Claims
- 1. An apparatus for outputting roll angle information comprising:
an input for receiving a signal indicative of roll rate; a first device, coupled to said input, for obtaining an Euler roll angle from said signal; a first error correction device, coupled to said first device, for correcting errors in said Euler roll angle; a second error correction device, coupled to said first error correction device, for supplying a roll angle estimate to said first error correction device, during a period of time when said Euler roll angle exceeds a predefined limit; and an output for outputting a signal indicative of corrected roll angle information.
- 2. The apparatus of claim 1 wherein said apparatus comprises a feedback control loop.
- 3. The apparatus of claim 1 wherein said second error correction device further comprises:
a roll angle estimator input for receiving a plurality of signals indicative of an airspeed and a yaw rate; a roll angle estimator for obtaining said roll angle estimate as a function of said airspeed, said yaw rate and acceleration due to gravity; and an output, coupled to said first error correction device, for outputting a signal indicative of said roll angle estimate.
- 4. The apparatus of claim 3 wherein said second error correction device further comprises:
an auxiliary input for receiving a roll level sensor signal; and means for combining said roll level signal with said roll estimate signal to obtain said signal indicative of said roll angle estimate.
- 5. The apparatus of claim 1 wherein said predefined limit is six degrees.
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a Division of U.S. application Ser. No. 09/746,128 titled “Method and Apparatus for Limiting Attitude Drift During Turns” filed Dec. 22, 2000; which in turn claims priority from copending U.S. application serial No. 60/206,966 titled “Technique for Estimating Aircraft Heading with Reduced Sensor Set,” filed May 25, 2000; and from copending U.S. application serial No. 60/171,721 titled “Method and Apparatus for Estimating Aircraft Attitude with Reduced Sensor Set,” filed Dec. 22, 1999; and from copending U.S. application serial No. 60/212,114 titled “Technique for Limiting Roll Attitude Drift During Turns in AHRS Applications,” filed Jun. 16, 2000, the entire specifications of each which are herein incorporated by reference.
Provisional Applications (3)
|
Number |
Date |
Country |
|
60206966 |
May 2000 |
US |
|
60171721 |
Dec 1999 |
US |
|
60212114 |
Jun 2000 |
US |
Divisions (1)
|
Number |
Date |
Country |
Parent |
09746128 |
Dec 2000 |
US |
Child |
10216478 |
Aug 2002 |
US |