Method for acceleration estimation, acceleration estimating apparatus, and mobile terminal

• US 20070146323A1
• Filed: 02/15/2007
• Published: 06/28/2007
• Est. Priority Date: 09/07/2004
• Status: Active Grant

• Current Assignee: Vodafone Group PLC
• Original Assignee: Vodafone KK (SoftBank Group Corp.)
• Inventors: Kusuda, Hirohisa, Nishikata, Naomi
• Granted Patent: US 8,521,467 B2
• Time in Patent Office: Days
• US Class Current: 345/158
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1684 Constructional details or arrangements related to integrated I/O peripherals not covered by groups G06F1/1635 - G06F1/1675
• CPC Class Codes: G06F 2200/1614 Image rotation following screen orientation, e.g. switching from landscape to portrait mode
• CPC Class Codes: G06F 2200/1637 Sensing arrangement for detection of housing movement or orientation, e.g. for controlling scrolling or cursor movement on the display of an handheld computer
• CPC Class Codes: G06F 3/017 Gesture based interaction, e.g. based on a set of recognized hand gestures interaction based on gestures traced on a digitiser G06F3/04883
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: G06V 30/228 of three-dimensional handwriting, e.g. writing in the air
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion

Abstract

Acceleration and attitude angles are measured by sensors mounted on a moving object and the measurement results are collected (step S21, step S22).

The measurement results of acceleration are separated into low-frequency acceleration components and high-frequency acceleration components (step S24), and a time-rate-of-changes of attitude angles are calculated based on the measurement results of the attitude angles (step S25A).

After finishing extraction of the high-frequency acceleration components and the low-frequency acceleration components, and finishing calculation of the time-rate-of-changes of attitude angles, the rotation contributing acceleration and translation contributing acceleration are estimated based on the high-frequency acceleration components, the low-frequency acceleration components, the attitude angles and the time-rate-of-change of attitude angles (step S26A). As a result, a translation contributing acceleration which contributes to a translational movement of a moving object, and a rotation contributing acceleration which contributes to a rotational movement of the moving object are estimated with improved accuracy.

Claims

1. A method for acceleration estimation of estimating a translation contributing acceleration which contributes to a translational movement of a moving object in a measurement result of acceleration along at least two axial directions from among a first axis, a second axis which is orthogonal to the first axis, and a third axis which is orthogonal to the first axis and the second axis, which are defined peculiarly for the moving object, and a rotation contributing acceleration which contributes to a rotational movement, comprising steps of:

collecting a measurement result of acceleration along the two axes, and a measurement result of an attitude angle which is an angle of rotation from a reference attitude of the moving object;

separating an acceleration frequency in a low-frequency acceleration component and a high-frequency acceleration component in the measurement result of the acceleration along the two axes;

deriving a rate of change of attitude angle at which a time rate of change of the attitude angle is derived; and

estimating the translation contributing acceleration and the rotation contributing acceleration based on the high-frequency acceleration component, the low-frequency acceleration component, the attitude angle, and the time rate of change of the attitude angle.

2. The method for acceleration estimation according to claim 1, wherein

the step of estimating the translation contributing acceleration and the rotation contributing acceleration comprises steps of:

estimating a high-frequency component, at which it is estimated that the high-frequency acceleration component does not include a component of the rotation contributing acceleration, and includes only a component of the translation contributing acceleration;

estimating a low-frequency component, at which, when an absolute value of the time rate of change of the attitude angle is less than a predetermined value, it is estimated that a resultant obtained upon subtracting a gravitational acceleration from the low-frequency acceleration component does not include the component of the rotation contributing acceleration, and includes only the component of the translation contributing acceleration, and when the absolute value of the time rate of change of the attitude angle is not less than the predetermined value, it is estimated that the resultant obtained upon subtracting the gravitational acceleration from the low-frequency acceleration component, does not include the component of the translation contributing acceleration, and includes only the component of the rotation contributing acceleration.

3. The method for acceleration estimation according to claim 1, wherein

at the step of deriving the rate of change of the attitude angle, a low-frequency component of the time rate of change of the attitude angle is derived, and

the step of estimating the translation contributing acceleration and the rotation contributing acceleration comprises steps of;

estimating a high-frequency component at which it is estimated that the high-frequency acceleration component does not include the component of the rotation contributing acceleration, and includes only the component of the translation contributing acceleration;

estimating a rotation contributing low-frequency component at which a rotation contributing low-frequency acceleration component which is a component of the rotation contributing acceleration in the low-frequency acceleration component is estimated based on the low-frequency component of the time rate of change of the attitude angle; and

estimating a translation contributing low-frequency component at which it is estimated that a resultant obtained upon subtracting the rotation contributing low-frequency acceleration component and a gravitational acceleration from the low-frequency acceleration component is a translation contributing low-frequency acceleration component which is a low-frequency component of the translation contributing acceleration.

4. The method for acceleration estimation according to claim 1, wherein

at the step of deriving the rate of change of attitude angle, a low-frequency component in the time rate of change of the attitude angle and a high-frequency component in the time rate of change of the attitude angle are separated, and

the step of estimating the translation acceleration comprises steps of:

estimating a rotation contributing high-frequency component at which a rotation contributing high-frequency acceleration component which is a high-frequency component of the rotation contributing acceleration in the high-frequency acceleration component is estimated, based on a high-frequency component of the time rate of change of the attitude angle;

estimating a translation contributing high-frequency component at which it is estimated that a resultant obtained upon subtracting the rotation contributing high-frequency acceleration component from the high-frequency acceleration component is a translation contributing high-frequency acceleration component which is a high-frequency component of the translation contributing acceleration;

estimating rotation contributing low-frequency component at which a rotation contributing low-frequency acceleration component which is a low-frequency component of the rotation contributing acceleration in the low-frequency acceleration component is estimated based on a low-frequency component of the time rate of change of the attitude angle; and

estimating a translation contributing low-frequency component at which it is estimated that a resultant obtained upon subtracting the rotation contributing low-frequency acceleration component and a gravitational acceleration from the low-frequency acceleration component is a translation contributing low-frequency acceleration component which is a low-frequency component of the translation contributing acceleration.

5. The method for acceleration estimation according to claim 1, wherein

at the step of separating the acceleration frequency, a component which can be evaluated as a direct current component is extracted as the low-frequency acceleration component, and

the step of estimating the translation contributing acceleration and the rotation contributing acceleration comprises steps of:

estimating a low-frequency component, at which the low-frequency acceleration component is derived only from a gravitational acceleration; and

estimating a high-frequency component, at which, when an absolute value of the time rate of change of the attitude angle is less than a predetermined value, it is estimated that the high-frequency acceleration component does not include a component of a rotation contributing acceleration which contributes to the rotational movement, and includes only a component of the translation contributing acceleration, and when the absolute value of the time rate of change of the attitude angle is not less than the predetermined value, it is estimated that the high-frequency component does not include the component of the translation contributing acceleration, and includes only the component of the rotation contributing acceleration.

6. The method for acceleration estimation according to claim 1, wherein

at the step of separating the acceleration frequency, a component which can be evaluated as a direct current component is extracted as the low-frequency acceleration component, and

the step of estimating the translation acceleration and the rotation acceleration comprises steps of:

estimating a low-frequency component, at which it is estimated that the low-frequency acceleration component is derived only from a gravitational acceleration;

estimating a rotation contributing component, at which a rotation contributing acceleration component which contributes to rotational movement in the high-frequency acceleration component is estimated based on the time rate of change of the attitude angle; and

estimating a translation contributing component, at which it is estimated that a resultant obtained upon subtracting the rotation contributing acceleration component from the high-frequency acceleration component is the translation contributing acceleration component.

7. An acceleration estimating apparatus which estimates a translation contributing acceleration which contributes to a translational movement of a moving object in a measurement result of acceleration along at least two axial directions from among a first axis, a second axis which is orthogonal to the first axis, and a third axis which is orthogonal to the first axis and the second axis, which are defined peculiarly for the moving object, and a rotation contributing acceleration which contributes to a rotational movement of the moving object, comprising:

a measurement result collecting means which collects a measurement result of acceleration along at least the two axes, and a measurement result of an attitude angle which is an angle of rotation from a reference attitude of the moving object;

an acceleration frequency separating means which separates an acceleration frequency in a low-frequency acceleration component and a high-frequency acceleration component in the measurement result of the acceleration along at least the two axes;

an attitude angle change rate deriving means which derives a time rate of change of the attitude angle; and

a translation rotation acceleration estimating means which estimates the translation contributing acceleration and the rotation contributing acceleration based on the high-frequency acceleration component, the low-frequency acceleration component, the attitude angle, and the time rate of change of the attitude angle.

8. The acceleration estimating apparatus according to claim 7, wherein

the translation rotation acceleration estimating means comprises:

a high-frequency component estimating means which estimates that the high-frequency acceleration component does not include a component of the rotation contributing acceleration which contributes to the rotation, and includes only a component of the translation contributing acceleration; and

a low-frequency component estimating means which, when an absolute value of the time rate of change of the attitude angle is less than a predetermined value, estimates that a resultant obtained upon subtracting a gravitational acceleration from the low-frequency acceleration component does not include the component of the rotation contributing acceleration, and includes only the component of the translation contributing acceleration, and when the absolute value of the time rate of change of the attitude angle is not less than the predetermined value, estimates that the resultant obtained upon subtracting the gravitational acceleration from the low-frequency acceleration component, does not include the component of the translation contributing acceleration, and includes only the component of the rotation contributing acceleration.

9. The acceleration estimating apparatus according to claim 7, wherein

the attitude angle change rate deriving means derives a low-frequency component of the time rate of change of the attitude angle, and

the translation rotation acceleration estimating means comprises:

a high-frequency component estimating means which estimates that the high-frequency acceleration component does not include the component of the rotation contributing acceleration;

includes only the component of the translation contributing acceleration;

a rotation contributing low-frequency component estimating means which estimates a rotation contributing low-frequency acceleration component which is a component of the rotation contributing acceleration in the low-frequency acceleration component, based on the low-frequency component of the time rate of change of the attitude angle; and

a translation contributing low-frequency component estimating means which estimates that a resultant obtained upon subtracting the rotation contributing low-frequency acceleration component and a gravitational acceleration from the low-frequency acceleration component is a translation contributing low-frequency acceleration component which is a low-frequency component of the translation contributing acceleration.

10. The acceleration estimating apparatus according to claim 7, wherein

the attitude angle change rate deriving means separates a low-frequency component and a high-frequency component in the time rate of change of the attitude angle, and

the translation rotation acceleration estimating means comprises:

a rotation contributing high-frequency component estimating means, which estimates a rotation contributing high-frequency acceleration component which is a high-frequency component of the rotation contributing acceleration in the high-frequency acceleration component, based on a high-frequency component of the time rate of change of the attitude angle;

a translation contributing high-frequency component estimating means, which estimates that a resultant obtained upon subtracting the rotation contributing high-frequency acceleration component from the high-frequency acceleration component is a translation contributing high-frequency component which is a high-frequency component of the translation contributing acceleration;

a rotation contributing low-frequency component estimating means which estimates a rotation contributing low-frequency acceleration component which is a low-frequency component of the rotation contributing acceleration in the low-frequency acceleration component, based on a low-frequency component of the time rate of change of the attitude angle; and

a translation contributing low-frequency component estimating means which estimates that a resultant obtained upon subtracting the rotation contributing low-frequency acceleration component and a gravitation acceleration from the low-frequency acceleration component is a translation contributing low-frequency acceleration component which is a low-frequency component of the translation contributing acceleration.

11. The acceleration estimating apparatus according to claim 7, wherein

the acceleration frequency separating means extracts a component which can be evaluated as a direct current component, as the low-frequency acceleration component, and

the translation rotation acceleration estimating means comprises:

a low-frequency component estimating means which estimates that the low-frequency acceleration component is derived only from a gravitational acceleration; and

a high-frequency component estimating means which, when an absolute value of the time rate of change of the attitude angle is less than a predetermined value, estimates that the high-frequency acceleration component does not include a component of a rotation contributing acceleration which contributes to a rotational movement, and includes only a component of the translation contributing acceleration, and when the absolute value of the time rate of change of the attitude angle is not less than the predetermined value, estimates that the high-frequency component does not include the component of the translation contributing acceleration, and includes only the component of the rotation contributing acceleration.

12. The acceleration estimating apparatus according to claim 7, wherein

the acceleration frequency separating means extracts a component which can be evaluated as a direct current component, as the low-frequency acceleration component, and

the translation rotation acceleration estimating means comprises:

a low-frequency component estimating means which estimates that the low-frequency acceleration component is derived only from a gravitational acceleration;

a rotation contributing component estimating means which estimates a rotation contributing acceleration component which contributes to a rotational movement in the high-frequency acceleration component, based on the time rate of change of the attitude angle; and

a translation contributing component estimating means which estimates that a resultant obtained upon subtracting the rotation contributing acceleration component from the high-frequency acceleration component is the translation contributing acceleration component.

13. A mobile terminal, which can be operated while moving, comprising:

the acceleration estimating apparatus according to claim 7.