Social alarm system with location detection in a dwelling

• US 9,997,055 B2
• Filed: 06/07/2016
• Issued: 06/12/2018
• Est. Priority Date: 06/08/2015
• Status: Active Grant

• Current Assignee: Tunstall Integrated Health & Care Limited
• Original Assignee: Tunstall Healthcare (UK) Ltd.
• Inventors: Ball, Edward Andrew
• Primary Examiner(s): Nguyen, Phung
• Application Number:
  US15/175,532
• Publication Number:
  US 20160358455A1
• Time in Patent Office: 735 Days
• Field of Search: 34053913, 340506, 34053921, 3405731, 340 1324
• CPC Class Codes: G01S 2205/06 Emergency
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G08B 21/0272 System arrangements wherein the object is to detect exact location of child or item using triangulation other than GPS
• CPC Class Codes: G08B 21/043 detecting an emergency event, e.g. a fall
• CPC Class Codes: G08B 25/016 Personal emergency signalling and security systems emergency non-personal manually actuated alarm activators G08B25/12
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence

Abstract

A social alarm system provides location detection within a dwelling. A personal radio trigger unit is carried by a client and transmits an alarm signal in response to a triggering event, such as by a manual alarm button or an automatic fall detection circuit. A client unit is operable to receive the alarm signal and initiate an alarm call to a remote monitoring center over a communications network. A plurality of radio receptor nodes monitor the wireless RF transmissions from the personal radio trigger to report respective received signal strength values. A location finder unit determines a location of the personal radio trigger, by using absolute error calculations and/or shape error calculations against previously recorded known locations in the dwelling.

Claims

1. A social alarm system with location detection in a dwelling, comprising:

a personal radio trigger configured to be carried by a client in the dwelling and operable to transmit an alarm signal by wireless radio frequency transmission in response to a triggering alarm event;

a client unit operable to receive the alarm signal and initiate an alarm call to a remote monitoring center over a communications network;

a plurality of radio receptor nodes operable to monitor the wireless radio frequency transmissions from the personal radio trigger, each radio receptor node being configured to report at least one respective received signal strength value; and

a location finder unit operable to determine a location of the personal radio trigger in the dwelling according to the received signal strength values reported from the plurality of radio receptor nodes;

wherein the location finder unit is configured to perform a location finding algorithm comprising;

receiving a set of observed signal strength values from the plurality of radio receptor nodes, comparing the set of observed signal strength values against sets of previously recorded signal strength values from a plurality of known locations in the dwelling, and thereby determining a current location of the personal radio trigger in the dwelling from amongst the plurality of known locations.

2. The social alarm system of claim 1, wherein the plurality of radio receptor nodes are distributed at separate locations around the dwelling.

3. The social alarm system of claim 1, wherein at least one of the radio receptor nodes comprises a plurality of antennas as a multi-antenna array.

4. The social alarm system of claim 3, wherein the plurality of radio antennas in the radio receptor node are spaced apart from each other by a distance D corresponding to a local null of the wireless radio transmissions in the dwelling.

5. The social alarm system of claim 3, wherein at least one of the plurality of antennas is separated from a main board of the radio receptor node and connected thereto by a flying lead wire.

6. The social alarm system of claim 3, wherein each of the radio receptor nodes further comprises a controller operable to determine a received signal level from each of the plurality of antennas of that radio receptor node and to derive the received signal strength value therefrom as reported by the respective radio receptor node to the location finder unit.

7. The social alarm system of claim 1, wherein the radio receptor nodes are coupled to the location finder unit by a backhaul network which is distinct from the wireless radio transmissions.

8. The social alarm system of claim 1, wherein the location finder unit is provided in a server apparatus remote from the dwelling.

9. The social alarm system of claim 1, wherein the location finding algorithm further comprises:

arranging the observed signal strength values from the plurality of nodes into a predetermined pattern, and comparing the arranged pattern of the observed signal strength values against likewise arranged patterns of the previously recorded signal strength values for the plurality of known locations in the dwelling.

10. The social alarm system of claim 9, wherein the location finder unit stores a set of power levels from each of the plurality of nodes for each of the observed recorded values, wherein the set of power levels are ordered by location of the nodes and the observed signal values are provided in the same location order.

11. The social alarm system of claim 9, wherein the location finding algorithm selects amongst the known locations according to absolute power levels from each of M said radio receptor nodes for each of a set of L known locations, where L and M are positive integers, against the current observed signal values according to provide an absolute power error against the current observed signal values ‘

p’

according to the equation;

12. The social alarm system of claim 9, wherein the location finding algorithm selects amongst the known locations according to normalized power levels from each of the M radio receptor nodes for each of the set of L known locations, where L and M are positive integers, against the current observed signal values ‘

p’

according to provide a shape power error according to the equations;

Node_Norm=Node−

MAX(Node(1 . . . M)) 

 

(Eq.

     2)

LUT_Norm(p,1 . . . M)=LUT(p,1 . . . M)−

MAX(LUT(p,1 . . . M)) 

 

(Eq.

     3), and

13. The social alarm system of claim 12, wherein the location finding algorithm selects amongst the known locations according to a combined error value based on both of the absolute power error and the shape power error.

14. The social alarm system of claim 9, wherein the location finder unit is operable to report two or more of the selected known locations as being the current location of the personal radio trigger with a relative confidence rating for each said known location.

15. The social alarm system of claim 1, wherein the social alarm system further comprises one or more anchor transmitters arranged at fixed locations in the dwelling and operable to emit the wireless radio transmissions similar to the personal radio trigger, and wherein the location finder unit is further operable to compare the observed signal values against observations of the anchor transmitters when determining a location of the personal radio trigger in the dwelling.

16. The social alarm system of claim 1, wherein the location finder unit is operable to make a binary determination of location of the personal radio trigger as being in one of ‘

inside’

or ‘

outside’

at the dwelling.

17. The social alarm system of claim 1, wherein the personal radio trigger is operable to emit the wireless radio transmission using a reserved frequency band in the range 100 MHz to 1 GHz.

18. The social alarm system of claim 1, wherein the personal radio trigger is configured as a pendant to be worn by the client and comprises an alarm button operable to manually initiate the triggering alarm event and/or a fall detector circuit operable to automatically initiate the triggering alarm event.

19. A method of location finding in a dwelling by a social alarm system, comprising:

transmitting an alarm signal by wireless radio frequency transmission in response to a triggering alarm event from a personal radio trigger carried by a client in the dwelling;

receiving the alarm signal at a client unit and initiating an alarm call to a remote monitoring center over a communications network;

monitoring the wireless radio frequency transmissions from the personal radio trigger by a plurality of radio receptor nodes to report at least one respective received signal strength value; and

determining a location of the personal radio trigger in the dwelling by performing a location finding algorithm comprising;

receiving a set of observed signal strength values from the plurality of radio receptor nodes, comparing the set of observed signal strength values against sets of previously recorded signal strength values from a plurality of known locations in the dwelling, and thereby determining a current location of the personal radio trigger in the dwelling from amongst the plurality of known locations.

20. The method of claim 19, further comprising:

comparing the received signal values against previously stored values for a plurality of known locations in the dwelling to derive an error value for each location; and

selecting a current location of the personal radio trigger from amongst the plurality of known locations in the dwelling according to the error values.