Method for compensating for acceleration vector offset, recording medium storing program for executing the method, and related apparatus

• US 20070118326A1
• Filed: 11/08/2006
• Published: 05/24/2007
• Est. Priority Date: 11/09/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ji, Byoung Kul, Lee, Dong Wook, Lee, Tae-Hoon, Starodubtsev, Dmitry, Jung, KwangJo
• Granted Patent: US 7,613,587 B2
• Time in Patent Office: Days
• US Class Current: 702/141
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0891 with indication of predetermined acceleration values G01P15/135 takes precedence
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups
• CPC Class Codes: G11B 19/043 by detecting a free-fall condition

Abstract

Embodiments of the invention provide a method for compensating for an acceleration vector offset of an acceleration detector, a recording medium storing a program for executing the method, and an apparatus adapted to perform the method. The method comprises determining whether the acceleration detector is in a stable resting state; if the acceleration detector is determined to be in a stable resting state, then determining whether any one of at least two orthogonal axes is a main axis; and, if the acceleration detector is determined to be in a steady resting state and one of the at least two orthogonal axes is determined to be a main axis, performing an acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector.

Claims

1. A method for compensating for an acceleration vector offset of an acceleration detector adapted to output measured acceleration values for at least two orthogonal axes, the method comprising:

determining whether the acceleration detector is in a stable resting state by evaluating measured acceleration vectors obtained during a first time period, wherein the measured acceleration vectors are calculated using the measured acceleration values;

if the acceleration detector is determined to be in a stable resting state, then determining whether any one of the at least two orthogonal axes is a main axis using the measured acceleration values; and

,

if the acceleration detector is determined to be in a steady resting state and one of the at least two orthogonal axes is determined to be a main axis, performing an acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector.

2. The method of claim 1, wherein determining whether the acceleration detector is in a stable resting state comprises determining that the acceleration detector is in a stable resting state when:

a variance of the measured acceleration vectors obtained during the first time period is less than a variance threshold; and

,

a mean value of the measured acceleration vectors obtained during the first time period is within a mean range.

3. The method of claim 2, wherein the first time period lasts for no more than 2 seconds.

4. The method of claim 1, wherein determining whether the acceleration detector is in a stable resting state comprises:

applying a moving average to the measured acceleration vectors; and

,

determining that the acceleration detector is in a stable resting state when;

a variance of the measured acceleration vectors obtained during the first time period is less than a variance threshold; and

,

a mean value of the measured acceleration vectors obtained during the first time period is within a mean range.

5. The method of claim 1, wherein:

determining whether any one of the at least two orthogonal axes is a main axis using the measured acceleration values comprises determining that a first axis of the at least two orthogonal axes is a main axis when the absolute value of a measured acceleration value for the first axis is greater than the sum of the absolute values of measured acceleration values for each of the remaining axes of the at least two orthogonal axes; and

,

the measured acceleration values comprise both the measured acceleration value for the first axis and the measured acceleration values for each of the remaining axes of the at least two orthogonal axes.

6. The method of claim 1, wherein performing an acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector comprises:

calculating the acceleration vector offset; and

,

compensating for an acceleration value offset for the main axis in accordance with the acceleration vector offset.

7. The method of claim 1, further comprising performing a temperature compensation operation before performing the acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector.

8. A computer-readable recording medium storing a program for executing a method for compensating for an acceleration vector offset of an acceleration detector adapted to output measured acceleration values for at least two orthogonal axes, the method comprising:

determining whether the acceleration detector is in a stable resting state by evaluating measured acceleration vectors obtained during a first time period, wherein the measured acceleration vectors are calculated using the measured acceleration values;

if the acceleration detector is determined to be in a stable resting state, then determining whether any one of the at least two orthogonal axes is a main axis using the measured acceleration values; and

,

if the acceleration detector is determined to be in a steady resting state and one of the at least two orthogonal axes is determined to be a main axis, performing an acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector.

9. The recording medium of claim 8, wherein determining whether the acceleration detector is in a stable resting state comprises determining that the acceleration detector is in a stable resting state when:

a variance of the measured acceleration vectors obtained during the first time period is less than a variance threshold; and

,

a mean value of the measured acceleration vectors obtained during the first time period is within a mean range.

10. The recording medium of claim 9, wherein the first time period lasts for no more than 2 seconds.

11. The recording medium of claim 8, wherein determining whether the acceleration detector is in a stable resting state comprises:

applying a moving average to the measured acceleration vectors; and

,

determining that the acceleration detector is in a stable resting state when;

a variance of the measured acceleration vectors obtained during the first time period is less than a variance threshold; and

,

a mean value of the measured acceleration vectors obtained during the first time period is within a mean range.

12. The recording medium of claim 8, wherein:

determining whether any one of the at least two orthogonal axes is a main axis using the measured acceleration values comprises determining that a first axis of the at least two orthogonal axes is a main axis when the absolute value of a measured acceleration value for the first axis is greater than the sum of the absolute values of measured acceleration values for each of the remaining axes of the at least two orthogonal axes; and

,

the measured acceleration values comprise both the measured acceleration value for the first axis and the measured acceleration values for each of the remaining axes of the at least two orthogonal axes.

13. The recording medium of claim 8, wherein performing an acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector comprises:

calculating the acceleration vector offset; and

,

compensating for an acceleration value offset for the main axis in accordance with the acceleration vector offset.

14. The recording medium of claim 8, further comprising performing a temperature compensation operation before performing the acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector.

15. The recording medium of claim 8, wherein in the determination of whether the main axis exists, when an axis having an absolute value of an acceleration detection value greater than a sum of the absolute values of acceleration detection values of the other axes exists, the axis is determined to be the main axis.

16. The recording medium of claim 14, wherein in the compensation, an offset of the main axis is compensated for based on an offset of the acceleration vector.

17. An apparatus adapted to compensate for an acceleration vector offset of an acceleration detector, the apparatus comprising:

the acceleration detector, wherein the acceleration detector is adapted to output measured acceleration values for at least two orthogonal axes; and

,

a controller adapted to compensate for the acceleration vector offset of the acceleration detector,

wherein the controller is adapted to;

determine whether the acceleration detector is in a stable resting state by evaluating measured acceleration vectors obtained during a first time period, wherein the measured acceleration vectors are calculated using the measured acceleration values;

determine whether any one of the at least two orthogonal axes is a main axis using the measured acceleration values, if the acceleration detector is determined to be in a stable resting state; and

,

perform an acceleration vector compensation operation to compensate for the acceleration vector offset of the acceleration detector, if the acceleration detector is determined to be in a steady resting state and one of the at least two orthogonal axes is determined to be a main axis.

18. The apparatus of claim 17, wherein the controller is adapted to compensate for an acceleration value offset of the main axis in accordance with the acceleration vector offset.