U.S. patent application number 11/482338 was filed with the patent office on 2008-01-10 for two-axis trajectory control system.
Invention is credited to Johnny E. Banks.
Application Number | 20080006736 11/482338 |
Document ID | / |
Family ID | 38918300 |
Filed Date | 2008-01-10 |
United States Patent
Application |
20080006736 |
Kind Code |
A1 |
Banks; Johnny E. |
January 10, 2008 |
Two-axis trajectory control system
Abstract
A trajectory control system includes a first control mechanism
having a pair of outputs operably associated with a first pair of
control surfaces, the first control mechanism operable to
articulate the first pair of control surfaces in unison and a
second control mechanism having a pair of outputs operably
associated with a second pair of control surfaces, the second
control mechanism operable to articulate the second pair of control
surfaces in unison. The second control mechanism is nested in the
first control mechanism such that the pair of outputs of the first
control mechanism is substantially coplanar with the pair of
outputs of the second control mechanism.
Inventors: |
Banks; Johnny E.; (Venus,
TX) |
Correspondence
Address: |
LAW OFFICES OF JAMES E. WALTON, PLLC
1169 N. BURLESON BLVD., SUITE 107-328
BURLESON
TX
76028
US
|
Family ID: |
38918300 |
Appl. No.: |
11/482338 |
Filed: |
July 7, 2006 |
Current U.S.
Class: |
244/3.21 ;
244/3.1; 244/3.15 |
Current CPC
Class: |
F42B 15/01 20130101;
F42B 10/64 20130101 |
Class at
Publication: |
244/3.21 ;
244/3.1; 244/3.15 |
International
Class: |
F42B 15/01 20060101
F42B015/01 |
Claims
1. A two-axis trajectory control system, comprising: a first
control mechanism having a pair of outputs operably associated with
a first pair of control surfaces, the first control mechanism
operable to articulate the first pair of control surfaces in
unison; and a second control mechanism having a pair of outputs
operably associated with a second pair of control surfaces, the
second control mechanism operable to articulate the second pair of
control surfaces in unison; wherein the second control mechanism is
nested in the first control mechanism such that the pair of outputs
of the first control mechanism is substantially coplanar with the
pair of outputs of the second control mechanism.
2. The two-axis trajectory control system, according to claim 1,
further comprising: a housing comprising a first portion in which
the first control mechanism is disposed and a second portion, mated
with the first portion, in which the second control mechanism is
disposed; and means for retaining the first portion to the second
portion; wherein the first control mechanism and the second control
mechanism are each supported by the first portion of the housing
and the second portion of the housing.
3. The two-axis trajectory control system, according to claim 1,
further comprising: a position sensor operably associated with one
of the first control mechanism and the second control
mechanism.
4. The two-axis trajectory control system, according to claim 1,
wherein the first control mechanism has a construction
substantially equivalent to the second control mechanism.
5. The two-axis trajectory control system, according to claim 1,
operably associated with one of an airborne and a waterborne
vehicle.
6. A two-axis trajectory control system, comprising: a first
control mechanism having outputs coupled with a first pair of
control surfaces, the first control mechanism operable to
articulate the first pair of control surfaces in unison; and a
second control mechanism having outputs coupled with a second pair
of control surfaces, the second control mechanism operable to
articulate the second pair of control surfaces in unison; wherein
the first control mechanism comprises: a motor; an axle coupled
with the first pair of control surfaces; and a worm shaft operably
associated with the motor and the axle, such that the axle rotates
when the motor is activated; and wherein the outputs of the first
control mechanism are substantially coplanar with the outputs of
the second control mechanism.
7. The two-axis trajectory control system, according to claim 6,
wherein the first control mechanism further comprises: a motor gear
fixedly attached to the motor; a worm drive gear fixedly attached
to the worm shaft and engaged with the motor gear, such that the
worm shaft rotates when the motor is actuated.
8. The two-axis trajectory control system, according to claim 6:
wherein the axle includes a clevis; and wherein the first control
mechanism further comprises: an axle drive nut engaged with the
worm shaft and rotatably attached to the clevis of the axle.
9. The two-axis trajectory control system, according to claim 8,
wherein the axle drive nut rotates with respect to the axle about a
first axis and the axle rotates about a second axis, which is
substantially parallel to the first axis, when the motor is
actuated.
10. The two-axis trajectory control system, according to claim 6,
further comprising: a housing having a first portion in which the
first control mechanism is disposed and a second portion in which
the second control mechanism is disposed; wherein the first control
mechanism is disposed in the first portion of the housing and the
worm shaft is supported by both the first portion and the second
portion of the housing.
11. The two-axis trajectory control system, according to claim 10,
wherein the second control mechanism is disposed in the second
portion of the housing and is supported by both the first portion
and the second portion of the housing.
12. The two-axis trajectory control system, according to claim 6,
wherein the second control mechanism includes an axle and the axle
of the first control mechanism includes a bend configured to
receive the axle of the second control mechanism.
13. The two-axis trajectory control system, according to claim 12,
wherein the axle of the second control mechanism includes a bend,
such that the axle of the first control mechanism is nested with
respect to the axle of the second control mechanism at the bends of
the axles.
14. A two-axis trajectory control system, comprising: a first
control assembly operably associated with a first pair of control
surfaces for articulating the first pair of control surfaces in
unison; and a second control assembly operably associated with a
second pair of control surfaces for articulating the second pair of
control surfaces in unison, the second control assembly comprising:
a housing portion; an end cap attached to the housing portion; a
motor rotatably supported by the housing portion and the end cap,
the motor having an output shaft; a motor gear fixedly attached to
the output shaft of the motor; a worm drive gear engaged with the
motor gear; a worm shaft rotatably supported by the housing portion
and engaged with the worm drive gear; a worm shaft end stop fixedly
attached to the worm shaft and rotatably supported by the first
control assembly; an axle drive nut engaged with the worm shaft;
and an axle coupled with the axle drive nut and the second pair of
control surfaces.
15. The two-axis trajectory control system, according to claim 14,
wherein the first control assembly comprises: a housing portion,
such that the worm shaft end stop is rotatably supported by the
housing portion of the first control assembly.
16. The two-axis trajectory control system, according to claim 14,
wherein the construction of the first control assembly corresponds
to the construction of the second control assembly.
17. The two-axis trajectory control system, according to claim 16,
wherein a worm shaft end stop of the first control assembly is
rotatably supported by the second control assembly.
18. The two-axis trajectory control system, according to claim 14,
wherein the first control assembly comprises: an axle operably
associated with the first pair of control surfaces; wherein the
axle of the second control assembly includes a bend for receiving
the axle of the first control assembly.
19. The two-axis trajectory control system, according to claim 18,
wherein the axle of the first control assembly includes a bend for
receiving the axle of the second control assembly.
20. The two-axis trajectory control system, according to claim 14,
wherein the axle drive nut rotates with respect to the axle about
an axis that is substantially parallel with an axis of rotation of
the axle when the motor is activated.
21. The two-axis trajectory control system, according to claim 14,
further comprising means for retaining the first control assembly
to the second control assembly.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to systems for controlling the
trajectory of airborne or waterborne vehicles.
[0003] 2. Description of Related Art
[0004] Airborne or waterborne vehicles, such as missiles, rockets,
torpedoes, and the like, are often used to deliver a payload to a
target location or to carry a payload over a desired area. For
example, vehicles may be used in combat situations to deliver a
payload, such as an explosive warhead or a kinetic energy
penetrator, to a target to disable or destroy the target.
Surveillance vehicles may carry a payload designed to sense certain
conditions surrounding the vehicle, such as objects on the ground
or weather activity. Such a vehicle typically includes a trajectory
control system having a plurality of control surfaces, such as
fins, canards, flares, etc., that are articulated by a system to
control the vehicle's direction and attitude.
[0005] Some vehicles are large in size and, thus, can accommodate
large systems for articulating the vehicle's control surfaces. A
large articulation system, however, may not be desirable, because
less volume of the vehicle is available for propellant and payload.
A smaller vehicle may simply not be viable for the purpose intended
for the vehicle if the articulation system occupies a large
percentage of the vehicle's volume. For example, a smaller vehicle
may not be able to reach a desired target or may not be capable of
carrying sufficient payload if the articulation system occupies a
large volume percentage of the vehicle. Outer diameters of some
projectile-type vehicles, such as rockets and missiles, are
constrained in size by the type of equipment used to launch the
vehicle. For example, "shoulder-launched" vehicles or vehicles
launched from personnel carriers often are limited in outer
diameter, as well as overall size. Larger, conventional
articulation systems for control surfaces are not well suited for
use in such vehicles.
[0006] Other conventional trajectory control systems provide
articulation systems that move each of the control surfaces
independently to provide control over roll, pitch, and yaw. In some
operational environments, vehicle roll is not a concern. In other
words, it is not important that the roll orientation of the vehicle
be maintained during operation of the vehicle. Using a trajectory
control system that provides roll control when the vehicle roll is
not important unduly adds to the cost, complexity, and weight of
the vehicle.
[0007] Conventional two-axis trajectory control systems that
control pitch and yaw of a vehicle are not sufficiently compact to
lend their use in smaller vehicles. Moreover, such conventional
two-axis trajectory control systems are not configured to withstand
the extreme loads experienced during high velocity maneuvers, such
as those employed by kinetic energy projectiles. Conventional
two-axis trajectory control systems are typically complex,
requiring many different components to be manufactured and
assembled.
[0008] It is generally desirable, however, for such vehicles to be
lighter in weight, rather than heavier, so that their ranges may be
extended while using an equivalent amount of propellant. Further,
it is generally desirable for the contents of the vehicle other
than the payload, e.g., the motors, power transmission assemblies,
and the like, to be more compact, so that larger payloads may be
used within the body of the projectile. It is also often desirable
to decrease the complexity of calculating the required orientation
of the control surfaces to attain the desired vehicle orientation
and commanding the actuation apparatuses to orient the control
surfaces accordingly.
[0009] There are many designs of trajectory control systems well
known in the art; however, considerable shortcomings remain.
SUMMARY OF THE INVENTION
[0010] There is a need for an improved trajectory control
system.
[0011] Therefore, it is an object of the present invention to
provide an improved trajectory control system.
[0012] This and other objects are achieved by providing a
trajectory control system that includes a first control mechanism
having a pair of outputs operably associated with a first pair of
control surfaces, the first control mechanism operable to
articulate the first pair of control surfaces in unison and a
second control mechanism having a pair of outputs operably
associated with a second pair of control surfaces, the second
control mechanism operable to articulate the second pair of control
surfaces in unison. The second control mechanism is nested in the
first control mechanism such that the pair of outputs of the first
control mechanism is substantially coplanar with the pair of
outputs of the second control mechanism.
[0013] In another aspect, the present invention provides a
trajectory control system. The system includes a first control
mechanism having outputs coupled with a first pair of control
surfaces, the first control mechanism operable to articulate the
first pair of control surfaces in unison and a second control
mechanism having outputs coupled with a second pair of control
surfaces, the second control mechanism operable to articulate the
second pair of control surfaces in unison. The first control
mechanism includes a motor; an axle coupled with the first pair of
control surfaces; and a worm shaft operably associated with the
motor and the axle, such that the axle rotates when the motor is
activated. The outputs of the first control mechanism are
substantially coplanar with the outputs of the second control
mechanism.
[0014] In yet another aspect of the present invention, a trajectory
control system is provided. The trajectory control system includes
a first control assembly operably associated with a first pair of
control surfaces for articulating the first pair of control
surfaces in unison and a second control assembly operably
associated with a second pair of control surfaces for articulating
the second pair of control surfaces in unison. The second control
assembly includes a housing portion; an end cap attached to the
housing portion, and a motor rotatably supported by the housing
portion and the end cap. The motor has an output shaft to which a
motor gear is fixedly attached. The second control assembly further
includes a worm drive gear engaged with the motor gear, a worm
shaft rotatably supported by the housing portion and engaged with
the worm drive gear, and a worm shaft end stop fixedly attached to
the worm shaft and rotatably supported by the first control
assembly. The second control assembly further includes an axle
drive nut engaged with the worm shaft and an axle coupled with the
axle drive nut and the second pair of control surfaces.
[0015] The present invention provides significant advantages,
including: (1) providing a two-axis trajectory control system that
occupies a smaller volume of a vehicle than conventional trajectory
control systems; (2) providing a two-axis trajectory control system
that is less complex in construction than conventional trajectory
control systems; and (3) providing a two-axis trajectory control
system that can withstand the loadings experienced during high
velocity vehicle operation.
[0016] Additional objectives, features, and advantages will be
apparent in the written description which follows.
DESCRIPTION OF THE DRAWINGS
[0017] The novel features believed characteristic of the invention
are set forth in the appended claims. However, the invention
itself, as well as, a preferred mode of use, and further objectives
and advantages thereof, will best be understood by reference to the
following detailed description when read in conjunction with the
accompanying drawings, wherein:
[0018] FIG. 1 is a partially exploded, perspective view of an
illustrative embodiment of a two-axis control surface actuation
system according to the present invention;
[0019] FIG. 2 is a partially exploded, perspective view of the
control surface actuation system of FIG. 1;
[0020] FIG. 3 is an exploded view of an illustrative embodiment of
a control assembly of the control surface actuation system of FIG.
1;
[0021] FIG. 4 is a partially exploded, perspective view of an axle
and related elements of the control surface actuation system of
FIG. 1;
[0022] FIG. 5 is a partially exploded, perspective view of a
vehicle incorporating the control surface actuation system of FIG.
1;
[0023] FIG. 6 is a cross-sectional view of a portion of the axle of
FIG. 4 take along line 6-6 of FIG. 4;
[0024] FIG. 7 is a perspective view of a control surface member
according to the present invention;
[0025] FIG. 8 is a partially exploded, perspective view of a
portion of the vehicle of FIG. 5; and
[0026] FIG. 9 is a partially exploded, perspective view of the
vehicle of FIG. 5.
[0027] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof have been shown
by way of example in the drawings and are herein described in
detail. It should be understood, however, that the description
herein of specific embodiments is not intended to limit the
invention to the particular forms disclosed, but on the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] Illustrative embodiments of the invention are described
below. In the interest of clarity, not all features of an actual
implementation are described in this specification. It will of
course be appreciated that in the development of any such actual
embodiment, numerous implementation-specific decisions must be made
to achieve the developer's specific goals, such as compliance with
system-related and business-related constraints, which will vary
from one implementation to another. Moreover, it will be
appreciated that such a development effort might be complex and
time-consuming but would nevertheless be a routine undertaking for
those of ordinary skill in the art having the benefit of this
disclosure.
[0029] In the specification, reference may be made to the spatial
relationships between various components and to the spatial
orientation of various aspects of components as the devices are
depicted in the attached drawings. However, as will be recognized
by those skilled in the art after a complete reading of the present
application, the devices, members, apparatuses, etc. described
herein may be positioned in any desired orientation. Thus, the use
of terms such as "above," "below," "upper," "lower," or other like
terms to describe a spatial relationship between various components
or to describe the spatial orientation of aspects of such
components should be understood to describe a relative relationship
between the components or a spatial orientation of aspects of such
components, respectively, as the device described herein may be
oriented in any desired direction.
[0030] The present invention represents a two-axis system for
controlling the trajectory of an airborne or waterborne vehicle. In
particular, the present system articulates a plurality of control
surfaces, such as a plurality of fins, to adjust the pitch and/or
yaw of the vehicle. As used in the present application, the term
"control surface" means a structure, such as an airfoil, that is
moveable to control or guide an airborne or waterborne vehicle. In
a preferred embodiment, the present system includes a housing that
encloses a first control mechanism, operably associated with a
first pair of control surfaces, and a second control mechanism,
operably associated with a second pair of control surfaces. The
control mechanisms nest with respect to one another such that the
output shafts of the control mechanisms are coplanar. Preferably,
the control mechanisms are identical in configuration to reduce the
cost and complexity of the system. The control mechanisms are
disposed in different portions of a housing. Each of the control
mechanisms and the housing portion corresponding to the control
mechanism forms a control assembly. The control assemblies mate
with one another to form a control surface actuation system.
[0031] FIG. 1 and FIG. 2 provide partially exploded, perspective
views of an illustrative embodiment of a two-axis control surface
actuation system 101 according to the present invention. Control
surface actuation system 101 comprises a housing 103, a first
control mechanism 105, a second control mechanism 107, and a
plurality of locking rings 109. Housing 103 comprises a first
portion 111 in which first control mechanism 105 is disposed and a
second portion 113 in which second control mechanism 107 is
disposed. First portion 111 and first control mechanism 105 make up
a first control assembly 115. Second portion 113 and second control
mechanism 107 make up a second control assembly 117. Control lines
119 extend between trajectory control mechanisms 105, 107 and, for
example, a guidance computer for the vehicle.
[0032] Locking rings 109 engage first portion 111 of housing 103
and second portion 113 of housing 103 to retain first portion 111
to second portion 113. As control mechanisms 105, 107 are disposed
in portions 111, 113, respectively, locking rings 109 retain first
control assembly 115 to second control assembly 117. By way of
example and illustration, locking rings 109 are but one means for
retaining first portion 111 of housing 103 to second portion 113 of
housing 103. Moreover, locking rings 109 are but one means for
retaining first control assembly 115 to second control assembly
117. Each of first control mechanism 105 and second control
mechanism 107 are configured to mate with and articulate a pair of
control surfaces (not shown in FIG. 1 or 2), as will be discussed
in greater detail below. Moreover, first control mechanism 105 and
second control mechanism 107 are configured to mate with one
another, as will also be described in greater detail below.
[0033] In the illustrated embodiment, first portion 111 of housing
103 and first control mechanism 105 are substantially equivalent in
construction to second portion 113 of housing 103 and second
control mechanism 107, respectively. In other words, first portion
111 of housing 103 is substantially equivalent in construction to
second portion 113 of housing 103 and first control mechanism 105
is substantially equivalent in construction to second control
mechanism 107. Accordingly, first control assembly 115 is,
preferably, substantially equivalent in construction to second
control assembly 117. It should be noted that the embodiment
illustrated in FIGS. 1 and 2 is merely preferred. Other embodiments
are contemplated by the present invention wherein first control
assembly 115 is different in construction from second control
assembly 117. For example, first portion 111 of housing 103 may
differ in construction from second portion 113 of housing 103, so
long as first portion 111 can be retained to second portion 113. In
another example, first control mechanism 105 may differ in
construction from second control mechanism 107, so long as first
control mechanism 105 and second control mechanism 107 mate with
one another or the outputs of first control mechanism 105 and
second control mechanism 107 are coplanar. It should be noted that
first portion 111 of housing 103 (and, thus, first control
mechanism 105) is clocked at about 90 degrees with respect to
second portion 113 of housing (and, thus second control mechanism
107), as illustrated in FIG. 2.
[0034] FIG. 3 provides an exploded view of first portion 111 of
housing 103 and first control mechanism 105. As the preferred
embodiment of the present invention contemplates second control
assembly 117 to be substantially equivalent in construction as
first control assembly 115, the following description of first
control assembly 115 applies equally to second control assembly
117. It should be noted that components of second control assembly
117, when referenced herein, are referred to by the corresponding
element reference number of first control assembly 115, followed by
the prime mark. For example, as will be discussed below, first
control mechanism 105 comprises an end cover 301. In the preferred
embodiment, second control mechanism 107 comprises an end cover
301' having a construction corresponding to end cover 301.
[0035] First control mechanism 105, in the illustrated embodiment,
comprises end cover 301, bearings 303a-303f, a rotor 305, a stator
307, a motor gear 309, a worm drive gear 311, a worm shaft 313, a
worm shaft end stop 315, an axle drive nut 317, and an axle 319.
Rotor 305 and stator 307 make up a motor 321 that, when powered and
activated, provides the motive force for actuating first control
mechanism 105. Rotor 305 is rotatably supported by end cover 301
via bearing 303a. Rotor 305 is also rotatably supported by first
portion 111 of housing 103 via bearing 303b. Rotor 305 comprises a
rotor shaft 323 fixedly coupled with motor gear 309. Motor gear 309
is engaged with worm drive gear 311, such that worm drive gear 311
rotates when motor 321 rotates. Worm drive gear 311 is fixedly
coupled with worm shaft 313, such that worm shaft 313 rotates when
worm drive gear 311 rotates. Worm shaft 313 is rotatably supported
by first portion 111 of housing 103 via bearing 303c. Worm shaft
end stop 315 is fixedly coupled with worm shaft 313.
[0036] Still referring to FIG. 3, worm shaft end stop 315 is
rotatably supported by second portion 113 (not shown in FIG. 3 but
shown in FIGS. 1 and 2) of housing 103 via a bearing 303d' (shown
in FIG. 2) of second control mechanism 107. A worm shaft end stop
315' (shown in FIG. 2) of second control mechanism 107 is rotatably
supported by first portion 111 of housing 103 via bearing 303d. The
coupling of worm shaft end stop 315 to second portion 113 of
housing 103 via bearing 303d' in combination with the coupling of
worm shaft end stop 315' to first portion 111 of housing 103 via
bearing 303d is but one means for mating first control assembly 115
to second control assembly 117. Moreover, the coupling of worm
shaft end stop 315 to second portion 113 of housing 103 via bearing
303d' in combination with the coupling of worm shaft end stop 315'
to first portion 111 of housing 103 via bearing 303d is but one
means for mating first control mechanism 105 to second control
mechanism 107.
[0037] Axle drive nut 317 is engaged with worm shaft 313, such that
axle drive nut 317 traverses along worm shaft 313 when worm shaft
313 rotates. Axle drive nut 317 is coupled with a clevis 325 of
axle 319, such that axle 319 rotates about a longitudinal axis 327
of axle as axle drive nut 317 traverses along worm shaft 313. It
should be noted that axle drive nut 317 is coupled with clevis 325
of axle 319 so that axle drive nut 317 rotates about an axis 329
that is substantially parallel to axis 327. In the present
embodiment, as best illustrated in FIG. 4, axle drive nut 317
comprises an upwardly extending pin 401a and a downwardly extending
pin 401b. Pins 401a and 401b each define a groove 403a and 403b,
respectively, configured to receive one of spring clips 405a and
405b, respectively. Bushings 407a and 407b each define an opening
409a and 409b, respectively. Pin 401a is disposed through opening
409a of bushing 407a and spring clip 405a is placed in groove 403a
of pin 401a to retain bushing 407a on axle drive nut 317. Pin 401b
is disposed through opening 409b of bushing 407b and spring clip
405b is placed in groove 403b of pin 401b to retain bushing 407b on
axle drive nut 317. Bushing 407a is disposed in a recess 411a of an
upper arm 413a of clevis 325. Bushing 407b is disposed in a recess
411b of a lower arm 413b of clevis 325. Bushings 407a and 407b are
retained in recesses 411a and 411b, respectively via the engagement
of axle drive nut 317 and worm shaft 313 when first control
assembly 115 is mated with second control assembly 117.
[0038] Note also that axle 319 includes a bend, generally at 419,
that is configured to receive axle 319' (shown in FIG. 2).
Preferably axle 319' has a configuration corresponding to axle 319,
such that axles 319 and 319' nest with respect to one another
generally at bend 419 of axle 319 and the corresponding bend of
axle 319'. Such a configuration conserves the volume required for
control surface actuation system 101. Accordingly, longitudinal
axis 327 of axle 319 and longitudinal axis 327' (shown in FIG. 2)
of axle 319' (and, thus, the outputs of control mechanisms 105 and
107) are substantially coplanar.
[0039] Returning now to FIG. 3, axle 319 is rotatably supported by
first portion 111 of housing 103 and second portion 113 (shown in
FIGS. 1 and 2) of housing 103 via bearings 303e and 303f when
locking rings 109 are engaged with first portion 111 and second
portion 113. Accordingly, when power is applied to motor 321 and
motor 321 is activated via control lines 119, rotor shaft 323
rotates, which, in turn rotates motor gear 309. Motor gear 309
rotates worm drive gear 311, which, in turn, rotates worm shaft
313. Worm shaft 313 advances axle drive nut 317 along worm shaft
313, which, in turn, rotates axle 319 about longitudinal axis
317.
[0040] FIG. 5 depicts one particular embodiment of a trajectory
control system 501 according to the present invention. In the
illustrated embodiment, trajectory control system 501 comprises a
plurality of control surface members 503a-503d operably associated
with control surface actuation system 101. Control surface members
503a-503d each comprises a corresponding shaft 505a-505d extending
from a control surface 507a-507d. Shafts 505a and 505b are coupled
with axle 319 of first control mechanism 105, while shafts 505c and
505d are coupled with axle 319' (shown in FIG. 2) of second control
mechanism 107. In the particular embodiment illustrated in FIG. 5,
control surfaces 507a-507d are fins. The scope of the present
invention, however, is not so limited. Rather, control surfaces
507a-507d may exhibit other forms, such as flares, canards, or the
like. First control mechanism 105 is actuated to articulate control
surfaces 507a, 507b in unison, via shafts 505a, 505b, respectively,
and change the yaw (indicated by an arrow 508a) of a vehicle 509
comprising trajectory control system 501. Second control mechanism
107 is actuated to articulate control surfaces 507c, 507d in
unison, via shafts 505c, 505d, to change the pitch (indicated by an
arrow 508b) of vehicle 509. It should be noted that, in a preferred
embodiment, longitudinal axis 327 of axle 319 is substantially
coplanar with a longitudinal axis 327' (shown in FIG. 2) of axle
319'. Accordingly, outputs of axles 319 and 319' (and, thus, the
outputs of control mechanisms 105 and 107) are coplanar in such a
preferred embodiment.
[0041] Referring to FIGS. 3, 5, and 6, axle 319 of first control
mechanism 105 comprises couplings 331a and 331b that are adapted to
mate with control surface members 503a and 503b, respectively. Axle
319' (shown in FIG. 2) of second control mechanism 107 comprises
couplings 331a' and 331b' (also shown in FIG. 2) that are adapted
to mate with control surface members 503c and 503d, respectively.
The following description pertains particularly to axle 319 and
coupling 331a thereof. It should be noted, however, that the
construction of coupling 331b corresponds to the construction of
coupling 331a in the preferred embodiment. Moreover, the
construction of axle 319' corresponds to the construction of axle
319 in the preferred embodiment.
[0042] Reference is now made to axle 319 of FIG. 4, the
cross-sectional view of coupling 331a of FIG. 6, and control
surface member 503a of FIG. 7. Coupling 331a defines a groove 601
(shown in FIG. 6) configured to receive a retainer 701 (shown in
FIG. 7) attached to shaft 505a of control surface member 503a.
Retainer 701 retains shaft 505a in coupling 331a. Shaft 505a
defines a groove 703 that, when aligned with a passageway 415a
defined by coupling 331a, receives a pin 417a. Coupling 331b
defines a corresponding passageway 415b. An interface between pin
417a, coupling 331a, and shaft 505a, provides a base orientation of
control surface member 503a with respect to first control assembly
115. It should be noted that, in the preferred embodiment, control
surface member 503b is retained in coupling 331b and is provided
with a base orientation with respect to first control assembly 115
in the same manner as discussed above in relation to control
surface member 503a. Referring to FIG. 3, in the preferred
embodiment, control surface member 503c is retained in coupling
331a' and control surface member 503d is retained in coupling 331b'
in the same way as described above in relation to control surface
member 503a. Moreover, in the preferred embodiment, control surface
members 503c and 503d are provided with base orientations with
respect to second control assembly 117 in the same way as discussed
above concerning control surface member 503a.
[0043] Referring again to FIG. 3, first control mechanism 105
further comprises a position sensor 333 that senses the position of
one or more other components of first control mechanism 105 to
determine the orientation of control surface members 503a and 503b
with respect to first control assembly 115. In various embodiments,
position sensor 333 comprises a Hall-effect sensor, a
photodiode-type sensor, or the like, that senses teeth of motor
gear 309. In one embodiment, position sensor 333 outputs a signal,
for each tooth of motor gear 309 sensed, to a controller, such as
the guidance computer, so that the controller can determine the
orientation of control surface members 503a and 503b with respect
to first control assembly 115. Note that, in a preferred
embodiment, second control mechanism 107 comprises a corresponding
position sensor (not shown) that operates in the same way as
position sensor 333. It should be noted, however, that such
position sensors are merely examples of a means for sensing an
orientation of a pair of control surfaces (e.g., control surfaces
507a, 507b or control surfaces 507c, 507d) or a pair of control
surface members (e.g., control surface members 503a, 503b or
control surface members 503c, 503d) according to the present
invention. Other constructions of such a means are possible and
encompassed within the scope of the present invention.
[0044] Referring again to the particular embodiment of FIG. 5,
control surface actuation system 101 is operably associated with a
body 511 of vehicle 509 by sliding, as indicated by arrow 519,
control surface actuation system 101 into a cavity 513 defined by
body 511. With control surface actuation system 101 disposed in
cavity 513, as shown in FIG. 8, pins 801 are inserted through pin
openings 515 defined by body 511 and into pin openings 121 defined
by housing 103. By way of example and illustration, pins 801 are
but one means for retaining control surface actuation system 101 in
body 511 of vehicle 509. Moreover, mechanical loads experienced
during operation of vehicle 509 are efficiently transmitted from
control surface members 503a-503d, through control surface
actuation system 101, to body 511. As illustrated in FIG. 9,
control surface members 503a-503d are then inserted into couplings
331a-331d through openings 517 defined by body 511, such that
retainers 701 are received in grooves 403 defined by couplings
331a-331d to retain control surface members 503a-503d in couplings
331a-331d and pins (e.g., pins 417a and 417b) are received in
grooves 601 of shafts 505a-505d to provide base orientations for
control surface members 503a-503d.
[0045] The particular embodiments disclosed above are illustrative
only, as the invention may be modified and practiced in different
but equivalent manners apparent to those skilled in the art having
the benefit of the teachings herein. Furthermore, no limitations
are intended to the details of construction or design herein shown,
other than as described in the claims below. It is therefore
evident that the particular embodiments disclosed above may be
altered or modified and all such variations are considered within
the scope and spirit of the invention. Accordingly, the protection
sought herein is as set forth in the claims below. It is apparent
that an invention with significant advantages has been described
and illustrated. Although the present invention is shown in a
limited number of forms, it is not limited to just these forms, but
is amenable to various changes and modifications without departing
from the spirit thereof.
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