Two-axis trajectory control system
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.
1. Field of the Invention
The present invention relates to systems for controlling the trajectory of airborne or waterborne vehicles.
2. Description of Related Art
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.
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.
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.
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.
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.
There are many designs of trajectory control systems well known in the art; however, considerable shortcomings remain.
SUMMARY OF THE INVENTIONThere is a need for an improved trajectory control system.
Therefore, it is an object of the present invention to provide an improved trajectory control system.
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.
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.
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.
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.
Additional objectives, features, and advantages will be apparent in the written description which follows.
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:
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 EMBODIMENTIllustrative 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.
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.
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.
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
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
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.
Still referring to
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
Note also that axle 319 includes a bend, generally at 419, that is configured to receive axle 319′ (shown in
Returning now to
Referring to
Reference is now made to axle 319 of
Referring again to
Referring again to the particular embodiment of
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.
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.
Type: Application
Filed: Jul 7, 2006
Publication Date: Jan 10, 2008
Inventor: Johnny E. Banks (Venus, TX)
Application Number: 11/482,338
International Classification: F42B 15/01 (20060101);