has a center of turning. This point is
Vessel-specific and is determined by the physical characteristics
of the Vessel. Variables that influence the center of turning
include but are not limited to keels, center boards, hydrofoils,
center of mass location, hull shape, chines, number of hulls,
quantity and location of cargo, and hull shape (e.g., continuously
varying curvature). Environmental factors can also influence the
center of turning such as water current speed and direction,
surface wind speed and direction, vessel speed, and vessel
list.
[0049] Large commercial Vessels that are essentially a long tube
with a bow, rudder(s) and no distinguishing hull characteristics
may turn on or near the Vessel center of gravity (CG). However, the
CG is not necessarily collocated with the center of turning for all
Vessel types. In this document, the Center of Turning (CT) defines
the point about which the vessel turns. The center of turning is
the location about which a Vessel pivots when all threes and
moments acting on the Vessel are considered. The center of turning
is not the center of an arc of travel of a Vessel, which is
normally located far from the Vessel.
[0050] The Track Assembly is attached to the Vessel. There are
several possible orientations of the Track Assembly with respect to
the Vessels hulks) long axis. In a first embodiment, the Track.
Assembly is parallel with the longitudinal axis of the Vessel. In
one application of the first embodiment, the Track Assembly
intersects the Vessels Center of Turning and continues for some
direction either side of the point of intersection.
[0051] In a second embodiment, the Track Assembly is perpendicular
to the longitudinal axis of the Vessel (i.e. transversely mounted).
In the first application of this embodiment, the Track Assembly
intersects the Center of Turning and continues beyond it in both
directions.
[0052] In another application of the second embodiment, the Track
Assembly does not intersect the Vessel's Center of Turning but is a
small percentage of the Vessels length away from the Center of
Turning (fore or aft of the center of turning) and continues for
some distance either side (port & starboard) of the proximity
to the Center of Turning.
[0053] In a third embodiment, a first Track Assembly attaches to a
second Track Assembly with, a translating degree of freedom. In one
embodiment, the two Track Assemblies are orthogonal and effectively
create a Cartesian coordinate system with X and Y degrees of
freedom.
[0054] In a fourth embodiment, the Track Assembly can be rotated
about a vertical (Z) axis of the Vessel to enable the Track
Assembly to be oriented in angles from 0.degree. to 180.degree.
with respect to the longitudinal axis of the Vessel. In this
embodiment, the Carriage location for Kite attachment follows a
polar coordinate system whereby the Track Assembly angle and
Carriage translational location (radius) defines the attachment
location with respect to the Vessel reference frame. In other
embodiments, the track sweep angle is from 0.degree. to
360.degree..
[0055] In a fifth embodiment, an assembly of Cables and pulleys are
used to locate and secure the location of the Coupling for Kite
attachment. In one application of the fifth embodiment, the Cables
are attached along the longitudinal axis of the Vessel in order to
move the Kite attachment point fore and aft with respect to the
center of turning. In another application of the fifth embodiment,
the Cables are attached transversely across the width of the
Vessel. In one embodiment, Cables connect a Coupling to three or
more locations on the Vessel, enabling X, Y, and Z motion of the
Kite connection point with respect to the Center of Turning. The
Coupling location with respect to the Vessel is controlled by
adjusting the length of one or more of the three or more Cables. In
one embodiment, the Cables that attach the Coupling are attached
coiled on motor-driven reels that are attached to posts that are
affixed to the Vessel. In some embodiments, a gear box is utilized
to provide mechanical advantage to the reel motor and to mitigate
against back-driving of the motor when it is de-powered. Other
embodiments utilizes clutches and/or brakes on the reel to control
reel rotational motion.
[0056] A Cable that affixes the Kite to the Vessel via an
attachment to the Carriage or Coupling can be adjusted in length
via a winch assembly. Unused cable is housed in a Cable storage
device. The cable storage device (e.g., a reel or drum) is located
on the carriage in sonic embodiments and remotely in other
embodiments. When the cable storage device is independent of the
carriage, coordinated motion between the reel and carriage is
required to permit independent motion while maintaining a target
length extended to the Kite.
[0057] The Cable length can be hundreds or thousands of feet in
length. Greater Cable length affords the opportunity for the Kite
to reach different elevations above sea level and thereby gain
access to different Wind speeds and directions relative to the Wind
at the water surface. The Cable winch assembly can be in any
location on the Vessel provided the Cable is routed through a
pulley, block or other device that facilitates connection between
the winch and Cable storage device and the Carriage or
Coupling.
[0058] In one embodiment, Cable(s) used to affix the Kite to the
Vessel can include electrical conductors and/or circuitry for power
and control appurtenances associated with the Kite and/or devices
such as sensors placed along the length of the Cable. In one
application power is provided through conductors for wind speed
sensors, direction sensors, temperature sensors, and/or pressure
sensors and other conductors are used to convey telemetry from the
sensors affixed to the Kite(s) or Cable to a Kite operational
control center on the Vessel. In another application, power is
provided through conductors in or on the Cable for actuators or
motors affixed to or near to the Kite(s) to adjust physical
characteristics of the Kite(s) and other conductors are used to
convey sensor data, and commands to and from sensors/equipment that
evaluate a change to the Kite's physical characteristics. The
telemetry is sent to a Kite's operational control center on the
Vessel and the commands come from the Kite's operational control
center.
[0059] In another embodiment the telemetry to and from devices
placed along the length of the Cable or affixed to the Kite(s) can
be transmitted via device that utilizes radio, microwave, or other
frequency (wireless) means of transmission. Devices on the Kite(s)
or cable can be powered by energy from, for example, a battery,
solar or wind turbine.
[0060] The position of the Carriage or Kite Connection with respect
to the Vessel frame of reference can be identified at any position
using automatic or manual devices. In the first embodiment, the
location of the Carriage on the track can be determined manually by
visually comparing an identifiable mark on the Carriage to a
numeric or other scale scribed on the track. In the second
embodiment, the Carriage position on the track is sensed by an
instrument. For example, a string-potentiometer, optical encoder,
pulley rotational potentiometer, pully optical encoder, LVDT,
contact switches, stepper motor counter, or other typical means.
Data generated by the sensor(s) are relayed via electrical
conductor or wireless device to the Kite operational control
center.
[0061] The Kite operational control center gathers data provided by
sensors and human machine interface (HMI) devices, retains, and
evaluates the data, then processes it with programs and/or
algorithms to generate display information on an HMI(s) and
transmit commands to devices that are integral to the Kite(s),
Cable, or other devices on the Vessel.
[0062] FIG. 1 depicts a block diagram of a Kite propulsion control
system. The central controller receives a course, trajectory,
vessel loading scheme and/or destination from a user or external
tracking program. The Controller receives information from the
Vessel related to Vessel systems (e.g., thrust, rudder position,
list sensor, orientation to the Earth's magnetic field,
accelerometers). The Controller also receives information from the
Kite system (e.g., carriage location, Kite cable length(s), cable
tension, carriage motor torque, kite cable direction, carriage
motor position). In some embodiments, the Kite also receives
information from external sources (e.g., radio, satellite data,
GPS, weather, wind speeds).
[0063] The Controller utilizes information received to determine a
Kite's location relative to the Vessel. These data are used to
locate the Kite force vector with respect to the Vessel coordinate
frame. In some embodiments, the controller utilizes the Kite(s)
and/or sensors along the Kite cables(s) to understand wind
conditions and determine a preferred Kite elevation and
orientation.
[0064] The Controller manipulates the position of the Carriage and
affixed Kite relative to the Vessel's CT to steer the Vessel. The
Controller can change the configuration of the Kite to manipulate
the elevation of the Kite to utilize favorable winds. The
Controller can also change the configuration of the Kite to
modulate the Kites tensile force generated by Kite-Wind
interaction. In some embodiments, the Controller modulates one or
more of the Vessel propulsion system(s) and rudder(s) to optimize
energy expenditure and smooth Vessel motion.
[0065] The Carriage can be moved to a designated position on the
track and maintained in that position manually or with the aid of
mechanical devices. In the first embodiment the Carriage position
can manually be adjusted and maintained in a specific position
using Cables or ropes that are pulled through a series of pulleys
or blocks (e.g., with pinch block devices) as shown in FIG. 2A.
FIG. 2A is an example of a manually operated Track Assembly.
[0066] In a second embodiment the Carriage can be moved and
maintained by a mechanical device. The first application of the
second embodiment includes but is not limited to hydraulic
cylinder(s), pneumatic cylinder(s) and electromagnetic
actuators.
[0067] The second application of the second embodiment is an
electrical, hydraulic, or pneumatic motor or other device affixed
to one or more Carriage and the Vessel. FIG. 2B depicts an
embodiment where the carriage translates on a Track. The Track is
rigidly connected to the Vessel. At one end of the Track is a motor
with pulley. On the other end of the Track is an idler pulley. A
cable is wrapped around both pulleys and connected to the carriage.
As the motor rotates, it moves the cable right and left thereby
moving the carriage.
[0068] In FIG. 2C, a hydraulic actuator is utilized to translate
the carriage right and left on a track. In some embodiments, the
hydraulic actuator extends with hydraulics and returns with spring
motion. In other embodiments, the actuator is hydraulically
actuated in both directions.
[0069] FIG. 2D depicts a carriage with motor and chain. A chain, or
other device is fastened to the Vessel on both ends, parallel to
the track. As the motor turns the chain wheel, the carriage
translates left and right on the track. A power cord for the motor
extends below the motor and flexes to accommodate the carriage
travel. In another example, the motor or other device is equipped
with a circular gear that engages with a linear gear or slotted
material attached to the track, analogous to a rack and pinion.
Numerous other solutions exist for translating a Carriage on a
Track under power.
[0070] Relative motion between Carriage and Track can be
accomplished by any number of means, including but not limited to
sliding and/or rolling on bearings or wheels.
Influence of Kite Point of Connection on Vessel Direction of
Travel
[0071] The marine industry has explored use of Kites on large
marine and smaller Vessels to reduce fuel consumption with Wind
energy. State of the art Kites are affixed via a Cable to a
specific location on the Vessel, generally at or near the bow of
the Vessel. The point of connection for the Cable that links the
Kite to the Vessel is generally a rigid pole or similar device.
[0072] The Kite connection at or near the bow will only provide
maximum energy in the direction of desired travel when the
direction of desired travel is coincident with wind direction.
Attachment of an external force, for example a Kite, to the bow of
a ship delivers a portion of the Kite's tensile force to enhance
the ship's direction of travel and part of the Kite's tensile force
is used to pull the bow of the ship toward the direction of the
Kite. Hence, when a Vessel elects to travel any course that differs
from the direction of pull from the Kite, the ship will require a
force induced by a rudder, or similar device to offset the Vessels
turning moment induced by the Kit's point of connection to the
Vessel's bow area. Rudder positions other than neutral introduce
drag to the vessel, resulting in lost velocity and/or greater fuel
expenditure.
[0073] Stated another way, when a Kite is not pulling in the
direction of the Vessel's travel, the Vessel experiences a
longitudinal and a lateral component to the Kite pulling force.
When a Kite is attached at or near the bow of a vessel, the lateral
component of the Kite force applies a moment to the Vessel that
will turn the Vessel towards the Kite, owing to the fact that the
Kite attachment point is in front of the center of turning. For the
Vessel to maintain a path that is not aligned with the wind
direction, rudders or tillers need to create a counter moment about
the center of turning to counteract the Kite-induced moment and
keep the vessel on its desired course.
[0074] FIG. 3 depicts the effects of Kite attachment to the bow of
a Vessel. The coordinate frame of the Vessel consists of a Y axis
in the longitudinal direction and an X axis in the transverse
direction. The Kite is pulling at an angle .THETA. with respect to
the Y axis. The Kite force vector can be broken into longitudinal
and transverse components as Fk cos(.THETA.) and Fk sin(.THETA.),
respectively. The transverse force vector is pointed to the right,
applying a clockwise (CW) moment about the Center of Turning,
making the Vessel steer towards the Kite.
[0075] The magnitude of the turning moment can be calculated as
F.sub.k*R, where F.sub.k is the Kite force in the XY plane and R is
the length of a vector from the center of turning to the Kite line
of action that is orthogonal with the Kite line of action. Another
way to calculate the turning moment is to calculate the
mathematical product of the transverse force, F.sub.T, applied to
the ship at the bow (Fk sin(.THETA.)) and the distance from the
center of turning to the Kite attachment point (L/2). In other
words. Turning moment=Fk sin(.THETA.)*L/2.
[0076] The Z (upwards) component of the Kite force can also affect
the Vessel.
[0077] The transverse, moment-generating component of the Kite
force can be very large, depending on the angle, .THETA.. Table 1
presents the lateral force applied to a Vessel by a Kite at varying
angle, .THETA., The larger the angle, the larger the lateral force
applied to the how of a Vessel. This results in larger turning
moment and the need for greater rudder or tiller input to counter
act the Kite-induced turning moment.
TABLE-US-00001 TABLE 1 Lateral force generated by a 1000 lb Kite
force vector Theta, .theta. Lateral Force (degrees) (lbs) 30 500 45
707 60 866
[0078] Hence, it can be surmised that how attachment of a Kite to a
Vessel is most effective when the wind blows the Kite in the
desired direction of travel. As the Kite pulling force becomes more
off-axis, its benefit decreases significantly.
[0079] FIG. 4 depicts a scenario with a longitudinal-mounted track
centered over the Center of turning. The point of contact between
the Kite and the Vessel (i.e. the Carriage) is at the Center of
Turning. In this scenario, the Kite force does not directly impart
a turning moment on the Vessel.
[0080] When all external forces on the Vessel such as Vessel
healing are accounted for, a Kite attachment point can be achieved
that enables a Vessel to travel on a course that is not pointed at
the Kite without rudder input. This is an important feature of the
novel process because it allows a Vessel to optimally use wind
energy without the penalty of drag from a rudder or tiller.
[0081] In the real world, there will be changes from external
forces that influence the Vessel's Center of Turning location. In
one embodiment, these changes in force can be compensated for in
real time by making a commensurate adjustment in the location of
the Kite connection point (i.e. Carriage) away from the Vessels
idealized Center of Turning by a distance necessary to offset the
external forces as shown in FIG. 4. In another embodiment, the
position of the Coupling can be moved away from the theoretical
Center of Turning by making adjustments to the Cables that affix
the Kite connection to the Vessel.
[0082] FIGS. 5A and 5B depict the effects of Carriage motion to the
system depicted in FIG. 4. When the desired direction of Vessel
travel is not aligned with the direction of the Wind, and the Wind
direction relative to the Vessel's direction is forward of the
center (beam) of the Vessel (i.e. on the forward horizon,
.THETA..ltoreq.85.degree.), it is possible to change the Vessel's
course without use of rudders/tillers by adjusting the Kites point
of connection with the Vessel. The direction and magnitude of the
moment applied by the Kite to the Vessel depends on the location of
the Kite force vector with respect to the center of turning. In the
example depicted in FIG. 5A, a counterclockwise (CCW) moment occurs
when the Kite is attached to a location between the CT and the stem
of the Vessel. FIG. 5B depicts how a CW moment occurs when the Kite
is attached to a location between the CT and the bow of the
Vessel.
[0083] As shown on FIG. 5, moving the point of connection toward
the back end of the vessel (aft end) applies a CCW moment and will
cause the front end of the vessel (bow) to move away from the
direction of the Wind, and moving the point of connection forward
will apply a CW moment causing the bow to move in the direction of
the Wind.
[0084] This fore-aft movement of the Carriage can also adjust for
variations in Vessel trajectory and water drag caused by vessel
heeling.
[0085] Applying this concept to a catamaran, the hull that is last
to experience the wind (leeward hull) will be exposed to more water
friction than the hull that is first to be exposed to the Wind
(windward hull) and the differences in hull drag will tend to cause
the vessel to turn in the direction of the leeward hull. An
adjustment of the Kite(s) point(s) of connection on the Vessel
toward the aft will compensate for the drag on the leeward hull
without the use of additional drag induced by rudders or equivalent
steering apparatus.
[0086] FIGS. 6A & 6B illustrate an embodiment of the Turning
effect caused by transverse movement of the Kite attachment point
that intersects the Center of Turning. FIG. 6A shows how the Vessel
will turn counterclockwise when an extension of the Kite force
F.sub.k line (shown in dashed line) intersects the "Y" axis (marked
with a circle) to the stern of the Vessels CT and FIG. 6B shows how
the vessel will turn clockwise when the Kite force F.sub.k line
intersects the "Y" axis (shown with a circle) toward the bow of the
Vessels CT.
[0087] The ability to maintain or change a vessel's course to port
or starboard is a function of the direction and magnitude of the
turning moment created by the Kite force about the Center of
Turning. As the Carriage position moves away from the Center of
Turning, the amount of leverage to create a turning moment
increases. When the line of force from the Kite (or an extension
thereof) crosses the center of turning, no turning moment is
applied to the vessel directly by the Kite. This novel placement of
Kite connection to the Vessel provides an ability to maintain a
course and change course without the added friction caused by using
a rudder or tiller.
[0088] FIGS. 7A and 7B depict a Kite pulling towards the starboard
side of the Vessel with a transversely mounted track positioned
behind (toward Vessel's stern) the Center of Turning by a large
percentage of the Vessel length. In this example, the Kite force
applies a CCW moment that causes the Vessel to turn to left (port)
irrespective of the Carriage position along the track. This is
because R is always on the same side of the center of turning and
the external force Fk intersects the Vessels "Y" axis to the stern
of the CT position. Hence, the Track must be mounted close enough
to the center of turning along the length of the Vessel (or
sufficiently wide) that the Carriage can locate the Kite force to
either side of the center of turning to impart both CW and CCW
moments.
[0089] FIG. 7A depicts a Carriage on the right side of the track.
FIG. 7B depicts the Carriage on the left side of the track. The
Kite force is the same in both images, however the distance R from
the line of action of the Kite force to the center of turning
varies. The larger R value in FIG. 7A creates a larger CCW turning
moment for the Vessel in the left (port) direction than the
Carriage position shown in FIG. 7B for the same kite force.
[0090] FIGS. 8A and 8B depict the effect a change in angle, .THETA.
has on the applied turning moment. In FIG. 8A, the Kite force is
applied in the generally starboard direction. The carriage is
located at the port end of the Track and a CCW moment is applied to
the vessel because the external force Fk crosses the Vessels "Y"
axis to the aft of the CT. In FIG. 8B, the Kite force is applied in
a generally forward direction. The Kite line has crossed the center
of turning toward the bow and generates a CW moment about the
center of turning to make the Vessel turn towards starboard. FIGS.
8A and 8B provide additional examples of how a Vessel can turn away
from or into the wind without the aid of rudder/tiller.
[0091] FIGS. 9A and 9B are a continuation of the story told in
FIGS. 8A and 8B. This figure clearly shows how changes in placement
of the track on the Vessel create different turning forces for
Vessels with the same .THETA. value and Carriage position on the
track. The F.sub.k Kite force vector shown in FIG. 9B is on the
portion of the Y axis that is forward of the CT, therefore the
turning moment will direct the Vessel to the right (into the Wind).
Conversely the Vessel depicted in FIG. 8A with the same angle has
the F.sub.k Kite force vector that crosses the Y axis to the aft of
the CT position so the turning moment will force the vessel to turn
to the left.
[0092] FIGS. 10A and 10B depicts the mechanics of a
transverse-mounted track located in front of the center of turning.
FIG. 10A depicts the carriage at the port end of the track so that
the Kite force vector crosses the longitudinal axis (Y axis) of the
Vessel in front of the Center of Turning, resulting in a clockwise
moment. FIG. 9B depicts the carriage at the starboard end of the
track so that the Kite force crosses the longitudinal axis behind
the Center of Turning resulting in a counterclockwise moment. In
some embodiments, the track is not aligned with the center of
turning. FIGS. 11A and 11B depict an embodiment where the track is
located along the deck railing of a Vessel. As can be seen in the
figure, fore-aft adjustment of the Carriage provides CW and CCW
moments about the Center of Turning, respectively. This location
provides a low Kite attachment point for reduced tilting moment.
Side-mounted track also minimizes interference between the Kite
system and equipment and freight located on the Vessel deck. A side
mounted Track can be as long as the Vessel in some
applications.
[0093] The sides of a Vessel hull are typically very strong and can
accommodate the loads applied from a track. In some embodiments,
the hull is reinforced to accommodate, the track, Carriage and Kite
loads. In some embodiments, the elevation of the side-mounted track
is at the deck railing. In other embodiments. the elevation of the
track is below the deck railing, along the side of the vessel.
Lower attachment points result in less tilting moment applied to
the vessel from the Kite. In general, the track is not located at
or near the water line due to the potential for salt-water
contamination of Kite system components.
[0094] The side-mounted track in FIG. 10 functions well for a Kite
on the starboard side. Typically, an equivalent track is utilized
on the port side for port side Kite loads. Various embodiments
exist for transferring the Kite connection point from one side of
the Vessel to the other. FIG. 12 depicts a Vessel with Tracks along
each side. The Kite cable is managed with a spool at the Bow. The
Kite cable is guided through pulleys at the bow and on the Carriage
to locate the Kite connection point to the Vessel. Coordinated
motion is required between the spool and Carriage to maintain a
particular Kite altitude. Multiple solutions exist for translating
the Carriage along the track, including but not limited to
additional cables, or a carriage-mounted motor. In some
embodiments, the Carriage is powered by electrical power rails in
the Track. Transfer from port to starboard (or vice versa) involves
transferring the Kite cable from the Carriage on side of the Vessel
to a Carriage on the other side of the Vessel.
[0095] FIG. 13 depicts an embodiment with continuous track from the
port side to the starboard side of the Vessel. This embodiment
enables continuous operation of the Kite system and automated
compensation when the Kite force crosses the centerline of the
Vessel. In some embodiments, the Kite cable spool is located on the
Carriage. In other embodiments, the Kite cable is managed with
pulleys from a Vessel-mounted spool. In some embodiments, the Kite
is depowered as the Carriage nears the bow or crosses the center
line to minimize disruption to the Vessel and rudder input.
[0096] FIG. 14 depicts a Kite-powered. Vessel executing a jibe
turn, (when the ship stern crosses through the wind). Starting with
the left image, the Vessel is traveling in direction Y with Fk
applying a moment to steer the ship towards Port. In the second
image, the Carriage is moved forward on Starboard side to turn the
ship towards the Kite with a CW moment. In the third image, the
Vessel rotates across the Kite direction. In some embodiments, the
Carriage is passively dragged around the curved track at the front
of the Vessel. In other embodiments, the Carriage is actively
driven around the curved track. In the fourth image, the Carriage
travels down port side to steer the ship.
[0097] FIG. 15 depicts an embodiment that utilizes a continuous
cable guided by pulleys that circumscribes all or part of the
Vessel hull. The carriage is connected to a location on the cable
and travels with the cable as it is moved. The track is continuous
around the bow of the Vessel. In the embodiment depicted, the cable
is moved by a pulley mounted in the bow of the Vessel, however the
drive pulley could be located at any point along the cable.
[0098] The number of forces and moments acting on a Vessel hull at
any one time is complex. FIG. 16 presents an example of the moments
applied to a Vessel from water pushing on the hull (tilt steering
moment) and from the Kite steering moment. Manipulation of the Kite
attachment point provides the ability to direct the vessel in
multiple directions independent of the tilt moment.
Sensors and Controls
[0099] It is well documented that at any given location on the
planet, the wind direction, temperature, and velocity vary with
change in elevation.
[0100] The use of Kites described in this document provide features
and benefits not available to sailing Vessels that support sails
from fixed masts. Conventional sails attached to masts do not have
the ability to be influenced by Wind force and direction at
elevations significantly above sea level, for example hundreds or
thousands of feet above sea level, but Kites do.
[0101] Two types of Kites are applicable to Vessel propulsion:
Stable and unstable. Unstable Kites conventionally used on Vessels
are limited to altitudes of a few hundred feet above sea level.
Furthermore, unstable Kites result in a continuously changing Kite
force vector. For large, heavy vessels where the Kite force makes
up a small fraction of the vessel propulsion, this variance in Kite
force vector is trivial. However, for smaller craft relying
significantly or solely on Kite propulsion, this variation in Kite
force vector results in inefficiency and complexity. In embodiments
of a Kite/carriage system where unstable Kites are used, carriage
location can be adjusted in real time to compensate for variations
in Kite force vector direction to keep a vessel course.
[0102] A further limitation to mast-mounted sails and conventional
Kites is that they do not have access to the faster Wind speeds and
multiple Wind directions available to higher flying Kites.
[0103] The technology included in this process description enables
Kite(s) and Cable(s) to accommodate instruments and control
technology that sense weather and air conditions at different
elevations and then change the Kite(s) elevation as required to
provide the Vessel with additional Kite powered directions and
rates of travel. FIGS. 17A, 17B, 17C, and 17D describe some of the
possible instrumentation that can be used to gather weather, air,
and wind data.
[0104] A Kite(s) lifts the Cable or other device that connects it
to a Vessel. The mass of the Cable provides a practical elevation
limit. Polymeric Cables made from materials like Dyneema or Spectra
provide sufficient strength with low weight. These features allow
more available Cable length to reach higher elevations with the
propensity to have different Wind properties and therefore more
options to access Kite force that can be utilized for Vessel
propulsion.
[0105] In one instrument use embodiment, the elevation of the Kite
is adjusted up and down to characterize the gradient of the wind
speed and direction, then the Kite elevation is adjusted in the
direction that provides greater Kite force or a component thereof
in the direction of Vessel travel. In another embodiment, Kite
elevations are swept (i.e. evaluated) periodically to determine the
optimum Kite elevation.
[0106] In another embodiment, sensors are mounted along the length
of the main Kite Cable to measure one or more of Wind speed, Wind
direction, temperature, and pressure. In another embodiment,
sensors are placed on a Cable that extends to a pilot chute for
data collection at elevations above the Kite. In another
embodiment, a weather sensing device with wireless communication
travels up and down a Kite Cable, collecting data as it travels.
The information from the weather sensing device is transmitted to
the main Kite control system either continuously or in packets.
Information from these sensor systems is used to determine the
optimal elevation of the Kite. The optimal elevation can vary real
time, requiring continuous adjustment. In one embodiment, an
automated system collects Kite sensor data and adjusts Kite
elevation and/or Kite attachment location in real time.
[0107] FIG. 17A depicts a Vessel with a transversely mounted Track.
The Kite Cable extends from the carriage up to a Lift Kite and a
Pilot Kite. Discrete sensors are located along the length of the
Kite Cable for data collection.
[0108] FIG. 17B depicts an example of a Kite Line-mounted sensor
capable of measuring wind direction, pressure, temperature, and
wind speed. In another embodiment (not shown), Kite line sensors
are removably attached and include a mechanism to scale (i.e.
traverse) the line. When information is to be collected, Kite users
attach a Kite sensor to the Kite cable and the sensor climbs the
cable is extended, collecting data as it ascends and descends.
[0109] FIG. 17C depicts an alternative embodiment of a Kite
Cable-mounted sensor assembly consisting of a collar rigidly
mounted to the Cable with pressure sensors around the periphery.
Embodiments with 3 or more pressure sensors mounted around the
periphery of the ring can be sufficient to determine a wind vector
direction by calculating the direction of the highest pressure.
When absolute pressure sensors are utilized, the pressure
measurement can be indicative of atmospheric pressure and/or
altitude. In some embodiments the cable-mounted sensor is powered
by electrical conductors in the Kite cable. In other embodiments,
the cable-mounted sensor assembly is powered by an internal
battery. The embodiment shown includes a data acquisition processor
(DAQ), battery (BAT) and wireless antenna (ANT). Data measurements
are communicated to the central control computer via either wired
or wireless means. In general, measurements are digitized before
transmission for more robust data transfer. In some embodiments,
the cable-mounted sensor array includes an electronic compass or
other means to orient the wind vector with respect to inertial
space.
[0110] FIG. 17D depicts another embodiment of a Kite Cable-mounted
sensor that includes a weathervane, mini generator, and propeller.
Wind directs the weathervane to be parallel to the wind and the
plane of the propeller to be orthogonal to the wind direction. The
wind turns the propeller at a rate proportional to wind speed,
turning a generator that generates an electrical signal
proportional to wind speed. In some embodiments, the wind speed is
determined by the rotational rate of a propeller, as measured by an
optical device, or equivalent means. In other embodiments, the
amount of power generated by the generator is utilized as a proxy
for wind speed. In some embodiments, there are two propellers: one
for wind speed measurement and one for power generation.
Deployment and Retrieval of a Kite
[0111] The methodology described in this document is Vessel
specific but there are some generalities. The Kite(s) are only used
in open waters, away from obstacles, for example bridges and power
lines that are common in harbors. Deployment requires orienting the
Vessel in a way that the Kite launching area is downwind. A pilot
Kite as shown in FIG. 17A is released first. Once it is stable in
flight, it is used to pull the main Kite into the air. Kite
retrieval is performed by reeling in the Kite's Cable. In some
embodiments, a Kite is depowered by reducing the surface area the
Kite exposes to the Wind prior to or during retrieval. FIG. 18
depicts one method of changing a Kites pull on the Cable. This is
used for depowering at Kite retrieval and adjustment of Kite force
as required for desired Vessel speed.
[0112] There are many ways to store Cable used to connect the. Kite
to the Carriage. In the first embodiment, it can be wound around a
drum with motorized release and retrieval and with layering
mechanism similar to that used on a fishing reel. The drum assembly
also includes an ability to release and retract Cable at varying
rates. The drum assembly can be located in any area that is
convenient. For example, it can be located near the Track Assembly
or at any location, on the Vessel, and then Cable is routed with
pullies or other devices to the Carriage affixed to the Track
Assembly. In the second embodiment, the Cable can be stored in a
toroidal shaped container with rectangular or other shape. The
shape stores and removes cable from an opening on the inner radius
or other location as shown in FIG. 19. The toroidal shape is
ideally motorized to deploy or retrieve the Cable at variable rates
and can be oriented horizontally, vertically, or at any other
angle.
Kite Design
[0113] FIG. 20 illustrates an embodiment of Examples of Kite
designs. Stable Kites provide consistent pulling force for a Vessel
with minimal control effort required. Several designs provide
stable Kite pulling force including, but not limited to, barn door
design (19A), Rokkaku (19B), Dopero (19C) and parafoil designs
(19D). All of these designs are examples of Kite technology that by
their design are inherently stable in flight and pulled from a
single Cable. Both of these attributes are desirable in a Kite
design.
[0114] In some embodiments, a maneuverable (less stable) Kite can
be controlled at a stable point when sufficient cables are
utilized. The use of a maneuverable Kite with sufficient control
cables enables a User or automated system to place and hold the
Kite in an orientation with respect to the wind that generates
maximum cable tension for maximum Vessel pulling three. An example
of a maneuverable Kite is a parafoil design with four control
cables, as shown in FIG. 21. The foil Kite is controlled by left
and right control cables and left and right brake cables.
[0115] In some embodiments, a Kite with inflatable leading edge is
utilized as shown in FIG. 18. This design facilitates recovery
after the Kite touches down on water. In other embodiments, open
cell foils are utilized.
Kite Power Adjustment
[0116] Wind acting on the Kite to form drag forces and lift forces
are the sources of Kite force applied to a Vessel. Features that
add to Kite drag and lift include: Kite area; Presence/absence/size
of a Kite tail. A tail provides drag (pulling force) and keeps Kite
oriented against the wind; and Presence/absence/size of a pilot
chute.
[0117] In some embodiments, the amount of drag of a Kite is
adjustable. This can be beneficial in the event of extreme winds or
to facilitate retrieval of a Kite. In one embodiment, Kite force is
automated adjustment by opening/closing windows in the surface of
the Kite as shown in FIG. 22. In another embodiment, the length of
the tail of a Kite is adjustable in order to vary Kite force. In
another embodiment, Kite throe adjustments are made electronically
by servomotors on the Kite as shown in FIG. 23. Power to the motors
can be from electrical cables within the main Kite Cable or from
batteries on board the Kite or solar cells mounted on the Kite. In
one embodiment, the Kite is adjusted via remote control through a
wireless (e.g., Bluetooth, or RF) connection.
[0118] FIG. 22 depicts an embodiment where the openings at the
leading edge of a Kite can be collapsed by cinching a cable or rope
that encircles one or more of the air channel openings. As the
cable/rope is tightened, the frontal area of the Kite decreases,
causing drag.
[0119] FIG. 23 depicts another embodiment of a Kite that achieves
adjustable lift via adjustable flaps on its surface that allow
varying amount of air to escape from the Kite. In one embodiment,
flaps are adjusted from the Vessel by means of Cables. In another
embodiment, motors on the Kite adjust the opening size via sliding
panels. In one embodiment, the opening is covered by a mechanism
resembling a motor-driven roll-up window shade with return springs
that shut the shade in the absence of force from the motor.
[0120] FIG. 24 depicts a Carriage design with four independent
motor-driven spools for controlling Kite control and brake cables.
In some embodiments, cable length is adjusted by each spool
independently as the Carriage moves to maintain Kite position and
stability. The Kite is released to higher elevations by unwinding
all spools simultaneously. The Kite is depowered by turning the
brake spools to reel in cable. In some embodiments, the spools of
cable and motors are located on the Carriage.
[0121] FIG. 25 depicts a Carriage that manages. Kite cable with
pulleys. The length of each Kite cable is controlled by spools that
are attached to the Vessel. In some embodiments, the spools are
manually turned. In other embodiments, the spools are turned by
motor. In some embodiments, motors are controlled by an automated
Kite control system. As the carriage moves along the track, the
motor-driven spools collect and release Kite line to maintain a
constant altitude and attitude of the Kite when so desired. In some
embodiments, the bracket that connects the pulleys to the carriage
are binged about an axis parallel to the track. This hinge permits
the pulleys on the carriage to adjust their angle with respect to
horizontal as the Kite lifts from sea level into the air. When the
Kite is level with the vessel, the pulleys are at or near
horizontal. As the Kite ascends into the sky, the pulleys passively
rotate on their respective hinges so that the plane of the pulleys
is aligned with the Kite cable and Kite. In some embodiments, the
incline of the plane of the Kite pulleys with respect to horizontal
is instrumented with a sensor (e.g., inclinometer, potentiometer,
encoder) to provide information on the direction of the Kite force
vector. In some embodiments, the force applied from the Kite to the
carriage, and/or the carriage to the track, and or the track to the
Vessel is measured with one or more sensors (e.g., strain gages,
load cells, etc.). In some embodiments, the Kite control system
uses Kite cable motor torque and/or current as a proxy for Kite
cable tension.
* * * * *