Granted Patent B2

US 10,863,596 · App. 16/799,209 · Granted Dec 8, 2020

Abstract

Claims (46)

1. A method of determining a drive signal provided to a light-emitting diode (LED), the method comprising:

sensing, via a first sensor, a natural light in a room;

sensing, via a second sensor, a light intensity for a zone of the room;

determining, via a controller, a task-to-sensor ratio for the second sensor;

determining, via the controller, an expected light intensity based on a first light intensity and the task to sensor ratio;

determining, via the controller, whether a second light intensity exceeds the expected light intensity; and

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

determining, via the controller, an artificial light intensity based on the task-to-sensor ratio,

determining, via the controller, a total natural light intensity based on the second light intensity and the artificial light intensity,

determining, via the controller, a non-useful natural light intensity based on the total natural light intensity, the first light intensity, and the task-to-sensor ratio,

determining, via the controller, the drive signal based on a desired light intensity for the zone of the room, the total natural light intensity, the non-useful natural light intensity, and the artificial light intensity, and

controlling, via the controller, the driver to provide a second drive signal to the LED.

2. The method 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 method of claim 1 , wherein the task-to-sensor ratio is a ratio of an intensity of a generated artificial light for the zone of the room to a sensed light intensity for the zone of the room; the sensed light intensity having been sensed with no natural light present in the zone of the room.

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

6. The method 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 method 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 of the room to determine a second difference.

8. A lighting system comprising:

a driver configured to provide a drive signal;

an LED coupled to the driver and configured to receive the drive signal and a 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

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 the task-to-sensor ratio,

determine the 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.

9. The system of claim 8 , wherein determining the artificial light intensity includes multiplying a light intensity value for the 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 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.

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.

Assignments (6)