System and method for estimating the position and orientation of a mobile communications device in a beacon-based positioning system

Patent metadata

Field	Value
Publication number	US-9989624-B2
Application number	US-201615066656-A
Country	US
Kind code	B2
Filing date	Mar 10, 2016
Priority date	Aug 12, 2014
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

An example of a technique for compensating for effects of Earth's magnetic field variations on a mobile device positioning system. A mobile device utilizes a compass to obtain an absolute heading when located relative to a visible light source. The mobile device obtains a heading correction value based on an identifier of the visible light source. An orientation of a map displayed on the mobile device is rotated based on the absolute heading and the heading correction value in order to provide an indication of a location of the mobile device properly oriented on the map.

First claim

What is claimed is:

1. A mobile device, comprising:
an image sensor;
a compass;
a processor coupled to the image sensor and the compass;
a user interface element comprising a display screen;
a wireless interface configured to communicate through a network over a wireless medium;
a memory configured to store for each of a plurality of visible light sources located within an interior space for light-based positioning, a respective location of a respective visible light source and a respective heading correction value for the respective visible light source; and
software in the memory to be run by the processor, wherein running of the software by the processor configures the mobile device to implement functions, including functions to:
operate the image sensor to capture one or more images including a plurality of signals modulated within visible light, wherein:
the visible light is transmitted from the plurality of visible light sources located within the interior space for light-based positioning;
each signal is modulated within visible light transmitted by the respective visible light source located within the interior space for light-based positioning; and
each signal corresponds to a respective identity of the respective visible light source;

process the one or more images captured by the image sensor to determine, based at least in part on the plurality of signals, an estimated location of the mobile device within the interior space, the estimated location being an intermediate point between the plurality of visible light sources that is not directly underneath any of the visible light sources;
operate the compass to capture a raw heading measurement at the intermediate point;
obtain a corrected heading estimate for the intermediate point, wherein the function to obtain the corrected heading estimate further includes functions to:
for each modulated signal by the respective visible light source:
obtain the respective location of the respective visible light source; and
retrieve, based on the respective location of the respective visible light source, the respective heading correction value, wherein the function to retrieve includes functions to:
 receive, via the wireless interface, the respective heading correction value and the respective location for each of the respective visible light sources; and
 store the respective heading correction value and the respective location for each of the respective visible light sources in the memory;

determine, based on the retrieved heading correction values, an estimated heading correction value for the intermediate point, wherein the function to determine includes functions to:
weight the retrieved heading correction values of the visible light sources by an inverse of distance from the respective location of the respective visible light source to the intermediate point; and
average the inversely weighted heading correction values to produce the estimated heading correction value for the intermediate point;

determine, based on the raw measurement and the estimated heading correction value, the corrected heading estimate for the intermediate point; and

operate the user interface element to display a map of the interior space, the displayed map including a depiction of the determined estimated location of the mobile device that is based on processing the one or more images captured by the image sensor including each signal modulated within visible light transmitted by the respective visible light source located within the interior space for light-based positioning and the displayed map being rotated, based on the corrected heading estimate, to be consistent with a physical orientation of a user of the mobile device within the interior space.

2. The mobile device of claim 1 , wherein the implemented functions further include functions to:
receive, upon entry into the interior space and via the wireless interface, data representing the map of the interior space; and
store data representing the map in the memory.

3. A mobile device, comprising:
an image sensor;
a compass;
a processor coupled to the image sensor and the compass;
a user interface element comprising a display screen;
a wireless interface configured to communicate through a network over a wireless medium;
a memory configured to store for each of a plurality of visible light sources located within an interior space for light-based positioning, a respective location of a respective visible light source and a respective heading correction value for the respective visible light source; and
software in the memory to be run by the processor, wherein running of the software by the processor configures the mobile device to implement functions, including functions to:
operate the image sensor to capture one or more images including a plurality of signals modulated within visible light, wherein:
the visible light is transmitted from the plurality of visible light sources located within the interior space for light-based positioning;
each signal is modulated within visible light transmitted by the respective visible light source located within the interior space for light-based positioning; and
each signal corresponds to a respective identity of the respective visible light source;

process the one or more images captured by the image sensor to determine, based at least in part on the plurality of signals, an estimated location of the mobile device within the interior space, the estimated location being an intermediate point between the plurality of visible light sources that is not directly underneath any of the visible light sources;
operate the compass to capture a raw heading measurement at the intermediate point;
obtain a corrected heading estimate for the intermediate point, wherein the function to obtain the corrected heading estimate further includes functions to:
for each modulated signal by the respective visible light source:
obtain the respective location of the respective visible light source; and
retrieve, based on the respective location of the respective visible light source, the respective heading correction value, wherein the function to retrieve includes functions to:
 receive, via the wireless interface, the respective heading correction value and the respective location for each of the respective visible light sources; and
 store the respective heading correction value and the respective location for each of the respective visible light sources in the memory;

determine, based on the retrieved heading correction values, an estimated heading correction value for the intermediate point, wherein the function to determine includes functions to:
weight the retrieved heading correction values of the visible light sources by distance from the respective location of the respective visible light source to the intermediate point such that closer visible light sources have a heavier weighting; and
average the weighted heading correction values to produce the estimated heading correction value for the intermediate point;

determine, based on the raw measurement and the estimated heading correction value, the corrected heading estimate for the intermediate point; and

operate the user interface element to display a map of the interior space, the displayed map including a depiction of the determined estimated location of the mobile device that is based on processing the one or more images captured by the image sensor including each signal modulated within visible light transmitted by the respective visible light source located within the interior space for light-based positioning and the displayed map being rotated, based on the corrected heading estimate, to be consistent with a physical orientation of a user of the mobile device within the interior space.

4. The mobil

Assignees

• Abl Ip Holding Llc

Inventors

• Ryan Daniel
• Green Kelby Edward
• Malandrakis Emanuel Paul
• Klitenik Konstantin

Classifications

• G01S2205/02

  Indoor · CPC title

• H04B10/116

  Visible light communication · CPC title

• H04W4/026

  using orientation information, e.g. compass · CPC title

• H04B10/1141

  One-way transmission · CPC title

• H04W4/029

  Location-based management or tracking services · CPC title