Calibration of orthogonal sensor suite

• US 20020100310A1
• Filed: 04/02/2001
• Published: 08/01/2002
• Est. Priority Date: 03/31/2000
• Status: Active Grant

• Current Assignee: Aurora Operations Incorporated (Aurora Innovation, Inc.)
• Original Assignee: Magellan DIS, Inc.
• Inventors: Begin, John D.
• Granted Patent: US 6,729,176 B2
• Time in Patent Office: Days
• US Class Current: 73/1.37
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A method for calibrating an orthogonal sensor suite includes the steps of imparting on the sensor suite a series of known accelerations at orientations known relative to each other, while recording readings from the sensors from each acceleration at each orientation. This data is used to create a transformation matrix which removes offsets from each sensor and removes any cross-coupling of the sensors.

Claims

1. A method for calibrating a plurality of sensors, each mounted in a fixed orientation relative to the other, the method including the steps of:

a) imparting a plurality of accelerations on the plurality of sensors;

b) measuring motion signals from the sensors resulting from the plurality of accelerations; and

c) generating a transformation matrix based upon the motion signals.

2. The method of claim 1 further including the step of:

d) storing the transformation matrix.

3. The method of claim 2 wherein said step d) further includes the step of:

e) storing the transformation matrix on the sensor suite.

4. The method of claim 1 wherein said step a) further includes the step of imparting a plurality of orthogonal accelerations upon the sensor suite.

5. The method of claim 4 wherein each of the orthogonal accelerations is equal in magnitude.

6. The method of claim 1 wherein the transformation matrix decouples the plurality of sensors.

7. The method of claim 1 further including the step of decoupling the plurality of sensors using the transformation matrix.

8. The method of claim 7 further including the step of computing an offset for each of the plurality of sensors.

9. The method of claim 8 further including the step of subtracting the offsets from each of the motion signals.

10. The method of claim 1 further including the step of:

d) generating an inverse of the transformation matrix comprising the motion signals minus the offsets.

11. The method of claim 1 further including the steps of:

d) mounting the plurality of sensors to a substrate; and

e) storing the transformation matrix on the substrate.

12. The method of claim 11 further including the steps of:

f) connecting the sensor suite to a processor; and

g) the processor reading the transformation matrix.

14. The sensor suite of claim 13 wherein the plurality of inertial sensors are mounted in a fixed orientation relative to one another.

15. The sensor suite of claim 14 wherein the plurality of inertial sensors are mounted on a substrate.

16. The sensor suite of claim 15 further including a memory mounted on the substrate and storing the transformation matrix.

17. The sensor suite of claim 13 wherein the transformation matrix removes offsets from the signals from the plurality of inertial sensors.

18. The sensor suite of claim 13 further including a memory mounted on the substrate and storing the transformation matrix.

13. An inertial sensor suite comprising:

a) a plurality of generally orthogonally oriented inertial sensors; and

b) a computer readable medium storing a transformation matrix, which when utilized by a processor, converts signals from the plurality of inertial sensor into orthogonal motion signals.