Methods and apparatus for a tandem divert and attitude control system

An aeronautical vehicle includes at least one set of tandem divert thrusters incorporated into the body. Each set of tandem divert thrusters includes a first divert thruster and a second divert thruster, each configured to provide substantially equal thrust forces at substantially the same time and in substantially opposite directions such that the moment reference point lies between the first and second divert thrusters.

The present application claims priority to U.S. Prov. Pat. Ser. No. 61/229,899, filed Jul. 30, 2009, which is hereby incorporated by reference.

TECHNICAL FIELD

The present invention generally relates to the control of missiles, kill vehicles, and other aeronautical vehicles, and more particularly relates to divert and attitude control systems (DACS) used in connection with such vehicles.

BACKGROUND

Ballistic missile threats and reentry vehicles continue to proliferate and evolve technically. Several anti ballistic missile (ABM) defense systems have been developed, however, which are capable of intercepting such missiles with precise hit-to-kill technologies. Nevertheless, currently known kill vehicles of this type tend to exhibit limited agility (i.e., high-g capability) and are not always capable of operating effectively in the high endo-atmosphere.

More particularly, conventional kill vehicles typically include a seeker assembly, a guidance electronics section, a divert and attitude and control system (DACS), power sources, and a communication system, all of which are enclosed within a structure and aero shell. As these subsystems continue to advance and acquire additional capabilities, the mass of the overall kill vehicle tends to increase, reducing its agility.

Furthermore, conventional DACS employ only a single divert thruster arrangement and a separate attitude control system, both of which are limiting factors given the typically constrained packaging envelope for thruster assemblies and associated attitude control system.

Accordingly, it is desirable to provide improved systems and methods for controlling aeronautical vehicles, such as kill vehicles and the like. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

BRIEF SUMMARY

A divert and attitude control system for an aeronautical vehicle generally includes a first thruster configured to produce a first force on the aeronautical vehicle proximate a first end of the aeronautical vehicle within a first plane, wherein the first force is substantially perpendicular to the major axis of the aeronautical vehicle, and wherein the major axis lies within the plane; and a second thruster configured to produce a second force on the aeronautical vehicle proximate a second end of the aeronautical vehicle and within the first plane, wherein the second force is perpendicular to the major axis of the aeronautical vehicle in a direction opposite that of the first force; wherein the first force is substantially the same as the second force, and wherein the first thruster and second thruster are configured to produce the first and second forces substantially simultaneously.

A method in accordance with one embodiment includes receiving a command associated with a required attitude adjustment within a first plane intersecting a major axis of the aeronautical vehicle; generating a first thrust force from the aeronautical vehicle proximate a first end of the aeronautical vehicle within the first plane, wherein the first thrust force has an orientation substantially perpendicular to the major axis of the aeronautical vehicle; and generating a second thrust force from the aeronautical vehicle proximate a second end of the aeronautical vehicle within the first plane; wherein the first thrust force has an orientation substantially opposite that of the first thrust force (i.e., rotated by 180°); wherein the first and second thrust forces are substantially equal and are generated substantially simultaneously.

An aeronautical vehicle in accordance with one embodiment includes a body having a moment reference point lying along a longitudinal axis; and at least one set of tandem divert thrusters incorporated into the body; wherein each set of tandem divert thrusters includes a first divert thruster and a second divert thruster, each configured to provide substantially equal thrust forces at substantially the same time and in substantially opposite directions, and wherein the moment reference point lies between the first and second divert thrusters.

DETAILED DESCRIPTION

The following discussion generally relates to improved methods and apparatus for removing connectors from circuit card assemblies. In that regard, the following detailed description is merely illustrative in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

In general, a tandem divert solution in accordance with various embodiments employs multiple (e.g., tandem) divert thrusters oriented in opposite directions within each plane of the vehicle, thereby doubling the effective thrust available to effect attitude control.

FIG. 1, which is not necessarily drawn to scale, depicts a simplified, external overview of a aeronautical vehicle100in accordance with one embodiment. As shown, aeronautical vehicle100includes a body110having a first end118(e.g., the “front end” close to a nose cover124) and a second end119(e.g., the “back end”) oriented along a major (or longitudinal) axis134. One or more divert-attitude-control jets (or simply “thrusters”)111-114and121-124are provided on, within, or otherwise mechanically coupled to body no such that one set of thrusters (111-114) is proximate to end118, and the other set of thrusters (121-124) is proximate to the opposite end, i.e., end119. The arrows therefore illustrate the forces on body110resulting from respective thrusters.

In accordance with one embodiment, the thrusters are configured in pairs, or in “tandem,” such that together they may produce opposite but substantially equal thrusts, thereby producing a moment within one or more rotational planes, e.g., orthogonal planes130and132. In addition, as illustrated in the figures, a divert operation may be accompanied by a change of altitude by proper application of thrust forces. Further in accordance with this embodiment, the thrusters within a given set of thrusters are located at equal distances along major axis134. As a result, the forces produced by thrusters on opposite sides of body110within each set are substantially collinear (e.g., forces produced by thrusters112and111).

Thruster112, when activated, is configured to produce a force having an amplitude that is predetermined based on the desired attitude change, and a direction that is substantially perpendicular to the major axis134within plane130(e.g., normal to the cylindrical surface of body110). Similarly, thruster121is configured to produce a force (simultaneously with activation of thruster112) that is substantially equal to that of thruster112within plane130but acts in the opposite direction (e.g., a delta of 180 degrees within plane130). Thrusters121and112are therefore said to operate in “tandem.”

Similarly, thrusters in and122operate in tandem to provide rotation in the opposite direction within plane130, as illustrated. In this way, four thrusters111,112,121, and122can be used to provide rotational control within plane130, and thrusters113,114,123, and124can be used to provide rotational control within plane132.

The placement and number of thrusters illustrated inFIG. 1is not intended to be limiting in any way, and are merely drawn in a manner that assists in describing the invention. Furthermore, additional thrusters in each plane may be provided in order to allow other forms of control, such as thrusters aligned with major axis134(e.g., axial thruster123).

Thrusters111-114and121-124may comprise any suitable thruster component or components known in the art. In one embodiment, for example, these thrusters are divert attitude control jets having conical nozzles of the same size and shape. The size of the jets may be optimized depending upon the application, and based on known principles.

Referring now to the conceptual side views illustrated inFIGS. 2-4, the body110generally encloses a gas source (or other type of fuel source)202, as well as a controller204communicatively coupled to gas source202and thrusters111,112,121,122.

Controller204, which may include any combination of hardware, software, and/or firmware, is configured to control the thrust produced by the thrusters in response to, for example, a torque command from a guidance system or other subsystem. In this regard, those skilled in the art will recognize that any number of additional, conventional electrical and mechanical components, such as valves, actuators, solenoids, power electronics, have been left out of these figures for the purposes of clarity. Furthermore, in the context of kill vehicles and the like, additional modules will typically be housed within body110, such as seeker assemblies, guidance electronics, batteries, and communication modules.

As shown inFIG. 3, when thrusters111and122are simultaneously activated via controller204, utilizing gas source202, body110experiences a moment within the plane (plane130ofFIG. 1) about a moment reference point (“MRP”)205, which will generally, but not necessarily, be located coincident with the center of body110. Similarly, as shown inFIG. 4, activation of thrusters121and112will produce a substantially equal, but opposite moment about MRP205.

Moreover, as depicted inFIG. 5, simultaneous divert and attitude control may be accomplished by application of forces of appropriate magnitudes and directions. These forces may be applied normal to each other or within a particular plane to accomplish the desired behavior of DACS100.

Conventional divert systems utilize much lower force attitude control thrusters, typically on the order of 1/10 or less the force of a divert thruster. As the magnitude of the moment around point205is equal to the product of the thrust force and the distance of the force from that point, embodiments in accordance with the present invention can therefore provide larger moments, allowing a greater degree of yaw within each plane. The primary benefits of the resulting embodiments are, for example, increased agility for a given vehicle diameter, and very large moments capable of overcoming aero torques when operating in the atmosphere.

In accordance with one embodiment, a single common gas source202is provided for all thrusters. This allows the propulsion system's complexity and mass to be reduced by eliminating the need for multiple rocket motors, plumbing, valves, attitude control systems, and the like. Suitable common gas sources include, for example, any of the various throttleable solid propellant gas sources known in the art.

In an embodiment incorporating a single common gas generator, axial thruster123can be incorporated into the same end as one or more of the tandem thrusters, providing greater operational flexibility.

While at least one example embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the example embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient and edifying road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention and the legal equivalents thereof.