Use of RF-based fingerprinting for indoor positioning by mobile technology platforms

• US 10,244,362 B2
• Filed: 09/29/2017
• Issued: 03/26/2019
• Est. Priority Date: 10/08/2013
• Status: Active Grant

• Current Assignee: Gozio, Inc.
• Original Assignee: Gozio, Inc.
• Inventors: Titus, Joshua, Lee, Kevin Garth
• Primary Examiner(s): Washington, Erika A
• Application Number:
  US15/719,552
• Publication Number:
  US 20180035263A1
• Time in Patent Office: 543 Days
• Field of Search: None
• CPC Class Codes: G01S 2205/02 Indoor
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/02585 at least one of the measurements being a non-radio measurement
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 4/30 Services specially adapted for particular environments, situations or purposes
• CPC Class Codes: H04W 4/33 for indoor environments, e.g. buildings
• CPC Class Codes: H04W 4/35 for the management of goods or merchandise
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method is provided for determining the position of a mobile technology platform within a structure, wherein the mobile technology platform is equipped with a gyroscope, a magnetometer and at least one accelerometer. The method includes deploying a set of RF (radio frequency) beacons within the structure, wherein each RF beacon emits an RF signal; recording, at each of a set of sampling locations within the structure, the RF signature created by the RF signals received at the location, wherein said recording is performed by a digital image correlation (DIC) platform which traverses the structure, and which correlates the recorded RF signatures to a floor map of the structure; forming an RF fingerprint of the structure from the recorded RF signatures; and using the RF fingerprint, in conjunction with readings from the gyroscope, magnetometer and at least one accelerometer to determine the location of the device within the structure.

Claims

1. A method for determining the position of a mobile technology platform within a structure, wherein the mobile technology platform is equipped with a gyroscope, a magnetometer and at least one accelerometer, the method comprising:

deploying a set of RF (radio frequency) beacons within the structure, wherein each RF beacon emits an RF signal, and wherein each RF beacon emits radio transmissions within the band of 2400 to 2800 MHz;

recording, at each of a set of sampling locations within the structure, the RF signature created by the RF signals received at the location, wherein said recording is performed by a digital image correlation (DIC) platform which traverses the structure, and which correlates the recorded RF signatures to a floor map of the structure;

forming an RF fingerprint of the structure from the recorded RF signatures; and

using the RF fingerprint, in conjunction with readings from the gyroscope, magnetometer and at least one accelerometer to determine the location of the mobile technology platform within the structure.

2. The method of claim 1, wherein using the RF fingerprint, in conjunction with readings from the gyroscope, magnetometer and at least one accelerometer to determine the location of the mobile technology platform within the structure, includes:

detecting the RF signatures received at a location; and

comparing the detected RF signatures to the RF fingerprint to determine the most likely location of the device.

3. The method of claim 2, wherein the device is equipped with an RF receiver, and wherein detecting the RF signatures received at a location includes detecting the RF signatures with the receiver.

4. The method of claim 2, wherein comparing the detected RF signatures to the RF fingerprint involves comparing the detected RF signatures to a copy of the RF fingerprint stored in a memory medium associated with the device.

5. The method of claim 1, wherein the mobile technology platform is equipped with a plurality of accelerometers, and wherein the RF fingerprint is used in conjunction with readings from the gyroscope, magnetometer and the plurality of accelerometers to determine the location of the mobile technology platform within the structure.

6. The method of claim 1, wherein each member of the set of RF beacons emits a unique RF signal.

7. The method of claim 1, wherein each member of the set of RF beacons encodes a unique set of data in the RF signal it transmits.

8. The method of claim 1, wherein each of the RF beacons is a BTLE (Bluetooth™

low energy) device, and wherein each of the RF beacons has a transmission range in excess of 100 m.

9. The method of claim 1, wherein the mobile technology platform uses at least one Bayes filter to calculate the probabilities of multiple beliefs to allow the mobile technology platform to infer its position and orientation at a site.

10. The method of claim 9, wherein the at least one Bayes filter is a Kalman filter.

11. The method of claim 9, wherein the at least one Bayes filter utilizes a true state, and wherein the true state utilized in the at least one Bayes filter is the actual location of the mobile technology platform, and is assumed to be an unobserved Markov process in calculating the probabilities of multiple beliefs.

12. The method of claim 9, wherein the mobile technology platform uses sequential Monte Carlo (SMC) methods to calculate the probabilities of multiple beliefs to allow the mobile technology platform to infer its position and orientation at a site, and wherein the SMC methods implement Bayesian recursion equations by using an ensemble based approach in which samples from a distribution are represented by a set of particles, with each particle having a weight assigned to it that represents the probability of that particle being sampled from a probability density function based on the calculated probabilities.

13. The method of claim 12, wherein a particle filter is used to estimate the posterior density of the state variables, given the observation variables, and wherein the particle filter is designed for a hidden Markov Model in which a system on which the model is based consists of hidden and observable variables.

14. The method of claim 13, wherein the mobile technology platform uses a Bayesian filter to infer its position and orientation at a site, and wherein the Bayesian filter outputs both a putative location for a device, along with a probability associated with that location which represents the degree of uncertainty associated with the putative location.

15. The method of claim 1, wherein the structure is a hospital.

16. The method of claim 1, wherein the mobile technology platform is selected from the group consisting of smartphones, smartwatches, smart glasses, tablet PCs, notebook computers, and wearable PCs.

17. The method of claim 1, wherein the mobile technology platform and the DIC platform are separate devices.

18. The method of claim 17, wherein the mobile technology platform is a smartphone.

19. A method for determining the position of a mobile technology platform within a structure, wherein the mobile technology platform is equipped with a gyroscope, a magnetometer and at least one accelerometer, the method comprising:

detecting, at a position within the structure, the RF signature created by the RF signals received from a plurality of RF beacons disposed within the structure, wherein each of the plurality of RF beacons emits radio transmissions within the band of 2400 to 2800 MHz; and

in conjunction with readings from the gyroscope, magnetometer and at least one accelerometer, comparing the detected RF signature to an RF fingerprint to determine the most likely location of the mobile technology platform within the structure;

wherein the RF fingerprint is created by sampling the RF signatures with a digital image correlation (DIC) platform at a plurality of locations within the structure.

20. The method of claim 19, wherein using the RF fingerprint to determine the location of the device within the structure includes:

detecting the RF signatures received at a location; and

comparing the detected RF signatures to the RF fingerprint to determine the most likely location of the device.

21. The method of claim 20, wherein the device is equipped with an RF receiver, and wherein detecting the RF signatures received at a location includes detecting the RF signatures with the receiver.

22. The method of claim 20, wherein comparing the detected RF signatures to the RF fingerprint involves comparing the detected RF signatures to a copy of the RF fingerprint stored in a memory medium associated with the device.

23. The method of claim 19, wherein each member of the set of RF beacons emits a unique RF signal.

24. The method of claim 19, wherein each member of the set of RF beacons encodes a unique set of data in the RF signal it transmits.

25. A system for determining the location of a device within a structure, the system comprising:

a plurality of RF beacons disposed within the structure, each of which emits an RF signal, wherein each of the plurality of RF beacons emits radio transmissions within the band of 2400 to 2800 MHz; and

a mobile technology platform equipped with a gyroscope, a magnetometer, at least one accelerometer, and a receiver which detects RF signatures formed by the signals which are emitted by the RF beacons and which are detected at a location, and which is further equipped with a non-transient memory medium containing (a) an RF fingerprint created by sampling the RF signatures at a plurality of locations within the structure with a digital image correlation (DIC) platform, and (b) suitable programming instructions which, when executed by one or more processors, determines the most likely location of the mobile technology platform within the structure by comparing a detected RF signature detected by the receiver to the RF fingerprint, in conjunction with readings from the gyroscope, magnetometer and at least one accelerometer.