U.S. patent application number 13/769342 was filed with the patent office on 2014-03-20 for autonomous hull navigation.
This patent application is currently assigned to Raytheon Company. The applicant listed for this patent is RAYTHEON COMPANY. Invention is credited to Glenn Colvin, Fraser M. Smith.
Application Number | 20140081504 13/769342 |
Document ID | / |
Family ID | 50273129 |
Filed Date | 2014-03-20 |
United States Patent
Application |
20140081504 |
Kind Code |
A1 |
Smith; Fraser M. ; et
al. |
March 20, 2014 |
Autonomous Hull Navigation
Abstract
An autonomous hull robot navigation subsystem for guiding a hull
robot on a hull of a vessel independent of external guidance
devices includes a drive subsystem onboard the robot for driving
and maneuvering the robot about the hull. A sensor subsystem
onboard the robot senses an environmental characteristic. A
navigation subsystem onboard the robot is responsive to the sensor
subsystem and includes a processor. The processor utilizes the
environmental characteristic to determine a position of the robot
on the hull.
Inventors: |
Smith; Fraser M.; (Salt Lake
City, UT) ; Colvin; Glenn; (Park City, UT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
RAYTHEON COMPANY |
Waltham |
MA |
US |
|
|
Assignee: |
Raytheon Company
Waltham
MA
|
Family ID: |
50273129 |
Appl. No.: |
13/769342 |
Filed: |
February 17, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61701512 |
Sep 14, 2012 |
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61701517 |
Sep 14, 2012 |
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61701523 |
Sep 14, 2012 |
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61701529 |
Sep 14, 2012 |
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61701534 |
Sep 14, 2012 |
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61701537 |
Sep 14, 2012 |
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Current U.S.
Class: |
701/23 ;
114/221R; 114/222; 290/54; 901/41 |
Current CPC
Class: |
B63B 17/00 20130101;
B62D 55/32 20130101; Y10S 901/44 20130101; B63B 59/06 20130101;
B62D 55/265 20130101; B63B 71/00 20200101; B63B 59/10 20130101;
B63G 8/001 20130101; B63B 59/08 20130101; Y10S 901/41 20130101;
G05D 1/00 20130101; G05D 1/021 20130101; Y10S 901/01 20130101; G05D
2201/0203 20130101 |
Class at
Publication: |
701/23 ; 114/222;
114/221.R; 290/54; 901/41 |
International
Class: |
G05D 1/00 20060101
G05D001/00; B63G 8/00 20060101 B63G008/00; B63B 59/06 20060101
B63B059/06 |
Claims
1. An autonomous hull robot navigation system for guiding a hull
robot on a hull of a vessel independent of external guidance
devices, comprising: a drive subsystem onboard the robot for
driving and maneuvering the robot about the hull; a sensor
subsystem onboard the robot configured to sense an environmental
characteristic; and a navigation subsystem onboard the robot and
responsive to the sensor subsystem, the navigation subsystem being
configured to determine a position of the robot on the hull and to
facilitate navigation based on the environmental
characteristic.
2. The system according to claim 1, further comprising a memory
onboard the robot including data concerning the configuration of
the hull and a desired path of travel for the robot.
3. The system according to claim 1, wherein the sensor subsystem
comprises a cleanliness detection system, and the environmental
characteristic near the robot is a cleanliness of the hull, and
wherein the navigation subsystem is configured to control the drive
subsystem to maneuver the robot to a less clean position on the
hull when a current position cleanliness is greater than a
predetermined threshold.
4. The system according to claim 1, wherein the sensor subsystem
comprises a cleanliness detection system, and the environmental
characteristic near the robot is an interface between a recently
cleaned portion of the hull and a yet-to-be-cleaned portion of the
hull.
5. The system according to claim 1, wherein the sensor subsystem
comprises a gravity-vector detector configured to sense a direction
of gravity relative to the robot, wherein the hull configuration
includes a continuously inclining surface, and wherein the
navigation subsystem is configured to determine a vertical position
of the robot on the hull based on a unique gravity vector
corresponding to a position on the continuously inclining
surface.
6. The system according to claim 1, wherein the sensor subsystem
comprises a pressure sensor configured to sense the fluid pressure
about any given location about the hull.
7. The system according to claim 1, wherein the sensor subsystem
comprises a flow field detector.
8. The system according to claim 1, wherein the sensor subsystem is
an acoustic detection subsystem configured to detect acoustic
fiduciaries.
9. The system of claim 8, wherein the acoustic fiduciaries comprise
at least one of vessel engine noise, noise generated from fluid
contacting a portion of the hull of the vessel, and noise generated
from operation of a propeller.
10. The system of claim 8, wherein the noise fiduciaries comprise
known audio frequencies specific to identified portions of the
vessel.
11. The system according to claim 1, wherein the sensor subsystem
comprises an ultrasonic hull signature detector.
12. The system according to claim 1, further comprising an energy
harvesting device for harvesting energy generated by movement of
the hull through a fluid to provide power to at least one of the
autonomous hull robot navigation system, the drive subsystem, the
sensor subsystem, and the navigation subsystem.
13. The system according to claim 1, further comprising a power
scavenging system for converting energy from fluid flow into usable
mechanical or electrical power.
14. The system according to claim 13, wherein the power scavenging
system is extendable to a region outside of the robot at least
beyond a boundary layer of the passing fluid.
15. The system according to claim 1, wherein the drive subsystem is
configured to maneuver the robot primarily along vertical paths on
a surface of the hull in a direction approximately orthogonal to a
direction of flow of a fluid past the hull, wherein the sensor
subsystem comprises a flow field detector, and the drive subsystem
is configured to maintain an orientation of the robot relative to
the flow of the fluid while the robot maneuvers along the vertical
paths to maximize energy harvested from the flow.
16. The system according to claim 1, further comprising a
switchable permanent magnetic fixation device independent of the
drive subsystem and configured to securely maintain a position of
the robot relative to the hull when the navigation subsystem is not
controlling the drive subsystem to maneuver the robot.
17. The system according to claim 1, wherein the environmental
characteristic comprises an edge of the vessel.
18. The system according to claim 1, wherein the sensor subsystem
comprises an ultrasonic inspection device and the environmental
characteristic comprises an ultrasonic signature of a portion of
the hull of the vessel.
19. The system according to claim 18, wherein the ultrasonic
signature includes at least one of a hull thickness, integrity of a
weld on the hull, a crack in the hull, a fissure in the hull, a
change in thickness of the hull and an irregularity of the
hull.
20. The system according to claim 18, wherein the ultrasonic
inspection device is functional during operation of the vessel and
comprises an ultrasonic emitter configured to emit an ultrasonic
wave and an ultrasonic detector configured to detect a reflected
ultrasonic wave reflected off of the hull, the reflected ultrasonic
wave useable to identify the ultrasonic signature.
21. A method of autonomous hull robot navigation for guiding a hull
robot on a hull of a vessel independent of external guidance
devices, comprising: sensing an environmental characteristic near
the hull robot using a sensor subsystem onboard the robot;
determining a position of the hull robot on the hull based on the
environmental characteristic using a navigation subsystem onboard
the robot which is responsive to the sensor subsystem; and
maneuvering the robot about the hull using a drive subsystem
onboard the robot based on the position of the hull robot.
22. The method according to claim 21, wherein sensing the
environmental characteristic comprises sensing a cleanliness of the
hull, and wherein maneuvering the robot comprises maneuvering the
robot to a less clean position on the hull when a current position
cleanliness is greater than a predetermined threshold.
23. The method according to claim 21, wherein sensing the
environmental characteristic comprises sensing an interface between
a recently cleaned portion of the hull and a yet-to-be-cleaned
portion of the hull.
24. The method according to claim 21, wherein sensing the
environmental characteristic comprises sensing a direction of
gravity relative to the robot, and determining the position of the
hull robot comprises determining a vertical position of the robot
on the hull based on a unique gravity vector corresponding to a
position on a continuously inclining surface of the hull.
25. The method according to claim 21, wherein sensing the
environmental characteristic comprises sensing at least one of a
pressure of fluid proximal to the robot and an acoustic
characteristic of or near the hull.
26. The method according to claim 21, further comprising harvesting
energy from a flow of fluid past the robot, and maintaining an
orientation of the robot relative to the flow of fluid to maximize
energy harvested from the flow while the robot maneuvers along
substantially vertical paths.
27. The method according to claim 21, further comprising fixing a
position of the robot relative to the hull when the robot is not
being maneuvered using a switchable permanent magnetic fixation
device independent of a drive subsystem of the robot.
28. A system for autonomous hull robot navigation on a hull of a
vessel independent of external guidance devices, comprising: a
sensor onboard a hull robot and configured to detect an
environmental characteristic; a database onboard the hull robot and
configured to store information about the hull of the vessel,
including correspondence information relating a position on the
hull with the environmental characteristic detected by the sensor;
a processor onboard the hull robot and configured to compare the
detected environmental characteristic with the correspondence
information in the database to determine the position of the hull
robot on the hull.
29. A method for fixing a position of a robot relative to a hull of
a vessel when the robot is at rest, the method comprising:
operating a hull robot about a hull of a vessel using a drive
subsystem, the hull robot having a fixation device independent of
the drive subsystem of the robot; and selectively actuating the
fixation device to at least temporarily secure the robot in place
about the hull.
30. A hull robot, comprising: a robot body; a drive subsystem
supported by the robot body for driving and maneuvering the robot
about the hull of a vessel while the vessel is in motion in a
fluid; structure in the robot for directing fluid flow about the
hull into a specific fluid flow path within the robot body; a
displacement energy extraction device supported by the robot body
within the fluid flow path, and comprising a displaceable member
moveable in response to the fluid flow acting upon the displaceable
member, the displacement energy extraction device being configured
to extract energy from the fluid flow useable by the hull
robot.
31. A hull robot comprising: a robot body; a drive subsystem
supported by the robot body for driving and maneuvering the robot
about the hull of a vessel while the vessel is in motion in a
fluid; structure in the robot for directing fluid flow about the
hull into a specific fluid flow path within the robot body; a
displacement energy extraction device in the form of a propeller
supported by the robot body within the fluid flow path, and
comprising a displaceable member moveable in response to the fluid
flow acting upon the displaceable member, the displacement energy
extraction device being configured to extract energy from the fluid
flow useable by the hull robot.
32. A hull robot comprising: a robot body; a drive subsystem
supported by the robot body for driving and maneuvering the robot
about the hull of a vessel while the vessel is in motion in a
fluid; structure in the robot for directing fluid flow about the
hull into a specific fluid flow path within the robot body; a
displacement energy extraction device comprising a water wheel
supported by the robot body within the fluid flow path, and
comprising a displaceable member moveable in response to the fluid
flow acting upon the displaceable member, the displacement energy
extraction device being configured to extract energy from the fluid
flow useable by the hull robot.
33. The robot of claim 32, wherein the water wheel comprises a
plurality of blades disposed about a rotor of the water wheel.
34. The robot of claim 32, wherein the water wheel comprises a
plurality of fluid containers disposed about a rotor of the water
wheel.
35. A hull robot comprising: a robot body; a drive subsystem
supported by the robot body for driving and maneuvering the robot
about the hull of a vessel while the vessel is in motion in a
fluid; structure in the robot for directing fluid flow about the
hull into a specific fluid flow path within the robot body; a
displacement energy extraction device comprising a flapper
supported by the robot body within the fluid flow path, and
comprising a displaceable member moveable in response to the fluid
flow acting upon the displaceable member, the displacement energy
extraction device being configured to extract energy from the fluid
flow useable by the hull robot.
36. A hull robot, comprising: a robot body; a drive subsystem
supported by the robot body for driving and maneuvering the robot
about the hull of a vessel while the vessel is in motion in a
fluid; structure in the robot for directing fluid flow about the
hull into a specific fluid flow path within the robot; an
oscillation-based energy extraction device supported by the robot
and within the fluid flow path, wherein the oscillation-based
energy extraction device oscillates in response to the fluid flow
acting upon the oscillation-based energy extraction device, the
oscillation-based energy extraction device being configured to
extract energy from the fluid flow useable by the hull robot.
37. The robot of claim 36, wherein the oscillation-based energy
extraction device comprises a flapper.
38. The robot of claim 37, wherein the flapper is coupled to a
rotating hinge and is oscillateable on the hinge.
39. The robot of claim 37, wherein the flapper comprises a
piezoelectric element and is oscillateable by flexing.
40. A method of powering a hull robot, comprising: maneuvering the
robot about the hull while the hull of a vessel while the vessel is
in motion in a fluid; directing fluid flow about the hull into a
specific fluid flow path within the robot toward a
oscillation-based energy extraction device within the robot and
within the fluid flow path, the oscillation-based energy extraction
device being oscillateable in response to the fluid flow acting
upon the oscillation-based energy extraction device; and extracting
energy from the fluid flow with the oscillation-based energy
extraction device, the energy being useable to provide to the hull
robot.
41. The method of claim 41, further comprising maintaining an
orientation of the robot relative to the fluid flow to maximize
energy harvested from the flow while driving and maneuvering the
robot about the hull.
42. The robot of claim 41, further comprising using the energy
extracted from the fluid flow to power a cleaning subsystem of the
hull robot to clean the hull of the vessel.
43. The robot of claim 41, further comprising using the energy
extracted from the fluid flow to power a drive subsystem of the
hull robot to drive and maneuver the robot about the hull of the
vessel.
44. A hull robot, comprising: a robot body; a drive subsystem
supported about the robot body for driving and maneuvering the
robot about the hull of a vessel while the vessel is in motion in a
fluid; an energy extraction device operable to extract energy from
a fluid flow about the vessel, the fluid flow resulting from the
motion of the vessel in the fluid; and a support structure for
positioning and supporting the energy extraction device without the
robot body, wherein the energy extraction device is in contact with
the fluid flow outside the robot body.
45. The robot of claim 44, wherein the energy extraction device is
extendable from a position within the robot body to a position
without the robot body, and wherein the energy extraction device is
retractable.
46. The robot of claim 44, wherein the support structure supports
the energy extraction device in a position beyond a boundary layer
of the fluid flow about the robot body.
47. The robot of claim 44, wherein the energy extracted from the
fluid flow is useable by the hull robot to clean the hull.
48. The robot of claim 44, wherein the energy extracted from the
fluid flow is useable by the drive subsystem to drive and maneuver
the robot about the hull.
49. The robot of claim 44, wherein the energy extraction device
comprises a turbine.
50. The robot of claim 44, wherein the displacement energy
extraction device comprises a propeller.
51. The robot of claim 44, wherein the displacement energy
extraction device comprises a water wheel.
52. The robot of claim 44, wherein the displacement energy
extraction device comprises a flapper.
53. A method of powering a hull robot, comprising: maneuvering the
robot about the hull of a vessel while the vessel is in motion in a
fluid; positioning an energy extraction device operable to extract
energy from a fluid flow relative to a vessel without a body of the
robot, the fluid flow resulting from the motion of the vessel in
the fluid; extracting energy from the fluid flow with the energy
extraction device, the energy being useable as power by the hull
robot.
54. The method of claim 53, further comprising retracting the
energy extraction device from without the body of the robot to
within the body of the robot to cease extracting the energy.
55. The method of claim 53, further comprising retractably
extending the energy extraction device from within the body of the
robot to without the body of the robot to begin extracting the
energy.
56. The method of claim 53, wherein positioning the energy
extraction device comprises positioning the energy extraction
device beyond a boundary layer of the fluid flow about the body of
the robot.
57. The method of claim 53, further comprising cleaning the hull
with the hull robot using the energy extracted from the fluid
flow.
58. The method of claim 53, further comprising driving and
maneuvering the robot about the hull using the energy extracted
from the fluid flow.
59. A hull robot, comprising: a drive subsystem onboard the robot
for driving and maneuvering the robot about a hull of a vessel; and
a robot body having a longitudinal axis extending between
longitudinal sides of the robot body and a lateral axis extending
between lateral sides of the robot body, the drive subsystem being
configured to drive the robot in a direction along the longitudinal
axis; an inlet formed along at least one of the lateral sides of
the robot body, wherein the robot is configured to travel about the
hull of the vessel in a direction transverse to a surface of a
fluid in which the vessel is operating.
60. The robot of claim 59, further comprising: a fluid flow path
within the robot body generated from fluid being received in the
inlet; and an energy extraction device supported about the robot
body and operable within the fluid flow path.
61. The robot of claim 59, wherein the robot body comprises a
hydrodynamic configuration tuned in a direction transverse to the
longitudinal axis and a direction of travel of the robot, such that
the hydrodynamics of the robot while being maneuvered in the
direction of travel are enhanced.
62. A hull robot, comprising: a drive subsystem onboard the robot
for driving and maneuvering the robot about a hull of a vessel; a
robot body comprising a hydrodynamic configuration tuned in a
direction transverse to a longitudinal axis extending between
longitudinal sides of the robot body, the longitudinal axis
extending in a direction in which the robot is driven by the drive
subsystem; wherein a fluid flow about the robot body resulting from
motion of the vessel travels over the robot body in the tuned
hydrodynamic direction to enhance efficiency of driving and
maneuvering of the robot.
63. The hull robot of claim 62, wherein the hydrodynamic
configuration is tuned in a direction substantially parallel with a
lateral axis extending between lateral sides of the robot body.
64. The hull robot of claim 62, further comprising an inlet formed
along a lateral side of the hull robot for receiving the fluid flow
and for generating a fluid flow path within the robot body.
65. The hull robot of claim 64, further comprising an energy
extraction device operable within the fluid flow path.
66. The hull robot of claim 65, wherein the energy extraction
device is oriented in the tuned hydrodynamic direction.
67. The hull robot of claim 71, wherein the lateral side extends
between the longitudinal sides and is substantially orthogonal to
the longitudinal sides.
68. The robot of claim 62, wherein the robot body is symmetrical
about at least a longitudinal axis and a lateral axis to facilitate
enhanced efficiency bi-directional driving of the hull robot about
multiple axes having different orientations.
69. The robot of claim 62, wherein the robot body is radially
symmetrical.
70. A method of enhancing efficient operation of a hull robot about
a hull of a vessel, comprising: configuring a robot body to
comprise a hydrodynamic configuration tuned in a direction
transverse to a direction of travel of the robot, and substantially
in a direction of fluid flow resulting from motion of the vessel
within a fluid; configuring a drive subsystem onboard the robot to
maneuver the robot about a hull of a vessel in a direction
transverse to a direction of the flowing fluid to enhance the
efficiency of the fluid flow about the robot body.
71. The method of claim 70, wherein the robot is maneuvered in a
direction substantially orthogonal to the direction of the flowing
fluid.
72. The method of claim 70, further comprising employing an energy
extraction device to extract energy from the fluid passing about
the robot body.
73. The method of claim 70, further comprising maneuvering the hull
robot in a substantially bi-directional manner to avoid turning the
hull robot around.
74. The method of claim 70, further comprising maneuvering the hull
robot up and down the hull of the vessel while moving from a front
of the ship towards a back of the ship.
75. The method of claim 70, further comprising configuring an inlet
along a lateral side of the robot body, the inlet configured to
receive a portion of the fluid therein and to generate a fluid flow
path within the robot body.
76. The method of claim 75, further comprising operatively
positioning an energy extraction device within the fluid flow
path.
77. A method of enhancing efficient operation of a hull robot,
comprising: configuring a hull robot to comprise a drive system
operable to maneuver and drive the hull robot about a hull of a
vessel along an axis extending from one of a top and bottom of the
hull; configuring a robot body of the hull robot to comprise a
longitudinal axis extending between longitudinal sides of the robot
body and a lateral axis extending between lateral sides of the
robot body, the drive subsystem being configured to drive the robot
in a direction along the longitudinal axis; forming an inlet along
at least one of the lateral sides of the robot body, wherein fluid
received in the inlet generates a fluid flow path within the robot
body; and providing an energy extraction device supported about the
robot body, the energy extraction device being operably positioned
within the fluid flow path.
78. A hull robot, comprising: a robot body; a drive subsystem
supported about the robot body for maneuvering the robot about a
hull of a vessel; and a magnetic fixation device operable with the
robot body and independent of the drive subsystem, the magnetic
fixation device being actuatable to securely maintain a position of
the robot relative to the hull when the drive subsystem is
inactive.
79. The hull robot of claim 78, wherein the drive subsystem
comprises a magnetic device for attaching the robot body to the
hull.
80. The hull robot of claim 78, wherein the magnetic fixation
device comprises a switchable magnet.
81. The hull robot of claim 78, further comprising a plurality of
magnetic fixation devices positioned about the robot body.
82. The hull robot of claim 78, wherein the magnetic fixation
device comprises an electromagnet.
83. The hull robot of claim 78, wherein the magnetic fixation
device comprises a permanent magnet.
83. The hull robot of claim 78, wherein the magnetic fixation
device restricts maneuvering of the robot by the drive subsystem
when securely maintaining the position of the robot relative to the
hull.
85. The hull robot of claim 78, wherein the magnetic fixation
device comprises a non-attachment configuration to enable the drive
subsystem to maneuver the robot about the hull of the vessel when
not securely maintaining the position of the robot relative to the
hull.
86. An autonomous hull robot navigation system for guiding a hull
robot on a hull of a vessel independent of external guidance
devices, comprising: a drive subsystem for driving and maneuvering
the robot about a hull of a vessel; a paint sensor subsystem
onboard the robot configured to sense a paint characteristic about
the hull; a navigation subsystem onboard the robot and response to
the paint sensor subsystem, being configured to facilitate
navigation based on the paint characteristic.
87. The robot of claim 86, wherein the paint characteristic
comprises the presence or lack of paint.
88. The robot of claim 86, wherein the paint characteristic
comprises a freshness of a coat of paint.
89. The robot of claim 86, wherein the paint sensor subsystem
comprises a camera.
90. A hull robot, comprising: a robot body; a drive subsystem
supported by the robot body for driving and maneuvering the robot
about the hull of a vessel while the vessel is in motion in a
fluid; a cleaning subsystem supported by the robot body and having
at least one cleaning element for cleaning the hull of the vessel;
and an energy extraction device supported by the robot body, the
energy extraction device being directly coupled to at least one of
the drive subsystem and the cleaning element, wherein the energy
extraction device is actuated by water passing over the hull of the
vessel while the vessel is in motion.
91. The hull robot of claim 90, wherein the energy extraction
device comprises a direct mechanical connection to the drive
subsystem.
92. The hull robot of claim 90, wherein the energy extraction
device supports one or more cleaning elements thereon, such that
actuation of the energy extraction device functions to actuate a
cleaning function by the energy extraction device.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of the following
provisional patent applications, the contents of each of which are
incorporated herein by reference in their entirety: U.S.
provisional patent application Ser. No. 61/701,512, filed on Sep.
14, 2012; U.S. provisional patent application Ser. No. 61/701,517,
filed on Sep. 14, 2012; U.S. provisional patent application Ser.
No. 61/701,523, filed on Sep. 14, 2012; U.S. provisional patent
application Ser. No. 61/701,529, filed on Sep. 14, 2012; U.S.
provisional patent application Ser. No. 61/701,534, filed on Sep.
14, 2012; and U.S. provisional patent application Ser. No.
61/701,537, filed on Sep. 14, 2012.
[0002] This application is related to copending United States
patent application Ser. No. ______, filed on ______(attorney docket
no. 2865-11-2182-US-NP); Ser. No. ______, filed on ______(attorney
docket no. 2865-11-2188-US-NP); Ser. No. ______, filed on
______(attorney docket no. 2865-11-2187-US-NP); Ser. No. ______,
filed on ______(attorney docket no. 2865-11-2189-US-NP); and Ser.
No. ______, filed on ______(attorney docket no.
2865-11-2192-US-NP), the contents of each of which is hereby
incorporated by reference herein in their entirety.
[0003] This application is also related to the following copending
United States patent applications: Ser. No. 12/313,643, filed on
Nov. 21, 2008; Ser. No. 12/583,346, filed on Aug. 19, 2009; Ser.
No. 12/586,248, filed on Sep. 18, 2009; Ser. No. 12/587,949, filed
on Oct. 14, 2009; and Ser. No. 12/800,486 filed on May 17, 2010;
the contents of each of which is hereby incorporated herein by
reference in their entirety.
BACKGROUND
[0004] The structural integrity of a vessel hull is an important
safety an economical concern. For example, frictional resistance
due to buildup on or fouling of the hull by algae, sea grass,
barnacles, and the like as a vessel moves through the water can
increase the fuel consumption of the vessel. As an example, an
added resistance of 30% due to moderate bio-fouling of a tanker
hull can increase the fuel consumption of the vessel by up to
twelve tons per day. The result is added cost to operate the
vessel, as well as increased emissions. Monitoring of damage to the
hull is useful in determining when and where repairs should be
made.
[0005] A variety of methods are currently employed to lower the
chance of bio-fouling and/or to rid vessel hulls of bio-fouling
through cleaning, as well as to monitor the structural integrity of
the hull. For example, typically, while the ship is dockside and/or
during normal unlading conditions, the hull is periodically
inspected manually by scuba divers. The cost of such an inspection
effort is high. The type of inspection effort may need to be
repeated at a predetermined period of months, such as every ten to
twenty months or sooner, particularly if there is suspicion of
damage to the vessel hull. To inspect the vessel hull, the hull
often must first be cleaned. As a complication, however, some
jurisdictions have made dockside cleaning illegal due to the
toxicity of anti-fouling paint particles removed during cleaning,
which can contaminate the water.
[0006] In response, robotic hull cleaners have been proposed. The
"Hismar" consortium, for example, has proposed a robotic platform
for hull cleaning during normal unlading conditions. The robot is
magnetically attached to the hull when the vessel is stationary and
is tethered to an operator control unit, a high pressure water
source, a suction subsystem, and a power subsystem. Various other
robots have also been proposed.
[0007] Despite some of their advantages over manual cleaning
procedures, prior hull cleaning robots suffer from various
shortcomings. For instance, most prior hull cleaning robots are
connected or tethered to a cable and powered and controlled by an
on-board power supply and control system and are able to operate
only on a stationary vessel. Further, inspection techniques for
determining the cleanliness of the hull are inefficient. Still
further, navigation of such robots may be by remote manual
navigation and rely on input of a human operator to guide the robot
about the hull.
SUMMARY
[0008] An autonomous hull robot navigation subsystem for guiding a
hull robot on a hull of a vessel independent of external guidance
devices, in accordance with an example embodiment of the present
technology, can include a drive subsystem onboard the robot for
driving and maneuvering the robot about the hull. A sensor
subsystem onboard the robot can sense an environmental
characteristic. A navigation subsystem onboard the robot can be
configured to be operable with and responsive to the sensor
subsystem and include a processor. The processor can utilize the
environmental characteristic to determine a position of the robot
on the hull, which facilitates continuous navigation.
[0009] A method of autonomous hull robot navigation for guiding a
hull robot on a hull of a vessel independent of external guidance
devices, in accordance with an example embodiment of the present
technology, can include sensing an environmental characteristic
near the hull robot using a sensor subsystem onboard the robot. A
position of the hull robot on the hull can be determined based on
the environmental characteristic using a navigation subsystem
onboard the robot, which is operable with and responsive to the
sensor subsystem. The robot can be maneuvered about the hull using
a drive subsystem onboard the robot based on the position of the
hull robot.
[0010] A system for autonomous hull robot navigation on a hull of a
vessel independent of external guidance devices, in accordance with
an example embodiment of the present technology, can include a
sensor onboard a hull robot configured to detect an environmental
characteristic. A database onboard the hull robot can be configured
to store information about the hull of the vessel, including
correspondence information relating a position on the hull with the
environmental characteristic detected by the sensor. A processor
onboard the hull robot can be configured to compare the detected
environmental characteristic with the correspondence information in
the database to determine the position of the hull robot on the
hull. The hull robot can thus navigate about the hull by
continuously or periodically detecting environmental
characteristics and comparing these for position determination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a bottom perspective view of a hull robot in
accordance with an embodiment of the present technology;
[0012] FIG. 2 is a top perspective cutaway view of the hull robot
of FIG. 1;
[0013] FIG. 3 is a bottom perspective view of a hull robot in
accordance with an embodiment of the present technology;
[0014] FIG. 4 is a block diagram of a hull robot system in
accordance with an embodiment of the present technology;
[0015] FIG. 5 is a detailed view of the navigation and electronic
subsystems of the hull robot system of FIG. 4;
[0016] FIG. 6 illustrates a vertical navigation path of a hull
robot on a hull of a vessel in accordance with an embodiment of the
present technology;
[0017] FIG. 7 is a perspective view of a symmetrical hull robot
traveling orthogonal to a fluid flow field in accordance with an
embodiment of the present technology;
[0018] FIG. 8 is a block diagram of a hull robot system including
power scavenging, magnetic fixation, and a deployable skirt in
accordance with an embodiment of the present technology;
[0019] FIGS. 9a-9c illustrate energy harvesting devices in
accordance with embodiments of the present technology;
[0020] FIG. 10 is a flow diagram of a method of autonomous hull
robot navigation for guiding a hull robot on a hull of a vessel
independent of external guidance devices, in accordance with an
embodiment of the present technology; and
[0021] FIG. 11 is a block diagram of a system for autonomous hull
robot navigation on a hull of a vessel independent of external
guidance devices, in accordance with an embodiment of the present
technology.
DETAILED DESCRIPTION
[0022] Before the present disclosure is described herein, it is to
be understood that this disclosure is not limited to the particular
structures, process steps, or materials disclosed herein, but is
extended to equivalents thereof as would be recognized by those
ordinarily skilled in the relevant arts. It should also be
understood that terminology employed herein is used for the purpose
of describing particular embodiments only and is not intended to be
limiting.
DEFINITIONS
[0023] The following terminology will be used in accordance with
the definitions set forth below.
[0024] As used herein, "robot body" is intended as a broad term to
define one or more structural components (e.g., a frame, chassis,
cover, etc.) capable of supporting one or more other components of
a hull robot or its subsystems, and/or capable of providing
covering and/or concealment of one or more components or subsystems
of the hull robot.
[0025] As used herein, the singular forms "a," and, "the" include
plural referents unless the context clearly dictates otherwise.
[0026] As used herein, the term "substantially" refers to the
complete or nearly complete extent or degree of an action,
characteristic, property, state, structure, item, or result. For
example, an object that is "substantially" enclosed would mean that
the object is either completely enclosed or nearly completely
enclosed. The exact allowable degree of deviation from absolute
completeness may in some cases depend on the specific context.
However, generally speaking the nearness of completion will be so
as to have the same overall result as if absolute and total
completion were obtained. The use of "substantially" is equally
applicable when used in a negative connotation to refer to the
complete or near complete lack of an action, characteristic,
property, state, structure, item, or result. For example, a
composition that is "substantially free of" particles would either
completely lack particles, or so nearly completely lack particles
that the effect would be the same as if it completely lacked
particles. In other words, a composition that is "substantially
free of" an ingredient or element may still actually contain such
item as long as there is no measurable effect thereof.
[0027] As used herein, the term "about" is used to provide
flexibility to a numerical range endpoint by providing that a given
value may be "a little above" or "a little below" the endpoint.
[0028] As used herein, a plurality of items, structural elements,
compositional elements, and/or materials may be presented in a
common list for convenience. However, these lists should be
construed as though each member of the list is individually
identified as a separate and unique member. Thus, no individual
member of such list should be construed as a de facto equivalent of
any other member of the same list solely based on their
presentation in a common group without indications to the
contrary.
Example Embodiments
[0029] Reference will now be made to the exemplary embodiments
illustrated, and specific language will be used herein to describe
the same. It will nevertheless be understood that no limitation of
the scope of the technology is thereby intended. Additional
features and advantages of the technology will be apparent from the
detailed description which follows, taken in conjunction with the
accompanying drawings, which together illustrate, by way of
example, features of the technology.
[0030] It is noted in the present disclosure that when describing
the system, or the related devices or methods, individual or
separate descriptions are considered applicable to one another,
whether or not explicitly discussed in the context of a particular
example or embodiment. For example, in discussing an energy
harvester configuration per se, the device, system, and/or method
embodiments are also included in such discussions, and vice
versa.
[0031] Furthermore, various modifications and combinations can be
derived from the present disclosure and illustrations, and as such,
the following figures should not be considered limiting.
[0032] FIGS. 1-3 show an example hull robot 10 with robot body 12
supporting combined turbine/generator units 32a and 32b. The
turbines are responsive to fluid moving past the vessel hull when
the vessel is underway, e.g., the turbine intakes are behind screen
30 and are responsive to fluid moving past the vessel hull. The
turbines drive the generators which in turn charge battery pack 38.
Electronic control module 40 is powered by battery pack 38 as are
the motors and other power devices on-board robot 10. Typically,
one motor drives, for example, gear 42b which in turn drives gears
42a and 42c. In this way, cleaning brushes 36a-36d are operated.
Another motor is typically associated with drive module 18 which
both holds the robot on the hull and maneuvers the robot about the
vessel hull. The motor system for drive module 18 may vary in
design. For example, the turbines could directly drive module 18
(and/or brushes 36a-36d). Also, brushes 36a-36d may be driven or
rotated in different directions. For example, FIG. 2 illustrates
two sets of counter-rotating brushes 36a-b and 36c-d supported by
the robot body 12, which are rotated using a belt and pulley system
actuated by the motor 40 (which may be powered by power source 38).
Any number of brushes or cleaning elements may be used to suit a
particular application, such as a greater or lesser number of
brushes. For example, a modified embodiment can include two
counter-rotating brushes (see counter-rotating brushes 36a-36b in
FIG. 3). The hull robot may include one or more drive modules.
[0033] The robot body 12 can include turbine intake vents 14a and
14b and cleaning brushes 16a, 16b, and 16c behind an outflow vent.
A magnetic drive belt 22 is typically disposed about rollers 21a
and 21b as shown.
[0034] In the example shown, turbines 26a and 26b drive generators
28a and 28b, respectively, each including an rpm sensor or voltage
sensor. By monitoring the output of each generator, any difference
between the outputs of turbines 26a and 26b can be detected and
minimized by turning the robot 10 on the hull. In still other
examples, a sensor or the like can be used to determine the
direction of fluid flow with respect to the robot body.
[0035] FIG. 4 illustrates an example including turbine subsystem 32
(including one or more devices actuatable by fluid flowing past the
hull) and generator 70 which recharges power source 40. One or more
motors such as motors 72a and 72b are powered by power source 40.
Motor 72a drives drive module 18 via drive train 74a. The direction
of travel of the robot can be reversed via electronic control
subsystem 41 which is configured to reverse the direction of motor
72a based on inputs, for example, from navigation subsystem 78
and/or communication subsystem 80. Electronic controller 41 is also
powered by power source 40. Similarly, motor 72b drives cleaning
subsystem 82 (e.g., one or more brushes as described above) via
drive train 74b. Motor 72b is also energized by power source 40. In
other embodiments, the one or more motors may operate on the basis
of a power source other than electricity. Motors are known, for
example, that are fluid driven. The turbine subsystem then may pump
fluid under pressure to the motors. If the cleaning subsystem is
passive, e.g., a pad and/or a squeegee, motor 72b and drive train
74b would not be required. In other examples, the drive shafts of
the turbines are mechanically linked to the cleaning brushes and/or
drive module. Thus, the design of the motive subsystem for the
drive module may vary.
[0036] FIG. 5 illustrates a more detailed view of the navigation
subsystem 78 and the electronic subsystems 41 of FIG. 4 in
accordance with various embodiments. One or more of the features
described below and shown in the drawing may be included in a
single robot. Also, any suitable combination of the features may
also be implemented.
[0037] The navigation subsystem 78 can be used to determine the
location of the hull robot about the hull and to assist in
navigation of the hull robot. For example, the navigation subsystem
can include a sensor or sensor subsystem in the form of a detector
(e.g., gravity vector detector 115, pressure detector/sensor 120,
flow field detector 125, acoustic energy (e.g., noise) detector
130, ultrasonic detector 135, and/or cleanliness detector 140)
operable to detect a characteristic of the environment surrounding
the hull robot, or in which the hull robot is operating, for use in
identifying a position of the hull robot about the vessel hull.
Thus, the robot can identify a position on the hull without receipt
of external signals or devices.
[0038] A number of sensor subsystems or detectors and/or methods
are described herein for use in the present technology. However,
the concepts described herein are non-exhaustive examples, and many
other implementations are also possible and are considered to be
within the scope of this disclosure. Some of the examples provided
may be able to perform the intended function independent of other
sensing or detecting devices or methods, while others may be
combined with others for more accurate or complete position
identification or determination. A hull robot navigation subsystem
may use one or more of the described technologies in any desirable
combination. Some example methods for navigating the hull robot
include use of a cleanliness detection system, use of gravity
vectors (also referred to herein as "g-vectors"), use of water
pressure or water flow fields, detection of noise or sound
(acoustic energy), ultrasonic detection, and so forth. These are
described in more detail below.
[0039] A hull robot system can include an onboard cleanliness
detection system 140 as one of the electronic subsystems 41. Such
systems can be used to perform a navigation function or position
identification function in addition to the cleanliness detection
function. For example, the hull robot may make any number of passes
across the ship in cleaning the hull, analyzing the hull,
determining a cleanliness level of the hull, and so forth. Each
pass may be offset by the previous pass so as to substantially not
maneuver over the same area of the ship again. In one aspect, the
cleanliness detection system can use the last or just completed
pass to guide a next pass. A database 145 onboard the hull robot
can store path information or a path configuration of the robot.
Thus, in operation, when the robot has traversed the hull a certain
number of passes, a processor 150 can reference the database to
identify approximately where on the hull the robot is currently
located.
[0040] Alternately, one or more sensor subsystems or detectors
within the navigation subsystem 78 can measure a distance traveled
by the robot, or characteristics of the environment around the
robot to determine an approximate location. This can take place
concurrently with cleanliness detection operations as performed by
the cleanliness detection subsystem (or other operations, such as
an inspection operation). In one example, the navigation subsystem
78 or cleanliness detection subsystem 140 may utilize a detector to
detect an edge of the ship. Thus, the detection of the edge of the
ship can serve the purpose of identifying a location which is not
part of the hull and need not be analyzed for cleanliness detection
or inspection purposes, and also can be used to identify a relative
position of the robot on the hull. For example, the detector for
detecting an edge of the ship may comprise a magnet for detecting
the presence of the metal hull, or a camera for optically detecting
the presence of the edge of the hull. Various other detectors may
also be used.
[0041] The navigation subsystem 78 can include a g-vector type
sensor subsystem or detector 115. More specifically, the g-vector
detector can be a gravitometer or gravimeter for detecting a
direction of gravity. A ship or vessel generally may have a hull
with a specific contoured shape. Different positions on the hull
between a top and a bottom of the hull may be angled differently
with respect to one another. A hull robot equipped with a
gravimeter can detect a unique g-vector for substantially any
vertical location about the hull. For example, a direction of
gravity may remain substantially the same, but an orientation of
the robot with respect to the direction of gravity may change as
the robot traverses the hull. Thus, in some examples, the g-vector
can be determined relative to an orientation of the robot, or more
specifically to a longitudinal and/or lateral axis or angular
orientation with respect to the detected direction of gravity. The
unique g-vectors for the various vertical locations about the hull
can be pre-determined and stored in a database that can be
referenced when the gravimeter detects the direction of gravity
with respect to a current robot position or orientation. Comparison
of known g-vectors with presently detected g-vectors can assist in
the detection of the position of the robot about the hull, and
navigation of the robot about the hull.
[0042] A simple measurement of an individual g-vector may be
sufficient to identify the approximate vertical position by
reference to the unique g-vector values stored in the database. In
some examples, the vertical position of the robot may provide
sufficient information for a desired application. However, in other
examples, a horizontal or lateral position may also be desired.
While other technologies or sensors could be combined with the
gravimeter to provide this information, the gravimeter itself can
be configured to provide sufficient information to roughly estimate
the lateral position as well. For example, the vertical change in
slope of the hull contour may vary along a length of the hull.
Thus, if the hull robot analyzes a change in vertical slope of the
hull contour as the robot traverses the hull, the lateral position
on the hull can be estimated in addition to the vertical
position.
[0043] In a more specific example, rather than, or in addition to,
use of the gravimeter, an accelerometer may be used to determine an
orientation of the hull robot relative to the ship. The detected
orientation data can be used similarly to the gravity data
described above. In addition, the orientation data can be used to
determine a lateral change in slope of the hull contour along the
length of the vessel. Thus, if the hull robot analyzes a change in
lateral slope of the hull contour as the robot traverses the hull,
the lateral and/or vertical position on the hull can be
estimated.
[0044] In another embodiment, fluid pressure (e.g., water pressure)
in which the vessel is floating can be used to determine location
information of the robot about the hull. The navigation subsystem
78 can include a water pressure type sensor subsystem or
detector/sensor 120 supported about the robot that is configured to
sense or measure pressure. The pressure generally will have a
direct correspondence with a depth beneath a surface of the water.
The sensor may operate in conditions where there is minimal
turbulence in the water and/or rocking of the vessel, but pressure
readings will be available in turbulent conditions, and/or when the
vessel is rocking. Pre-determined pressure information can be
generated and stored in a database onboard the robot for later
comparison to facilitate identification of an approximate vertical
position on the side of the vessel hull. In one aspect, with the
robot and the pressure sensor submersed, when a pressure is
detected, reference to the database using a processor can identify
the current pressure and the associated approximate vertical
position about the hull by comparing the current pressure to those
stored. In another aspect, the pressure sensor, or one or more
different sensors, can further be configured to detect a pressure
out of water as well. Thus, the pressure sensor(s), alone or in
combination if multiple sensors are present, can determine whether
the robot is above or beneath (or at) the water level, as well as
an approximate vertical position about the hull. In addition, the
pressure sensor can also be configured to determine a distance the
robot is away from the water level, with depth or pressure
measurements corresponding to a distance above or below the water,
wherein an at-the-water line pressure can be determined and used
for comparison.
[0045] In accordance with another example, the navigation subsystem
78 is configured to detect one or more characteristics of a fluid
flow field using a fluid flow field type sensor subsystem or
detector 125. The fluid flow field detector 125 can be configured
to measure fluid flow velocity or the rate of fluid flow. As such,
various types of flow sensors or flow meters are contemplated. The
fluid flow detector 125 can be supported about the robot in a
manner so as to be able to sense or detect fluid flow. The fluid
flow detector can be a stationary detector or a deployable
detector. Exemplary types of flow detectors can comprise mechanical
flow detectors, such as piston meter/rotary piston, rotameters,
turbine flow meters, Woltmann meters, single jet meters, paddle
meters, multiple jet meters, pelton wheels, oval gear meters,
current meters, etc. Other types of flow detectors can comprise
pressure-based meters, such as venture meters, orifice plate
meters, Dall tubes, pitot tubes, multi-hole pressure probes, etc.
Still other exemplary flow detectors can comprise optical
detectors, such as laser-based detectors. Still other types can
comprise thermal mass flow meters, electromagnetic-based detectors,
ultrasonic-based detectors, coriolis flow meters, laser-based flow
meters, and others. Moreover, one or more of these can be used in
combination about the hull robot if necessary or desired.
[0046] In fluid dynamics the flow velocity, or velocity flow field,
or flow rate of a fluid comprises a vector field which can be used
to mathematically describe the motion of a fluid. The length of the
flow velocity vector is representative of the flow velocity.
Depending upon the configuration of the hull, the flow field about
the hull may be different at various locations about the vessel
hull. For example, the fluid dynamics of the water as it flows over
the hull can vary from the front of the vessel to the back, and
from the surface of the water to the bottom of the vessel. As such,
fluid flow and/or fluid flow rate can be detected or measured at
one or more locations about the hull. Pre-determined flow or flow
rate information can be obtained and stored in a database for later
reference and comparison in facilitating determination of a
position of the robot about the hull when the flow field about the
robot is detected.
[0047] In one aspect, the flow field detector can be an energy
harvesting device, such as a turbine, water wheel, piezoelectric
element, or the like, exposed to the flow of fluid. The energy
harvested by the energy harvesting device can be interpreted as a
function of location on the hull. In one aspect, because fluid flow
can vary over the expanse of the hull, a local relative fluid flow
can be measured or sensed to indicate a position of the robot on
the hull. For example, the amount of energy harvested over a unit
of time along a given path can be indicative of a force or speed or
direction of fluid flow, which information can then be used to
determine the position of the robot on the hull in a similar manner
by comparing this currently obtained information with predetermined
stored information.
[0048] The energy harvesting device may be a displacement energy
extraction device configured to extract energy from the environment
due to displacement of at least a displaceable member or component
of the energy extraction device. For example, turbines, propellers,
water wheels, flappers (e.g., a hinged extraction device that
"flaps" as fluid flows past, wherein the "flapping" motion
generates harvestable energy), piezoelectric elements and so forth
may be displaced in the form of rotation, oscillation, flexing and
so forth as a result of fluid flow past the robot in order to
generate energy which may be harvested and used by the robot. The
displaceable member may be turbines, propellers or the like which
rotate about an axis defined by a rotor, or may be piezoelectric or
other oscillation-based devices where the flexing, bending, or
hinging component is the displaceable member.
[0049] In one example, the water wheel configuration may comprise a
plurality of blades disposed about a rotor of the water wheel which
cause rotation of the rotor when the fluid flows against the
blades. In another example, the water wheel configuration may
include a plurality of fluid containers or "buckets" disposed about
the rotor of the water wheel and configured to capture fluid
therein to cause rotation of the rotor.
[0050] In one example, the displacement energy extraction device
may be an oscillation-based energy extraction device. Piezoelectric
elements and flapper devices as described previously are examples
of oscillation-based energy extraction devices configured to
harvest energy based on an oscillating movement, or rather a
movement back and forth between multiple different positions. The
oscillation-based energy extraction device may be oscillateable in
response to the fluid flow acting upon the oscillation-based energy
extraction device.
[0051] In one example, a fluid flow path may exist in the robot
body, which may be defined by structure of the robot body, to
direct the fluid flow toward the displacement energy extraction
device. In one example, the fluid flow path may be in the form of a
tube for receiving fluid at one end and directing fluid toward the
extraction device at another end. In another example, the fluid
flow path may be a path defined by sides of the robot body or other
structure for restricting, directing or otherwise affecting a
direction of flow of the fluid.
[0052] In one example, the fluid flow path may exist without the
robot body, or rather may be positioned outside of the robot body
within the fluid flow field created by the passing water as a
result of movement of the vessel as it is underway. The fluid flow
path may be the flow of the fluid past the vessel as the vessel
moves within the fluid. The fluid flow path may also be impacted by
a shape of the robot body, which may cause the fluid to flow around
the robot body. The energy extraction device may be operable to
extract energy from the fluid flow about the vessel resulting from
the motion of the vessel in the fluid. The hull robot may include a
support structure for positioning and supporting the energy
extraction device without the robot body such that the energy
extraction device is in contact with the fluid flow outside the
robot body.
[0053] Energy harvested may be useable by cleaning subsystems,
drive subsystems or other subsystems to perform various different
functionalities. For example, the cleaning subsystem may use the
energy to operate a cleaning element configured to perform a
cleaning function to clean the hull of the vessel. The drive
subsystem may use the energy to power one or more drive elements
configured to drive and maneuver the robot about the hull of the
vessel.
[0054] Energy harvested using the extraction device may be used to
directly power the robot or subsystems of the robot, or may be
stored for later use, such as by storing generated power in a power
supply or battery.
[0055] In examples where a hull robot is shaped or otherwise
configured to receive fluid flow in a particular direction or at a
particular portion of the robot, the hull robot may be optimized to
maintain an orientation of the robot relative to the fluid flow to
maximize energy harvested from the flow while driving and
maneuvering the robot about the hull. For example, a maximal amount
of energy may be harvested from the fluid flow when the fluid flows
directly toward an energy extraction device or toward an opening
which directs the fluid along a fluid flow path toward the energy
extraction device. A fluid flow field detector may detect whether
energy being harvested is maximized, but causing the robot to
change orientation relative to the flow field surrounding the robot
to determine whether a change results in an increase in energy
harvested. If so, the flow field detector may cause the robot to
maintain the changed orientation. If not, the flow field detector
may cause the robot to alter the orientation of the robot, such as
a return to the original orientation. In another example, a
velocity of the flow may be detected using the fluid flow detector,
which may provide an indication as to whether the energy extraction
device is receiving the full velocity of the fluid due to the
velocity of the motion of the vessel.
[0056] In accordance with another example, acoustic energy (i.e.,
noise or sound) can be detected and used to determine the robot
location, and to facilitate in navigation of the robot about the
hull. More specifically, the navigation subsystem 78 can make use
of environmental characteristics or conditions in the form of
existing or natural boat derived noise fiduciaries to identify an
approximate location of the robot on the hull, and to facilitate
navigation of the robot. In one exemplary embodiment, the
navigation subsystem can include a microphone or other suitable
acoustic energy type sensor subsystem or detector 130 for detecting
naturally derived noise fiduciaries that are native to the vessel,
such as those generated merely by operation of the vessel. As such,
the vessel need not include specially designed noise generation
systems, although these are also contemplated. In one aspect,
detectable acoustic energy may be generated by the engine itself,
propeller operation in the water, or by other systems onboard the
vessel. In another aspect, detectable acoustic energy may be
generated by the interaction of various vessel structural
components as the vessel moves through the water (e.g., bow noise
generated as the vessel displaces water during operation).
[0057] In addition to detecting the acoustic energy being
generated, position correspondence data can also be determined and
stored for later use. Position correspondence data can comprise
information regarding the relationship of measured characteristics
of the vessel and/or the noise fiduciaries to the position of the
robot on the hull. For instance, the robot can be caused to
maneuver about the hull under various operating conditions.
Acoustic energy generated under such conditions can be detected and
measured for later comparison. The acoustic energy provided by the
various energy sources of fiduciaries as the vessel is operated
will likely be generated at different frequencies, each of which
can be measured or detected by the acoustic detector and
distinguished so it can be determined which particular energy
source is which at any given time. In a specific example, vessel
speed can be determined (e.g., by monitoring the performance and/or
output of the turbines (e.g., the rate the turbines are rotating,
etc.)). At a given speed, say 15 knots, the volume of the acoustic
energy from the various energy sources or fiduciaries (such as the
bow, the engine and the propeller, which locations or positions are
all known and fixed) can be detected and measured at various
locations about the hull. This relationship information can then be
stored in a database as part of the overall collection of position
correspondence data. The process can be repeated until sufficient
acoustic energy data is gathered at any desired number of vessel
speeds. This position correspondence data can be compiled, stored
and made accessible to the robot later for navigational
purposes.
[0058] In operation, the navigation subsystem can use these (or any
other) noise fiduciaries to determine the location of and navigate
the robot about the hull by comparing currently detected acoustical
energy to the pre-determined position correspondence data
associated with the sources of the acoustic energy as stored. Using
this technique, the noise fiduciaries can be used to navigate the
robot about the hull. For example, vessel engine noise, noise
generated from fluid contacting a portion of the bow of the vessel,
and noise generated from operation of a propeller may provide noise
fiduciaries having known audio frequencies, which fiduciaries may
be used to identify a position of the robot and/or navigate the
robot about the hull.
[0059] In other exemplary embodiments, non-native or non-naturally
occurring systems, equipment, etc. associated with or otherwise
located on or about the vessel at various locations may also be
deployed to generate identifiable or detectable acoustic energy
that can be detected by an acoustic detector for use in similar
robot location determination and navigation techniques. For
example, one or more dedicated noise generation systems outputting
acoustic energy at different frequencies can be placed about the
vessel at various locations, and position correspondence data can
be gathered and stored for later use in determining the position of
the robot, and for navigation.
[0060] In another exemplary embodiment, ultrasonic signals or
ultrasonic inspection via an ultrasonic type sensor subsystem or
detector 135 can be used to identify a position, and facilitate
navigation of the robot about the hull and may be functional during
operation of the vessel. Ultrasonic inspection is a form of
non-destructive inspection. In ultrasonic inspection, very short
ultrasonic pulse-waves with center frequencies ranging from 0.1-50
MHz can be directed into the hull from an ultrasonic emitter, from
which the waves may be reflected and detected using an ultrasonic
detector to identify an ultrasonic signature, which may be
representative of internal flaws or a characterization of hull
properties. For example, the hull properties may be detected as
ultrasonic signatures, and some non-limiting examples of such hull
properties may include one or more of a hull thickness, integrity
of a weld on the hull, a crack in the hull, a fissure in the hull,
a change in thickness of the hull, an irregularity of the hull, and
so forth. In one example, ultrasonic inspection can be used to
determine a thickness of the hull to, for example, monitor
corrosion.
[0061] In ultrasonic inspection, an ultrasound transducer connected
to a diagnostic machine (both of which may be included in the
inspection robot) is passed over the hull. The transducer may be
separated from the hull by a couplant. While oil as a couplant may
be used in some examples, the couplant is preferably water, due to
the likely immersion of the robot under water on the vessel in
motion.
[0062] Methods or modes of receiving the ultrasonic energy or
waveform can include reflection and attenuation modes. In the
reflection mode (otherwise known as the pulse-echo mode), the
transducer sends and receives pulsed ultrasonic waves. The
ultrasonic waves are reflected off of the hull back to the receiver
or diagnostic machine. Reflected ultrasonic waves result from an
interface with the hull, such as with the back wall of the hull or
an imperfection within the hull. The diagnostic machine can store
the results in the form of a signal with an amplitude representing
the intensity of the reflection and the distance of signal travel
as determined by a speed of the ultrasonic signal and an amount of
time from when the signal was emitted to when the signal was
received at the receiver after reflecting from the hull.
[0063] In the attenuation mode (otherwise known as the
through-transmission mode), a transmitter sends ultrasonic energy
through one surface of the hull, and a separate receiver on another
surface detects an amount of ultrasonic energy traveling through
the hull. Imperfections or other conditions in the space between
the transmitter and receiver reduce the amount of ultrasonic energy
transmitted, thus revealing the presence of such imperfections or
conditions. The couplant increases the efficiency of the process by
reducing the losses in the ultrasonic wave energy due to separation
between the surfaces.
[0064] Ultrasonic inspection can be highly penetrating, allowing
the detection of flaws deep in the hull. Ultrasonic inspection
enables the detection of extremely small flaws. Ultrasonic
inspection may be performed using an ultrasonic inspection device,
such as an ultrasonic detector 135, and can be used to estimate a
size, orientation, shape and nature of a defect in the hull.
[0065] Ultrasonic technology, including the ultrasonic detector
135, can be implemented in the robot to create and store an
ultrasonic map of the hull. The map may comprise a collection of
ultrasonic signatures relating to various positions about the hull,
which ultrasonic signatures can be collected and stored for later
use. The ultrasonic signatures may represent an environmental
characteristic detectable by the sensor subsystem (i.e., the
ultrasonic detector in this example). In operation, as the robot
traverses the hull and as the ultrasonic pulse-waves are directed
at and reflected off the hull, a plurality of ultrasonic signatures
may be obtained. These electronic signatures can be used to
generate a map representative of various portions of the hull.
Therefore, in subsequent operational scenarios, the hull robot can
determine its position about the hull by deploying an ultrasonic
detector and comparing the current electronic signatures to those
in the map that are pre-determined and stored in the database.
Indeed, reference to the electronic signatures and/or the map based
on a current detected ultrasonic signature can identify a position
of the hull robot on the hull and can be used in navigating the
robot.
[0066] It is contemplated herein that specific navigational
direction of the robot about the hull may be less of a concern for
a robot deployed while the vessel is docked at port because the
vessel is stationary and the robot is not subject to forces induced
by water flow. However, operation of the hull robot when the vessel
is underway and in motion about the vessel, such that a flow field
is created about the hull robot, may be more of a concern as this
subjects the robot to additional forces as the passing water acts
on the robot, and particularly the surfaces of the body of the
robot. Therefore, to minimize or at least reduce the forces acting
on the robot as caused by the passing water, rather than navigating
about the hull along various horizontal paths, the robot may be
configured to navigate along the hull of the vessel about vertical
paths, as shown in FIG. 6 (e.g., paths extending between a bottom
of the hull to a top of the hull even though the path may not be
necessarily orthogonal to the surface of the water due to the hull
configuration (as viewed from a front or rear view of the vessel
and hull). In this way, energy can be conserved because the robot
is not constantly working against the direction of the fluid flow
on every other pass along the hull as it would when following a
horizontal path about the hull (path extending from front to back
of the hull). As a result, smaller and less-expensive drive motors
may be used to drive the robot. In addition, traversing along
vertical paths, the robot can navigate up and down, working its way
from back to front or front to back, whichever is preferred. The
vertical path can comprise a route that is transverse (e.g.,
orthogonal or approximately orthogonal) to the direction of fluid
flow about the hull or to a surface of the fluid in which the
vessel is operating. Traversing the hull in vertical or
substantially vertical paths can reduce the energy expenditures of
the robot as greater levels of efficiency are obtained over
traversing horizontal paths.
[0067] Moreover, in these situations, the energy harvested can be a
function of where the robot is on the hull, and the associated
water flow field at that location. Indeed, the fluid flow field at
any particular location about the vessel hull can be measurable and
used further, such as for determining the location of the robot
about the hull (comparing a measured flow field parameter to one or
more pre-determined and stored parameters).
[0068] It is contemplated herein that the robot can be configured
to navigate vertical paths along the hull in still a more efficient
manner by employing a hull robot configuration where the robot (and
particularly the robot body) is designed to be more hydrodynamic in
a particular direction. More specifically, in some exemplary
embodiments, the robot body can be hydrodynamically tuned in a
direction transverse (e.g., orthogonal, or at least offset at some
angle) to a direction of travel of the robot and/or a direction of
functionality (e.g., cleaning, inspecting, etc.) of the robot,
which hydrodynamically tuned direction is in the direction of fluid
flow, such that the hydrodynamics of the robot while being
maneuvered in the direction of travel are enhanced. Stated
differently, the robot can comprise a configuration in which the
robot body is tuned to be hydrodynamic in the direction of fluid
flow, even though the hull robot may be caused to traverse the hull
in a direction that is not necessarily in line with the fluid flow
(e.g., transverse to the direction of fluid flow). For example, in
an embodiment in which the robot is configured to operate about the
hull in a vertical direction, as discussed above, the robot, and
particularly the robot body, can comprise hydrodynamics that are
tuned to be optimally efficient with the flow field while the robot
faces or navigates in a direction orthogonal to or at an incline
with the flow field. FIG. 7 illustrates a robot with a robot body
160 configured for hydrodynamically efficient travel in a vertical
direction 165 about the hull of the vessel, which direction is
orthogonal to a direction of a flow of fluid 170, or fluid flow
field. In this embodiment, the robot body comprises an outer
surface being hydrodynamically tuned along a lateral axis (which
axis is parallel to or in line with a direction of fluid flow) in a
direction ninety degrees from a longitudinal axis (which axis is
parallel to or in line with a vertical travel direction), wherein
the robot is further configured to travel in a direction parallel
to the longitudinal axis. In this embodiment, the robot could
traverse the hull of the vessel in a vertical direction, while
still having enhanced hydrodynamics in the direction of the flowing
fluid. The robot body in the tuned hydrodynamic direction may
result in the fluid flow (resulting from motion of the vessel) over
and about the robot body for enhanced efficiency of driving and
maneuvering of the robot in the vertical direction.
[0069] With continued reference to FIG. 7, in another exemplary
embodiment the hull robot, and particularly the body 160 of the
hull robot, may be configured with a symmetrical shape (along any
axis) to more efficiently facilitate movement of the robot about
the vessel hull (e.g., in a bi-directional manner). For example,
the robot body can be symmetric along a longitudinal axis extending
between longitudinal sides (e.g., front to back) of the robot body.
In addition, the hydrodynamics of the robot may be tuned to be
optimally efficient along the longitudinal axis. Therefore, the
robot can maneuver about the hull in a horizontal bi-directional
manner with efficiencies provided in both directions rather than in
only one direction. Of course, the robot can also be configured to
be symmetric (and the hydrodynamics tuned) along a lateral axis
extending between lateral sides of the robot body, along both
longitudinal and lateral axes, along one or more axes other than
longitudinal and/or lateral axes, and so forth to facilitate
enhanced efficiency bi-directional driving of the hull robot about
multiple axes having different orientations.
[0070] In one example, the robot body may comprise a semispherical
shape with a substantially infinite number of axes of symmetry
(e.g., radially symmetrical). Providing a symmetrical configuration
allows the robot to be operated to clean and extract energy
efficiently while operating in a bi-directional manner while facing
the same direction (i.e., operating without having to turn around).
Of course, the hull robot can turn around upon detecting an edge of
hull and face an opposite direction, if desired.
[0071] As discussed above, the robot may be configured to drive in
a direction along the longitudinal axis of the robot such that a
fluid flow transverse to the longitudinal axis is against a lateral
side of the robot body. The robot may be tuned or configured with
the hydrodynamic configuration in a direction substantially
parallel with a lateral axis extending between the lateral sides of
the robot body, which lateral sides may extend between the
longitudinal sides. Furthermore, an inlet may be formed in or along
at least one lateral side of the robot body for receiving the fluid
flow and for generating a fluid flow path within the robot body. A
fluid flow path within the robot body may be generated from fluid
being received in the inlet. The fluid flow path may be at least
partially defined by structure within the robot body, such as the
side walls of the robot body, a tube or pipe provided for fluid to
flow through, and so forth. As described in this disclosure, the
robot may comprise an energy extraction device 161, which, in this
embodiment, may be supported about the robot body and oriented or
tuned to be operable with the inlet and within the fluid flow path
171 to generate energy usable by the robot to perform various
functions, such as driving, cleaning, and so forth. Similar to a
shape of the robot body or an orientation of the inlet, the energy
extraction device may be oriented and tuned in the tuned
hydrodynamic direction. Tuning the energy extraction device in this
direction may result in a maximized amount of energy or power which
may be harvested by the energy extraction device.
[0072] In practice, efficient operation of a hull robot about a
hull of a vessel may be enhanced by configuring the robot body with
the hydrodynamic configuration tuned in a direction transverse to a
direction of travel of the robot, and substantially in a direction
of fluid flow resulting from motion of the vessel within a fluid;
and configuring a drive subsystem onboard the robot to maneuver the
robot about the hull of the vessel in a direction transverse to a
direction of the flowing fluid to enhance the efficiency of the
robot within the fluid flow. More specifically, the robot may be
maneuvered in a direction substantially orthogonal to the direction
of the flowing fluid (i.e., in a vertical direction) and the robot
may be maneuvered in a substantially bi-directional manner to avoid
turning the hull robot around, such as when an edge of the vessel
is reached (e.g., a top or bottom of the hull of the vessel when
the robot navigates along substantially vertical paths, such as by
maneuvering the hull robot up and down the hull of the vessel while
moving from a front of the ship towards a back of the ship).
[0073] As an example method of enhancing efficient operation of a
hull robot, a hull robot may be configured to comprise a drive
system operable to maneuver and drive the hull robot about a hull
of a vessel along an axis extending from one of a top and bottom of
the hull. A robot body of the hull robot may be configured to
comprise a longitudinal axis extending between longitudinal sides
of the robot body and a lateral axis extending between lateral
sides of the robot body, the drive subsystem being configured to
drive the robot in a direction along the longitudinal axis. An
inlet may be formed along at least one of the lateral sides of the
robot body, where fluid received in the inlet generates a fluid
flow path within the robot body as tuned in the direction of the
fluid flow. An energy extraction device may also be provided which
is supported about the robot body, the energy extraction device
being operably positioned within the fluid flow path.
[0074] As the robot traverses the hull, it may be desirable to stop
movement, at least temporarily, and to secure the robot about the
hull, such as due to water turbulence, completion of a task, or any
of a variety of other reasons. In such situations, the hull robot
can comprise a fixation system or device operable to secure the
hull robot to the hull of the vessel more securely than with the
general securing device (i.e., the magnetic track). One example
technology for securing the robot to the hull, such as when the
hull robot is parked on the hull, includes magnetic fixation. In
this example, the robot may be configured to utilize or deploy a
magnetic fixation system or device operable with the robot body and
independent of the drive subsystem which incorporates much stronger
or much more aggressive magnets than are used with the drive
subsystem and which are caused to selectively engage the hull than
those that are used to keep the robot secured to the hull when the
robot is driving about the hull. The magnetic fixation device may
be actuatable to securely maintain a position of the robot relative
to the hull. For example, switchable magnets that are supported
about the underside of the robot, but that are independent of the
tracks, may be used. These can be selectively actuated, such as
when the speed of the drive subsystem approaches zero or when the
drive subsystem is inactive or otherwise not driving or maneuvering
the robot about the hull. One or more magnetic fixation devices may
be employed, such as one or more switchable magnets may be included
in the magnetic fixation device, to secure the robot relative to
the hull. The magnetic fixation devices may be positioned about the
robot body, such as at opposing ends or sides of the robot body, at
corners of the robot body, or in any other suitable position or
configuration.
[0075] In another example, the stronger magnets can be incorporated
into tracks or into wheels, but with separate magnetic systems from
the tracks or wheels that can be deployed. Such a system can be
designed to secure the robot in place. Example implementations of
switchable magnets are described in U.S. application Ser. No.
12/587,949, which is incorporated herein by reference, as set forth
above. Any of a variety of magnet types may be used, such as, for
example, electromagnets which are switchable on and off, or
permanent magnets which may be switchable by movement or rotation
of the magnets. FIG. 8 illustrates a hull robot 175 with a
switchable (i.e., rotatable) magnet 187 actuatable by an actuator
185 via an arm 189, the actuator being powered by an onboard
battery or generator, or powered directly by drive subsystem (i.e.,
a magnetic belt 194). The arm can further be movable or telescoping
in order to move the magnet closer or farther from the hull.
[0076] The magnetic fixation device may operably restrict
maneuvering of the robot by the drive subsystem when securely
maintaining the position of the robot relative to the hull. The
magnetic fixation device may have an attachment configuration for
restricting movement of and securing the robot about the hull, and
may further have a non-attachment configuration which enables the
drive subsystem to maneuver the robot about the hull of the vessel
when not securely maintaining the position of the robot relative to
the hull.
[0077] Also, various technologies can be used to assist in more
securely maintaining robot attachment to the vessel while the robot
is moving about the hull. Some of these examples will now be
described.
[0078] In one aspect, passing water to can be used to assist in
maintaining the hull robot on the hull. The hull robot may be
configured with a series of ports that receive passing water. Some
of these ports may be used to turn turbines and the like to power
the robot, as has been described above. Some of the ports may
provide outlets for water which flows into the robot and may
generally not be a water intake. Fluid flow along the surface of
the robot body can flow over the outlet and create a low pressure
area at the outlet that draws water out from inside the robot.
Thus, the water pressure inside or under the robot can be reduced
as compared with the water pressure on the outside of the robot
body, urging the robot body against the hull. Providing a robot
body with such a configuration facilitates suction against the hull
surface. A partial vacuum can thus be created within the hull robot
about the surface of the vessel. In some embodiments, the robot
need not be fully sealed against the hull in order to create a
sufficient pressure difference to assist in securing the hull robot
to the hull.
[0079] In another aspect, the hull robot may be more securely
attached to the hull using active suction fixation. In one aspect,
the hull robot can be configured to scavenge power to power the
active suction fixation. In an example shown in FIG. 7, the hull
robot 175 may include a deployable skirt 180 or other structure
that can be deployed using a motor 182 or gearing to create at
least a partial seal against the hull, whereupon water within the
robot can be actively pumped out and at least a partial vacuum (or
at least low pressure area) created. The pump can be powered by
scavenging passing water much the same way power is provided by the
turbines. The active suction fixation can also be used in
combination with magnetic fixation, hydrodynamic force, or other
means of securing the hull robot to hull.
[0080] As the robot is on the surface of the hull, passing water,
or fluid flowing relative to the vessel or robot, can pass through
and over the hull robot body. The passing water can be used with
power scavenging systems, such as the turbines described above, or
any other suitable power scavenging device, to power the robot. In
one aspect, power scavenging systems can be optimized by enabling
the power scavenging system 198 to extend or be extendable to reach
outside the hull robot body, and beyond a boundary layer of the
passing fluid to achieve a more consistent or constant input of
passing water. Indeed, a boundary layer may create an inconsistent
velocity profile. Getting outside the boundary layer can subject
the power scavenging system to a more uniform velocity profile that
provides a more consistent input. The power scavenging systems can
be configured to be dynamically adjustable to various positions
thereof with respect to the robot and the direction and strength of
the fluid flow field using an actuator 196 to obtain the proper or
desired position to obtain consistent flow input, and thus
consistent power scavenging. For example, a support structure for
supporting the power scavenging device (e.g., an energy extraction
device) at a position without the robot body and/or beyond a
boundary layer of the fluid flow may be retractable to draw the
power scavenging device to a position within the robot body. In
other words, the power scavenging device may be supported about the
robot, and may be retractably extendable (i.e., moveable from a
retracted position into an extended position, and vice versa) to
without the body of the robot to begin extracting the energy.
[0081] Some power scavenging systems have been described in the
patent applications related to the current application, which
applications are identified in the "Related Applications" section
of this document. Other power scavenging systems are also
contemplated, such as oscillation based devices or systems. For
example, as shown in FIG. 9a, a flapper device 250 can be supported
on the robot, wherein the flapper device 250 can be configured to
extend from the robot to be positioned to receive or engage the
passing water. The flapper device 250 can be supported about a
rotating device 252 (e.g., a hinge) to orient the flapper device
with the passing water. The flapper device can further comprise, or
can otherwise be associated with, an energy generator 261. In
operation, passing water causes the flapper device to oscillate,
and to generate power via the generator, which can be extracted
with extraction electronics 263 and used to power various
components of the robot or can be stored in an on-board battery 265
for later use.
[0082] In another example shown in FIGS. 9b-9c, the flapper device
255 can be fixed about the hull robot rather than configured to
rotate. In this example, the flapper device 255 can incorporate one
or more piezoelectric elements configured to flex and oscillate at
a flexible portion 260. Oscillation of the flapper caused by the
passing water can cause the piezoelectric element(s) to generate a
usable electric signal that can be used to power devices and/or
charge batteries.
[0083] Still other types of power scavenging systems are
contemplated, such as rotation-based energy scavenging devices or
systems similar to the turbines or propellers shown in FIGS. 1-3,
and described above. Other exemplary rotation-based extractors can
comprise water wheels (e.g., a Pelton wheel), which can rotate
about an axis and which can comprise a rotor assembly. The rotor
assembly can include a plurality of blades or buckets situated or
disposed about a rotor. The passing water can then impart
rotational energy to the rotor as it contacts the blades or
buckets.
[0084] In some embodiments, passing water can also be used to
directly operate cleaning systems or elements onboard the robot.
Directly powering the cleaning systems or elements using passing
water can eliminate the use, cost, and complexity of electric
motors. For example, brushes or other cleaning elements can be
mechanically coupled to an energy extraction device in the form of
a water wheel 192 or another scavenging or extraction device which
is configured to power and turn the brushes. In this embodiment,
the energy extraction device supports the one or more cleaning
elements (brushes) thereon, such that actuation of the energy
extraction device functions to actuate a cleaning function that can
be carried out by the energy extraction device. For example, as
water passes over the hull of the vessel due to the vessel being in
motion as it is underway, the resulting fluid flow can actuate the
water wheel, thus causing the brushes supported thereon to rotate.
These can be caused to contact the hull surface to perform a
cleaning function. Alternatively, the scavenging device can
comprise a direct mechanical connection (e.g., direct drive train)
to the drive subsystem, wherein passing water operates or activates
the energy extraction or scavenging device, which then directly
powers the drive subsystem 194 (FIG. 8). Other non-motorized
cleaning systems or elements that utilize the passing water to be
powered or actuated are also contemplated even though not
specifically described herein or shown in the drawings.
Nonetheless, such devices or elements will be apparent to those
skilled in the art upon reading the disclosure herein.
[0085] Essentially, all systems and/or devices used to scavenge
electrical power can be incorporated into the hull robot and used
to convert passing water to mechanical output. Thus direct powering
of systems can be enabled, as opposed to using an intervening
motor. Systems may still implement a transmission of some kind to
achieve a desired torque, as will be recognized by those skilled in
the art. Furthermore, the robot can comprise a governor to limit a
maximum RPM of the brushes, Pelton wheel, or any other component
used.
[0086] In other embodiments, passing water can turn a generator to
be able to decrease a size of a motor in the robot. The generator
can also be configured to charge a battery. Smaller motors may be
used when the robot is operating above the water since the robot
will not be subject to fluid flow. In one aspect, the battery can
be charged when the robot is below water to provide power to the
various cleaning, navigation and/or drive subsystems when the robot
is above and/or out of the water.
[0087] In one aspect, a velocity threshold may exist for passing
fluid to actuate drive subsystems, cleaning subsystems, energy
extraction devices (e.g., power scavenging devices) and so forth. A
velocity of passing fluid may be a result of the vessel to which
the hull robot is attached being in motion at a velocity meeting or
exceeding a pre-determined velocity or the velocity threshold.
[0088] Referring to FIG. 10, a flow diagram of a method of
autonomous hull robot navigation for guiding a hull robot on a hull
of a vessel independent of external guidance devices is illustrated
in accordance with an example embodiment of the present technology.
The method includes sensing 310 an environmental characteristic on
or about the vessel hull using a sensor subsystem onboard the
robot. A position of the hull robot on the hull can be determined
320 by detecting the environmental characteristic using a
navigation subsystem onboard the robot, which is responsive to the
sensor subsystem. The robot can be maneuvered 330 about the hull
using a drive subsystem onboard the robot based on a current
position of the hull robot.
[0089] In one aspect of the method, sensing the environmental
characteristic comprises sensing a cleanliness of the hull; and
maneuvering the robot comprises maneuvering the robot to a less
clean position on the hull when a current cleanliness is greater
than a predetermined threshold. In other words, the robot can be
configured to sense hull cleanliness and can be caused navigate to
areas needing to be cleaned. In this aspect, the interface between
the cleaned and yet-to-be-cleaned surface area on the hull
represents a fiduciary that can be utilized to guide the robot,
such as to clean the area adjacent the most recently cleaned area
of the hull.
[0090] In one aspect of the method, sensing the environmental
characteristic comprises sensing a direction of gravity relative to
the robot; and determining the position of the hull robot comprises
determining a vertical position of the robot on the hull based on a
previously determined unique gravity vector corresponding to a
position on the surface of the hull, as described above.
[0091] In one aspect of the method, sensing the environmental
characteristic comprises sensing a fluid pressure or an acoustic
characteristic of or near the hull, as described above. For
example, sensing the environmental characteristic may comprise
detecting an edge of the vessel to which the robot is attached.
When an edge of the vessel is detected, the robot may change
direction, such as by turning or moving in reverse.
[0092] In another example, sensing the environmental characteristic
may comprise sensing a paint characteristic about the hull using a
paint sensor subsystem. The navigation subsystem may be responsive
to the paint sensor subsystem to facilitate navigation based on the
paint characteristic. For example, the paint characteristic may be
the presence or lack of paint. Such presence or lack of paint,
particularly where a defined area is detected with or without
paint, may be used to determine a position of the robot about the
hull for navigation purposes, such as by identification of specific
characteristics of the particular area which distinguish the area
from other painted/non-painted areas of the ship. In another
example, the presence or lack of paint may be used when the hull
robot is configured to paint the hull of the vessel. The robot can
detect whether paint is present to determine whether to paint the
portion of the hull at which the robot is positioned. In another
aspect, the paint characteristic may be a freshness of a coat of
paint, which may be determined by reflectivity, brightness,
smudging and so forth. The presence or lack of paint, as well as
the freshness of the coat of paint may be detectable optically,
such as by using an optical detector (i.e., a camera). Coloration,
reflectivity, brightness, and so forth may be programmed into logic
processed by a processor causing the camera to capture images and
to paint the hull of the vessel, in order to determine the paint
characteristic for navigation, painting or any other suitable
purpose.
[0093] In one aspect, the method further includes scavenging energy
from a flow of fluid past the robot, and maintaining an orientation
of the robot relative to the flow of fluid to maximize energy
harvested from the flow while the robot maneuvers along
substantially vertical paths, as described above.
[0094] In one aspect, the method further includes fixing a position
of the robot relative to the hull when the robot is not being
maneuvered using a fixation device independent of a drive subsystem
of the robot, as described above.
[0095] Referring to FIG. 11, a system 400 for facilitating
autonomous hull robot navigation about a hull of a vessel
independent of external guidance devices is illustrated in
accordance with an example embodiment of the present technology. As
shown, the system includes a sensor 410 located onboard a hull
robot and configured to detect an environmental characteristic. A
database 415 onboard the hull robot can be configured to store
information about the hull of the vessel, including correspondence
information relating a position of the robot on the hull with the
environmental characteristic detected by the sensor. A processor
420 onboard the hull robot can be configured to compare currently
detected environmental characteristic information with the
correspondence information in the database to determine the
position of the hull robot on the hull, and to facilitate
navigation.
[0096] The system can include a memory 425 onboard the robot
including data concerning the configuration of the hull and a
desired path of travel for the robot. In one aspect, the memory may
be a non-transitory computer readable storage media. In another
aspect, the memory may compress random access memory (RAM). In yet
another aspect, the memory may comprise both the non-transitory
media and the RAM and the detected characteristic may be stored in
the RAM while the stored characteristic (i.e., the correspondence
information) is stored on the non-transitory media. The processor
can access both the RAM and the non-transitory media to compare the
data, according to computer readable program instructions, to
identify the position of the robot about the hull.
[0097] The methods and systems of certain examples may be
implemented in hardware, software, firmware, or combinations
thereof. The methods disclosed herein can be implemented as
software or firmware that is stored in a memory and that is
executed by a suitable instruction execution system (e.g., a
processor). If implemented in hardware, the methods disclosed
herein can be implemented with any suitable technology that is well
known in the art.
[0098] Also within the scope of this disclosure is the
implementation of a program or code that can be stored in a
non-transitory machine-readable medium to permit a computer or
processor to perform any of the methods described above.
[0099] Some of the functional units described in this specification
have been labeled as modules, in order to more particularly
emphasize their implementation independence. The various modules,
engines, tools, etc., discussed herein may be, for example,
software, firmware, commands, data files, programs, code,
instructions, or the like, and may also include suitable
mechanisms. For example, a module may be implemented as a hardware
circuit comprising custom VLSI (very large scale integration)
circuits or gate arrays, off-the-shelf semiconductors such as logic
chips, transistors, or other discrete components. A module may also
be implemented in programmable hardware devices such as field
programmable gate arrays, programmable array logic, programmable
logic devices or the like.
[0100] Modules may also be implemented in software for execution by
various types of processors. An identified module of executable
code may, for instance, comprise one or more blocks of computer
instructions, which may be organized as an object, procedure, or
function. Nevertheless, the executables of an identified module
need not be physically located together, but may comprise disparate
instructions stored in different locations which comprise the
module and achieve the stated purpose for the module when joined
logically together.
[0101] A module of executable code may be a single instruction, or
many instructions, and may even be distributed over several
different code segments, among different programs, and across
several memory devices. Similarly, operational data may be
identified and illustrated herein within modules, and may be
embodied in any suitable form and organized within any suitable
type of data structure. The operational data may be collected as a
single data set, or may be distributed over different locations
including over different storage devices. The modules may be
passive or active, including agents operable to perform desired
functions.
[0102] While the forgoing examples are illustrative of the
principles of the present technology in one or more particular
applications, it will be apparent to those of ordinary skill in the
art that numerous modifications in form, usage and details of
implementation can be made without the exercise of inventive
faculty, and without departing from the principles and concepts of
the technology. Accordingly, it is not intended that the technology
be limited, except as by the claims set forth below.
* * * * *