Carrier modulating accelerometer

• US 8,291,765 B2
• Filed: 05/04/2009
• Issued: 10/23/2012
• Est. Priority Date: 05/04/2009
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Wells, Michael L., Jenkins, Thomas E., Chaplin, Carl P., Nguyen, Hongthu K.
• Primary Examiner(s): Williams, Hezron E
• Assistant Examiner(s): Shabman, Mark A
• Application Number:
  US12/435,098
• Publication Number:
  US 20100275688A1
• Time in Patent Office: 1,268 Days
• Field of Search: None
• US Class Current: 73/514.32
• CPC Class Codes: G01C 21/18 Stabilised platforms, e.g. by gyroscope
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/09 by piezoelectric pick-up
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

An accelerometer module for measuring acceleration in a stabilized platform system includes a power supply configured to accept an input AC reference signal and to generate a regulated DC signal and a reference signal in phase with the input AC reference signal; an accelerometer configured to receive the regulated DC signal from said power supply and to generate an output signal in response to an external force acting on the accelerometer module and an analog multiplier unit configured to receive the output signal from the accelerometer and the reference signal from the power supply, and to modulate the reference signal with the output signal so as to output a modulated accelerometer signal. A method for servicing a stabilized platform system comprising is also provided.

Claims

1. An accelerometer module for measuring acceleration in a stabilized platform system comprising:

a power supply configured to accept an input AC reference signal and to generate a regulated DC signal and a reference signal in phase with the input AC reference signal;

an accelerometer configured to receive the regulated DC signal from said power supply and to generate an output signal in response to an external force acting on the accelerometer module; and

an analog multiplier unit configured to receive the output signal from the accelerometer and the reference signal from the power supply, and to modulate the reference signal with the output signal so as to output a modulated accelerometer signal.

2. The accelerometer module according to claim 1, wherein the accelerometer comprises a solid state or differential capacitance accelerometer.

3. The accelerometer module according to claim 1, wherein the output of the accelerometer comprises a time-varying DC signal.

4. The accelerometer module according to claim 1, wherein the analog multiple comprises an analog 4-quadrant multiplier.

5. The accelerometer module according to claim 1, wherein the power supply is configured to accept a 900 Hz input signal.

6. The accelerometer module according to claim 5, wherein the 900 Hz input signal comprises 20 VAC.

7. The accelerometer module according to claim 1, further comprising a voltage offset applied to the multiplier so as to adjust the modulated accelerometer signal.

8. The accelerometer module according to claim 1, further comprising:

a housing configured to mount the power supply;

the accelerometer; and

the analog multiplier,

wherein the accelerometer is aligned with reference axes of the housing.

9. The accelerometer module according to claim 1, further comprising an attenuator to adjust the amplitude of the reference signal that is supplied to the analog multiplier unit.

10. The accelerometer module according to claim 1, further comprising an integrator configured to filter the output of the accelerometer.

11. The accelerometer module according to claim 1, wherein the regulated DC signal comprises one or both of 5 or 12 VDC.

12. The accelerometer module according to claim 1, wherein the analog multiplier unit is configured to generate an amplitude modulated (AM) accelerometer signal.

13. The accelerometer module according to claim 1, wherein the power supply comprises a transformer having a secondary winding configured to generate the reference signal.

14. The accelerometer module according to claim 1, wherein the power supply comprises an optically coupled linear isolator configured to generate the reference signal.

15. A system for measuring acceleration in a stabilized platform comprising:

two accelerometer units, according to claim 1, for measuring acceleration in each of two reference directions of the stabilized platform system.

16. The system according to claim 15, wherein the two reference directions correspond to the elevation and azimuth gimbal axes.

17. The system according to claim 15, wherein the accelerometer modules have different keyed pin connectors.

18. A method of servicing a stabilized platform system comprising:

removing an existing accelerometer module from the stabilized platform system; and

installing the accelerometer module of claim 1 in the stabilized platform system.

19. The method according to claim 18, further comprising:

providing one or more service centers for providing service or repairs for the stabilized platform system.