The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 2004
Filed:
Jul. 17, 2002
Seth J. Teller, Cambridge, MA (US);
Nissanka B. Priyantha, Somerville, MA (US);
Allen K. L. Miu, Cambridge, MA (US);
Hari Balakrishnan, Winchester, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
The position and orientation of a mobile unit is determined from ultrasonic waves received from beacons of known location. Orientation is determined from a phase difference of the sensed ultrasonic wave at plural receivers on the mobile unit. Signals from multiple beacons may be processed to solve for x, y and z position and for speed of sound. The receivers are spaced at greater than a half wavelength of the ultrasonic wave and signals from plural receivers are processed to remove multiple wavelength phase ambiguity. Two non-collinear sets of collinear receivers allow ambiguity resulting from symmetry of the receivers to be broken.