Proximity detection method

• US 9,730,049 B1
• Filed: 12/20/2016
• Issued: 08/08/2017
• Est. Priority Date: 09/27/2016
• Status: Active Grant

• Current Assignee: Top Victory Investments Limited (TPV Technology Co., Ltd. (f/k/a Nanjing Huadong Electronics Information & Technology))
• Original Assignee: TP Vision Holding BV (TPV Technology Co., Ltd. (f/k/a Nanjing Huadong Electronics Information & Technology))
• Inventors: Malik, Salman
• Primary Examiner(s): Gonzales, April G
• Application Number:
  US15/384,684
• Time in Patent Office: 231 Days
• Field of Search: 455 412
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 2205/02 Indoor
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• 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 8/005 Discovery of network devices, e.g. terminals

Abstract

A proximity detection method implemented by a detecting device includes: (a) receiving detection signals from multiple signal providing devices that include a target device and at least one reference device; (b) for each of the detection signals, collecting signal strength values of the detection signal at a variety of time points; (c) filtering out a portion of the signal strength values based on a predetermined criterion; (d) for each of the detection signals, calculating a signal level according to a sum of the signal strength values; and (e) calculating proximity of the target device in relation to the at least one reference device according to the signal level.

Claims

1. A proximity detection method comprising steps of:

(a) receiving, by a detecting device, a plurality of detection signals respectively provided by a plurality of signal providing devices that include a target signal providing device and at least one reference signal providing device, wherein the detecting device and the signal providing devices are in a same room;

(b) for each of the detection signals, collecting, by the detecting device, a plurality of signal strength values of the detection signal at a variety of time points;

(c) for each of the detection signals, filtering out, by the detecting device, a portion of the signal strength values based on a predetermined criterion;

(d) for each of the detection signals, calculating, by the detecting device, a signal level according to a sum of the signal strength values that remain after step (c); and

(e) calculating, by the detecting device, proximity of the target signal providing device in relation to the at least one reference signal providing device according to the signal level calculated in step (d).

2. The proximity detection method of claim 1, wherein step (c) includes:

for each of the detection signals, filtering out, by the detecting device, a predetermined percentage of smallest signal strength values.

3. The proximity detection method of claim 1, further comprising:

before step (d), for each of the detection signals, performing, by the detecting device, noise reduction filtering on the signal strength values that remain after step (c).

4. The proximity detection method of claim 1, wherein step (d) includes sub-steps of:

(d-1) offsetting each of the signal strength values that remain after step (c); and

(d-2) for each of the detection signals, summing up the signal strength values that are offset in sub-step (d-1) and that correspond to the detection signal, to obtain the corresponding signal level.

5. The proximity detection method of claim 4, wherein each of the signal strength values that remain after step (c) is offset according to a minimum among all of the signal strength values remain after step (c).

6. The proximity detection method of claim 1, wherein the at least one reference signal providing device includes a plurality of reference signal providing devices, and the proximity calculated in step (e) includes proximity of the target signal providing device with respect to each of the reference signal providing devices, which is calculated according to the signal level of each of the detection signals.

7. The proximity detection method of claim 1, wherein the proximity calculated in step (e) includes proximity of the target signal providing device with respect to one of the at least one reference signal providing device, which is calculated according to the signal level of one of the detection signals that is provided by the target signal providing device, and the signal level of one of the detection signals at is provided by the one of the at least one reference signal providing device.

8. The proximity detection method of claim 1, wherein, in step (d), for each of the detection signals, the corresponding signal level is calculated according to γ

_i=Σ

(S_i−

min(S_k), where γ

_i represents the signal level corresponding to an i^th one of the detection signals, S_i represents one of the signal strength values of the i^th one of the detection signals that remain after step (c), S_k represents the signal strength values of all of the detection signals that remain after step (c).

9. The proximity detection method of claim 8, wherein the proximity calculated in step (e) includes proximity of the target signal providing device with respect to each of the at least one reference signal providing device, which is calculated according to

10. The proximity detection method of claim 8, wherein the proximity calculated in step (e) includes proximity of the target signal providing device with respect to one of the at least one reference signal providing device, which is calculated according to

11. The proximity detection method of claim 1, wherein step (b) includes sub-steps of:

(b-1) for each of the detection signals, recording, by the detecting device, the signal strength values respectively at the variety of time points within a predetermined length of time; and

(b-2) for each of the detection signals, when a number of the signal strength values recorded in sub-step (b-1) is less than a predetermined minimum number, the detecting device randomly duplicating a part of the signal strength values recorded in sub-step (b-1), and placing the signal strength values thus duplicated among the signal strength values recorded in sub-step (b-1), such that a total number of the signal strength values is not less than the predetermined minimum number.

12. The proximity detection method of claim 1, further comprising steps of:

(f) receiving, by a calibration device, a calibration detection signal provided by a calibration signal providing device, wherein the calibration device and the calibration signal providing device are disposed apart from each other by a calibration distance in a same room, and the calibration distance is selected from a plurality of predetermined distances;

(g) for each of the predetermined distances serving as the calibration distance, collecting, by the calibration device, a plurality of calibration signal strength values of the calibration detection signal at a variety of time points;

(h) for each of the predetermined distances serving as the calibration distance, filtering out, the calibration device, a portion of the calibration signal strength values based on the predetermined criterion;

(i) acquiring a representative calibration signal strength value according to the calibration signal strength values that remain after step (h) and that correspond to one of the predetermined distances;

(j) acquiring a path loss exponent based on the calibration signal strength values that remain after step (h); and

(k) calculating, by the detecting device, a distance between the detecting device and the target signal providing device according to S_i=−

10α

log₁₀(d_i)+S₀(d₀), where S_i represents a representative signal strength value associated with the signal strength values of one of the detection signals that is provided by the target signal providing device, α

is the path loss exponent, d_i represents the distance between the detecting device and the target signal providing device, and S₀(d₀) is the representative calibration signal strength value.

13. The proximity detection method of claim 12, wherein step (j) includes:

performing curve fitting on the calibration signal strength values that remain after step (h) with respect to each of the predetermined distances serving as the calibration distance to obtain a linear fitting curve; and

obtaining the path loss exponent based on the linear fitting curve.

14. The proximity detection method of claim 12, wherein, in step (d), for each of the detection signals, the corresponding signal level is calculated according to γ

_i=Σ

(S_i−

min(S_k)), where γ

_i represents the signal level corresponding to an i^th one of the detection signals, S_i represents one of the signal strength values of the i^th one of the detection signals that remain after step (c), S_k represents the signal strength values of all of the detection signals that remain after step (c); and

the proximity calculated in step (e) includes proximity of the target signal providing device with respect to one of the at least one reference signal providing device, which is calculated according to

15. The proximity detection method of claim 14, wherein the j^th one of the at least one reference signal providing device is a nearest one of the reference signal providing devices with respect to the detecting device.

16. The proximity detection method of claim 1, wherein step (b) includes sub-steps of:

for each of the detection signals, recording, by the detecting device, a plurality of the signal strength values of the detection signal at a variety of time points; and

correcting, by the detecting device, each of the signal strength values, according to