Systems and methods for determining a location of an electronic device using bilateration

• US 10,743,141 B2
• Filed: 06/05/2018
• Issued: 08/11/2020
• Est. Priority Date: 06/05/2018
• Status: Active Grant

• Current Assignee: Kenmar Corporation
• Original Assignee: Kenmar Corporation
• Inventors: Fairbanks, Neal, Nader, Frederick R., Rusk, Collin M.
• Primary Examiner(s): Shaawat, Mussa A
• Application Number:
  US16/000,530
• Publication Number:
  US 20190373415A1
• Time in Patent Office: 798 Days
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 4/40 for vehicles, e.g. vehicle-to-pedestrians [V2P]
• CPC Class Codes: H04W 4/46 for vehicle-to-vehicle communication [V2V]
• 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

Abstract

A method of determining a location, using bilateration, of an electronic device that is spaced from transmitting devices is disclosed. The electronic device receives first and second signals of the same or different signal type from first and second transmitting devices, respectively, with a tunable antenna. The electronic device determines a signal quality of each signal based on: 1) a received signal strength indicator (RSSI) or a received signal power and a received signal gain, and 2) signal propagation characteristics specific for the transmitting devices. The signals with the two highest signal qualities are used for location determination and the antenna is tuned for each of the signal types received. The distance from the transmitting devices can be determined based on one or more of: a received signal power and signal gain for both signals, a transmitted power and signal gain of both signals, or location information associated with the transmitting devices. The method determines two points of intersection based on the distance, determine which intersection is reliable, generates new coordinates for the electronic device.

Claims

1. A method for determining a location of an electronic device using bilateration, the electronic device having a tunable antenna connected thereto, said method comprising the steps of:

obtaining a first location comprising coordinates of the electronic device;

receiving a plurality of signals having different signal types emitted from transmitting devices within a vicinity of the electronic device with the antenna;

determining a signal quality for a first signal transmitted from a first transmitting device having a first signal type based on;

a received signal strength indicator or a received signal power and a received signal gain for the first signal, and

signal propagation characteristics for the first transmitting device;

designating the first signal having the highest signal quality for location determination;

tuning the antenna for the first signal type and receiving the first signal with the tuned antenna;

determining a distance from the first transmitting device based on one or more of;

a received signal power and a received signal gain for the first signal as received by the tuned antenna,

a transmitted power and a transmitted signal gain of the first signal for the first transmitting device, or

location information associated with the first transmitting device identified by at least one of a media access control (MAC) address and an internet protocol (IP) address;

determining a signal quality for a second signal from a second transmitting device having a second signal type based on;

a received signal strength indicator or a received signal power and a received signal gain for the second signal, and

signal propagation characteristics for the second transmitting device;

designating the second signal having the next highest signal quality for location determination;

tuning the antenna for the second signal type and receiving the second signal with the tuned antenna;

determining a distance from the second transmitting device based on one or more of;

a received signal power and a received signal gain for the second signal as received by the tuned antenna,

a transmitted power and a transmitted signal gain of the second signal for the second transmitting device, or

location information associated with the second transmitting device identified by at least one of a media access control (MAC) address and an internet protocol (IP) address; and

generating new coordinates for the electronic device based upon the distances from the first and second transmitting devices and recording the new coordinates as a current location of the electronic device.

2. The method as set forth in claim 1 wherein the step of generating new coordinates further comprises the steps of developing first and second transmission circles based upon the distances from the first and second transmitting devices and the transmitting device information;

determining points of intersection where the first and second transmission circles intersect;

determining which of the two points of intersection is reliable; and

generating new coordinates for the electronic device based upon the reliable intersection.

3. The method as set forth in claim 1 further comprising the step of retrieving a current direction of the electronic device and comparing the current direction to an initial direction and restarting said method in response to the current direction and the initial direction being the same.

4. The method as set forth in claim 1 further comprising the step of retrieving a current direction of the electronic device and comparing the current direction to an initial direction and determining whether the current location is within specified boundaries.

5. The method as set forth in claim 4 further comprising the step of restarting said method in response to the current direction being outside of the specified boundaries.

6. The method as set forth in claim 1 further comprising the step of calculating an estimated location based on the first location, velocity and direction of the electronic device, and establishing an tolerance associated with the estimated location.

7. The method as set forth in claim 6 further comprising the step of comparing the estimated location to the current location to determine if the current location is within the tolerance and storing locations within the tolerance.

8. The method as set forth in claim 1 further comprising the step of re-tuning the antenna to maintain the first and second signal while the electronic device is in motion.

9. The method as set forth in claim 1 wherein the step of generating the new coordinates occurs at least 10 times per second.

10. The method as set forth in claim 9 further comprising the step of continuing to monitor the first and second signals for a predetermined time while the electronic device is in motion.

11. The method as set forth in claim 10 further comprising the step of initiating a new search for a new plurality of signals and re-measuring signal quality after expiration of the predetermined time and selecting the two signals with the highest signal quality.

12. The method as set forth in claim 1 further comprising the step of determining signal quality for a third signal from a third transmitting device having a third signal type based on a received signal strength indicator or a received signal power and a received signal gain for the third signal, and signal propagation characteristics for the third transmitting device.

13. The method as set forth in claim 12 further comprising the step of dropping the signal with the lowest signal quality and designating the third signal with the higher signal quality for location determination.

14. The method as set forth in claim 13 further comprising the steps of tuning the antenna for the third signal type and receiving the third signal with the tuned antenna;

determining a distance from the third transmitting device based on one or more of;

a received signal power and a received signal gain for the third signal as received by the tuned antenna,

a transmitted power and a transmitted signal gain of the third signal for the third transmitting device, or

location information associated with the first transmitting device identified by at least one of a media access control (MAC) address and an internet protocol (IP) address; and

generating new coordinates for the electronic device based upon the distances from the first and third transmitting devices and recording the new coordinates as a current location of the electronic device.

15. The method as set forth in claim 14 wherein the step of generating new coordinates further comprises the steps of developing a third transmission circle based upon the distance from the third transmitting device and the transmitting device information;

determining points of intersection between the third transmission circle and the remaining one of the first and second transmission circles;

determining which of the two points of intersection is reliable; and

generating new coordinates for the electronic device based upon the reliable intersection.

16. The method as set forth in claim 1 wherein the transmitting device information includes one or more of device manufacturer and device type.

17. The method as set forth in claim 2 further comprising the step of obtaining velocity and direction inputs by the electronic device associated with movement of the electronic device.

18. The method as set forth in claim 17 wherein the step of determining which of the two points of intersection are reliable is further defined as comparing the points of intersection with the initial location relative to the velocity and direction inputs and determine which of the points is feasible.

19. The method as set forth in claim 1 further comprising the steps of outputting the first location and current location to a mapping program for display to a user.

20. The method as set forth in claim 1 wherein the step of determining the distance is determined according to the following formula:

d=10{circumflex over ( 

)}[log₁₀(λ

)−

(P_r−

P_t−

G_t−

G_r)/20−

log₁₀(4π

)];

where d is distance in meters;

λ

is the wavelength of the signal in meters, P_r is the power of the received signal in decibels, P_t is the power of the transmitted signal in decibels, G_t is the gain of the transmitted signal in decibels, and G_r is the gain of the received signal in decibels.

21. The method as set forth in claim 1 wherein the step of determining the distance is determined according to the following formula:

d=10{circumflex over ( 

)}((27.55−

(20.0*10{circumflex over ( 

)}v)+|RSSI|)/20)+45;

where d is distance in meters;

v is the frequency of the signal in MHz, and RSSI is received signal strength by the electronic device.

22. The method as set forth in claim 1 further comprising the step of instructing the transmitting devices within the vicinity of the electronic device to transmit a signal.

23. The method as set forth in claim 1 further comprising the step of detecting movement of the electronic device to a subsequent location.

24. The method as set forth in claim 1 wherein the velocity and direction are provided by at least one or more of an accelerometer or a gyroscope.