System and method for estimating inertial acceleration bias errors

• US 7,962,255 B2
• Filed: 12/12/2006
• Issued: 06/14/2011
• Est. Priority Date: 12/12/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Krogh, Steven B., Lapp, Tiffany R.
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Amin; Bhavesh V
• Application Number:
  US11/609,798
• Publication Number:
  US 20080140315A1
• Time in Patent Office: 1,645 Days
• Field of Search: None
• US Class Current: 701/5
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

A method for estimating inertial acceleration bias errors including obtaining uncorrected acceleration measurements on board a vehicle; obtaining independent position and independent velocity data of the vehicle; transforming the uncorrected acceleration measurements into a reference frame of the independent position and independent velocity data; blending the transformed acceleration measurements with the independent position and the independent velocity data to produce feedback errors; transforming the feedback errors into the reference frame of the acceleration measurements; multiplying the feedback errors by a gain and integrating to estimate the acceleration measurement bias errors.

Claims

1. A system for estimating inertial acceleration bias errors for a vehicle, comprising:

a first transformation module for receiving uncorrected acceleration measurements of the vehicle, receiving at least one of independent position data of the vehicle and independent velocity data of the vehicle, and transforming the uncorrected acceleration measurements into a first coordinate frame of the at least one of the independent position data and independent velocity data, wherein transforming produces transformed measurements;

a plurality of complementary filters for blending the transformed measurements with the at least one of the independent position data and the independent velocity data to produce feedback errors; and

a second transformation module for transforming the feedback errors into a second coordinate frame of the uncorrected acceleration measurements to form transformed feedback errors, and then multiplying the transformed feedback errors by a gain to form multiplied feedback errors and integrating the multiplied feedback errors to form estimates of the inertial acceleration bias errors.

2. The system of claim 1, wherein the second frame of the uncorrected acceleration measurements are in a local frame of reference, having a first axis along a length of the vehicle, a second axis across a width of the vehicle, and a third axis normal to the first axis and second axis.

3. The system of claim 1, wherein the at least one of the independent position data and the independent velocity data are received from a global positioning satellite system (GPS).

4. The system of claim 1, wherein the vehicle comprises an aircraft and wherein the inertial acceleration bias errors are used to estimate a position of the aircraft using an autopilot system for landing.

5. A method for estimating inertial acceleration bias errors for a vehicle, comprising:

obtaining uncorrected acceleration measurements on board the vehicle;

obtaining at least one of independent position data and independent velocity data of the vehicle;

transforming the uncorrected acceleration measurements into a first reference frame of the at least one independent position data and independent velocity data, wherein transforming produces transformed measurements;

blending the transformed acceleration measurements with the at least one of the independent position data and the independent velocity data to produce feedback errors;

transforming the feedback errors into a second reference frame of the uncorrected acceleration measurements to form transformed feedback errors; and

multiplying the transformed feedback errors by a gain to form multiplied feedback errors and integrating the multiplied feedback errors to form estimated inertial acceleration bias errors.

6. The method of claim 5, wherein the vehicle comprises an aircraft.

7. The method of claim 6, wherein the estimated inertial acceleration bias errors are used to correct acceleration measurements of the aircraft using an autopilot system for landing.

8. The method of claim 5, wherein a set of complementary filters blend the transformed measurements with the at least one of the independent position data and the independent velocity data.

9. The method of claim 8, wherein the set of complementary filters include an X-axis complementary filter, a Y-axis complementary filter, and a Z-axis complementary filter.

10. The method of claim 9, wherein the X-axis complementary filter estimates a feedback error in the X-axis, the Y-axis complementary filter estimates a feedback error in the Y-axis and the Z-axis complementary filter estimates a feedback error in the Z-axis.

11. The method of claim 5, wherein the at least one of the independent position data and the independent velocity data are received from a global positioning satellite system (GPS).

12. The method of claim 5, wherein the at least one of the independent position data and independent velocity data are received from an Instrument Landing System.

13. The method of claim 5, wherein the second reference frame comprises a body axis of the vehicle.