METHODS, SYSTEMS, AND APPARATUS FOR INTELLIGENT LIGHTING

• US 20140292208A1
• Filed: 05/01/2014
• Published: 10/02/2014
• Est. Priority Date: 11/03/2011
• Status: Active Grant

• Current Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Original Assignee: Digital Lumens, Inc. (Ams-Osram AG)
• Inventors: Chemel, Brian, Johnston, Scott D., Kondo, Steve T., Massicotte, Matthew W., Morgan, Frederick M., Piepgras, Colin N., Elledge, Christopher L., Egan, John F., Kuhn, Jesse F., Sick, Henry B.
• Granted Patent: US 9,510,426 B2
• Time in Patent Office: Days
• US Class Current: 315/154
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21W 2131/40 Lighting for industrial, commercial, recreational or military use
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• 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: H05B 47/16 by timing means
• CPC Class Codes: H05B 47/17 Operational modes, e.g. switching from manual to automatic mode or prohibiting specific operations
• CPC Class Codes: H05B 47/175 by remote control
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

An ambient light sensor measures an ambient light level at one point in an illuminated environment, such as a warehouse, office, shop, cold-storage facility, or industrial facility, and provides an indication of the measured ambient light level to a processor. The processor maps the measured ambient light level to an estimated ambient light level at a different point in the illuminated environment from the measured ambient light level (e.g., a “task height” about three feet from a warehouse floor). The processor may determine the difference between the estimated ambient light level and a desired light level at the task height, and may change the artificial illumination provided by a light fixture to make the actual ambient light level at task height match the desired light level at the task height.

Claims

1. A lighting fixture to illuminate an environment, the lighting fixture comprising:

A) a memory to store a first transfer function mapping first ambient light levels at a first position within the environment to corresponding second ambient light levels at a second position within the environment;

B) an ambient light sensor to measure an actual ambient light level at the first position within the environment;

C) a processor, communicatively coupled to the memory and the ambient light sensor, to determine;

C1) an expected ambient light level at the second position, based on the actual ambient light level measured at the first position and the first transfer function stored in the memory; and

C2) a change in a light output of the lighting fixture to provide a desired ambient light level at the second position, based at least in part on the expected ambient light level at the second position; and

D) at least one light source, communicatively coupled to the processor, to generate the change in the light output of the lighting fixture so as to provide the desired ambient light level at the second position.

2. The lighting fixture of claim 1, wherein the environment comprises at least one of:

a warehouse,

a cold-storage facility,

an office space,

a retail space,

an educational facility,

an entertainment venue,

a sports venue,

a transportation facility, and

a correctional facility.

3. The lighting fixture of claim 1, wherein the first position is at the lighting fixture and the second position is at a task height within the environment.

4. The lighting fixture of claim 1, wherein the memory is configured to store a plurality of transfer functions, including the first transfer function, mapping ambient light levels at the first position within the environment to corresponding ambient light levels at the second position within the environment, wherein each transfer function of the plurality of transfer functions corresponds to a different state of the environment, and wherein the lighting fixture further comprises at least one of:

E) a communications interface to accept a user input selecting the first transfer function from among the plurality of transfer functions; and

F) a state parameter sensor to provide a state parameter measurement used by the processor to select the first transfer function from among the plurality of transfer functions.

5. The lighting fixture of claim 4, further comprising:

G) a real-time clock, communicatively coupled to the processor, to provide a timing signal,

wherein the processor is configured to select the first transfer function from among the plurality of transfer functions based at least in part on the timing signal.

6. The lighting fixture of claim 1, wherein the processor is configured to determine at least one of:

a portion of the actual ambient light level provided by the lighting fixture; and

a portion of the actual ambient light level provided by one or more light sources other than the lighting fixture.

7. The lighting fixture of claim 1, wherein the ambient light sensor is configured to sense a wavelength of at least one spectral component of the actual ambient light level, and

wherein the processor is further configured to determining a portion of the actual ambient light level based on the wavelength sensed by the ambient light sensor.

8. The lighting fixture of claim 1, wherein the processor is configured to control the at least one light source to generate the change in the light output of the lighting fixture so as to provide the desired ambient light level at the second position by adjusting at least one of:

an intensity of the light output;

a beam pattern of the light output;

a direction of the light output;

a color of the light output; and

a color temperature of the light output.

9. The lighting fixture of claim 1, further comprising:

H) an occupancy sensor, communicatively coupled to the processor, to sense a presence of at least one occupant within the environment and to provide an occupancy signal indicative of the at least one occupant,

wherein the processor is configured to select the desired ambient light level at the second position within the environment based at least in part on the occupancy signal.

10. The lighting fixture of claim 9, wherein the occupancy sensor is configured to sense at least one of:

a number of occupants within the environment,

a location of the at least one occupant within the environment, and

a motion of the at least one occupant within the environment.

11. The lighting fixture of claim 1, wherein the ambient light sensor is configured to measure a changed actual ambient light level at the first position after the change in the light output of the lighting fixture generated by the at least one light source, and

wherein the processor is configured to:

C3) determine a changed expected ambient light level at the second position based on the first transfer function stored in the memory and the changed actual ambient light level;

C4) determine a difference between the changed expected ambient light level and the desired ambient light level; and

C5) adjust the transfer function stored in the memory based on the difference between the changed expected ambient light level and the desired ambient light level.

12. A method of illuminating an environment with a lighting fixture, the method comprising:

A) storing, in a memory, a first transfer function mapping ambient light levels at a first position within the environment to corresponding ambient light levels at a second position within the environment;

B) measuring, with an ambient light sensor, an actual ambient light level at the first position within the environment;

C) determining an expected ambient light level at the second position, based at least in part on the first transfer function stored in A) and the actual ambient light level at the first position measured in B);

D) determining a change in a light output of the lighting fixture to provide a desired ambient light level, based at least in part on the expected ambient light level at the second position determined in C); and

E) causing the change in the light output of the lighting fixture determined in D) so as to provide the desired ambient light level at the second position.

13. The method of claim 12, wherein the environment comprises at least one of:

a warehouse,

a cold-storage facility,

an office space,

a retail space,

an educational facility,

an entertainment venue,

a sports venue,

a transportation facility, and

a correctional facility.

14. The method of claim 12, wherein A) comprises storing a plurality of transfer functions, including the first transfer function, mapping ambient light levels at the first position within the environment to corresponding ambient light levels at the second position within the environment, wherein each transfer function of the plurality of transfer functions corresponds to a different state of the environment, and wherein C) further comprises:

C1) selecting the first transfer function from among the plurality of transfer functions according to at least one of a user input and a measurement of a state of the environment.

15. The method of claim 14 wherein C1) comprises selecting the first transfer function from among the plurality of transfer functions based on at least in part on at least one of:

a time of day,

a day of the week, and

a day of the year.

16. The method of claim 12, wherein the first position is at the lighting fixture and the second position is at a task height within the environment.

17. The method of claim 12, wherein C) comprises:

C1) determining a portion of the actual ambient light level provided by the lighting fixture; and

C2) determining a portion of the actual ambient light level provided by one or more light sources other than the lighting fixture.

18. The method of claim 17, wherein B) comprises sensing a wavelength of at least one spectral component of the actual ambient light level, and

wherein at least one of C1) and C2) comprises determining the portion of the actual ambient light level based on the wavelength sensed in B).

19. The method of claim 12, wherein E) comprises changing at least one of:

an intensity of the light output;

a beam pattern of the light output;

a direction of the light output;

a color of the light output; and

a color temperature of the light output.

20. The method of claim 12, further comprising:

F) sensing, with an occupancy sensor, a presence of at least one occupant within the environment; and

G) selecting the desired ambient light level at the second position within the environment based at least in part on the presence of the at least one occupant sensed in F).

21. The method of claim 20, wherein F) comprises sensing at least one of:

a number of occupants within the environment,

a location of the at least one occupant within the environment, and

a motion of the at least one occupant within the environment.

22. The method of claim 12, further comprising:

H) measuring a changed actual ambient light level at the first position after the change in the light output of the lighting fixture caused in D);

I) determining a changed expected ambient light level at the second position based on the first transfer function stored in A) and the changed actual ambient light level at the first position measured in H);

J) determining a difference between the changed expected ambient light level determined in I) and the desired ambient light level at the second position; and

K) adjusting the transfer function stored in A) based on the difference determined in I).

23. A lighting fixture to illuminate an environment, the lighting fixture comprising:

A) a memory to store at least one transfer function mapping ambient light levels at a first position within the environment to corresponding ambient light levels at a second position within the environment;

B) an ambient light sensor to perform a first measurement of an actual ambient light level at the first position within the environment and provide a first ambient light signal indicative of the first measurement;

C) an occupancy sensor to sense a presence of at least one occupant at the second position within the environment and to provide an occupancy signal indicative of the presence of the at least one occupant;

D) a processor, communicatively coupled to the memory, the ambient light sensor, and the occupancy sensor, to;

D1) determine a first expected ambient light level at the second position, based on the first ambient light signal and the at least one transfer function stored in the memory; and

D2) select a desired ambient light level at the second position within the environment, based at least in part on the occupancy signal; and

D3) determine a change in a light output of the lighting fixture to provide the desired ambient light level at the second position, based at least in part on the first expected ambient light level and the desired ambient light level; and

E) at least one light source to generate the change in the light output of the lighting fixture so as to provide the desired ambient light level at the second position,

wherein the ambient light sensor is configured to perform a second measurement the actual ambient light level at the first position after the change in the light output of the lighting fixture generated by the at least one light source and to produce a second ambient light signal indicative of the second measurement, and

wherein the processor is further configured to;

D4) determine a second expected ambient light level at the second position based on the at least one transfer function stored in the memory and the second ambient light signal;

D5) determine a difference between the second expected ambient light level and the desired ambient light level; and

D6) adjust the at least one transfer function stored in the memory based on the difference between the second expected ambient light level and the desired ambient light level.

24. A method of illuminating an environment with a lighting fixture, the method comprising:

A) storing, in a memory, at least one transfer function mapping ambient light levels at a first position within the environment to corresponding ambient light levels at a second position within the environment;

B) measuring, with an ambient light sensor, an actual ambient light level at the first position within the environment;

C) determining a first expected ambient light level at the second position based at least in part on the at least one transfer function stored in A) and the ambient light level at the first position measured in B);

D) sensing, with an occupancy sensor, a presence of at least one occupant at the second position within the environment;

E) selecting a desired ambient light level at the second position within the environment based at least in part on the presence of the at least one occupant sensed in D);

F) determining a change in a light output of the lighting fixture to provide the desired ambient light level at the second position based at least in part on the first expected ambient light level at the second position determined in C) and the desired ambient light level at the second position selected in E);

G) causing the change in the light output of the lighting fixture determined in F) so as to provide the desired ambient light level at the second position;

H) measuring the actual ambient light level at the first position after a change in the light output of lighting fixture illuminating the environment;

I) determining a second expected ambient light level at the second position based on the at least one transfer function stored in A) and the actual ambient light level at the first position measured in H);

J) determining a difference between the second expected ambient light level at the second position determined in I) and the desired ambient light level at the second position selected in E); and

K) adjusting the at least one transfer function stored in A) based on the difference determined in I).

25. A sensing module comprising:

A) an ambient light sensor to generate an actual output representative of a change in an actual ambient light level of the environment caused by a change in a light output of at least one light source illuminating the environment;

B) a memory to store at least one transfer function mapping ambient light levels of an environment to corresponding outputs of the ambient light sensor;

C) a processor, communicatively coupled to the ambient light sensor and the memory, to;

C1) determine an expected output of the ambient light sensor based on the at least one transfer function stored in the memory and the change in the ambient light level;

C2) determining a difference between the actual output and the expected output; and

C3) update the at least one transfer function stored in the memory based on the difference between the actual output and the expected output.

26. The sensing module of 25, further comprising:

D) a communications interface, communicatively coupled to the processor, to transmit a signal that causes the at least one light source to generate the change in the light output.

27. The sensing module of 25, wherein the processor is configured to log, in the memory, the output, the expect output, and the change in the light output of the at least one light source illuminating the environment.

28. A ballast interface for a light-emitting diode (LED) lighting fixture, the ballast interface comprising:

a power input to receive alternating current (AC) power;

an LED driver circuit, operatively coupled to the power input, to transform the AC power to power suitable for driving at least one LED in the LED lighting fixture;

a power meter, operatively coupled to the power input, to sense a waveform of the AC power; and

a power management unit, communicatively coupled to the power meter, to adjust the LED driver circuit in response to the waveform of the AC power.

29. The ballast interface of claim 28, wherein the power meter is configured to measure at least one of a phase angle, a power factor, and a noise level of the AC power.

30. The ballast interface of claim 28, wherein the power management unit is configured to determine a presence of at least one of a brownout and a lightning strike based on the waveform of the AC power.

31. The ballast interface of claim 28, wherein the power management unit is configured to limit a current drawn by the LED driver circuit to power the at least one LED in response to the waveform of the AC power.

32. The ballast interface of claim 28, further comprising:

a memory, communicatively coupled to at least one of the power meter and the power management unit, to store a representation of the waveform of the AC power.

33. A method of powering a light-emitting diode (LED) lighting fixture, the method comprising:

A) receiving alternating current (AC) power;

B) transforming the AC power received in A) to power suitable for driving at least one LED in the LED lighting fixture;

C) sensing a waveform of the AC power received in A);

D) identifying at least one fault condition based at least in part on the waveform sensed in C);

E) generating a digital signal based at least in part on the at least one fault identified in D); and

F) adjusting the LED driver circuit in response to the digital signal generated in E).

34. The method of claim 33, wherein C) comprises measuring at least one of a phase angle, a power factor, and a noise level of the AC power.

35. The method of claim 33, wherein D) comprises determining a presence of at least one of a brownout and a lightning strike based on the waveform sensed in C).

36. The method of claim 33, wherein F) comprises limiting a current drawn by the LED driver circuit to drive the at least one LED.

37. The method of claim 33, further comprising:

G) storing, in a memory, a representation of at least one of the waveform sensed in C) and the at least one fault identified in D).