Methods and systems for calibrating a sensor using a vector field
View Patent ↗Systems and methods according to exemplary embodiments address, among other features, the area of calibrating a sensor using a constant vector field. In one exemplary embodiment, a method for calibrating a sensor includes the steps of placing the sensor in a cube, rotating the cube between a plurality of different orientations, collecting at least one reading from the sensor from each of the plurality of different orientations and calibrating the sensor using the collected readings.
1. A method for calibrating a sensor comprising the steps of:
placing the sensor in a cube;
rotating said cube between a plurality of different orientations;
collecting at least one reading from said sensor from each of said plurality of different orientations; and
calibrating said sensor using said collected readings, wherein said sensor is a magnetometer.
2. The method of claim 1 , further comprising the steps of:
placing said cube in a cube holder; and
rotating said cube between said plurality of different orientations within said cube holder.
3. The method of claim 2 , wherein said step of rotating occurs according to a predetermined rotation sequence.
4. The method of claim 1 , wherein said collected readings are processed through a sensor model.
5. The method of claim 4 , wherein said sensor model is the following equation:
R I *H E =a s *R*f(M/m s ), wherein a s and m s are arbitrary scaling vectors, M is the 3×1 vector of said sensor measurement, R is a 3×3 rotation matrix that includes rotation, scale and skew, R I is a 3×3 rotation matrix corresponding to a placement of said cube in said cube holder, H E is a value of said vector, and f is a transformation function.
6. The method of claim 5 , wherein H E is represented in spherical coordinates.
7. The method of claim 1 , wherein said step of collecting further comprises transmitting said at least one reading from said sensor from each of said plurality of different orientations to a computing device for processing.
8. The method of claim 7 , wherein said step of calibrating said sensor using said collected readings further comprises receiving processed data from said computing device.
9. The method of claim 8 , wherein said sensor is linked to said computing device for processing.
10. The method of claim 1 , further comprising the step of calibrating the vector direction.
11. A system for calibrating a sensor comprising:
a sensor to be calibrated;
a cube within which said sensor is mounted, wherein said sensor is a magnetometer; and
a cube holder on which said cube can be rotated between a plurality of measurement positions.
12. The system of claim 11 , wherein said cube collects at least one reading from said sensor from each of said plurality of measurement positions.
13. The system of claim 11 , wherein rotation occurs according to a predetermined rotation sequence.
14. The system of claim 11 , wherein readings are collected at each one of said plurality of measurement positions by a sensor model.
15. The system of claim 14 , wherein said sensor model is the following equation:
R I *H E =a s *R*f(M/m s ), wherein a s and m s are arbitrary scaling vectors, M is the 3×1 vector of said sensor measurement, R is a 3×3 rotation matrix that includes rotation, scale and skew, R I is a 3×3 rotation matrix corresponding to a placement of said cube in said cube holder, H E is a value of said vector, and f is a transformation function.
16. The system of claim 15 , wherein H E is represented in spherical coordinates.
17. The system of claim 12 , wherein said cube transmits collected data to a computing device for processing.
18. The system of claim 17 , wherein said sensor receives processed data from a computing device for calibration.
19. The system of claim 18 , wherein said sensor is linked to said computing device.
20. The system of claim 11 , wherein said sensor is calibrated for the vector direction.
21. A system for calibrating a sensor comprising:
means for placing the sensor in a cube;
means for rotating said cube between a plurality of different orientations;
means for collecting at least one reading from said sensor from each of said plurality of different orientations; and
means for calibrating said sensor using said collected readings, wherein said sensor is a magnetometer.
22. The method of claim 1 , further comprising:
using a constant vector field for reading, wherein said constant vector field allows said sensor to measure multiple readings of a constant magnitude.
23. The method of claim 3 , wherein said predetermined rotation sequence includes twenty four different cube orientations.
24. The system of claim 11 , wherein a constant vector field is used for reading, further wherein said constant vector field allows said sensor to measure multiple readings of a constant magnitude.
25. The system of claim 13 , wherein said predetermined rotation sequence includes twenty four different cube orientations.