Device and method for measuring orientation of a solid with measurement correction means

• US 7,269,532 B2
• Filed: 04/02/2003
• Issued: 09/11/2007
• Est. Priority Date: 04/05/2002
• Status: Expired due to Term

• Current Assignee: Movea
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Caritu, Yanis, David, Dominique
• Primary Examiner(s): Bui; Bryan
• Assistant Examiner(s): TEIXEIRA MOFFAT, JONATHAN CHARLES
• Application Number:
  US10/509,987
• Publication Number:
  US 20050125191A1
• Time in Patent Office: 1,623 Days
• Field of Search: 702/151
• US Class Current: 702/151
• CPC Class Codes: G01C 21/185 for gravity
• CPC Class Codes: G01C 25/00 Manufacturing, calibrating, cleaning, or repairing instruments or devices referred to in the other groups of this subclass testing, calibrating or compensating compasses G01C17/38

Abstract

The present invention relates to a device for detecting the orientation of a solid including a sensor of angular position, capable of being affixed to the solid and of supplying at least a measuring datum representative of the orientation of the solid. The device also includes means for generating test data representative of an estimated orientation of the solid, and means for modification of the estimated orientation of the solid by confrontation of the measuring datum and test data.

Claims

1. Capture device of the orientation of a solid comprising:

a sensor of angular position, capable of being affixed to the solid and of supplying at least a measuring datum representative of the orientation of the solid, wherein the sensor of angular position being sensitive to at least one of gravity or a magnetic field;

calculation means for generating test data representative of a random estimated orientation of the solid; and

means for modifying the random estimated orientation of the solid by confrontation of the solid orientation that the measuring datum represents and test data.

2. Device as claimed in claim 1, wherein the modification means of the random estimated orientation comprise a first comparator connected to the sensor and to the calculation means for generating test data, for receiving the measuring datum and at least a test datum, and for establishing at least a difference between the test datum and the solid orientation that the measuring datum represents.

3. Device as claimed in claim 2, further comprising a second comparator with a threshold for comparing the difference established by the first comparator to a threshold value and to validate the random estimated orientation, when the difference established by the first comparator is less than the threshold value.

4. Device as claimed in claim 1, wherein the sensor sensitive to gravity comprises at least an accelerometer and the sensor sensitive to a magnetic field comprises at least a magnetometer.

5. Device as claimed in claim 1, comprising two sensors each having three axes of sensitivity.

6. Device as claimed in claim 1, wherein the calculation means for generating test data comprise a calculator for calculating test data as a function of parameters characteristic of a response of the angular position sensor.

7. Device as claimed in claim 6, wherein the calculator is localised on the solid.

8. Device as claimed in claim 1, wherein the modification means of the random estimated orientation and/or the calculation means for generating a test datum comprise a calculator for establishing a new estimated orientation and/or a new test datum according to an error gradient descent method.

9. Device as claimed in claim 8, wherein the calculator is localised on the solid.

10. Device as claimed in claim 1 further comprising means for registering successive estimations of the orientation of the solid.

11. Device as claimed in claim 10, wherein the means for registering are localised on the solid.

12. Device as claimed in claim 10, comprising a timer for rating registration of the successive estimations of the orientation of the solid.

13. A process for estimation of the orientation of a solid comprising:

a) capture of measuring data originating from at least one angular position sensor and the establishment of a test datum representative of a random estimated orientation of the solid, the sensor of angular position being sensitive to at least one of gravity or a magnetic field;

b) confrontation of the test datum and the solid orientation that the measured datum represents; and

c) establishment of a new test datum representative of a new estimated orientation of the solid, corrected as a function of the preceding confrontation.

14. Process as claimed in claim 13, wherein the capture of measuring data and the confrontation of the test datum are repeated until the confrontation reveals a difference between the test datum and the measuring datum less than a determined threshold.

15. Process as claimed in claim 13, wherein, correction calculation is made according to a error gradient descent method during the establishment of the new test datum.

16. Process as claimed in claim 13, wherein confrontation between the test data and the solid orientation that the measuring datum represents comprises the establishment of difference data between successive test data and the solid orientation that the measuring datum represents.

17. Process as claimed in claim 13 wherein the capture, the confrontation and the establishment is repeated with successive measuring data.