Communication system

• US 5,062,151 A
• Filed: 04/27/1990
• Issued: 10/29/1991
• Est. Priority Date: 01/13/1983
• Status: Expired

• Current Assignee: Hill-Rom Services Incorporated (Baxter International Inc.)
• Original Assignee: Fisher Berkeley Corporation
• Inventors: Shipley, Robert T.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): PASCAL, LESLIE C
• Application Number:
  US07/518,309
• Time in Patent Office: 550 Days
• Field of Search: 340/311.1, 340/825.44, 340/825.47, 340/825.49, 340/825.59, 455/602, 455/603, 455/605-608, 455/617-619
• US Class Current: 398/108
• CPC Class Codes: G06K 7/1097 Optical sensing of electronic memory record carriers, such as interrogation of RFIDs with an additional optical interface
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence
• CPC Class Codes: G08B 25/014 Alarm signalling to a central station with two-way communication, e.g. with signalling back
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/116 Visible light communication
• CPC Class Codes: H04M 3/42229 Personal communication services, i.e. services related to one subscriber independent of his terminal and/or location diverting calls from one subscriber to another subscriber, i.e. two different subscriptions H04M3/54; selecting arrangements in intelligent networks H04Q3/005
• CPC Class Codes: H04M 9/00 Arrangements for interconnection not involving centralised switching

Abstract

Personnel locating system for use in a facility having a plurality of rooms having doorways therein comprised of a plurality of portable transmitters. Each of the transmitters includes a battery and each generates an infrared signal. The system also comprises a plurality of fixed receivers positioned to cover different rooms at a facility. Each room has a receiver therein positioned to accept infrared radiation from a substantial portion of the volume of the room. Each receiver is capable of sensing and storing any of the infrared signals generated by the transmitters during any time the transmitters are located anywhere in the facility including when located within a room. The system also includes apparatus for polling the receivers to determine the location of any transmitter independent of the previous location of the transmitter.

Claims

1. In a personnel locating system for use in a facility having a plurality of rooms having doorways therein, a plurality of portable transmitters, each including a battery and each generating an infrared signal, a plurality of receivers, each room having a wall-mounted receiver positioned within the room to accept infrared radiation from a substantial portion of the volume of the room, each receiver in each room being capable of sensing and storing any of said infrared signals generated by said transmitters during any time said transmitters are located anywhere in said each room and means for polling said receivers to determine the actual location in real time of any transmitter in use in the facility independent of the previous location said any transmitter in the facility.

2. A system as in claim 1 wherein the power in said infrared signal from each of said portable transmitters is sufficient to allow said infrared signal to be reflected off objects and off the walls of said each room and still be sensed by said receiver in said each room, said infrared signal also being of a low duty ratio to minimize energy drawing on said battery of said portable transmitter.

3. A system as in claim 2 wherein said infrared signal has a duty cycle of less than approximately 0.003%.

4. A system as in claim 1 wherein each of said receivers includes optical filter means for filtering out visible light and ultraviolet energy and additional electrical filter means for controlling high frequency response.

5. A system as in claim 1 wherein each of said receivers include means for storing at least one infrared.

6. A system as in claim 1 where the infrared signal includes an error detection code.

7. A system as in claim 1 wherein said transmitter transmits its unique signal with a unique transmit interval which is not a multiple of another transmit interval whereby the collision of signals from said transmitters will occur infrequently.

8. A system as in claim 1 wherein said infrared radiation has a wavelength of substantially 880 nanometers.

9. A system as in claim 1 wherein each receiver has a unique location address corresponding to said area in said facility in which it is located, and wherein said polling means also includes means for polling said receivers for said location addresses.

10. A system as in claim 9 wherein said polling means includes a central computer having a memory in which there is stored said location addresses of said receivers and the infrared signals associated with said transmitters.

11. A system as in claim 10 together with means for erasing said memory if it has not been updated within a predetermined time interval.

12. A system as in claim 1 together with means for determining and recording the absence from the system of a said infrared signal if said infrared signal has not been sensed within a predetermined time interval.

13. A system as in claim 1 together with telecommunication means for automatically establishing an audio connection to at least certain of said rooms in said facility.

14. A system as in claim 1 wherein each transmitter includes means operable by the personnel for altering the infrared signal to indicate a preselected condition.

15. A system as in claim 1 wherein said means for polling continuously senses, on a cyclic basis, which of said unique pulsed infrared signals are stored at said receivers.

16. In a method for locating personnel using infrared energy and for installation in premises including a plurality of rooms defined by walls impermeable to infrared energy and providing surfaces for reflecting infrared energy therefrom and having entrances through which personnel can pass by the use of a plurality of portable battery powered infrared transmitters with each transmitter emitting infrared energy and a plurality of infrared receivers, the method comprising the steps of causing each of the personnel to be located to carry an assigned transmitter, positioning one of said infrared receivers in each room on the wall of the room to accept infrared radiation from a substantial portion of the volume of said each room and so that it is capable of receiving infrared energy emitted by any of said infrared transmitters in said each room either directly by line-of-sight or by reflection from surfaces of objects in said each room or from surfaces of the walls of said each room, polling said plurality of receivers, utilizing the information obtained by polling said plurality of receivers for ascertaining the actual location in real time and identity of any transmitters in said each room independent of the previous locations of said transmitters in said each room.

17. A method as in claim 16 wherein the infrared signal is of sufficient power so that when it is reflected by surfaces of objects in the room and/or surfaces of walls of the room it can still be sensed by the receiver in said each room.

18. A method as in claim 17 wherein the infrared signal is generated with a low duty cycle to minimize power requirements.

19. In a personnel locating system of the type utilizing infrared energy and for installation in premises including a plurality of separate rooms defined by walls impermeable to infrared energy and providing surfaces for reflecting energy, the rooms having entrances thereto through which personnel can pass, a plurality of portable battery powered infrared transmitters, each transmitter having circuitry for emitting infrared energy to provide infrared signals at transmit intervals, said transmitters being of a size so that an assigned transmitter can be carried by each of the personnel, a plurality of infrared receivers, each of the rooms in the premises having a wall-mount infrared receiver therein exposed to the interior of the room positioned to accept infrared radiation from a substantial portion of the room, the receiver in said each room being capable of receiving infrared energy emitted by any infrared transmitter in the room either directly from the transmitter by line-of-sight and/or by reflection from the surfaces of the objects in said each room and/or from surfaces of the walls of said each room, each receiver having an ascertainable address, a control console and means establishing communication with each receiver in the system and the console, said console having associated therewith a computer memory for receiving and storing information received from the receivers, said control console including means for polling said receivers and for storing information in the computer memory, said control console having means associated therewith for indicating the actual location and identity of each transmitter by utilizing the information in the computer memory, said control console having means associated therewith for indicating the actual location and identify of each transmitter by utilizing the information obtained by polling the receivers by having each transmitter transmit at sufficiently frequent intervals and conduct polling at sufficiently frequent intervals whereby the location and identify of any transmitter in said each room is ascertained continuously and accurately independent of the previous location of said any transmitter in relationship to a two second time interval.

20. A system as in claim 19 wherein said control console includes means for erasing the information in said memory with respect to any transmitter if the information with respect to that transmitter has not been updated within a predetermined time interval.

21. A system as in claim 19 wherein said control console includes means for recording the absence of a transmitter if a signal from the transmitter has not been sensed by a receiver within a predetermined interval.

22. A system as in claim 19 together with a telephone located in at least certain rooms and means associated with the control console for selectively ringing the telephone most closely adjacent to a predetermined transmitter.

23. A system as in claim 19 wherein said infrared signals have a duty cycle at least an order of magnitude less than one percent.

24. A system as in claim 19 wherein each transmitter transmits its signal with a unique transmit interval which is not a multiple of the transmit interval of another transmitter.

25. A system as in claim 19 wherein the receivers are polled sequentially in an endless loop.

26. In a personnel locating system for use in a facility having a plurality of rooms defined by walls and having doorways therein, a plurality of portable transmitters, each including a battery and each generating an infrared signal at transmit intervals, each of personnel carrying one of said transmitters, a plurality of infrared receivers each room having a receiver therein within the confines of the walls defining said each room and exposed to the interior of said each room for receiving infrared energy from anywhere in said each room, each receiver in said each room being capable of sensing and storing any of said infrared signals generated by any of said transmitters located within said each room and means for polling said receivers in the facility, each of said transmitters transmitting at sufficiently frequent intervals and said means for polling said receivers polling at sufficiently frequent intervals to provide an effectively continuous and accurate location of said plurality of transmitters.