Systems and methods for daylight harvesting

• US 10,575,375 B2
• Filed: 05/02/2019
• Issued: 02/25/2020
• Est. Priority Date: 05/02/2018
• Status: Active Grant

• Current Assignee: Hubbell Lighting Incorporated (Hubbell, Inc.)
• Original Assignee: Hubbell, Inc.
• Inventors: Weber, Theodore E., Arbouw, Terrence R., Muecke, Michael L.
• Primary Examiner(s): Chai, Raymond R
• Application Number:
  US16/401,847
• Publication Number:
  US 20190342957A1
• Time in Patent Office: 299 Days
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/30 Driver circuits
• 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 47/13 by using passive infrared detectors
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A lighting system including a driver providing a first drive signal and a second drive signal; an LED array coupled to the driver and configured to receive the first second drive signals; a sensor positioned to sense light intensity for a zone; and an electronic controller. The electronic controller configured to control the driver to provide the first drive signal to the LED array; receive, from the sensor, a first light intensity; retrieve from the memory a task-to-sensor ratio for the sensor; retrieve from the memory a non-useful light intensity; determine an artificial light intensity based on first drive signal and the task-to-sensor ratio; determine the second drive signal based on a desired light intensity for the zone, the non-useful natural light intensity, and the artificial light intensity; and control the driver to provide the second drive signal to the LED array.

Claims

1. A lighting system comprising:

a driver configured to provide a first drive signal and a second drive signal;

a light-emitting diode (LED) array coupled to the driver and configured to receive the first drive signal and the second drive signal;

a first sensor positioned to sense natural light in a room;

a second sensor positioned to sense light intensity for a zone of the room; and

an electronic controller, coupled to the driver, the first sensor, and the second sensor, including a memory and an electronic processor configured to

control the driver to provide the first drive signal to the LED array;

receive, from the first sensor, a first light intensity;

receive, from the second sensor, a second light intensity;

retrieve from the memory a task-to-sensor ratio for the second sensor;

determine an expected light intensity based on the first light intensity, the first drive signal, and the task to sensor ratio;

determine whether the second light intensity exceeds the expected light intensity; and

in response to determining that the second light intensity exceeds the expected light intensity,

determine an artificial light intensity based on first drive signal and the task-to-sensor ratio;

determine a total natural light intensity based on the second light intensity and the artificial light intensity;

determine a non-useful natural light intensity based on the total natural light intensity, the first light intensity, and the task-to-sensor ratio;

determine the second drive signal based on a desired light intensity for the zone, the total natural light intensity, the non-useful natural light intensity, and the artificial light intensity; and

control the driver to provide the second drive signal to the LED array.

2. The system of claim 1, wherein determining whether the second light intensity exceeds the expected light intensity includes comparing a difference between the second light intensity and the expected light intensity to a difference threshold.

3. The system of claim 1, wherein the task-to-sensor ratio is a ratio of an intensity of a generated artificial light for the zone to a sensed light intensity for the zone;

the sensed light intensity having been sensed with no natural light present in the zone.

4. The system of claim 1, wherein determining the artificial light intensity includes multiplying a light intensity value for the first drive signal by the task-to-sensor ratio.

5. The system of claim 1, wherein determining the total natural light intensity includes subtracting the artificial light intensity from the second light intensity.

6. The system of claim 1, wherein determining the non-useful natural light intensity includes multiplying the first light intensity by the task-to-sensor ratio, and subtracting the product from the total natural light intensity.

7. The system of claim 1, wherein determining the second drive signal includes

subtracting the non-useful natural light intensity from the total natural light intensity to determine a first difference;

and

subtracting the first difference and the artificial light intensity from the desired light intensity for the zone to determine a second difference.

8. A lighting system comprising:

a driver configured to provide a first drive signal and a second drive signal;

an LED array coupled to the driver and configured to receive the first drive signal and the second drive signal;

a sensor positioned to sense light intensity for a zone; and

an electronic controller, coupled to the driver and the sensor, including a memory and an electronic processor configured to

control the driver to provide the first drive signal to the LED array;

receive, from the sensor, a first light intensity;

retrieve from the memory a task-to-sensor ratio for the sensor;

receive a non-useful light intensity;

determine an artificial light intensity based on first drive signal and the task-to-sensor ratio;

determine the second drive signal based on a desired light intensity for the zone, the non-useful natural light intensity, and the artificial light intensity; and

control the driver to provide the second drive signal to the LED array.

9. The system of claim 8, wherein determining the artificial light intensity includes multiplying a light intensity value for the first drive signal by the task-to-sensor ratio.

10. The system of claim 8, wherein the task-to-sensor ratio is a ratio of an intensity of a generated artificial light for the zone to a sensed light intensity for the zone;

the sensed light intensity having been sensed with no natural light present in the zone.

11. The system of claim 10, wherein the non-useful natural light intensity is determined by

subtracting a sensed light intensity for the zone, taken at a representative time by the first sensor, from an expected light intensity for the sensor;

wherein the expected light intensity is determined by multiplying a second sensed light intensity for the zone, taken at the representative time by a second sensor at task level, by the task-to-sensor ratio, and

wherein the representative time is representative of the direct and reflected natural light that will be present throughout the day.

12. The system of claim 8, wherein determining the second drive signal includes

subtracting the non-useful natural light intensity and the artificial light intensity from the desired light intensity for the zone to determine a difference.

13. The system of claim 8, wherein the non-useful light intensity is retrieved from the memory.

14. The system of claim 8, wherein the non-useful light intensity is based on the first light intensity received from the sensor.

15. The system of claim 14, wherein the non-useful light intensity is further based on an algorithm.

16. The system of claim 15, wherein the algorithm includes subtracting a value from the first light intensity.

17. The system of claim 16, wherein the value is determined based on a dim level of the LED array.

18. The system of claim 16, wherein the value is a predetermined value.

19. The system of claim 8, wherein the non-useful light intensity is received from a second sensor.