ROOM OCCUPANCY SENSING APPARATUS AND METHOD

• US 20150234048A1
• Filed: 09/12/2013
• Published: 08/20/2015
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: MBDA UK Ltd. (MBDA SAS)
• Original Assignee: MBDA UK Ltd. (MBDA SAS)
• Inventors: Miller, Lee Douglas, McKee, Karen Louise
• Granted Patent: US 9,575,180 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/484 Transmitters
• CPC Class Codes: G08B 13/122 for a perimeter fence features peculiar to electrified fences A01K3/00
• CPC Class Codes: G08B 13/124 with the breaking or disturbance being optically detected, e.g. optical fibers in the perimeter fence
• CPC Class Codes: G08B 13/186 using light guides, e.g. optical fibres
• CPC Class Codes: G08B 13/187 by interference of a radiation field

Abstract

A building comprising a plurality of rooms (10) includes a room occupancy sensing apparatus. A light source (20) emits a series of light pulses (22), a plurality of waveguides deliver light from the light source to output nodes (60) located in the rooms, and a signal capture unit (30) receives output signals resulting from light reflected by objects in the rooms. The apparatus detects movement, of for example a person (40), in a room and ascertains the room concerned by virtue of (i) detecting a difference between the shape of the waveform of the signal (24 i) received at the signal capture unit (30) in response to a first emitted light pulse and the shape of the waveform of the signal (24m) received at the signal capture unit in response to a second emitted light pulse and (ii) relating said reflected light pulses to the appropriate output node and therefore to the room (10) associated with that output node (60).

Claims

1. A method of sensing occupancy in a room, wherein the method comprises the following steps:

delivering a series of light pulses via one or more waveguides to one or more output nodes located in the room,

the scene in the room reflecting the light pulses emitted by the one or more output nodes,

detecting the reflected light pulses,

monitoring for a difference between (a) the shape of the detected waveform of a first reflected light pulse reflected from the pulse emitted from an output node and (b) the shape of the detected waveform of a second reflected light pulse from the same output node, and performing such a monitoring step in respect of each of the output nodes, and

detecting movement in the room by means of detecting such a difference between the shapes of the detected waveforms.

2. A method according to claim 1, wherein there are a plurality of output nodes and the series of light pulses are emitted from the output nodes in a set sequence with a set time delay between the successive emissions.

3. A method according to claim 2, wherein the step of monitoring for a difference between the shapes of the detected waveforms of the first and second reflected light pulses is performed in respect of the shape of the waveforms resulting from light reflected from the pulse emitted from all output nodes.

4. A method according to claim 1, wherein the method is performed to detect room occupancy within a building having a plurality of rooms, each room having at least one output node.

5. A method according to claim 4, wherein the method includes

delivering a series of light pulses via a plurality of waveguides to one or more output nodes located in each of the plurality of rooms,

the scene in each room reflecting the light pulses emitted by the output nodes, and

ascertaining the room or rooms corresponding to movement so detected.

6. A method according to claim 4, wherein the method is performed during a period of planned occupancy of at least one room being monitored.

7. A method according to claim 1, wherein the step of monitoring for a difference between the shapes of the detected waveforms of the first and second reflected light pulses comprises performing a direct comparison between (a) the shape of the detected waveform of the first reflected light pulse and (b) the shape of the detected waveform of the second reflected light pulse.

8. A method according to claim 1, wherein the step of monitoring for a difference between the detected waveforms is performed by means of a signal processor.

9. A method according to claim 1, further including a step of storing in the memory of an electronic data storage unit data concerning the shape of a multiplicity of detected waveforms.

16. A kit of parts comprising:

at least one light source for emitting a series of light pulses,

a plurality of waveguides,

one or more input and/or output nodes,

at least one signal capture unit, and

a signal processor,

wherein

the kit of parts is so arranged as to be suitable for performing the method of claim 1.

10. A building comprising a plurality of rooms and a room occupancy sensing apparatus, the room occupancy sensing apparatus comprising:

at least one light source arranged to emit a series of light pulses,

a plurality of waveguides, at least some of the waveguides being arranged to deliver light from the light source to one or more output nodes located in each of the plurality of rooms,

at least one signal capture unit arranged to receive output signals resulting from light reflected by objects in the plurality of rooms, and

a signal processor,

wherein the apparatus is arranged so as to be able to distinguish between a light pulse reflected by an object in a room delivered to that room via any one output node from a reflected light pulse originating from any output node associated with any different room,

the apparatus is so arranged that, in use, the signal processor compares the shape of the waveform of the signal received at the signal capture unit in response to a first emitted light pulse with the shape of the waveform of the signal received at the signal capture unit in response to a second emitted light pulse,

whereby the apparatus is able both to detect movement in a room and to ascertain the particular room in which movement has occurred by virtue of (i) detecting a difference between the shapes of the waveforms of the signals received by the signal capture unit resulting from reflected light pulses from such first and second emitted light pulses and (ii) relating said reflected light pulses to the room concerned.

11. A building according to claim 10, wherein the room occupancy sensing apparatus comprises one or more transducers for converting varying light signals reflected by objects in the rooms into electric signals having a resolution sufficient to enable detection of changes in light intensity of a duration of a nanosecond.

12. A building according to claim 10, wherein at least some of the plurality of waveguides are arranged for both delivering light reflected by objects in the plurality of rooms, via one or more input nodes in each room, to the signal capture unit and for delivering light from the light source to one or more output nodes.

13. A building according to claim 12, wherein at least one input node also performs the function of an output node.

14. A building according to claim 10, wherein the apparatus is configured, during an uninterrupted state of actively monitoring the building,

to detect movement or occupancy in a room,

to indicate that the room is so occupied,

to deem subsequently that the room is no longer occupied, and

to indicate that the room is no longer occupied.

15. A kit of parts comprising:

at least one light source for emitting a series of light pulses,

a plurality of waveguides,

one or more input and/or output nodes,

at least one signal capture unit, and

a signal processor,

wherein

the kit of parts is so arranged as to be suitable for converting a building comprising a plurality of rooms into a building according to claim 10.