Method to determine physical properties of the ground

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.