Title: Stabilization of a drogue body
Abstract: A refueling drogue adapted to connect to a refueling hose extending from a refueling aircraft. The drogue may include a rotatable mass adapted to effectively stabilize the refueling drogue via a gyroscopic effect of the rotating mass on the refueling drogue when the refueling drogue is placed in an airstream.
Patent Number: 6,994,294 Issued on 02/07/2006 to Saggio, III, et al.
| Inventors:
|
Saggio, III; Frank (Grand Rapids, MI);
Ribbens; William B. (Ann Arbor, MI);
Ooi; Kean K. (Yorba Linda, CA)
|
| Assignee:
|
Smiths Aerospace, Inc. (Grand Rapids, MI)
|
| Appl. No.:
|
697564 |
| Filed:
|
October 31, 2003 |
| Current U.S. Class: |
244/135A; 141/382 |
| Current Intern'l Class: |
B64D 39/00 (20060101) |
| Field of Search: |
244/135 A,135.R,136,323
141/382
|
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Other References
"Vision Based Sensor and Navigation System for Autonomous Aerial Refueling";
John Valasck et al.; Texas A&M University; Texas; pp 1-9.
"Basics of Gyroscopes"; Carl Machover; J.F. Ryder Pub.; New York, 1960;
pp. 2-99-2-108.
"Guided Drogue Flight Test Report"; Technical Report No. E-23027; Beech Aircraft
Corporation; Wichita, Kansas; Naval Air Systems Command, Sep. 6, 1977; p. 6.
|
Primary Examiner: Eldred; J. Woodrow
Attorney, Agent or Firm: Foley & Lardner LLP
Parent Case Text
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This application claims priority to U.S. Provisional Application Ser. No. 60/498,641
filed on Aug. 29, 2003, the contents of which is incorporated by reference herein
in its entirety.
Claims
What is claimed is:
1. A refueling drogue, comprising:
a rotatable mass; and
a flexible joint located between the rotatable mass and a connector on the refueling
drogue adapted to connect the refueling drogue to a refueling hose; wherein the
rototable mass is adapted to effectively stabilize the refueling drouge via a gyroscopic
effect of the rotating mass on the refueling drouge when the refueling drogue is
connected to a refueling hose and placed in an airstream.
2. The refueling drogue according to claim 1, wherein the rotatable mass is adapted
to effectively stabilize the refueling drogue via a gyroscopic effect of the rotating
mass on the refueling drogue when the refueling drogue is placed in an airstream
having a relative velocity to the refueling drogue of more than about 80 KEAS.
3. The refueling drogue of claim 1, wherein the rotating mass includes a refueling
drogue basket.
4. The refueling drogue of claim 1, wherein the rotating mass includes a refueling
drogue body or a portion of the refueling drogue body.
5. The refueling drogue of claim 4, wherein the refueling drogue body is connected
to at least one of a refueling hose and a component that is connected to a refueling
hose by a coupler adapted to permit the refueling drogue body to rotate relative
to the refueling hose.
6. The refueling drogue of claim 1, wherein the refueling drogue includes a refueling
drogue basket, and wherein the rotating mass is adapted to rotate relative to the
refueling drogue basket.
7. The refueling drogue of claim 1, wherein the refueling drogue includes a refueling
drogue body, and wherein the rotating mass is adapted to rotate relative to the
refueling drogue body.
8. The refueling drogue of claim 2, further comprising a refueling hose.
9. The refueling drogue of claim 2, further comprising a refueling hose in fluid
communication with the refueling drogue, wherein the refueling hose interior diameter
is about 2.2 inches to about 3.0 inches in diameter.
10. The refueling drogue of claim 2, wherein the refueling drogue extends from
an airborne refueling aircraft and is adapted to transfer aviation fuel from the
airborne refueling aircraft to a receiver aircraft.
11. The refueling drogue of claim 2, wherein the refueling drogue is adapted
to physically connect one airborne aircraft to another airborne aircraft.
12. The refueling drogue of claim 2, wherein the refueling drogue is adapted
to physically connect with a refueling probe of a receiver aircraft, wherein the
rotating mass has an axis of rotation, wherein the axis of rotation is adapted
to be substantially coaxial with an axis of symmetry of the refueling drogue, and
wherein the axis of symmetry of the refueling drogue passes through the center
of gravity of the refueling drogue.
13. The refueling drogue of claim 1, wherein effective stabilization is obtained
without the use of an active control system.
14. The refueling drogue of claim 1, wherein effective stabilization is obtained passively.
15. The refueling drogue of claim 1, wherein the drogue is adapted to harness
an air stream flowing past the refueling drogue that results from a forward velocity
of the refueling drogue through the atmosphere to rotate the rotatable mass to
produce the gyroscopic effect.
16. The refueling drogue of claim 1, wherein the refueling drogue comprises a
plurality of rotatable surfaces that, when exposed to an air stream flowing past
the refueling drogue that results from a forward velocity of the refueling drogue
through the atmosphere, are adapted to rotate the rotatable mass due to aerodynamic
forces on the surfaces to produce the gyroscopic effect.
17. The refueling drogue of claim 16, wherein the surfaces are outside of the
refueling drogue.
18. The refueling drogue of claim 16, wherein the surfaces are inside the refueling drogue.
19. The refueling drogue of claim 1, wherein the refueling drogue comprises a
plurality of surfaces that, when exposed to an airstream coming from a compressed
air supply, are adapted to rotate the rotatable mass due to aerodynamic forces
on the surfaces to produce the gyroscopic effect.
20. The refueling drogue of claim 1, wherein the rotating mass is connected to
an air turbine, and wherein the air turbine is adapted to rotate the rotatable
mass when exposed to the air stream when the air stream has a relative velocity
to the refueling drogue in excess of about 50 KEAS to produce the gyroscopic effect.
21. The refueling drogue of claim 20, wherein the air turbine is located on the
outside of the refueling drogue.
22. The refueling drogue of claim 20, wherein the air turbine extends radially
from the refueling drogue.
23. The refueling drogue of claim 20, wherein the air turbine is located on the
inside of the refueling drogue.
24. The refueling drogue of claim 23, wherein the air turbine is also located
on the outside of the refueling drogue.
25. A refueling drouge, comprising:
a rotatable mass; wherein
the rotatable mass is adapted to effectively stabilize the refueling drouge via
a gyroscopic effect of the rotating mass on the refueling drogue when the refueling
drogue is placed in an airstream;
wherein the rotating mass is connected to an air turbine;
wherein the air turbine is adapted to rotate the rotatable mass when exposed
to the air stream when the air stream has a relative velocity to the refueling
drouge in excess of about 50 KEAS to produce the gyroscopic effect; and wherein
the air turbine is adapted to extend outward away from the refueling drogue and
retract inward towards the refueling drouge.
26. The refueling drogue of claim 25, wherein the air turbine is adapted to retract
substantially completely inside the refueling drogue.
27. The refueling drogue of claim 21, further comprising a refueling drogue basket,
wherein a maximum diameter of air turbine is less than a greatest exterior diameter
of the refueling drogue basket when the refueling drogue basket is fully deployed.
28. The refueling drogue of claim 21, wherein the rotating mass is supported
by the air turbine.
29. The refueling drogue of claim 20, wherein the refueling drogue further comprises
an air intake adapted to direct air from the air stream into the refueling drogue,
and wherein the air directed into the refueling drogue is directed past the air
turbine to expose the air turbine to the air stream to rotate the rotatable mass.
30. The refueling drogue of claim 29, wherein the air turbine is a radial turbine.
31. The refueling drogue of claim 30, wherein the refueling drogue is adapted
to direct the air directed into the refueling drogue into a cavity in the radial
turbine and direct the air through slots extending at angles through the radial
turbine to rotate the radial turbine.
32. The refueling drogue of claim 30, wherein the radial turbine is the rotating
mass or part of the rotating mass.
33. The refueling drogue of claim 30, wherein the radial turbine includes slots
extending radially and substantially equally spaced through the radial turbine.
34. The refueling drogue of claim 30, wherein the radial turbine has an axis
of rotation that is about parallel to a longitudinal axis of the refueling drogue.
35. The refueling drogue of claim 30, wherein the radial turbine has an axis
of rotation that is coaxial to a longitudinal axis of the refueling drogue.
36. The refueling drogue of claim 30, wherein the radial turbine has an axis
of rotation that is not coaxial to a longitudinal axis of the refueling drogue.
37. The refueling drogue of claim 1, wherein the refueling drogue is adapted
to be effectively stabilized when the mass rotates with a speed between about 1000
RPM and about 20,000 RPM.
38. The refueling drogue of claim 1, wherein the rotatable mass is about 10%
to about 20% of the total mass of the refueling drogue.
39. The refueling drogue of claim 1, wherein the rotatable mass is about 40%
to about 60% of the total mass of the refueling drogue.
40. The refueling drogue of claim 1, wherein the refueling drogue is adapted
to generate electricity by harnessing an air stream flowing past the refueling
drogue that results from a forward velocity of the refueling drogue through the
atmosphere to energize or power components onboard the refueling drogue.
41. The refueling drogue of claim 20, wherein a generator is attached to the
air turbine, and wherein the air turbine is adapted to rotate the rotor of the
generator when exposed to the air stream to generate electricity to energize or
power components onboard the refueling drogue.
42. The refueling drogue of claim 40, wherein a generator is connected to the
rotating mass such that the rotation of the rotating mass rotates a portion of
the generator to generate the electricity.
43. The refueling drogue of claim 1, further comprising a plurality of rotatable
masses, wherein the rotatable masses are adapted to effectively stabilize the refueling
drogue via a gyroscopic effect of the rotating masses on the refueling drogue when
the refueling drogue is placed in an airstream.
44. The refueling drogue of claim 43, wherein respective centerlines of rotation
of the plurality of rotating masses are coaxially aligned.
45. The refueling drogue of claim 43, wherein respective centerlines of rotation
of the plurality of rotating masses are parallel to one another.
46. The refueling drogue of claim 43, wherein respective centerlines of rotation
of the plurality of rotating masses are uniformly arrayed about the center of mass
of the refueling drogue.
47. The refueling drogue of claim 1, further including aerodynamic surfaces adapted
to passively stabilize the refueling drogue.
48. The refueling drogue of claim 47, wherein the aerodynamic surfaces are located
on a refueling hose.
49. The refueling drogue of claim 47, wherein the aerodynamic surfaces are located
on the refueling drogue.
50. A refueling drogue spin stabilization kit comprising:
a spin stabilization pack including a rotatable mass, wherein the spin stabilization
pack is adapted to connect to a conventional refueling drogue, and wherein the
spin stabilization pack is adapted such that when connected to the refueling drogue,
the spin stabilization pack effectively stabilizes the refueling drogue via a gyroscopic
effect of the rotating mass on the refueling drogue when the refueling drogue is
placed in and airstream.
51. The kit of claim 50, wherein at least a portion of the spin stabilization
pack is adapted to rigidly connect to the refueling drogue such that the orientation
of the refueling drogue is substantially fixed with respect to the orientation
of the spin stabilization pack.
52. The kit of claim 50, wherein the rotating mass is connected to a air turbine,
and wherein the air turbine is adapted to rotate the rotatable mass when exposed
to the air stream when the air stream has a relative velocity to the spin stabilization
kit in excess of about 50 KEAS to produce the gyroscopic effect.
53. The kit of claim 52, wherein the air turbine is enclosed in the spin stabilization pack.
54. The refueling drogue of claim 52, wherein the air turbine is a radial turbine.
55. The refueling drogue of claim 54, wherein the spin stabilization kit is adapted
to direct air from an air stream flowing past the spin stabilization pack into
a cavity in the radial turbine and to direct the air through slots extending at
angles through the radial turbine to rotate the radial turbine.
56. The refueling drogue of claim 54, wherein the radial turbine is the rotating mass.
57. A method of effectively stabilizing a refueling drogue, comprising:
extending a refueling drogue connected to a refueling hose from an aircraft into
an air stream; and
rotating a rotatable mass to create an effective gyroscopic effect on the refueling
drogue to effectively stabilize the refueling drogue, wherein a flexible joint
is located between the rotatable mass and the refueling hose.
58. The method of claim 57, wherein the refueling drogue is effectively stabilized
by the gyroscopic effect in an airstream having a relative velocity to the refueling
drogue of more than about 80 KEAS.
59. The method of claim 57, wherein the refueling drogue is extended from a refueling
hose, further comprising:
supplying aviation fuel to an aircraft through the refueling drogue.
60. The method of claim 57, wherein effective stabilization is obtained without
the use of an active stabilization system.
61. The method of claim 57, wherein effective stabilization is obtained passively.
62. The method of claim 57, further comprising harnessing air from the air stream
to rotate the rotatable mass to produce the effective gyroscopic effect.
63. The method of claim 62, further comprising using an air turbine to harness
the air from the air stream to rotate the rotatable mass.
64. The method of claim 57, further comprising actively controlling the refueling
drogue while the refueling drogue is extended in the air stream.
65. The method of claim 64, further comprising regulating the vertical and horizontal
position of the drogue to maintain a substantially fixed orientation relative to
a refueling aircraft.
66. The method of claim 64, further comprising regulating the vertical and horizontal
position of the drogue utilizing with the active control system utilizing twp pairs
of control surfaces orthogonal to one another.
67. The method of claim 64, further comprising regulating the vertical and horizontal
position of the drogue utilizing with the active control system utilizing two pairs
of control surfaces, the pairs being orthogonal to one another, while the refueling
drogue rotates about its longitudinal axis.
68. The method of claim 64, further comprising regulating a pitch angle and a
yaw angle of an axis through the center of the refueling hose at the location where
the refueling hose connects to the refueling drogue.
69. The method of claim 68, wherein the yaw angle is regulated to substantially
zero degrees from a direction of the air stream.
70. The method of claim 69, wherein the pitch angle is regulated to substantially
constant non-zero angle from a reference plane corresponding to a horizontal plane.
71. The method of claim 64, wherein actively controlling the refueling drogue comprises:
measuring a varying angle between an axis through the center of the refueling
hose at the location where the refueling hose connects to the refueling drogue
and a direction of the air stream.
72. The method of claim 67, wherein actively controlling the refueling drogue comprises:
measuring a first varying angle between an axis through the center of the refueling
hose at the location where the refueling hose connects to the refueling drogue
and a direction of the air stream;
measuring a second varying angle between axis through the center of the refueling
hose at the location where the refueling hose connects to the refueling drogue
and the direction of the airstream; and
regulating the location of the refueling drogue based on the measured first varying
angle and the measured second varying angle.
73. The method of claim 64, wherein actively controlling the refueling drogue comprises:
measure the pitch angle and the yaw angle of an axis through the center of the
refueling hose at the location where the refueling hose connects to the refueling
drogue.
74. The method of claim 73, further comprising approximating at least one of
a displacement and a position of the refueling drogue based on the measured pitch
angle and the measured yaw angle of the axis through the center of the refueling
hose at the location where the refueling hose connects to the refueling drogue hose.
75. The method of claim 73, wherein the displacement and the position of the
refueling drogue is approximated utilizing an algorithm having a foundation in
the equations:
y=f(θ′), and
z=g(Ψ′), where
y=a distance in the plane in which the angle θ′ lies,
z=a distance in the plane in which the angle Ψ′ lies,
θ′=the pitch angle of the refueling hose, and
Ψ′=the yaw angle of the refueling hose,
where
f and g are functions that describe the relation between y and θ′
and z and Ψ′.
76. The method of claim 64, further comprising varying the position of the refueling
drogue so that a centerline of the refueling drogue remains substantially coaxial
with a centerline of a refueling probe of a receiver aircraft that is not yet in
contact with the refueling drogue.
77. The method of claim 76, wherein the position of the refueling drogue is varied
based on received radiation indicative of the position of an end of the refueling
probe of the receiver aircraft.
78. The method of claim 64, further comprising automatically maneuvering the
refueling drogue to a refueling probe of a receiver aircraft.
79. The method of claim 64, further comprising measuring an angle between the
refueling drogue and a refueling probe of a receiver aircraft.
80. The method of claim 64, further comprising automatically measuring a first
angle between the refueling drogue and a refueling probe of a receiver aircraft
measured on a first plane and measuring a second angle between the refueling drogue
and the refueling probe of the receiver aircraft measured on a second plane.
81. The method of claim 80, further comprising automatically adjusting the location
of the refueling drogue relative to the refueling probe of the receiver aircraft
so that the first and second angles are reduced.
82. The method of claim 81, further comprising automatically adjusting the location
of the refueling drogue relative to the refueling probe of the receiver aircraft
so that the first and second angles are reduced to substantially zero degrees.
83. A refueling drogue, comprising:
a rotatable mass;
an active control system; and
a flexible joint located between the rotatable mass and a connector on the refueling
drogue adapted to connect the refueling drogue to a refueling hose; wherein
the rotatable mass is adapted to effectively stabilize the refueling drogue via
a gyroscopic effect of the rotating mass on the refueling drogue when the refueling
drogue is connected to a refueling hose and placed in an airstream.
84. The refueling drogue of claim 83, wherein the active control system is adapted
to regulate the vertical and horizontal position of the drogue to maintain a substantially
fixed orientation relative to a refueling aircraft.
85. The refueling drogue of claim 84, wherein the active control system is adapted
to regulate the vertical and horizontal position of the drogue to maintain a substantially
fixed orientation relative to a refueling aircraft when the refueling aircraft
is flying at a substantially constant altitude, airspeed and heading.
86. The refueling drogue of claim 83, wherein the active control system comprises
a plurality of control surfaces located on the refueling drogue.
87. The refueling drogue of claim 86, wherein the plurality of control surfaces
are located on a refueling drogue hose connector.
88. The refueling drogue of claim 83, wherein the active control system comprises
two pairs of control surfaces orthogonal to one another.
89. The refueling of drogue of claim 88, wherein the active control system is
adapted to actively regulate the location of the refueling drogue at substantially
any rotation angle of the control surfaces from at least one of a horizontal plane
and a vertical plane.
90. The refueling of drogue of claim 89, further comprising a sensor adapted
to measure the rotation of angle γ.
91. The refueling of drogue of claim 83, wherein the refueling is adapted to
be connected to a refueling hose, and wherein the active control system further
comprises a control system adapted to regulate an θand an angle ψof
an axis through the center of the refueling hose at the location where the refueling
hose connects to the refueling drogue.
92. The refueling of drogue of claim 91, further comprising a refueling hose
connector rigidly connected to the refueling hose, wherein at least a portion of
the refueling hose connector is adapted to move relative to a main body of the
refueling drouge, and wherein the angle θand the ψof the axis through
the center of the refueling hose is regulated by regulating angles of the refueling
hose connector.
93. The refueling drogue of claim 91, wherein the control system is adapted to
substantially maintan the angle θand the angle ψof the axis through
the center of the refueling hose at respective references angles.
94. The refueling drogue of claim 93, wherein a yaw angle of the axis of the
refueling drogue is measured in a horizontal plane and is substantially zero degrees
from a direction of the air stream, and wherein a pitch angle of the axis of the
refueling drogue is measured in a vertical plane and is non-zero angle from a reference
plane corresponding to the horizontal plane.
95. The refueling drogue of claim 83, wherein the active control system comprises:
a sensor adapted to measure a varying angle between an axis through the center
of the refueling hose at a location where the refueling hose is connected to the
refueling drogue and a direction of the air stream.
96. The refueling drogue of claim 83, further comprising:
a first sensor adapted to measure a first varying angle between an axis through
the center of the refueling hose and a direction of the air stream; and
a second sensor adapted to measure a second separate varying angle between an
axis through the center of the refueling hose and the direction of the air stream;
wherein
the active control system is adapted to regulate the location of the refueling
drogue based on the measured first varying angle and the measured second varying
angle.
97. The refueling drouge of claim 96, wherein the drogue is adapted to permit
the first sensor and the second sensor to rotate relative to the horizontal plane
and the vertical plane.
98. The refueling drogue of claim 96, wherein the first varying angle lies on
a plane that is substantially orthogonal to a plane on which the second varying
angle lies.
99. The refueling drogue of claim 96, wherein the first varying angle lies on
a plane that is not substantially orthogonal to a plane on which the second varying
angle lies.
100. The refueling drogue of claim 98, further comprising a pair of control surfaces
orthogonal to another pair of control surfaces, wherein the plane on which the
first varying angle lies is on a plane through an axis of symmetry of the refueling
drogue and orthogonal to a plane on which one of the pairs of control surface lies.
101. The refueling drogue of claim 98, further comprising a first pair of control
surfaces orthogonal to a second pair of control surfaces, wherein the plane on
which the first varying angle lies on a plane through the first pair of control
surfaces and wherein the plane on which the second varying angle lies is on a plane
through the second pair of control surfaces.
102. The refueling drogue of claim 96, wherein at least one of the first sensor
and the second sensor includes a rotary vane adapted to pivot about a vane axis
and a sensor adapted to output a signal indicative of the angle of pivot about
the vane axis.
103. The refueling drogue of claim 96, wherein at least one of the first and
second sensors is located substantially at a refueling hose-refueling drogue pivot point.
104. The refueling drogue of claim 83, wherein the active control system is adapted
to reduce displacement of the refueling drogue of about 12 inches or less when
exposed to moderate turbulence.
105. The refueling drogue of claim 84, wherein the active control system is adapted
to reduce displacement of the refueling drogue to about 6 inches or less when exposed
to moderate turbulence.
106. The refueling drogue of claim 83, wherein the active control system is adapted
to reduce displacement of the refueling drogue to a few inches or less when exposed
to moderate turbulence.
107. The refueling drogue of claim 83, wherein the refueling drogue is connected
to a refueling hose, wherein the active control system is adapted to compute a
pitch angle θ' and a yaw angle Ψ' of an axis through the center of
the refueling hose at a location where the refueling hose connects to the refueling drogue.
108. The refueling drogue of claim 107, further comprising a computer adapted
to calculate at least one of a displacement and a position of the refueling drogue
based on the measured pitch angle and the yaw angle of the axis through the center
of the refueling hose.
109. The refueling drogue of claim 107, further comprising a computer adapted
to calculate at least one of a displacement and a position of the refueling drogue
based on the measured pitch angle and the yaw angle of the axis through the center
of the refueling hose and a proportionality constant.
110. The refueling drogue of claim 109, wherein the displacement and the position
of the refueling drogue is calculated utilizing an algorithm having a foundation
in the equations: y=f(θ'), and z=g(Ψ'), where y= a distance in the
plane in which the angle θ lies; z= a distance in the plane in which the
angle Ψ lies, θ' = the pitch angle of the refueling hose, and Ψ'
the yaw angle of the refueling hose, and f and g are functions that describe the
relation between y and θ' and z and Ψ'.
111. The refueling drogue of claim 83, further comprising an autonomous docking system.
112. The refueling drogue of claim 84, further comprising an autonomous docking system.
113. The refueling drogue of claim 111, wherein the autonomous docking system
is adapted to vary the position of the refueling drogue so that a centerline of
the refueling drogue remains substantially coaxial with a centerline of a refueling
probe of a receiver aircraft that is not yet in contact with the refueling drogue.
114. The refueling drogue of claim 113, wherein the autonomous docking system
comprises a sensor, and wherein the autonomous docking system is adapted to vary
the position of the refueling drogue based on information received by the sensor
indicative of the position of an end of the refueling probe of the receiver aircraft.
115. The refueling drogue of claim 113, wherein the autonomous docking system
is adapted to measure and angle ηand an angle λbetween the refueling
drogue and a point on the refueling probe of the receiver aircraft, and wherein
the autonomous docking system is adapted to vary the position of the refueling
drogue based on the measurements of these angles.
116. The refueling drogue of claim 115, wherein the autonomous docking system
is adapted to measure a plurality of angles η and average the plurality of
angles λ and an a plurality of angles η and average the plurality of
angles λ between the refueling drogue and a point on the refueling probe
of the receiver aircraft, and wherein the autonomous docking system is adapted
to vary the position of the refueling drogue based on the averages of these angles.
117. The refueling drogue of claim 115, wherein the autonomous docking system
is adapted to position the refueling drogue so that the average of the measured
plurality of angles η and average the plurality of measured angles η
are substantially reduced to zero.
118. The refueling drogue of claim 113, wherein the autonomous docking system
comprises a radiation receiver, and wherein the autonomous docking system is adapted
to vary the position of the refueling drogue based on received radiation indicative
of the position of an end of the refueling probe of the receiver aircraft.
119. The refueling drogue of claim 118, further comprising a radiation emitter
located on the refueling drogue.
120. The refueling drogue of claim 118, wherein the receiver is adapted to receiver
radiation emitted from a receiver aircraft.
121. The refueling drogue of claim 118, wherein the receiver is adapted to receive
radiation emitted from a receiver aircraft.
122. The refueling drogue of claim 118, wherein the receiver is adapted to receive
an identification code, and wherein the autonomous docking system is configured
to compare the identification code to a code in a database.
123. The refueling drogue of claim 118, wherein the receiver is adapted to sense
at least one of a varying signal and a varying field, wherein the at least one
of a varying signal and a varying field varies based on the location of the receiver aircraft.
124. The refueling drogue of claim 111, wherein the autonomous docking system
is adapted to automatically maneuver the refueling drogue to the refueling probe
of the receiver aircraft.
125. The refueling drogue of claim 111, wherein the autonomous docking system
is adapted to measure an angle between the refueling drogue and the refueling probe
of the receiver aircraft.
126. The refueling drogue of claim 111, wherein the autonomous docking system
is adapted to measure a first angle between the refueling drogue and the refueling
probe of the receiver aircraft measured on a first plane and to measure a second
angle between the refueling drogue and the refueling probe of the receiver aircraft
measured on a second plane.
127. The refueling drogue of claim 126, wherein the autonomous docking system
is adapted to regulate the location of the refueling drogue relative to the refueling
probe of the receiver aircraft so that the first and second angles are reduced.
128. The refueling drogue of claim 127, wherein the autonomous docking system
is adapted to adjust the location of the refueling drogue relative to the refueling
probe of the receiver aircraft so that the first and second angles are reduced
to substantially zero degrees.
129. The refueling drogue of claim 128, further comprising a control circuit
utilizing an error signal input to regulate the location of the refueling drogue
so that the first and second angles are reduced to substantially zero degrees,
wherein the circuit is adapted to convert the first and second angles to error signals.
130. The refueling drogue of claim 83, further comprising an autonomous docking
system, wherein the autonomous docking system is in communication with the control
system to vary the position of the refueling drogue so that a centerline of the
refueling drogue remains substantially coaxial with a centerline of a refueling
probe of a receiver aircraft that is not yet in contact with the refueling drogue.
131. The refueling drogue of claim 83, further comprising an autonomous docking
system, wherein the autonomous docking system is in communication with the control
system and adapted to maneuver the refueling drogue to a refueling probe of a receiver aircraft.
132. The refueling drogue of claim 83, wherein the active control system comprises
an autonomous docking system, adapted to maneuver the refueling drogue to a refueling
probe of a receiver aircraft.
133. The refueling drogue of claim 1, wherein the flexible joint is adapted to
enable a portion of the refueling drogue including the rotatable mass to pivot
with respect to the refueling hose.
134. The kit of claim 50, wherein the spin stabilization pack includes a flexible
joint that is adapted to flexibly connect the spin stabilization pack to a refueling hose.
135. The refueling drogue of claim 134, wherein the flexible joint is adapted
to enable a portion of the refueling drogue including the rotatable mass to pivot
with respect to the refueling hose.
136. The new method of claim 1, wherein the flexible joint is adapted to enable
a portion of the refueling drogue including the rotatable mass to pivot with respect
to the refueling hose.
Description
BACKGROUND OF THE INVENTION
Aerial refueling via the probe and drogue method is known. In an exemplary
refueling scenario, a refueling drogue connected to a refueling hose is unreeled
from a refueling aircraft towards a receiver aircraft (an aircraft to be refueled),
such as a fighter plane. The receiver aircraft has a refueling probe extending
from the aircraft. The receiver aircraft maneuvers to the refueling drogue and
inserts its refueling probe into the refueling drogue, at which point the refueling
drogue "locks" onto the refueling probe, and a transfer of fuel from the refueling
aircraft to the receiver aircraft is conducted.
It is desirable that the drogue remain as stationary as possible and/or that
the
drogue not rotate when extended from the refueling hose away from the refueling
aircraft towards the receiver aircraft, at least before contact between the drogue
and the probe is made. Unfortunately, the hose-drogue combination has a relatively
large dynamic response to disturbances, so when the drogue is subjected to wind
gusts and/or turbulence, the motion of the drogue becomes somewhat unpredictable,
as forces imparted onto the drogue by the air cause the drogue to move and/or rotate,
thus making it difficult to position the refueling probe of the aircraft to be
refueled into the refueling drogue.
Thus, there is a need to reduce the disturbance response of a refueling drogue
that has been extended on a refueling hose so that the movement of the drogue resulting
from wind/turbulence is substantially reduced to improve the ease by which the
refueling probe can be inserted in the refueling drogue.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic view of a first embodiment of the present invention.
FIG. 2 shows an implementation of an embodiment of the present invention.
FIG. 3 shows another embodiment of the present invention.
FIG. 4 shows yet another embodiment of the present invention.
FIG. 5 shows a detailed view of a component of the embodiment shown in FIG. 4.
FIG. 5
a shows a cross-sectional view of the component shown in FIG. 5.
FIG. 6 shows yet another embodiment of the present invention.
FIG. 7 shows yet another embodiment of the present invention.
FIG. 8 shows yet another embodiment of the present invention.
FIG. 9 shows yet another embodiment of the present invention.
FIG. 10 shows yet another embodiment of the present invention.
FIG. 11 shows yet another embodiment of the present invention.
FIG. 12 shows yet another embodiment of the present invention.
FIG. 13 shows the orientation of the axis of the refueling hose with respect
to the velocity vector of the airstream as seen from one reference point.
FIG. 14 shows the orientation of the axis of the refueling hose with respect
to the velocity vector of the airstream as seen from another reference point.
FIG. 15 shows the orientation of the control surfaces of the drogue 100
as seen when looking down the axis of the drogue 100.
FIG. 16 shows the orientation of the axis of the drogue 100 with respect
to a refueling probe as seen from one reference point.
FIG. 17 shows the orientation of the axis of the drogue 100 with respect
to a refueling probe as seen from another reference point.
FIG. 18 shows the orientation of a plurality of sensors on the drogue 100
with respect to a refueling probe as seen from one reference point.
FIG. 19 shows the orientation of other sensors on the drogue 100 with
respect to a refueling probe as seen from another reference point.
FIG. 20 shows another embodiment of the invention, where the location of the
refueling drogue is determined based on angles between the refueling aircraft and
the refueling drogue.
FIG. 21 shows an exemplary embodiment of a conventional refueling drogue.
DETAILED DESCRIPTION OF SOME OF THE EMBODIMENTS
In a first embodiment of the present invention, as shown in FIG. 1, there is a
refueling drogue
100 comprising a rotatable mass
200 mechanically
coupled to an air turbine
300, such that when the refueling drogue
100
is placed in an air stream
900 that flows past the refueling drogue
100,
air
910 is inducted into the drogue
100 and passes the air turbine
300 rotating the air turbine
300 and imparting a rotation onto the
rotating mass
200 to produce a gyroscopic effect that effectively passively
stabilizes the refueling drogue
100 as it is being dragged through the air
behind a refueling aircraft
1000, such as a KC-
135 and/or A-6 refueling
aircraft and/or KC-
130 and/or rotary wing refueling aircraft
1000
as shown in FIG.
2. The particular details of the present invention will
now be described.
FIG. 2 shows a schematic of the refueling drogue
100 according to the
present invention being utilized to refuel a receiver aircraft
2000 by a
tanker
1000. In FIG. 2, it may be seen that a refueling hose
800
extends from the tanker
1000 and is connected to refueling drogue
100.
Refueling drogue
100 is further connected to refueling probe
2100
extending from the receiver aircraft
2000. In the first embodiment of the
invention, once the refueling probe
2100 of the receiver aircraft
2000
is captured in the refueling drogue
100, aviation fuel may be transferred
from the tanker
1000 through the refueling hose
800, through the
refueling drogue
100, and then through the refueling probe
2100,
and into tanks (not shown) in the receiver aircraft
2000. In the first embodiment
of the invention, the refueling drogue
100 is adapted to physically connect
to the refueling probe
2100. Connection can be performed in some embodiments
per military standards. In the first embodiments of the invention, the refueling
hose
800 is approximately three inches in interior diameter, while in other
embodiments, it is approximately two inches or four inches in interior diameter.
In some embodiments, the hose is about 2.375, 2.625 and 2.875 inches in interior
diameter. Thus, some embodiments of the present invention may be practiced with
hoses of different sizes depending on the desired maximum fuel off loads of the
refueling aircraft.
The refueling drogue
100 may be effectively passively stabilized by rotating
a mass
200 in the refueling drogue
100 at a sufficient speed to produce
a gyroscopic effect that will result in the refueling probe
100 being effectively
passively stabilized as it is pulled through the atmosphere behind the refueling
aircraft
1000. The resulting angular momentum may be harnessed to fix the
drogue's orientation in space, thus stabilizing the drogue. Based upon the principle
of gyroscopic motion, the amount of disturbance torque that the drogue can reject
is directly related to the angular momentum of the rotating mass
200 (the
greater the momentum, the greater the amount of disturbance torque the drogue
100
can reject), where angular momentum may be increased by increasing the spin speed
and/or the polar moment of inertia (mass distribution) of the rotating mass. By
rotating the mass
200, a sufficient angular momentum can be achieved so
that the drogue
100 may sufficiently reject disturbance forces and thus
effectively passively stabilizing the drogue
100. What is, the refueling
drogue
100 tends to have a fixed orientation in space and is capable of
effectively rejecting a disturbance moment (such as turbulence), thus, providing
a substantially stable reference hose for the refueling drogue
100 due to
the gyroscopic effect of the rotating mass. By "stabilized," it is meant that the
disturbance response of the drogue
100 is significantly reduced. By way
of example, the angular displacement of the longitudinal axis of the drogue
100
due to turbulence can be reduced. By "passively stabilized," it is meant that the
refueling drogue
100 may be stabilized without the need of control surfaces
or other surfaces such as rudders and/or elevators, that alter the orientation
and/or position of the refueling drogue
100 (or more precisely, physically
impart a force or moment on the refueling drogue to counter the effects of turbulence,
etc., on the refueling drogue
100 to substantially fix its angular orientation
in space).
In a first embodiment of the present invention, the refueling drogue
100
may be configured to harness an air stream
900 flowing past the refueling
drogue
100 due to the forward velocity of the drogue
100 as it is
dragged through the atmosphere to spin the rotating mass
200 to obtain the
gyroscopic effect to passively stabilize the refueling drogue
100. Air stream
velocities may be below 80 KEAS, 80 KEAS, 100 KEAS, 150 KEAS, 200 KEAS, 250 KEAS,
300 KEAS, 350 KEAS, 400 KEAS, or more, or any speed or range of speeds therebetween
in increments of 1 KEAS, and is typically a function of the forward velocity of
the refueling aircraft
1000.
Source of Rotation of the Rotatable Mass
In the first embodiment of the invention, the refueling drogue 100 includes
an air turbine 300 that when exposed to the relative air stream, rotates
the rotatable mass 200 as a result of the aerodynamic forces on the air
turbine 300. In a first embodiment of the present invention, as shown in
FIG. 1, air 910 from air stream 900 is inducted into the refueling
drogue 100 and directed past the air turbine 300, which in some embodiments
of the invention, may be configured much like a fan, and then exits the refueling
drogue 100 out an exhaust port 130 and back into the air stream 900.
Because the air turbine 900 is mechanically connected to the mass 200,
(in the embodiment shown in FIG. 1, the air turbine is directly mounted on the
rotatable mass 200) the rotation of the air turbine 300 is imparted
onto the mass 200 which is supported by bearings 220, thus permitting
the mass 100 to rotate about the centerline of rotation 210 of the
rotating mass.
It is noted that some embodiments of the present invention can be practiced utilizing
compressed air that is passed by the air turbine 300 to impart the rotation
onto the rotating mass 200. Thus, in some embodiments of the invention,
a ram air device may be utilized to compress the air to a sufficient degree such
that when the air is permitted to expand in proximity to the air turbine 300,
the air turbine rotates and a rotation is imparted onto the mass 200.
As can be seen from FIG. 1, a first embodiment of the present invention may be
practiced with the air turbine 300 inside the refueling drogue 100.
That is, the air turbine in some embodiments of the invention may be internal to
the refueling drogue 100 in a manner that is, by way of example, analogous
to the turbine of a conventional jet engine. However, it is noted that in some
embodiments of the present invention, as shown in FIG. 3, the air turbine 300
may be located on the outside the refueling drogue 100. Thus, in some embodiments
of the present invention, the blades 300 can extend from the refueling drogue
100, as shown in FIG. 3. In yet further embodiments of the present
invention, a portion of the air turbine 300 may be both located inside the
refueling drogue and outside of the refueling drogue. In yet further embodiments,
a plurality of air turbines may be used, some of which may be located inside the
drogue 100 and some on the outside of the drogue 100.
In some embodiments of the present invention, the basket 110 that extends
from the rear of the refueling drogue is configured such that the basket will rotate,
thus imparting a rotation onto the body of the refueling drogue and/or the rotating
mass 200 portion of the refueling drogue.
It is noted that the present invention may be practiced with a variety of types
of air turbines 300. In the first embodiment of the invention, as shown
in FIGS. 1 and 3, the air turbine 300 can comprise a plurality of radially
extending blades and/or vanes that serve to capture energy from the air stream
900/910 passing through the blades in a manner quite similar to the
blades of a conventional bladed fan or windmill. However, in other embodiments
of the present invention, the air turbine 300 can comprise a plurality of
passages (holes, slots, spaces, bores, etc.) in a body, the air turbine 300
having a configuration such that when air is passed through the passages, a rotation
is imparted on the air turbine 300. By way of example only and not by way
of limitation, a air turbine 300 having a radial turbine configuration as
shown in FIG. 4, may be used to practice the invention (as will be discussed in
greater detail below). Some embodiments of the present invention may be practiced
with any device that may enable energy to be extracted from an air stream to create
a rotational moment that may be used to rotate and/or assist in rotating the rotating
mass 200. Indeed, in some embodiments of the present invention, the air
turbine 300 may comprise a disk having a plurality of angled bores through
the disk at angles such that when air traveling in the axial direction towards
the disk passes through the bores, a rotational moment is imparted on the disk,
which then may be imparted on the rotating mass 200.
As mentioned above, a first embodiment of the present invention may utilize a
radial turbine (which may be of a configuration commonly referred to as a squirrel
cage) as the air turbine 300 to impart a rotation on the rotating mass 200.
As can be seen from FIGS. 4-5, the radial turbine 350 may be aligned with
its axis of rotation 210 parallel or substantially to the direction of the
air stream 900. In the embodiment shown in FIG. 4, air 910 from the
air stream 900 enters through air inlets 120 facing the air stream
900. This air is directed into a cavity 360 in the radial turbine
350. The air then passes through slots 370 in the radial turbine
350 and then through passageways 130 arranged axially around the
exterior of the refueling drogue 100 leading to the exterior of the drogue
100. The configuration of the slots 370 in the radial turbine 350
and/or the configuration of the drogue 100 is such that passage of the air
through the slots imparts a rotation onto the radial turbine. In a first embodiment,
the slots 370 are spaced about every 18 degrees around the circumference
of the radial turbine 350, although in other embodiments, the slots may
be spaced differently.
In the embodiment shown in FIG. 4, the rotating mass 200 is the radial
turbine 350. That is, the radial turbine 350 is of sufficient design
(mass, geometry, etc.) such that as it rotates, it may produce a sufficient gyroscopic
effect on the refueling drogue 100 sufficient to passively stabilize the
drogue. However, it is noted that in other embodiments of the present invention,
the radial turbine 350 may be mechanically connected to a separate rotating
mass 200.
It is noted that in some embodiments of the invention, the air turbine 300
may utilize any type of surface/body that may extract mechanical energy from an
air stream 900 flowing past the refueling drogue 100 (including the
inducted air 910). Thus, in some embodiments of the present invention, the
air turbine 300 may simply have a plurality of surfaces that, when exposed
to an air stream 900 having a relative velocity to the refueling probe in
excess of a certain value, are adapted to rotate and thus rotate the rotatable
mass 200 as a result of aerodynamic forces on the surfaces. In some embodiments
of the invention, these surfaces may be lifting surfaces (LID greater than 1),
may be drag surfaces (L/D less than 1), or a combination of lift surfac
