INFORMATION PROCESSING METHOD, APPARATUS, AND PROGRAM

• US 20120065915A1
• Filed: 09/07/2011
• Published: 03/15/2012
• Est. Priority Date: 09/13/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: HARA, Masahiro, MAEDA, Kazuho, YAGINUMA, Yoshinori
• Granted Patent: US 9,226,713 B2
• Time in Patent Office: Days
• US Class Current: 702/96
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1121 Determining geometric values, e.g. centre of rotation or angular range of movement
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: G01M 1/122 Determining position of centre of gravity
• CPC Class Codes: G01P 7/00 Measuring speed by integrating acceleration measuring travelled distance by double integration of acceleration G01C21/16
• CPC Class Codes: G16H 20/30 relating to physical therapies or activities, e.g. physiotherapy, acupressure or exercising
• CPC Class Codes: G16H 40/60 for the operation of medical equipment or devices

Abstract

A method executed by a computer includes applying a correction to an acceleration value of an object at an interval; calculating an initial speed of the object by assigning the corrected acceleration value in a period to a third relational expression that is obtained by transforming a first relational expression and a second relational expression so as to obtain an initial speed from the acceleration in the period and the interval, where the first relational expression is to obtain an object position from acceleration and an initial speed, and the second relational expression represents force applied to the object due to fluctuation of the center of gravity of the object as a motion equation of a spring model; and calculating coordinate values over a horizontal plane that indicates a center of gravity of the object by assigning the corrected acceleration value and the initial speed to the first relational expression.

Claims

1. An information processing method executed by a computer comprising:

receiving an acceleration value, measured by an acceleration sensor, of an object at a sampling interval;

applying a correction to the received acceleration value and storing the corrected acceleration value in a data storage unit;

calculating an initial speed of the object by inputting the corrected acceleration value of a period to a third relational expression which is obtained by transforming a first relational expression and a second relational expression so as to obtain the initial speed from the corrected acceleration in the period and the sampling interval, the first relational expression obtaining a position of the object from the corrected acceleration and the initial speed, and the second relational expression representing a force applied to the object due to a change of a center of gravity of the object as a motion equation of a spring model and storing the calculated initial speed in a storage device; and

calculating coordinate values over a horizontal plane that indicates a center of gravity of the object by inputting the corrected acceleration value and the calculated initial speed to the first relational expression and storing the calculated coordinate values in the storage device.

2. The information processing method according to claim 1, wherein the object is a user, the method further comprising:

identifying a state of the user by analyzing the calculated coordinate values stored in the storage device.

3. The information processing method according to claim 2, wherein the identifying the state of the user further comprises:

dividing the horizontal plane into regions with an angle by a straight line that passes through a center point among plural points over the horizontal plane that are represented by the calculated coordinate values;

identifying, for each of the regions, a first point where a distance from the center point is substantially a maximum and which is represented by the calculated coordinate values, converting the calculated coordinate values of the first point into coordinate values in which the center point is used as a reference point, and storing the converted coordinate values in the storage device; and

identifying a user state candidate that is calculated from the calculated coordinate values of the first point and a second point by analyzing a state database that stores coordinate values of a second point in each of the regions corresponding to each of the user state candidates and that a distance from the user state candidate to all of the regions is a substantially minimum.

4. The information processing method according to claim 1, wherein the object is a user, and the correction comprises:

transforming a template stored in a template storage unit storing the template that indicates a standard acceleration value while the user is walking so that the template is aligned with a gait cycle and an amplification of acceleration identified by the acceleration value measured during a period in which the user is assumed to be walking; and

subtracting the standard acceleration value during the walking from the acceleration value measured during the period in which the user is assumed to be walking by using the transformed template.

5. The information processing method according to claim 1, wherein

the calculating an initial speed calculates a variable K according to an expression (where “

i”

indicates a sample number)

6. The information processing method according to claim 1, further comprising:

measuring the acceleration values at the sampling interval Δ

t by the acceleration sensor and sequentially storing the measured acceleration values in a measurement result storage unit;

the calculating an initial speed, wherein the number of samplings in the period being N, the calculating the initial speed, for each of the periods, includes;

reading corrected acceleration values “

ai”

(where i is an integer from 0 to N−

1) of the number of N accelerations generated in the period to be processed from the data storage unit;

calculating a variable K in the period to be processed by assigning the number of N corrected acceleration values “

ai”

that are read to an expression

7. A non-transitory computer-readable recording medium that stores a program for causing a computer to execute a process comprising:

receiving an acceleration value, measured by an acceleration sensor, of an object at a sampling interval;

correcting the received acceleration value and storing the corrected acceleration value in a storage unit;

calculating an initial speed of the object by inputting the corrected acceleration value of a period to a third relational expression which is obtained by transforming a first relational expression and a second relational expression so as to obtain the initial speed from the corrected acceleration in the period and the sampling interval, the first relational expression obtaining a position of the object from the corrected acceleration and the initial speed, and the second relational expression representing a force applied to the object due to a change of a center of gravity of the object as a motion equation of a spring model and storing the calculated initial speed in the storage device; and

calculating coordinate values over a horizontal plane that indicates a center of gravity of the object by inputting the corrected acceleration and the calculated initial speed to the first relational expression and storing the calculated coordinate values in the storage device.

8. An information processing apparatus comprising:

a receiving unit configured to receive an acceleration value, measured by an acceleration sensor, of an object at a sampling interval;

a correction unit configured to apply a correction to the received acceleration value and to store the corrected acceleration value in the data storage unit;

an initial speed calculation unit configured to calculate an initial speed of the object by inputting the corrected acceleration value of a period to a third relational expression which is obtained by transforming a first relational expression and a second relational expression so as to obtain the initial speed from the corrected acceleration and the sampling interval, the first relational expression obtaining a position of the object from the corrected acceleration and the initial speed, and the second relational expression representing a force applied to the object due to a change of a center of gravity of the object as a motion equation of a spring model and to store the calculated initial speed in a storage device; and

a center of gravity position calculation unit configured to calculate coordinate values over a horizontal plane that indicates the center of gravity of the object by inputting the corrected acceleration value stored in the data storage unit and the initial speed stored in the storage device to the first relational expression and to store the calculated coordinate values in the storage device.

9. The information processing apparatus according to claim 8, wherein

the acceleration sensor measures the acceleration of the object at the sampling interval and sequentially stores the acceleration of the object in a measurement result storage unit, and

wherein the correction unit reads the acceleration values of the object measured in the period from the measurement result storage unit and applies the correction.

10. The information processing apparatus according to claim 8, wherein the object is a user, the information processing apparatus further comprising:

a state identification unit configured;

to divide the horizontal plane into regions with an angle respectively by a straight line that passes through a center point among plural points over the horizontal plane represented by the calculated coordinate values stored;

to identify, for each of the regions, a first point where a distance from the center point is substantially a maximum and which is represented by the calculated coordinate values;

to convert the calculated coordinate values of the first point into coordinate values in which the center point is used as a reference point;

to store the converted coordinate values in the storage device; and

to identify a user state candidate that is calculated from the calculated coordinate values of the first point and a second point by analyzing a state database that stores coordinate values of a second point in each of the regions corresponding to each of the user state candidates and that a distance from the user state candidate to all of the regions is substantially minimum.