Method to determine physical properties of the ground

• US 10,024,660 B2
• Filed: 08/26/2013
• Issued: 07/17/2018
• Est. Priority Date: 08/27/2012
• Status: Active Grant

• Current Assignee: Universite Du Quebec A Chicoutimi (University of Quebec)
• Original Assignee: Universite Du Quebec A Chicoutimi (University of Quebec)
• Inventors: Otis, Martin Jean-Denis, Menelas, Bob-Antoine Jerry
• Primary Examiner(s): DO, AN H
• Application Number:
  US14/424,803
• Publication Number:
  US 20150260514A1
• Time in Patent Office: 1,786 Days
• Field of Search: 702 2, 702 5, 702 11, 702158, 702160
• CPC Class Codes: A43B 3/34 with electrical or electronic arrangements
• CPC Class Codes: A43B 3/44 with sensors, e.g. for detecting contact or position
• CPC Class Codes: A43D 1/08 Measuring devices for shoe parts
• CPC Class Codes: A61B 5/6807 Footwear
• CPC Class Codes: G01B 21/30 for measuring roughness or irregularity of surfaces
• CPC Class Codes: G01N 19/02 Measuring coefficient of friction between materials testing of tyres G01M17/02; determinations of friction coefficient used in vehicle braking or traction control systems B60T8/172
• CPC Class Codes: G01P 15/02 by making use of inertia forces using solid seismic massesG01P15/14 takes precedence
• CPC Class Codes: G01V 9/00 Prospecting or detecting by methods not provided for in groups G01V1/00 - G01V8/00

Abstract

The method can determine physical properties of the ground stepped upon by a user wearing a footwear incorporating an accelerometer, and includes: receiving a raw signal from the accelerometer during at least one step being taken by the user on the ground; identifying, in the received raw signal, at least one characteristic signature; associating the at least one characteristic signature to physical properties of the ground; and generating a signal indicating the physical properties based on said association. The generated signal can further be used to advise a user of a risk of falling based on at least the physical properties of the ground.

Claims

1. A method of determining at least a physical property of the ground stepped upon by a user, the method comprising:

stepping onto the ground using a footwear incorporating an accelerometer;

receiving a raw signal from the accelerometer during at least one step being taken by the user on the ground;

identifying, in the received raw signal, at least one characteristic signature, said identifying further comprising obtaining a spectral representation of the at least a portion of the raw signal;

associating the at least one characteristic signature to at least a physical property of the ground; and

generating a signal indicating the physical property.

2. The method of claim 1, wherein said identifying includes identifying at least a portion of the raw signal corresponding to a duration of one of said at least one step.

3. The method of claim 2, wherein said identifying at least a portion includes identifying a beginning and an end of said at least one step.

4. The method of claim 3 further comprising receiving a signal from a force sensor incorporated in the footwear while the raw signal is received from the accelerometer, and said identifying a beginning and an end of said at least one step in the raw signal is based on the force sensor signal.

5. The method of claim 1, wherein said obtaining a spectral representation includes effecting a fast Fourier transform of the at least a portion of the raw signal.

6. The method of claim 1, wherein said associating further includes associating a type of ground to the at least a physical property determined.

7. The method of claim 1, wherein said at least one characteristic signature has at least one characteristic signature relating to at least one of a spectral representation, energy computation, time signature and spatio-temporal alignment.

8. The method of claim 1, wherein the at least a physical property includes a deformability of the ground.

9. The method of claim 1 further comprising determining a risk of falling of the user based at least on the at least a physical property determined.

10. The method of claim 9, wherein said determining a risk of falling is further based on a determination of variations of the gait of the user.

11. The method of claim 9, wherein said determining a risk of falling is further based on human parameters.

12. The method of claim 9 further comprising activating a haptic indicator incorporated in the footwear of the user based on the determined risk of falling thereby advising the user of a risk of falling.

13. The method of claim 1, further comprising at least one indicator located in the footwear is activatable to communicate the at least a physical property determined to the user.

14. The method of claim 13, wherein at least one of the at least one indicator is an acoustic wave generator generating a sound audible by the user thereby communicating the at least a physical property of the ground stepped onto by to the user.

15. The method of claim 13, wherein at least one of the at least one indicator is an haptic indicator generating vibration to the foot of the user thereby communicating the at least a physical property of the ground stepped onto by the user.

16. The method of claim 15, wherein the haptic indicators are incorporated in the sole of the footwear.

17. A method of determining at least a physical property of the ground stepped upon by a user, the method comprising:

stepping onto the ground using a footwear incorporating an accelerometer;

receiving a raw signal from the accelerometer during at least one step being taken by the user on the ground;

identifying, in the received raw signal, at least one characteristic signature, said identifying further comprising obtaining a spectral representation of the at least a portion of the raw signal, said identifying including converting at least a portion of the raw signal corresponding to a duration of one of said at least one step from the time domain to the frequency domain, and obtaining a centroid of said at least a portion of the raw signal in the frequency domain, wherein said associating includes associating the centroid to a region in the frequency domain corresponding to the at least a physical property determined;

associating the at least one characteristic signature to at least a physical property of the ground; and

generating a signal indicating the physical property.

18. A method of determining at least a physical property of the ground stepped upon by a user, the method comprising:

stepping onto the ground using a footwear incorporating an accelerometer;

receiving a raw signal from the accelerometer during at least one step being taken by the user on the ground;

identifying, in the received raw signal, at least one characteristic signature, said identifying further comprising obtaining a spectral representation of the at least a portion of the raw signal;

associating the at least one characteristic signature to at least a physical property of the ground;

generating a signal indicating the physical property; and

determining a risk of falling of the user based at least on the at least a physical property determined, said determining a risk of falling being further based on values of at least one of temperature and humidity sensed in the environment of the ground.