Visible light sensor configured for glare detection and controlling motorized window treatments

• US 10,822,873 B2
• Filed: 03/02/2018
• Issued: 11/03/2020
• Est. Priority Date: 03/03/2017
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Technology Company LLC
• Inventors: Casey, Craig A., Protzman, Brent
• Primary Examiner(s): Woldermariam, Aklilu K
• Application Number:
  US15/910,943
• Publication Number:
  US 20180252035A1
• Time in Patent Office: 977 Days
• Field of Search: 382100, 315149, 315150, 315152, 315158, 315159, 348241
• CPC Class Codes: E05F 15/70 with automatic actuation
• CPC Class Codes: E05F 15/77 using wireless control
• CPC Class Codes: E05Y 2400/40 Control units therefore
• CPC Class Codes: E05Y 2400/44 Sensors therefore E05Y2400/322, E05Y2400/33, E05Y2400/55, E05Y2400/56, E05Y2400/852 take precedence
• CPC Class Codes: E05Y 2900/146 Shutters
• CPC Class Codes: E06B 2009/6818 using sensors
• CPC Class Codes: E06B 2009/6827 sensing light
• CPC Class Codes: E06B 9/42 Parts or details of roller blinds, e.g. suspension devices, blind boxes brackets or adjustable mountings for roller blinds and drawable curtains A47H1/13
• CPC Class Codes: E06B 9/68 Operating devices or mechanisms, e.g. with electric drive
• CPC Class Codes: E06B 9/72 comprising an electric motor positioned inside the roller
• CPC Class Codes: G01J 1/4204 with determination of ambient light solar light G01J2001/4266
• CPC Class Codes: G01J 1/44 Electric circuits for command of an exposure part G03B7/02
• CPC Class Codes: G01J 2001/448 Array [CCD]
• CPC Class Codes: G05B 11/32 with inputs from more than one sensing element; with outputs to more than one correcting element
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/20076 Probabilistic image processing
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: H04L 12/2823 Reporting information sensed by appliance or service execution status of appliance services in a home automation network device-related reporting H04L43/065; arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom H04Q9/00
• CPC Class Codes: H04L 12/2825 Reporting to a device located outside the home and the home network access arrangements H04L12/2856; for remote control or remote monitoring of applications H04L67/025; telephonic communication systems adapted for combination with telemetering systems H04M11/002
• CPC Class Codes: H05B 47/105 in response to determined parameters
• CPC Class Codes: H05B 47/11 : by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/125 : by using cameras
• CPC Class Codes: H05B 47/13 : by using passive infrared detectors
• CPC Class Codes: Y02B 80/00 : Architectural or constructional elements improving the thermal performance of buildings

Abstract

A sensor may detect glare from a recorded image and a shade position of a motorized window treatment may be controlled based on the position of the detected glare in the image. A luminance of a pixel may be calculated in an image and a glare condition may be detected based on the luminance of the pixel. For example, the sensor may start at a first pixel in a bottom row of pixels and step through each of the pixels on the bottom row before moving to a next row of pixels. When the sensor detects a glare condition, the sensor may cease processing the remaining pixels of the image. The sensor may calculate a background luminance of the image by reordering the pixels of the image from darkest to lightest and calculating the luminance of a pixel that is a predetermined percentage from the darkest pixel.

Claims

1. A sensor for detecting a location of a glare condition for controlling a shade position of a motorized window treatment, the sensor comprising:

a visible light sensing circuit configured to record one or more images, each of the one or more images comprising rows of pixels; and

a control circuit configured to process the rows of pixels to calculate a respective luminance of multiple pixels of a non-warped image, the control circuit configured to process the rows of pixels by starting at a first pixel on a first row of pixels at a bottom portion of the non-warped image and step through each of the multiple pixels on the first row before continuing to a next row of pixels to determine the respective luminance of each of the multiple pixels of the non-warped image until the location of the glare condition is detected, the control circuit configured to detect the location of the glare condition from which the shade position of the motorized window treatment is controlled in response to the luminance of at least one of the multiple pixels of the non-warped image;

wherein, upon detection of the location of the glare condition, the control circuit is configured to cease processing the non-warped image to avoid determination of the respective luminance for remaining unprocessed pixels of the non-warped image.

2. The sensor of claim 1, wherein the control circuit is configured to determine a background luminance representative of a luminance of a background of the non-warped image.

3. The sensor of claim 2, wherein the control circuit is configured to determine the background luminance by reordering the pixels of the non-warped image from darkest to lightest and calculating the luminance of a pixel that is a predetermined percentage of the distance from the darkest pixel to the lightest pixel.

4. The sensor of claim 3, wherein the predetermined percentage is 25%.

5. The sensor of claim 2, wherein the control circuit is configured to detect the glare condition if the ratio of the luminance of a specific pixel to the background luminance is greater than a predetermined contrast threshold.

6. The sensor of claim 1, wherein the control circuit is configured to detect the glare condition in response to the luminance of a specific pixel, calculate a profile angle of the glare source in response to the location of the specific pixel in the non-warped image, and determine the shade position to which to control a motorized window treatment in response to the profile angle.

7. The sensor of claim 6, wherein the control circuit is configured to transmit a shade control command in response to the shade position determined from the profile angle.

8. The sensor of claim 1, wherein the control circuit is configured to retrieve a high-dynamic-range image and de-warp the high-dynamic-range image to produce the non-warped image.

9. The sensor of claim 8, wherein the control circuit produces the non-warped image by generating rows of constant profile angle from the warped image.

10. The sensor of claim 1, wherein the control circuit is configured to detect the glare condition if the luminance of a specific pixel is greater than a luminance threshold.

11. The sensor of claim 1, wherein the first row is the bottom row of the non-warped image.

12. The sensor of claim 1, wherein the next row of pixels is immediately above the first row of pixels.

13. The sensor of claim 1, wherein the control circuit is configured to calculate the respective luminance of each of the multiple pixels.

14. The sensor of claim 1, wherein the image comprises an HDR image, and the control circuit is configured to retrieve the respective luminance of each of the multiple pixels from data of the HDR image.

15. A sensor for detecting a location of glare condition from which a shade position of a motorized window treatment is controlled, the sensor comprising:

a visible light sensing circuit configured to record one or more images; and

a control circuit configured to calculate a background luminance of an image, wherein the background luminance is a value from which the glare condition is detected for controlling the shade position of the motorized window treatment, wherein the control circuit is configured to reorder pixels of the image from darkest to lightest, calculate a luminance of a first pixel that is a predetermined percentage of the distance from the darkest pixel to the lightest pixel, and set the luminance of the first pixel as the background luminance;

wherein the control circuit is configured to detect the location of the glare condition when a ratio of the luminance of a second pixel to the background luminance is greater than a predetermined contrast threshold.

16. The sensor of claim 15, wherein the predetermined percentage is 25%.

17. A method for controlling a shade level of a motorized window treatment, the method comprising:

receiving an image of a view outside of a window on which the motorized window treatment is installed;

processing multiple pixels of the image to identify a profile angle that defines a position of a glare source outside of the window, wherein the profile angle that defines the position of the glare source is identified in response to a respective luminance of at least one of the multiple pixels of the image, wherein the processing comprises starting at a first pixel in a first row of pixels at a bottom portion of the image and stepping through each of the one or more pixels and ceases upon identifying the position of the glare source; and

controlling the shade level of the motorized window treatment based on the profile angle of the glare source.

18. The method of claim 17, further comprising:

determining a pixel that represents a glare condition; and

retrieving the profile angle from a predefined lookup table in memory based on the determined pixel.

19. The method of claim 17, wherein the shade level is controlled by wirelessly transmitting a digital message to the motorized window treatment that indicates the shade level.

20. The method of claim 17, wherein the multiple pixels are processed to identify a contrast between a luminance of at least two pixels in the image.

21. The method of claim 20, wherein the profile angle is identified when the contrast between the luminance of the at least two pixels is greater than a luminance threshold.

22. The method of claim 17, further comprising:

calculating the shade level of the motorized window treatment using the profile angle and a maximum penetration distance.

23. The method of claim 17, further comprising:

transmitting the profile angle prior to controlling the shade level.