Footprint location system
First Claim
1. A footprint location system for determining a user'"'"'s position by user'"'"'s footprints, which include first footprints and second footprints, comprising:
- a first shoe comprising a first measuring unit and generating first footprints when both shoes touch the ground at the same time;
a second shoe comprising a second measuring unit and generating second footprints when both shoes touch the ground at the same time;
a vector measuring unit measuring displacement vectors between the first footprints and the second footprints based on coordinates provided by the first measuring unit and the second measuring unit; and
a location calculation unit calculating the user'"'"'s position by summing up all displacement vectors with reference to a starting point,wherein the first measuring unit has at least two ultrasonic infrared receivers and an orientation sensor, which provides a rotation angle .theta. in the global coordinate system;
the second measuring unit has at least one ultrasonic infrared transmitter; and
the first measuring unit, the second measuring unit and the orientation sensor measure coordinates and the rotation angle .theta., to calculate a displacement vector in a global coordinate system.
1 Assignment
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Accused Products
Abstract
A footprint location system installed on footwear is disclosed. A user simply has to wear the shoes to track his/her locations without any setup or calibration efforts. The footprint location system measures and tracks the displacement vectors along a trail of footprints. The position of a user can be determined by summing up the current and all previous displacement vectors. In addition to being infrastructure-free, the footprint location method does not have problems found in existing indoor location systems, such as obstacles, multi-path effects, signal noises, signal interferences, and dead spots.
13 Citations
14 Claims
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1. A footprint location system for determining a user'"'"'s position by user'"'"'s footprints, which include first footprints and second footprints, comprising:
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a first shoe comprising a first measuring unit and generating first footprints when both shoes touch the ground at the same time; a second shoe comprising a second measuring unit and generating second footprints when both shoes touch the ground at the same time; a vector measuring unit measuring displacement vectors between the first footprints and the second footprints based on coordinates provided by the first measuring unit and the second measuring unit; and a location calculation unit calculating the user'"'"'s position by summing up all displacement vectors with reference to a starting point, wherein the first measuring unit has at least two ultrasonic infrared receivers and an orientation sensor, which provides a rotation angle .theta. in the global coordinate system; the second measuring unit has at least one ultrasonic infrared transmitter; and the first measuring unit, the second measuring unit and the orientation sensor measure coordinates and the rotation angle .theta., to calculate a displacement vector in a global coordinate system. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A footprint location method for determining a user'"'"'s position by user'"'"'s footprints, which include first footprints and second footprints, comprising:
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providing a first shoe comprising a first measuring unit and generating first footprints when both shoes touch the ground at the same time; providing a second shoe comprising a second measuring unit and generating second footprints when both shoes touch the ground at the same time; measuring displacement vectors between the first footprints and the second footprints based on coordinates provided by the first measuring unit and the second measuring unit; and calculating the user'"'"'s position by summing up the current and all previous displacement vectors with reference to a starting point, wherein the first measuring unit has at least two ultrasonic infrared receivers and an orientation sensors which provides a rotation angle θ
in a global coordinate system;the second measuring unit has at least one ultrasonic infrared transmitter; and the first measuring unit, the second measuring unit and the orientation sensor measure coordinates and the rotation angle θ
, to calculate a displacement vector in a global coordinate system. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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Specification