System and method for rotational motion capture of a solid

• US 20080052034A1
• Filed: 08/17/2007
• Published: 02/28/2008
• Est. Priority Date: 04/05/2002
• Status: Abandoned Application

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Caritu, Yanis, David, Dominique
• Application Number:
  US11/893,877
• Publication Number:
  US 20080052034A1
• Time in Patent Office: Days
• 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

A capture device of the orientation of a solid comprising a sensor of angular position, capable of being affixed to the solid and supplying a measuring datum related to a real orientation of the solid, wherein the sensor is sensitive to gravity/magnetic field; calculation means for generating test data independent of any measuring datum and related to an estimated orientation of the solid; and means for modifying the estimated orientation by confrontation of the measuring datum and test data. A process including capturing a measuring datum related to a real orientation of the solid, the measuring datum originating from an angular position sensor sensitive to gravity/a magnetic field; establishing test data independent of any measuring datum and related to an estimated orientation of the solid; confronting the test data and the measuring datum; and establishing a new estimated orientation of the solid based on the result of the confrontation.

Claims

1. A 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 related to a real 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 independent of any measuring datum and related to an estimated orientation of the solid; and

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

2. Device as claimed in claim 1, wherein said means for modifying the estimated orientation of the solid comprise a first comparator connected to said sensor and to said calculation means, the first comparator configured to receive the measuring datum and at least a test datum, wherein the first comparator is configured to establish at least a difference between the test datum and the measuring datum.

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 estimated orientation of the solid, when the difference established by the first comparator is less than the threshold value.

4. Device as claimed in claim 1, wherein the sensor is sensitive to gravity, the sensor comprises at least an accelerometer.

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

6. Device as claimed in claim 1, wherein the sensor further comprises two sensors each having three axes of sensitivity.

7. Device as claimed in claim 1, wherein said calculation means comprises a calculator configured to calculate test data as a function of parameters characteristic of a response of the angular position sensor.

8. Device as claimed in claim 7, wherein the calculator is localized on the solid.

9. Device as claimed in claim 1, wherein said means for modifying the estimated orientation of the solid further comprises a calculator for establishing a new estimated orientation of the solid according to an error gradient descent method.

10. Device as claimed in claim 1, wherein said calculation means comprises a calculator for establishing a new test datum according to an error gradient descent method.

11. Device as claimed in claim 10, wherein the calculator is localized on the solid.

12. Device as claimed in claim 1, further comprising means for registering successive estimated orientations of the solid.

13. Device as claimed in claim 12, wherein said means for registering is localized on the solid.

14. Device as claimed in claim 13, comprising a timer configured to rate registration of the successive estimated orientations of the solid.

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

capturing at least a measuring datum related to a real orientation of the solid, the measuring datum originating from at least one angular position sensor sensitive to at least one of gravity or a magnetic field;

establishing test data independent of any measuring datum and related to an estimated orientation of the solid;

confronting the test data and the measuring datum; and

establishing a new estimated orientation of the solid based on the result of the confrontation.

16. Process as claimed in claim 15, wherein said capture and said confrontation are repeated until said confrontation reveals a difference between test data and the measuring datum less than a determined threshold.

17. Process as claimed in claim 15, wherein a correction calculation is made according to an error gradient descent method during the establishment of the new estimated orientation of the solid.