Movement state information calculation method and movement state information calculation device

• US 9,599,475 B2
• Filed: 03/17/2014
• Issued: 03/21/2017
• Est. Priority Date: 03/25/2013
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Sato, Akinobu, Mizuochi, Shunichi, Uchida, Shuji, Kumar, Anand
• Primary Examiner(s): Sweeney, Brian P
• Application Number:
  US14/766,363
• Publication Number:
  US 20160146610A1
• Time in Patent Office: 1,100 Days
• Field of Search: 701/500
• US Class Current: 1/1
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1112 Global tracking of patients, e.g. by using GPS
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 22/006 Pedometers

Abstract

A traveling direction velocity calculation device 1 calculates a posture of an acceleration sensor 10 with respect to a user, using a detection result represented in a local coordinate system associated with the acceleration sensor 10, detecting acceleration, which is worn on a user'"'"'s body, when a change in the detection result of the acceleration sensor 10 satisfies a predetermined specific condition. The detection result of the acceleration sensor 10 at a time different from that when the posture is calculated and at a time when the specific condition is satisfied is transformed, using the calculated posture, to a mobile body coordinate system associated with a user. A velocity in a traveling direction of the user is calculated using the transformed detection result.

Claims

1. A movement state information calculation method comprising:

using a processing unit;

calculating a posture of a sensor with respect to a user, using a detection result represented in a coordinate system associated with the sensor, detecting any of a velocity and acceleration, which is worn on a user'"'"'s body, when a change in the detection result satisfies a predetermined specific condition;

transforming the detection result at a time different from that when the posture is calculated and at a time when the specific condition is satisfied, using the posture, to a mobile body coordinate system associated with the user; and

calculating movement state information which is any of a position and a velocity of the user, using the transformed detection result.

2. The movement state information calculation method according to claim 1, further comprising correcting a value of a component other than a traveling direction component of the user included in the transformed detection result.

3. The movement state information calculation method according to claim 2, wherein calculating the movement state information includes:

calculating an amplitude of acceleration in a traveling direction of the user, using the transformed detection result; and

calculating a velocity in a traveling direction of the user on the basis of the amplitude.

4. The movement state information calculation method according to claim 1, wherein calculating the movement state information includes:

calculating an amplitude of acceleration in a traveling direction of the user, using the transformed detection result; and

calculating a velocity in a traveling direction of the user on the basis of the amplitude.

5. The movement state information calculation method according to claim 1, wherein calculating the posture includes determining a timing at which the specific condition is satisfied on the basis of a change in a vertical velocity which is obtained from the detection result of the coordinate system associated with the sensor.

6. The movement state information calculation method according to claim 5, wherein determining the timing includes determining that the specific condition is satisfied when the vertical velocity is set to a value of a central portion in a varying range, and a direction of change of the velocity is an increasing direction or a decreasing direction.

7. The movement state information calculation method according to claim 1, wherein the sensor is worn on a predetermined region other than an arm of the user.

8. A movement state information calculation device comprising:

a sensor, detecting any of a velocity and acceleration, which is worn on a user'"'"'s body; and

a processing unit, wherein the processing unit includes;

a posture calculation unit that calculates a posture of the sensor with respect to the user, using a detection result of the sensor represented in a coordinate system associated with the sensor when a change in the detection result satisfies a predetermined specific condition;

a coordinate transformation matrix calculation unit that calculates a coordinate transformation matrix which is used for transforming the detection result at a time different from that when the posture is calculated and at a time when the specific condition is satisfied, using the posture, to a mobile body coordinate system associated with the user; and

a movement state information calculation unit that calculates movement state information of the user, using the coordinate transformation matrix, and the detection result at a time different from that when the posture is calculated and at a time when the specific condition is satisfied.