Location tracking using one or more beacons

Abstract

A location tracking system using encoded light beams emitted from a stationary beacon and a receiver mounted onto an object within a three-dimensional (3D) space within the field of view of the stationary beacon. The receiver receives and processes the encoded light beams from two or more stationary beacons. The receiver is configured to decode information from the received light beams and to calculate the position of the object within the 3D space over a span of several meters, with resolution in the range of a few mm or cm. The receiver location is calculated as a single point at the intersection of three light beam or angular planes. A typical configuration of one-dimensional array beacon consists of a plurality of light sources mounted on a cylindrical curved surface of a particular radius. A vertical apodizing slit placed at the center of the circular curve limits the horizontal angular profile of encoded light beams as can be seen or received by the receiver in the far field to roughly 1-5 encoded light beams at a time. Each light source emits a light beam encoded with a unique code that allows the receiver to identify the light source that emitted the light beam. Certain signal processing techniques allow the receiver to detect, process, and decode information from the light beam including light intensity profile of each received light beam. This information is used by the receiver to infer a point where the receiver is located at the intersection of three angular planes where it is located relative to the beacons, and thus the location of the object is fully determined in 3D space.