Bluetooth crowd-sourced triangualtion

Patent metadata

Field	Value
Publication number	US-10094907-B2
Application number	US-201414460886-A
Country	US
Kind code	B2
Filing date	Aug 15, 2014
Priority date	Aug 15, 2014
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

Beacon devices transmit beacon messages to alert an application on a mobile user device of the Beacon device's proximity. A Received Signal Strength Indication (RSSI) field may indicate the power level at which the beacon message was received at the mobile device. Where the transmission power of the beacon device is standardized, the application can infer the distance between the mobile user device the beacon device based upon the RSSI field. By considering successive RSSI values over time while the mobile device is in motion, in conjunction with GPS information for the mobile device, the location of the beacon device relative to the mobile device may be inferred. Multiple mobile devices may be used together to infer the beacon device's position.

First claim

What is claimed is:

1. A method for determining a position of a beacon device, the method comprising:
receiving, at a computer, a first sensing event from a mobile computing device at a first time, the first sensing event including a beacon device identifier associated with a beacon device and a first timestamp associated with a transmission of a first beacon message and a receipt of the first beacon message at the mobile computing device, a first location of the mobile computing device, and a first power level associated with the receipt of the first beacon message at the mobile computing device, wherein the first sensing event has occurred within a first beacon message interval,
storing, at the computer, the first sensing event;
receiving, at the computer, a second sensing event from the mobile computing device at a second time, the second sensing event including the beacon device identifier associated with the beacon device and a second timestamp associated with a transmission of a second beacon message and a receipt of the second beacon message at the mobile computing device, a second location of the mobile computing device, and a second power level associated with the receipt of the second beacon message at the mobile computing device, wherein the second sensing event has occurred within the first beacon message interval;
storing, at the computer, the second sensing event;
receiving, at the computer, a third sensing event from the mobile computing device at a third time, the third sensing event including the beacon device identifier associated with the beacon device and a third timestamp associated with a transmission of a third beacon message and a receipt of the third beacon message at the mobile computing device, a third location of the mobile computing device, and a third power level associated with the receipt of the third beacon message at the mobile computing device, wherein the third sensing event has occurred within the first beacon message interval;
determining, at the computer, a first distance between the mobile computing device and the beacon device corresponding to the first time based on the stored first sensing event comprising the first timestamp and the first power level;
determining, at the computer, a second distance between the mobile computing device and the beacon device corresponding to the second time based on the stored second sensing event comprising the second timestamp and the second power level;
determining, at the computer, a third distance between the mobile computing device and the beacon device corresponding to the third time based on the third sensing event comprising the third timestamp and the third power level;
verifying, at the computer, that the beacon device is stationary based at least on the first, second, and third timestamps, the first, second, and third locations, and the first, second, and third power levels;
determining, at the computer, an intersection of a plurality of circles about the mobile computing device, the plurality of circles having radii corresponding to the first, second, and third distances; and
determining, at the computer, a position of the beacon device based upon the intersection.

2. The method of claim 1 , further comprising:
identifying a table associated with the beacon device identifier, the table indicating a correspondence between power intensity and distance; and
comparing the first, second, and third power levels with the table to determine a distance value.

3. The method of claim 1 , the method further comprising discarding at least one of the first, second, and third sensing events failing a determination that the at least some of the first, second, and third sensing events fall outside a same beacon message interval.

4. The method of claim 1 , the method further comprising determining that the first, second, and third sensing events do not reflect the receipt of a same beacon message based on a beacon message interval.

5. The method of claim 4 , the method further comprising determining at least one of the first, second, and third distances based upon an interpolation of data from several sensing events.

6. The method of claim 1 , further comprising verifying the first, second, and third distances by normalizing the first, second, and third distances to a common elevation.

7. A non-transitory computer-readable medium storing instructions configured to cause at least one processor to perform a method, the instructions comprising:
instructions for receiving, at a computer, a first sensing event from a mobile computing device at a first time, the first sensing event including a beacon device identifier associated with a beacon device and a first timestamp associated with a transmission of a first beacon message and a receipt of the first beacon message at the mobile computing device, a first location of the mobile computing device, and a first power level associated with the receipt of the first beacon message at the mobile computing device, wherein the first sensing event has occurred within a first beacon message interval;
instructions for storing, at the computer, the first sensing event;
instructions for receiving, at the computer, a second sensing event from the mobile computing device at a second time, the second sensing event including the beacon device identifier associated with the beacon device and a second timestamp associated with a transmission of a second beacon message and a receipt of the second beacon message at the mobile computing device, a second location of the mobile computing device, and a second power level associated with the receipt of the second beacon message at the mobile computing device, wherein the second sensing event has occurred within the first beacon message interval;
instructions for storing, at the computer, the second sensing event;
instructions for receiving, at the computer, a third sensing event from the mobile computing device at a third time, the third sensing event including the beacon device identifier associated with the beacon device and a third timestamp associated with a transmission of a third beacon message and a receipt of the third beacon message at the mobile computing device, a third location of the mobile computing device, and a third power level associated with the receipt of the third beacon message at the mobile computing device, wherein the third sensing event has occurred within a first beacon message interval;
instructions for determining, at the computer, a first distance between the mobile computing device and the beacon device corresponding to the first time based on the stored first sensing event comprising the first timestamp and the first power level;
instructions for determining, at the computer, a second distance between the mobile computing device and the beacon device corresponding to the second time based on the stored second sensing event comprising the second timestamp and the second power level;
instructions for determining, at the computer, a third distance between the mobile computing device and the beacon device corresponding to the third time based on the third sensing event comprising the third timestamp and the third power level;
instructions for verifying, at the computer, that the beacon device is stationary based at least on the first, second, and third timestamps, the first, second, and third locations, and the first, second, and third power levels;
instructions for determining, at the computer, an intersection of a plurality of circles about the mobile computing device, the plurality of circles having radii corresponding to the first, second and third distances; and
instructions for determining, at the computer, a position of the beacon device based upon the intersection.

8. T

Assignees

• Facebook Inc

Inventors

• Niewczas Mateusz Marek
• Modi Manish

Classifications

• G01S5/14 Primary

  Determining absolute distances from a plurality of spaced points of known location · CPC title