SYSTEM AND METHOD OF OCCUPANCY ESTIMATION UTILIZING TRANSMITTED SIGNALS

• US 20160294492A1
• Filed: 03/31/2016
• Published: 10/06/2016
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: MOSTOFI, Yasamin, MURALIDHARAN, Arjun, DEPATLA, Saandeep
• Granted Patent: US 9,866,337 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

A method estimating number of occupants in a region includes receiving at one or more receiving unit a signal or signals transmitted from one or more transmitting units, wherein the transmitting units are not associated with the one or more occupants located in the region. In addition, the method includes measuring one or more attributes of the received signal for a duration of time and calculating an occupancy estimate based, at least in part, on the measured attribute of the received signal.

Claims

1. A method of counting occupants in a region, the method comprising:

receiving at one or more receiving units a signal transmitted from one or more transmitting units, wherein the transmitting units are not associated with the one or more occupants located in the region;

measuring one or more attributes of the received signal for a duration of time; and

estimating an occupancy in the region based, at least in part, on the measured attribute of the received signal.

2. The method of claim 1, wherein the signal is a WiFi signal or a radio frequency (RF) signal.

3. The method of claim 1, wherein the one or more attribute of the received signal includes at least one of received signal strength, received signal strength indicator (RSSI), signal-to-noise ratio (SNR), received channel power indicator (RCN), or received signal phase.

4. The method of claim 1, further including:

generating a theoretical model that describes a relationship between signal attributes or functions of signal attributes of a received signal and various numbers of possible occupants; and

comparing the measured attributes or functions of measured attributes of the received signal to the theoretical model, wherein occupancy is estimated based on a best fit between the measured attributes and the theoretical model.

5. The method of claim 4, wherein the theoretical model utilizes a statistical or probabilistic function, a probability density function or probability mass function of the signal attributes as they relate to various numbers of occupants, and wherein the measured signal attribute is expressed statistically, probabilistically, or as a probability density function or a probability mass function of the measured signal attribute.

6. The method of claim 4, wherein the generating the theoretical model includes generating a model that is based, in part, on line-of-sight (LOS) blocking or crossing of the received signal.

7. The method of claim 4, wherein generating the theoretical model includes generating a model that is based, in part, on multi-path (MP) scattering/fading of the received signal.

8. The method of claim 4, wherein generating the theoretical model includes generating a model that is based, in part, on both line-of-sight (LOS) blocking of the received signal and multi-path (MP) scattering/fading of the received signal.

9. The method of claim 4, wherein the theoretical models are generated, in part, based on one or more measured signal attributes measured with a known number of occupants located in the monitored region.

10. The method of claim 4, wherein the theoretical model are generated, in part, based on simulations of the measured signal attributes measured with a known number of occupants located in the monitored region.

11. The method of claim 4, wherein the theoretical model further includes some modeling of motion behaviors of occupants within the monitored region.

12. An occupant estimation system comprising:

at least one transmitting unit that transmits a signal;

at least one receiving unit that includes an antenna for receiving the signal;

at least one signal measurement unit that measures one or more attributes associated with the received signal; and

a processor that implements an occupancy estimation unit, wherein the occupancy estimation unit estimates number of occupants in a region based on the one or more measured attributes of the received signal.

13. The system of claim 12, wherein transmitting unit and the receiving unit communicate via at least one of WiFi or radio frequency (RF) signals.

14. The system of claim 12, wherein the signal measurement unit measures at least one of received signal strength, received signal strength indicator (RSSI), signal-to-noise ratio (SNR), received channel power indicator (RCPI), or received signal phase.

15. The system of claim 12, further including a memory unit associated with the signal measurement unit, wherein the memory unit stores theoretical models generated to describe a relationship between signal attributes or functions of signal attributes of a received signal and various numbers of possible occupants, wherein the occupancy estimation unit compares the measured attributes or functions of the measured attributes of the received signal to the theoretical model, wherein occupancy is estimated based on a best fit between the measured attributes or functions of attributes and the theoretical model.

16. The system of claim 15, wherein the theoretical model utilizes a statistical or probabilistic function, a probability distribution function or probability mass function of the signal attributes as they relate to various numbers of occupants, and wherein the measured signal attribute is expressed statistically, probabilistically, or as a probability density function or a probability mass function of the measured signal attribute.

17. The system of claim 15, wherein the theoretical model is based, in part, on line-of-sight (LOS) blocking or crossing of the received signal.

18. The system of claim 15, wherein the theoretical model is based, in part, on multi-path (MP) scattering/fading of the received signal.

19. The system of claim 15, wherein the theoretical model is based, in part, on both line-of-sight (LOS) blocking of the received signal and multi-path (MP) scattering/fading of the received signal.

20. The system of claim 15, wherein the theoretical model is based, in part, on modeling of motion behaviors of occupants within the monitored region.