Space-conditioning control employing image-based detection of occupancy and use

• US 6,645,066 B2
• Filed: 11/19/2001
• Issued: 11/11/2003
• Est. Priority Date: 11/19/2001
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Colmanarez, Antonio José, Trajkovic, Miroslav, Gutta, Srinivas
• Primary Examiner(s): Joyce, Harold
• Application Number:
  US09/988,945
• Publication Number:
  US 20030096572A1
• Time in Patent Office: 722 Days
• Field of Search: 454/229, 454/239, 454/256, 236/49.3
• US Class Current: 454/229
• 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 11/65 for selecting an operating mode
• CPC Class Codes: F24F 11/74 for controlling air flow rate or air velocity
• CPC Class Codes: F24F 2120/10 Occupancy
• CPC Class Codes: F24F 2120/14 Activity of occupants

Abstract

Cameras and image processing techniques are applied to the control of HVAC systems. Occupancy is detected using head-counting or motion detection. Activities are recognized in images and image sequences by machine-recognition techniques. The nature of activities, the intensity of activities, the number of occupants and their activities, etc. are all inferred from images and image sequences and used to predict current loads and/or required control signals for regulating an HVAC system.

Claims

1. A control system for a space conditioning system, comprising;

at least one optical imaging device configured to capture at least one image of a scene in a conditioned space;

at least one processor having an output and connected to receive said at least one image from said at least one optical imaging device;

said at least one processor being configured to detect from said at least one image at least one of an occupancy rate, an occupant activity rate, and an occupant activity class and to generate a control signal for controlling a space conditioning system responsively thereto.

2. A control system as in claim 1, wherein said at least one image is multiple images and said processor is programmed to detect motion in said multiple images, said occupant activity rate detected by said at least one processor being at least partially based upon detected motion.

3. A control system as in claim 1, wherein said at least one processor is configured to count occupants in said at least one image, said control signal being responsive to a result of counting occupants in said at least one image.

4. A method of controlling a space-conditioning system, comprising the steps of:

capturing an image of a scene of a conditioned space;

identifying at least one of an occupancy rate, an occupant activity rate, and an occupant class by analyzing at least one image resulting from said step of capturing;

controlling at least a portion of a space-conditioning system responsively to a result of said step of identifying.

5. A method as in claim 4, wherein said step of capturing includes receiving an image using a digital camera.

6. A method as in claim 4, wherein said step of identifying includes segmenting an image to count individuals present.

7. A method as in claim 4, wherein said step of identifying includes subtracting a background image from a current image to determine occupancy rates.

8. A method as in claim 7, wherein said step of identifying includes recognizing a class of behavior of occupants in said image.

9. A method as in claim 4, wherein said step of identifying includes recognizing a class of behavior of occupants in said image.

10. A method as in claim 4, wherein said step of controlling includes deriving a control signal from a lookup table correlating occupant count with control signal values.

11. A method as in claim 4, wherein said step of identifying includes generating a motion vector field from a sequence of current images.

12. A method as in claim 11, wherein said step of generating includes segmenting said current images.

13. A method of controlling space-conditioning system, comprising the steps of:

capturing an image of a space to be conditioned;

counting a number of occupants in said image;

comparing said number to a previous number;

adjusting a cooling capacity of said space-conditioning responsively to a result of said step of comparing.

14. A method as in claim 13, wherein said step of generating includes segmenting said current images.

15. A method of controlling a space-conditioning system for an area, the method comprising:

imaging a scene of a conditioned space;

identifying an occupancy rate in two or more sub portions of the area by analyzing at least one image resulting from said step of imaging; and

controlling a portion of a space-conditioning system corresponding to a sub portion of the area responsively to a result of said step of identifying.

16. A method as in claim 15, wherein said controlling comprises directing additional cooling from the portion of the space-conditioning system corresponding to a sub portion of the two or more sub portions having a higher occupancy rate.

17. A control system for a space conditioning system, comprising;

at least one optical imaging device configured to capture at least one image of a scene in a conditioned space;

at least one processor having an output and connected to receive said at least one image from said at least one optical imaging device;

said at least one processor being configured to detect from said at least one image, an occupant activity class and to generate a control signal for controlling a space conditioning system responsively thereto.