MISSILE AIRFRAME AND STRUCTURE COMPRISING PIEZOELECTRIC FIBERS AND METHOD FOR ACTIVE STRUCTURAL RESPONSE CONTROL

• US 20100264251A1
• Filed: 06/25/2010
• Published: 10/21/2010
• Est. Priority Date: 03/07/2007
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Hlavacek, Gregg J., Seasly, Craig D., Moore, Robert T., Facciano, Andrew B.
• Granted Patent: US 8,049,148 B2
• Time in Patent Office: Days
• US Class Current: 244/3.150
• CPC Class Codes: F42B 10/00 Means for influencing, e.g. improving, the aerodynamic properties of projectiles or missiles; Arrangements on projectiles or missiles for stabilising, steering, range-reducing, range-increasing or fall-retarding F42B6/00 takes precedence
• CPC Class Codes: F42B 15/10 Missiles having a trajectory only in the air

Abstract

Embodiments of a missile, an airframe and a structure comprising piezoelectric fibers and a method for active structural response control are generally described herein. In some embodiments, a housing structure includes a composite material containing a plurality of piezoelectric fibers adapted to generate an electrical signal in response to a deformation in the structure and to deform the structure in response to an electrical signal applied thereto. A control circuit receives the sensed signal from the fibers and generates an excitation signal that is applied to the fibers to increase the stiffness or compliance of the fibers at predetermined frequencies. In an illustrative embodiment, the control signal is adapted to provide low frequency stiffness and strength performance while attenuating high frequency vibrations to protect electronics housed within the structure.

Claims

1. A missile comprising:

a missile airframe;

a guidance system for controlling a flight path of the missile;

a first housing for housing the guidance system, the housing containing a plurality of piezoelectric fibers adapted to generate a sensor signal in response to a deformation in the housing and to deform the housing in response to an excitation signal applied thereto;

a control circuit to generate the excitation signal adapted to tune a structural response of the housing in response to frequency components associated with the deformation of the structure, and to apply the excitation signal to the fibers; and

a mounting structure for mounting the first housing to the missile airframe.

2. The missile of claim 1 wherein the control circuit includes a plurality of operational modes, each mode adapted to generate a different excitation signal for providing a different structural response,

wherein the operational modes comprise a booster mode and a guidance mode,

wherein during the booster mode, the control circuit is configured to generate an excitation signal to reduce stiffness by increasing compliance of the fibers to attenuate vibrations at higher frequencies, and

wherein during the guidance mode, the control circuit is configured to generate an excitation signal to increase stiffness of the fibers at lower frequencies.

3. The missile of claim 2 wherein the control circuit is adapted to receive a signal from the guidance system for selecting one of the operational modes.

4. The missile of claim 1 wherein the control circuit is adapted to receive the sensor signal from the fibers and modulate the signal based on the frequency components to form the excitation signal.

5. The missile of claim 1 wherein the missile airframe contains a second plurality of piezoelectric fibers adapted to generate a second sensor signal in response to a deformation in the airframe and to deform the airframe in response to a second an excitation signal applied thereto.

6. The missile of claim 5 wherein the mounting structure contains a third plurality of piezoelectric fibers adapted to generate a third sensor signal in response to a deformation in the structure and to deform the structure in response to a third an excitation signal applied thereto.

7. The missile of claim 6 wherein the control circuit is adapted to provide excitation signals to the fibers in the first housing, airframe, and mounting structure to tune a structural response in the first housing, airframe, and mounting structure.

8. The missile of claim 7 wherein the control circuit is adapted to provide excitation signals adapted to increase compliance of the fibers at high frequencies to provide high frequency vibration isolation to protect guidance system electronics, and increase stiffness of the fibers at low frequencies to provide a stable platform for the guidance system.

9. The missile of claim 1 wherein the missile further includes a seeker assembly for sensing a signal from a missile target.

10. The missile of claim 9 wherein the missile further includes a second housing for housing the seeker assembly, the second housing containing a plurality of piezoelectric fibers adapted to generate a sensor signal in response to a deformation in the second housing and to deform the second housing in response to an excitation signal applied thereto.

11. The missile of claim 10 wherein the control circuit is adapted to provide an excitation signal to the second housing.

12. The missile of claim 11 wherein the excitation signal is adapted to attenuate line-of-sight jitter and smearing in the seeker assembly.

13. A method for controlling vibrations in a missile having piezoelectric fibers integrated into structural components of the missile, the method comprising:

receiving a sensor signal from the piezoelectric fibers measuring a change in motion in the components;

modulating the sensor signal to form an excitation signal adapted to increase stiffness or compliance of the fibers at predetermined frequencies to tune a structural response of the components; and

applying the excitation signal to the fibers,

wherein the excitation signal is generated to tune the structural response of the components based on frequency components of the sensor signal.

14. The method of claim 13 further comprising:

receiving an operational mode signal from a guidance system to indicate one of a plurality of operational modes comprising at least a booster mode and a guidance mode; and

providing a different excitation signal for each of the modes to provide a different structural response.

15. The method of claim 14 wherein during the booster mode, the method includes generating the excitation signal to reduce stiffness by increasing compliance of the fibers to attenuate vibrations at higher frequencies, and

wherein during the guidance mode, the method includes generating the excitation signal to increase stiffness of the fibers at lower frequencies.

16. A missile airframe comprising:

an airframe structure fabricated from a composite material containing a plurality of piezoelectric fibers adapted to generate an electrical signal in response to a deformation in the structure and to deform the structure in response to an excitation signal applied thereto and

a control circuit configured to receive the electrical signal from the fibers, to modulate the signal to form an excitation signal adapted to increase stiffness or compliance of the fibers at predetermined frequencies to tune a frequency response of the structure, and to apply the excitation signal to the fibers,

wherein the electrical signal includes frequency components associated with the deformation of the structure and the control circuit generates the excitation signal to tune the frequency response of the structure based on the frequency components.

17. A mounting structure comprising:

a mounting structure fabricated from a composite material containing a plurality of piezoelectric fibers adapted to generate an electrical signal in response to a deformation in the structure and to deform the structure in response to an excitation signal applied thereto and

a control circuit configured to receive the electrical signal from the fibers, to modulate the signal to form an excitation signal adapted to increase stiffness or compliance of the fibers at predetermined frequencies to tune a frequency response of the structure, and to apply the excitation signal to the fibers,

wherein the electrical signal includes frequency components associated with the deformation of the structure and the control circuit generates the excitation signal to tune the frequency response of the structure based on the frequency components.

18. A control circuit for controlling vibrations in a structure containing piezoelectric fibers adapted to generate a sensor signal in response to a deformation in the structure and to deform the structure in response to an excitation signal applied thereto, the control circuit comprising:

a first circuit for receiving the sensor signal, the sensor signal including frequency components associated with the deformation of the structure; and

a second circuit for modulating the sensor signal to form an excitation signal adapted electronically tune a structural response of the structure based on the frequency components of the sensor signal,

wherein at least some of the piezoelectric fibers that generate the sensor signal in response to the deformation are the same piezoelectric fibers that deform the structure in response to the excitation signal applied thereto.

19. The control circuit of claim 18 wherein the control circuit includes a plurality of operational modes, each mode adapted to generate a different excitation signal for providing a different structural response,

wherein the operational modes comprise a booster mode and a guidance mode,

wherein during the booster mode, the second circuit is configured to generate the excitation signal to reduce stiffness by increasing compliance of the fibers to attenuate vibrations at higher frequencies, and

wherein during the guidance mode, the second circuit is configured to generate the excitation signal to increase stiffness of the fibers at lower frequencies.

20. The control circuit of claim 19 wherein the control circuit further includes circuitry to receive a signal for selecting one of the operational modes.