OCCUPANCY DETECTION METHOD AND SYSTEM

• US 20150286948A1
• Filed: 10/08/2013
• Published: 10/08/2015
• Est. Priority Date: 10/17/2012
• Status: Abandoned Application

• Current Assignee: Philips Lighting BV (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Luca, Tiberi, Flinsenberg, Ingrid Christina Marie, Sarroukh, Bahaa Eddine, Barroso, Andre
• Application Number:
  US14/436,619
• Publication Number:
  US 20150286948A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2120/00 Control inputs relating to users or occupants
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G06N 5/047 Pattern matching networks; Rete networks
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/115 by determining the presence or movement of objects or living beings
• CPC Class Codes: H05B 47/13 by using passive infrared detectors
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

The present invention relates generally to the field of occupancy detection, and more particularly to an occupancy detection system and a corresponding method suitable for a presence controlled system. A method and system for determining occupancy of a room is provided, in which a signal from a movement sensor positioned in the room is analyzed to detect variations in the signal which correspond to movements of an occupant of the room. The room is determined to be empty if in the received signal a leave pattern is identified. The leave pattern is a predetermined pattern which has been associated with an occupant leaving the room. The method and system provide reliable occupancy detection in more or less static environments like for instance offices, and when utilized in for instance a presence controlled lighting system, the number of frustrating erroneous “switch-off” events of the light in a situation where a room is still occupied by occupants involved in relative still/static activities is then decreased.

Claims

1. A method of determining occupancy of a room, the method comprising:

receiving a signal from at least one movement sensor positioned in the room;

detecting variations in the signal which correspond to movements of an occupant of the room;

analyzing the detected variations in order to identify one or more patterns therein; and

determining that the room is empty if the one or more patterns comprises a leave pattern associated with an occupant leaving the room, based on at least one of;

a first delay T1 after which said occupancy state is set to ‘

empty’

if no movement is detected after said leave pattern is detected, and

a second delay T2 after which said occupancy state is set to ‘

empty’

if no movement is detected after a last detected movement in the room.

2. A method according to claim 1, wherein said leave pattern is based on detecting a minimum amount of movement within a predetermined maximum time period LT.

3. A method according to claim 2, wherein said minimum amount of movement is based on detecting a minimum number NM of consecutive signal rising or falling edges within said maximum time period LT, or is based on detecting a minimum amount of time TH when said signal indicates movement within said maximum time period LT.

5. A method according to claim 1, further comprising detecting any switch of said occupancy state from an occupied state ‘

occupied’

, to and an empty state ‘

empty’

, and for each switch detected over time;

recording at least one occupancy detection parameter related to the switch of the occupancy state; and

processing said at least one occupancy detection parameter in order to reduce the probability of failure of the method for detecting occupancy.

4. (canceled)

6. An occupancy detection system comprising:

at least one movement sensor for providing a signal corresponding to movements of at least one occupant of a room;

an occupancy estimator operably connected to said at least one movement sensor for providing an occupancy state based on said signal; and

an output operably connected to the occupancy estimator to communicate the occupancy state generated by the occupancy estimator;

wherein said occupancy estimator is arranged for analyzing variations in said signal in order to identify one or more patterns therein, and setting said occupancy state to indicate a room monitored by said at least one movement sensor to ‘

empty’

based on identifying that said one or more patterns comprises a leave pattern associated with an occupant leaving the room, based on at least one of;

a first delay T1 after which said occupancy state is set to ‘

empty’

if no movement is detected after said leave pattern is detected, and

a second delay T2 after which said occupancy state is set to ‘

empty’

if no movement is detected after a last detected movement in the room.

7. An occupancy detection system according to claim 6, further comprising an input operably connected to said occupancy estimator for receiving occupancy detection parameters associated with said leave pattern and/or said setting of said occupancy state from a user input or an external data base.

8. An occupancy detection system according to claim 6, further comprising storage means for recording said occupancy state and signal over time, and wherein said occupancy estimator is further arranged for controlling occupancy detection parameters.

9. A lighting system comprising at least one light source, an occupancy detection system according to claim 6, and a lighting controller for controlling the at least one light source based on said occupancy state provided by the occupancy detection system.

10. An HVAC system comprising at least one HVAC unit, an occupancy detection system according to claim 6, and a HVAC controller for controlling the at least one HVAC unit based on said occupancy state provided by the occupancy detection system.