Personnel locating system

• US 6,339,709 B1
• Filed: 11/29/1999
• Issued: 01/15/2002
• Est. Priority Date: 04/09/1997
• Status: Expired due to Fees

• Current Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Original Assignee: Commonwealth Scientific & Industrial Research Organisation (Commonwealth Of Australia As Represented By Department Of Industry, Innovation, Climate Change, Science, Research And Tertiary Education)
• Inventors: Dekker, David, Gladwin, Michael
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): Nguyen, Thuan T.
• Application Number:
  US09/448,898
• Time in Patent Office: 778 Days
• Field of Search: 455/456, 455/457, 455/458, 455/31.3, 455/38.2, 342/358, 342/465, 340/573
• US Class Current: 455/115.1
• CPC Class Codes: G01S 1/685 using pulse modulation, e.g. pulse frequency modulation
• CPC Class Codes: G01S 5/0295 Proximity-based methods, e.g. position inferred from reception of particular signals

Abstract

There is described a system and method for locating, and optionally monitoring the status of, a mobile entity in a given area fitted with a radio beacon. In one embodiment, the system features a network of bi-directional radio beacons which transmit on the same frequency at random intervals. A method for processing and relaying unique message identifiers throughout the system is disclosed which allows the vicinity of the mobile entity to be determined from any beacon in the network.

Claims

1. A system for locating a mobile entity in an area including:

a) a network of fixed communication beacons for relaying messages, said fixed beacons arranged in predetermined locations, the fixed beacons disposed in a flat structure in which all messages are communicable throughout all fixed beacons;

b) a mobile communication beacon adapted to be attached to the entity to be located and for transmitting mobile messages, said mobile messages being coded to uniquely identify the message and to uniquely identify the mobile communication beacon;

the beacons being arranged so that operatively, the mobile communication beacon transmits said mobile messages to at least one fixed communication beacon of the network located in its vicinity, said at least one beacon modifying said message by appending a unique beacon identifier and transmitting the modified message to adjacent beacons for transmission throughout the beacon network so that the identity of the at least one fixed communication beacon which first modified the message is stored at each fixed beacon throughout the network.

2. A system according to claim 1, wherein the beacons, be they fixed or mobile, include sensing means for determining external parameters.

3. A system according claim 2, wherein the sensing means of a mobile beacon is adapted to detect the value of a parameter indicative of the operational status of the entity to which said beacon is operatively attached.

4. A system according to claim 3, wherein the mobile beacon is operatively attached to a person, and wherein the sensing means comprises a sensor for monitoring a physiological parameter of said person.

5. A system according to claim 4 wherein the sensing means includes at least one conductive loop for monitoring the heartbeat of said mine worker.

6. A system according to claim 3, wherein the sensing means comprises an accelerometer for monitoring the attitude of said entity.

7. A system according to claim 2, wherein the sensing means of a fixed beacon is adapted to detect the value of a parameter indicative of the external environment adjacent said fixed beacon.

8. A system according to claim 2, wherein the messages generated by beacons, be they fixed or mobile, include information derived from said sensing means.

9. A system according to claim 1, further including a control centre in communication with at least one of said fixed beacons, the control centre including a processing means for processing information derived from said network.

10. A system according to claim 1, wherein the beacons include means for communicating with each other using radio frequency signals.

11. A system according to claim 9, wherein the control centre includes a register of the identities of the beacons in the area and the geographical location of the fixed beacons.

12. A system according to claim 10, wherein the control centre routinely interrogates the message memory of the at least one fixed communication beacon by means of a signal communication connection to ascertain the status of the network.

13. A system according to claim 12, wherein the control centre includes an alarm that is coupled to the processing means and activated by the processing means in the event that no message is received from a mobile beacon in a predetermined timeframe.

14. A system according to claim 13, wherein the control centre determines the last location at which a message was received from the mobile beacon.

15. A method for locating a mobile entity in an area containing a network of beacons, including fixed communication beacons and mobile communication beacons, said fixed beacons being located at recorded positions and in a flat structure in which all messages are communicable throughout all fixed beacons, said mobile entity being fitted with a mobile communication beacon, said method including the steps of:

a) transmitting from the mobile communication beacon a unique message, including data identifying said beacon, to a first one of said fixed communication beacons in the vicinity of said mobile beacon;

b) appending to said message a unique identifier associated with the first at least one fixed communication beacon, thereby forming a modified message;

c) repeatedly transmitting the modified message from communication beacon to adjacent beacons and storing details of the modified message, including the identity of the first at least one beacon which created the modified message at beacons throughout the network;

d) interrogating a beacon to determine the identify of the beacon which created the modified message in order to determine the vicinity of the mobile communication beacon at the time the unique message was transmitted.

16. A method according to claim 15 wherein step c) further includes the steps of:

upon receiving the modified message at a beacon, comparing the unique identifiers of the message with a list of message identifiers and, if said comparison detects a match then taking no further action, and if said comparison does not detect a match then recording the unique identifiers of the message and re-transmitting the modified message to adjacent beacons.

17. A method according to claim 16 further including the step of:

interrogating the unique message identifier list associated with a beacon in order to verify the integrity of the network.

18. A method according to claim 17 wherein the step of verifying the integrity of the network includes:

interrogating the unique message identifier list associated with a beacon to ensure that transmissions have been received from all beacons of the network in a certain timeframe.

19. A method according to claim 17 further including the step of:

upon determining that the integrity of the network has failed raising an alarm.

20. A method according to claim 17 further including the step of:

upon determining that a transmission from a beacon has not been received in a certain timeframe determining the last message received from said beacon.

21. A system for determining the approximate location of each one of a plurality of mobile entities located in an area, the system including:

a plurality of mobile beacons adapted to be worn or carried by each individual and being capable of generating a signal containing an identifier;

a network of at least two fixed beacons having a flat structure in which all traffic is communicable with all beacons, the beacons being located throughout the operating area, each fixed beacon being capable of transmitting a signal and of receiving the signal generated by at least one mobile beacon and the signal generated by at least one other fixed beacon;

means by which the transmitted information may be self-routed to all beacons in the network where it may be stored or interrogated;

means by which the location of the mobile-beacons can be determined, stored and available from at least one other beacon; and

a control or monitoring means capable of receiving the signal generated by at least one fixed beacon and therefrom providing an output indicative of the location of each said entity.

22. A system for determining the approximate location of each one of a plurality of mobile entities located in an area and for monitoring at least operational parameter of each of said entities, the system including:

a plurality of mobile beacons adapted to be worn or carried by each individual and being capable of generating a signal containing an identifier and data indicative of the at least one monitored vital sign, each transmitter being associated with a respective sensor capable of monitoring at least one vital sign of the entity wearing or carrying the transmitter;

a network of at least two fixed beacons having a flat structure in which all traffic is communicable with all beacons, the beacons being located throughout the operating area, each fixed beacon being capable of transmitting a signal and of receiving the signal generated by at least one mobile beacon and the signal generated by at least one other fixed beacon;

means by which the transmitted information may be self-routed to all beacons in the network where it may be stored or interrogated;

means by which the location and the status of the entities associated with the mobile beacons can be determined, stored and available from at least one fixed beacon, and

a control or monitoring means capable of receiving the signal generated.

23. A system for locating a mobile entity in an area, comprising:

a network of fixed communication beacons arranged in predetermined locations in the area, where a message may be delivered to a fixed communication beacon through plural paths in the network and where the fixed communication beacons are configured to communicate the message to all fixed communication beacons in the network, and

a mobile communication beacon attachable to the mobile entity to be located for transmitting a mobile message coded to uniquely identify the message and to uniquely identify the mobile communication beacon,

wherein when the mobile communication beacon transmits the mobile message to at least one fixed communication beacon of the network located in its vicinity, the at least one fixed communication beacon is configured to modify the mobile message by appending a unique beacon identifier and to transmit the modified message over plural network paths to adjacent fixed communications beacons for transmission throughout the beacon network so that the identity of the at least one fixed communication beacon which first modified the message is stored at each fixed beacon throughout the network.

24. A system according to claim 23, wherein the fixed and mobile beacons include sensors for determining one or more external parameters.

25. A system according to claim 24, wherein one or more sensors of a fixed beacon is adapted to detect the value of a parameter indicative of the external environment adjacent to the fixed beacon.

26. A system according to claim 24, wherein a message generated by the beacons, be they fixed or mobile, includes information derived from the one or more sensors.

27. A system according to claim 23, wherein a sensor of a mobile beacon is adapted to detect the value of a parameter indicative of an operational status of the entity to which the mobile beacon is operatively attached.

28. A system according to claim 23, wherein the mobile beacon is operatively attached to a person, and includes a sensor for monitoring a physiological parameter of the person.

29. A system according to claim 26, wherein the sensor includes at least one conductive loop for monitoring the heartbeat of the person.

30. A system according to claim 26, wherein the sensor includes an accelerometer for monitoring an attitude of the person.

31. A system according to claim 23, further comprising:

a control center for communicating with at least one of the fixed beacons including a processor for processing information derived from the network.

32. A system according to claim 31, wherein the control center includes a register of identities of the beacons in the area and a geographical location of the fixed beacons.

33. A system according to claim 31, wherein the control center is configured to routinely interrogate a message memory of the at least one fixed communication beacon to ascertain a status of the network.

34. A system according to claim 33, wherein the control center includes an alarm that is coupled to the processing and activated by the processor in the event that no message is received from a mobile beacon in a predetermined time frame.

35. A system according to claim 34, wherein the control center is configured to determine a last location at which a message was received from a mobile beacon.

36. A system according to claim 23, wherein the beacons are configured to communicate with each other using radio frequency signals.

37. A system according to claim 23, wherein functioning fixed communication beacons can still communicate even if there is a failure in part of the network.

38. A method for locating a mobile entity in an area containing a network including fixed communication beacons located at recorded positions in the area and mobile communication beacons, where a message may be delivered to a fixed communication beacon over plural paths in the network so that the message is communicated with all fixed communication beacons, the mobile entity being fitted with a mobile communication beacon, comprising:

a) transmitting from the mobile communication beacon a mobile message, including data identifying the mobile communication beacon, to one of the fixed communication beacons in the vicinity of the mobile communication beacon;

b) appending to the mobile message a unique identifier associated with the one fixed communication beacon, thereby forming a modified message;

c) transmitting the modified message from the one fixed communication beacon to adjacent fixed communication beacons via the plural network paths and storing thereat information associated with the modified message, including the identity of the one beacon which created the modified message, so that the information associated with the modified message is relayed to all fixed communication beacons in the network; and

d) interrogating a fixed communication beacon to determine the identity of the one beacon which created the modified message in order to determine the vicinity of the mobile communication beacon at the time the mobile message was transmitted.

39. A method according to claim 38, wherein step c) further includes the steps of:

upon receiving the modified message at a fixed communication beacon, comparing the unique identifier of the message with a list of message identifiers, and if a match is not detected, then recording the unique identifier of the message and re-transmitting the modified message to adjacent beacons.

40. A method according to claim 39, further including the step of:

interrogating the message identifier list to verify the integrity of the network.

41. A method according to claim 40, wherein verifying the integrity of the network includes:

interrogating the message identifier list associated with a beacon to ensure that transmissions have been received from all fixed communications beacons of the network in a certain time frame.

42. A method according to claim 40, further including the step of:

upon determining that the integrity of the network has failed, raising an alarm.

43. A method according to claim 40, further including the step of:

upon determining that a transmission from a beacon has not been received in a certain time frame, determining a last message received from the beacon.

44. A method according to claim 38, wherein a functioning fixed beacon can still communicate via the network even if there is a failure in part of the network.

45. The system for determining an approximate location of each one of a plurality of mobile entities located in an area and for monitoring at least one operational parameter of each of the mobile entities, comprising:

a plurality of mobile beacons each adapted to be worn or carried by an individual and being capable of generating a signal containing an identifier and data indicative of the at least one monitored parameter, each mobile beacon being associated with a respective sensor capable of monitoring at least one physiological parameter of the mobile entity wearing or carrying the mobile beacon;

a network of fixed beacons each being capable of communicating with all fixed beacons, the fixed beacons being located throughout the operating area, each fixed beacon being capable of receiving information from at least one mobile beacon and of transmitting that information to another fixed beacon such that the transmitted information is propagated to all fixed beacons in the network; and

a controller capable of receiving the transmitted information and determining the location and status of the mobile entities associated with the mobile beacons including the status of the at least one physiological parameter of each mobile entity.

46. The system in claim 45, wherein a functioning fixed beacon can still communicate via the network even if there is a failure in part of the network.