Traveling direction measuring apparatus and traveling direction measuring method

• US 8,027,803 B2
• Filed: 02/26/2010
• Issued: 09/27/2011
• Est. Priority Date: 03/28/2005
• Status: Active Grant

• Current Assignee: Asahi Kasei Corporation
• Original Assignee: Asahi Kasei Corporation
• Inventors: Kitamura, Toru, Yamashita, Masaya
• Primary Examiner(s): KUNDU, SUJOY K
• Application Number:
  US12/659,170
• Publication Number:
  US 20100191501A1
• Time in Patent Office: 578 Days
• Field of Search: 702/141, 702/149, 702/150, 702/160, 701/200, 701/206, 701/207, 377/24.2, 73/13.7, 73/13.8
• US Class Current: 702/150
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1112 Global tracking of patients, e.g. by using GPS
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G01P 13/02 Indicating direction only, e.g. by weather vane
• CPC Class Codes: G08G 1/005 including pedestrian guidance indicator

Abstract

The present invention relates to a traveling direction measuring apparatus usable as a pedestrian navigation system in locations where it is difficult to obtain high positioning accuracy such as inside buildings or around multistory buildings where a GPS cannot be used. An acceleration detecting section (1) detects 3-axes acceleration of the traveling direction measuring apparatus, which varies with the walking of the pedestrian. An acceleration data acquiring section (2) obtains 3-axes acceleration data repeatedly by the number of prescribed times or more, said 3-axes acceleration data varies with the walking of the pedestrian. A first gravity acceleration calculating section (3) calculates, when the pedestrian is walking with holding the traveling direction measuring apparatus in a generally fixed attitude, gravity acceleration by averaging acceleration data sets during several steps obtained by the acceleration data acquiring section (2). A first moving direction estimating section (4) estimates the moving direction of the pedestrian from frequency components corresponding to the duration of one step of the acceleration data sets projected on a plane perpendicular to the gravity acceleration calculated by the first gravity acceleration calculating section (3).

Claims

1. A traveling direction measuring apparatus including 3-axes acceleration detecting means for detecting acceleration, and acceleration data acquiring means for obtaining 3-axes acceleration data repeatedly by a number of prescribed times or more, said 3-axes acceleration data varies with walking of a pedestrian, said traveling direction measuring apparatus comprising:

first gravity acceleration calculating means for calculating, when the pedestrian is walking with holding said traveling direction measuring apparatus in a generally fixed attitude, gravity acceleration by averaging acceleration data sets during several steps obtained by said acceleration data acquiring means;

frequency component calculating means for calculating frequency components corresponding to duration of one step of the acceleration data sets projected on a plane perpendicular to the gravity acceleration calculated by said first gravity acceleration calculating means;

first moving direction estimating means for estimating a moving direction of the pedestrian seen from a terminal coordinate system associated with said traveling direction measuring apparatus according to the frequency components;

3-axes geomagnetism detecting means for detecting geomagnetism;

geomagnetism data acquiring means for obtaining 3-axes geomagnetism data repeatedly by a number of prescribed times or more, said 3-axes geomagnetism data varies with the walking of the pedestrian; and

first walking direction estimating means for estimating, when the pedestrian is walking with holding said traveling direction measuring apparatus in a generally fixed attitude, the walking direction of the pedestrian with respect to a terrestrial coordinate system from geomagnetism data sets obtained by said geomagnetism data acquiring means and the moving direction of the pedestrian estimated by said first moving direction estimating means.

2. A traveling direction measuring apparatus including 3-axes acceleration detecting means for detecting acceleration, and acceleration data acquiring means for obtaining 3-axes acceleration data repeatedly by a number of prescribed times or more, said 3-axes acceleration data varies with walking of a pedestrian, said traveling direction measuring apparatus comprising:

frequency component calculating means for calculating, when the pedestrian is walking with holding and swinging said traveling direction measuring apparatus, norms of individual acceleration data obtained by said acceleration data acquiring means, and for calculating frequency components varying during one step of the acceleration norm data sets calculated, and frequency components corresponding to duration of one step of the acceleration data sets obtained by said acceleration data acquiring means;

second gravity acceleration calculating means for calculating, when the pedestrian is walking with holding and swinging said traveling direction measuring apparatus, gravity acceleration seen from a coordinate system associated with said traveling direction measuring apparatus at the time when the swing is at a lowest point based on a frequency component corresponding to duration of one step of the acceleration norm data sets calculated by individual acceleration data obtained by said acceleration data acquiring means, and frequency component corresponding to duration of one step of the acceleration data sets obtained by said acceleration data acquiring means;

frequency component calculating means for calculating frequency components corresponding to duration of two steps of the acceleration data sets projected on a plane perpendicular to the gravity acceleration calculated by said second gravity acceleration calculating means; and

second moving direction estimating means for estimating from the frequency component corresponding to the duration of two steps the moving direction of the pedestrian seen from a terminal coordinate system associated with said traveling direction measuring apparatus at the time when the swing is at the lowest point.

3. The traveling direction measuring apparatus as claimed in claim 2, further comprising:

3-axes geomagnetism detecting means for detecting geomagnetism;

geomagnetism data acquiring means for obtaining 3-axes geomagnetism data repeatedly by a number of prescribed times or more, said 3-axes geomagnetism data varies with the walking of the pedestrian; and

second walking direction estimating means for estimating, when the pedestrian is walking with holding and swinging said traveling direction measuring apparatus, the walking direction of the pedestrian with respect to a terrestrial coordinate system from geomagnetism data at the time when the swing is at the lowest point, which is obtained by said geomagnetism data acquiring means, and from the moving direction of the pedestrian estimated by said second moving direction estimating means.

4. A traveling direction measuring method in a traveling direction measuring apparatus including 3-axes acceleration detecting means for detecting acceleration, and acceleration data acquiring means for obtaining 3-axes acceleration data repeatedly by a number of prescribed times or more, said 3-axes acceleration data varies with walking of a pedestrian, said traveling direction measuring method comprising:

a first gravity acceleration calculating step of calculating, when the pedestrian is walking with holding said traveling direction measuring apparatus in a generally fixed attitude, gravity acceleration by averaging acceleration data sets during several steps obtained by said acceleration data acquiring means;

a frequency component calculating step of calculating frequency components corresponding to duration of one step of the acceleration data sets projected on a plane perpendicular to the gravity acceleration calculated at the first gravity acceleration calculating step;

a first moving direction estimating step of estimating a moving direction of the pedestrian seen from a terminal coordinate system associated with said traveling direction measuring apparatus according to the frequency components;

a 3-axes geomagnetism detecting step of detecting geomagnetism;

a geomagnetism data acquiring step of obtaining 3-axes geomagnetism data repeatedly by a number of prescribed times or more, said 3-axes geomagnetism data varies with the walking of the pedestrian; and

a first walking direction estimating step of estimating, when the pedestrian is walking with holding said traveling direction measuring apparatus in a generally fixed attitude, the walking direction of the pedestrian with respect to a terrestrial coordinate system from geomagnetism data sets obtained at the geomagnetism data acquiring step and the moving direction of the pedestrian estimated at the first moving direction estimating step.

5. A traveling direction measuring method in a traveling direction measuring apparatus including 3-axes acceleration detecting means for detecting acceleration, and acceleration data acquiring means for obtaining 3-axes acceleration data repeatedly by a number of prescribed times or more, said 3-axes acceleration data varies with walking of a pedestrian, said traveling direction measuring method comprising:

a frequency component calculating step of calculating, when the pedestrian is walking with holding and swinging said traveling direction measuring apparatus, norms of individual acceleration data obtained by said acceleration data acquiring means, and for calculating frequency components varying during one step of the acceleration norm data sets calculated, and frequency components corresponding to duration of one step of the acceleration data sets obtained by said acceleration data acquiring means;

a second gravity acceleration calculating step of calculating, when the pedestrian is walking with holding and swinging said traveling direction measuring apparatus, gravity acceleration seen from a coordinate system associated with said traveling direction measuring apparatus at the time when the swing is at a lowest point based on a frequency component corresponding to duration of one step of the acceleration norm data sets calculated by individual acceleration data obtained by said acceleration data acquiring means, and frequency component corresponding to duration of one step of the acceleration data sets obtained by said acceleration data acquiring means;

a frequency component calculating step of calculating frequency components corresponding to duration of two steps of the acceleration data sets projected on a plane perpendicular to the gravity acceleration calculated at the second gravity acceleration calculating step; and

a second moving direction estimating step of estimating from the frequency component corresponding to the duration of two steps the moving direction of the pedestrian seen from a terminal coordinate system associated with said traveling direction measuring apparatus at the time when the swing is at the lowest point.

6. The traveling direction measuring method in the traveling direction measuring apparatus as claimed in claim 5, further comprising:

a 3-axes geomagnetism detecting step of detecting geomagnetism;

a geomagnetism data acquiring step of obtaining 3-axes geomagnetism data repeatedly by a number of prescribed times or more, said 3-axes geomagnetism data varies with the walking of the pedestrian; and

a second walking direction estimating step of estimating, when the pedestrian is walking with holding and swinging said traveling direction measuring apparatus, the walking direction of the pedestrian with respect to a terrestrial coordinate system from geomagnetism data at the time when the swing is at the lowest point, which is obtained at the geomagnetism data acquiring step, and from the moving direction of the pedestrian estimated at the second moving direction estimating step.