Method of and system for measuring performance during an exercise activity, and an athletic shoe for use in system

• US 6,356,856 B1
• Filed: 02/22/1999
• Issued: 03/12/2002
• Est. Priority Date: 02/25/1998
• Status: Expired due to Term

• Current Assignee: Embedded Sensor Solutions B.V.
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Schiller, Christoph, Damen, Erik P. N.
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): PRETLOW, DEMETRIUS R
• Application Number:
  US09/255,630
• Time in Patent Office: 1,114 Days
• Field of Search: 702/160, 702/57, 702/108, 702/124, 702/139, 702/142, 702/149, 702/66, 702/67, 702/68, 702/164, 702/165, 702/178, 702/182, 702/183, 702/187, 235/105, 377/24.2, 482/8, 482/9, 482/3, 734/90, 735/03, 735/731, 734/93
• US Class Current: 702/160
• CPC Class Codes: A43B 3/00 Footwear characterised by the shape or the use
• CPC Class Codes: A63B 2071/0663 worn on the wrist, e.g. wrist bands
• CPC Class Codes: A63B 2220/40 Acceleration
• CPC Class Codes: A63B 2230/06 heartbeat rate only
• CPC Class Codes: A63B 24/00 Electric or electronic controls for exercising apparatus of preceding groups; Controlling or monitoring of exercises, sportive games, training or athletic performances
• CPC Class Codes: A63B 69/0028 for running, jogging or speed-walking movable endless bands A63B22/02
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G01P 3/50 for measuring linear speed G01P3/56 takes precedence
• CPC Class Codes: G06F 2218/08 Feature extraction
• CPC Class Codes: G06V 40/25 Recognition of walking or running movements, e.g. gait recognition

Abstract

A system for measuring the speed of a person while running or walking along a surface. A single acceleration sensor measures the acceleration in the forward direction and provides an acceleration signal which is amplified and subsequently sampled by analog to digital converter. The digital signal is processed by a microprocessor which executes an algorithm that determines the stride length and the stride duration from the digitized acceleration signal and calculates the speed and the distance traversed. The information thus obtained is transmitted by means of a radio frequency transmitter and received by a radio frequency receiver in a watch or other device which comprises a display which can be viewed by the runner or walker. The speed and distance traversed is displayed on the display, along with other useful information, such as average speed, maximum speed, total distance traversed, calories expended, and heart beat.

Claims

1. A system for measuring performance during an exercise activity comprising:

an acceleration sensor for measuring acceleration in a moving direction of a foot of an exerciser and for providing an acceleration signal in response to said acceleration;

signal processing means comprising;

means for analyzing a waveform of the acceleration signal and for determining from the analyzing a beginning and an end of movement of the foot during a stride made by the foot of the exerciser;

means for single integrating and for double integrating the acceleration signal between said beginning and said end of movement in order to compute the speed of the foot as a function of time during the stride and the distance traversed by the foot as a function of time during the stride, respectively;

means for computing an acceleration error by equalizing the acceleration error with the speed at the end of the movement of the foot divided by the time lapsed between the end and the beginning of the stride;

means for computing a distance error by double integrating the acceleration error over said time lapsed between the end and the beginning of the movement of the foot;

means for computing a corrected distance by subtracting the distance error from the distance traversed during the stride.

2. A system as claimed in claim 1, wherein the signal processing means further comprises:

means for computing a speed of the exerciser by dividing the corrected distance by a time lapsed between successive strides.

3. A system as claimed in claim 1, wherein the moving direction is substantially parallel to a line between the heel and the toes of the foot of the exerciser.

4. A system as claimed in claim 1, wherein the moving direction is substantially perpendicular to a line between the heel and the toes of the foot of the exerciser.

5. A system as claimed in claim 1, further comprising:

means for inputting personal data of the exerciser to the signal processing means.

6. A system as claimed in claim 5, wherein the data comprises a mass of the exerciser, the signal processing means being operative to compute a number of calories expended by the exerciser from the speed and the mass.

7. A system as claimed in claim 6, wherein the data comprises a heart rate of the exerciser, the signal processing means being operative to compute a fitness indication from the heart rate and the calories expended per unit of time.

8. A system as claimed in claim 1, further comprising:

display means coupled to the signal processing means for displaying exercise parameters.

9. A system as claimed in claim 8, wherein the exercise parameters comprise at least one of:

current speed, average speed, maximum speed, stride length, distance traversed, elapsed time, number of calories expended, and fitness indication.

10. A system as claimed in claim 8, further comprising a wireless transmitter and receiver for coupling the signal processing means to the display means.

11. An athletic shoe comprising an acceleration sensor for use in the system as claimed in claim 1, the acceleration sensor being mounted for measuring acceleration in a moving direction of the athletic shoe for providing an acceleration signal in response to said acceleration.

12. An athletic shoe as claimed in claim 11, wherein the moving direction is substantially parallel to a line between the heel and the nose the shoe.

13. An athletic shoe as claimed in claim 11, wherein the moving direction is substantially perpendicular to a line between the heel and the nose the shoe.

14. An athletic shoe as claimed in claim 11, further comprising a transmitter for transmitting data related to or derived from the acceleration signal.

15. An athletic shoe as claimed in claim 11, further comprising signal processing means, the signal processing means comprising:

means for analyzing a waveform of the acceleration signal and for determining from the analyzing a beginning and an end of movement of the foot during a stride made by the foot of the exerciser;

means for single integrating and for double integrating the acceleration signal between said beginning and said end of movement in order to compute the speed of the foot as a function of time during the stride and the distance traversed by the foot as a function of time during the stride, respectively;

means for computing an acceleration error by equalizing the acceleration error with the speed at the end of the movement of the foot divided by the time lapsed between the end and the beginning of the stride;

means for computing a distance error by integrating the acceleration error over said time lapsed between the end and the beginning of the movement of the foot;

means for computing a corrected distance by subtracting the distance error from the distance traversed during the stride.

16. An athletic shoe as claimed in claim 11, wherein the signal processing means further comprises:

means for computing a speed of the exerciser by dividing the corrected distance by a time lapsed between successive strides.

17. A method of measuring performance during an exercise activity comprising the steps of:

measuring, by means of an acceleration sensor, acceleration in a moving direction of a foot of an exerciser and providing an acceleration signal in response to said acceleration;

processing the acceleration signal, the processing comprising the steps of;

analyzing a waveform of the acceleration signal and determining from the analyzing a beginning and an end of movement of the foot during a stride made by the foot of the exerciser;

single integrating and double integrating the acceleration signal between said beginning and said end of movement in order to compute the speed of the foot as a function of time during the stride and the distance traversed by the foot as a function of time during the stride, respectively;

computing an acceleration error by equalizing the acceleration error with the speed at the end of the movement of the foot divided by the time lapsed between the end and the beginning of the movement of the foot;

computing a distance error by double integrating the acceleration error over said time lapsed between the end and the beginning of the stride;

computing a corrected distance by subtracting the distance error from the distance traversed during the stride.

18. A method as claimed in claim 17, wherein the signal processing further comprises the step of:

computing a speed of the exerciser by dividing the corrected distance by a time lapsed between successive strides.

19. A method as claimed in claim 17, wherein the moving direction is selected substantially parallel to a line between the heel and the toes of the foot of the exerciser.

20. A system as claimed in claim 17, wherein the moving direction is selected substantially perpendicular to a line between the heel and the toes of the foot of the exerciser.