Apparatus and method of energy efficient illumination

• US 8,810,138 B2
• Filed: 07/16/2013
• Issued: 08/19/2014
• Est. Priority Date: 05/20/2009
• Status: Active Grant

• Current Assignee: Express Imaging Systems, LLC
• Original Assignee: Express Imaging Systems, LLC
• Inventors: Reed, William G.
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): HAMMOND, DEDEI KHALIEAH
• Application Number:
  US13/943,537
• Publication Number:
  US 20130307418A1
• Time in Patent Office: 399 Days
• Field of Search: None
• US Class Current: 315/152
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/16 by timing means
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

An illumination system correlates solar time to a clock and controls lighting or illumination based on time. The illumination system may turn ON light source(s) at a first level at a turn ON time, correlated to be around or at dusk, and turn OFF light source(s) at a turn OFF time, correlated to be around or at dawn. The illumination system may reduce a level of light output, and hence power consumption, at a time after turning ON a light source, and increases the level of light output at a time prior to turning OFF the light source. Turn ON, turn OFF, decrease and increase times may be determined based on recent levels of light or illumination in the environment, for example via average or median levels over a number of previous daily cycles. Filtering may eliminate aberrant events.

Claims

1. A method of operating an illumination system, the method comprising:

processing by at least one control subsystem information indicative of a number of levels of illumination in an environment sensed by at least one sensor at respective ones of a plurality of times during each of a plurality of daily cycles;

the processing by the at least one control subsystem including;

determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor;

storing the information indicative of the sensed levels of illumination in at least one nonvolatile storage medium;

determining at least a first illumination adjustment time with reference to a clock of the control subsystem at which to adjust a level of illumination produced by at least one illumination source during a current one of the plurality of daily cycles based at least in part on the determined time of the first event during the first one of the daily cycles and filtering out information corresponding to a short term event from the information based on at least one threshold value that specifies a minimum duration; and

adjusting the level of illumination produced by the least one illumination source responsive to the occurrence of the determined at least one illumination adjustment time as indicated by the clock of the control subsystem.

2. The method of claim 1 wherein determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of dusk based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

3. The method of claim 1 wherein determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of dawn based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

4. The method of claim 1 wherein determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of solar midnight based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

5. The method of claim 1 wherein determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of solar midday based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

6. The method of claim 1, further comprising:

determining a time of a second event during the first one of the daily cycles based at least in part on each of the plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor.

7. The method of claim 6 wherein determining a time of a second event during the first one of the daily cycles based at least in part on each of the plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of dusk based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

8. The method of claim 6 wherein determining a time of a second event during the first one of the daily cycles based at least in part on each of the plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of dawn based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

9. The method of claim 6 wherein determining a time of a second event during the first one of the daily cycles based at least in part on each of the plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of solar midnight based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

10. The method of claim 6 wherein determining a time of a second event during the first one of the daily cycles based at least in part on each of the plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining a time of solar midday based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

11. The method of claim 1 wherein determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining at least one of a time of dusk or a time of dawn based on a percentage of the plurality of illumination levels associated with the first event in the first one of the daily cycles.

12. The method of claim 11 wherein determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining at least one of a time of dusk or a time of dawn based on a percentage of the plurality of illumination levels associated with the first event in the first and at least a second one of the daily cycles.

13. The method of claim 11 wherein determining a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor includes determining at least one of a minimum illumination level, a maximum illumination level, a minimum rate of change in illumination level, a maximum rate of change of illumination level, a change in direction from increasing illumination level to decreasing illumination level or a change in direction from decreasing illumination level to increasing illumination level based on three or more levels of illumination sensed by the at least one sensor during the first one of the daily cycles.

14. The method of claim 11 wherein determining at least one illumination adjustment time with reference to the clock of the control subsystem further includes limiting a change in at least one of a time of dusk or time of dawn in a current one of the daily cycles from a determined time of dusk or time of dawn from at least one previous one of the daily cycles based at least in part on a defined permitted value.

15. The method of claim 1 wherein adjusting a level of illumination includes at least one of:

causing at least one illumination source to be turned ON at a first illumination level during a current one of the daily cycles;

or

causing at least one illumination source to be turned OFF during the current one of the daily cycles.

16. The method of claim 1 wherein adjusting a level of illumination includes at least one of:

causing a level of illumination produced by the at least one illumination source to be reduced from the first level to a non-zero level between the at least one illumination source being turned ON and OFF during the current one of the daily cycles;

or

causing the level of illumination produced by the at least one illumination source to be increased between the causing the level of illumination produced by the at least one illumination source to be reduced and the at least one illumination source being turned OFF during the current one of the daily cycles.

17. An illumination system, the illumination system comprising:

a control subsystem that includes at least one control circuit, the control subsystem communicatively coupled to receive information indicative of a number of levels of illumination in an environment sensed by at least one sensor at respective ones of a plurality of times during each of a plurality of daily cycles, and that;

determines a time of a first event during a first one of the daily cycles based at least in part on each of a plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor;

stores the information indicative of the sensed levels of illumination in at least one nonvolatile storage medium;

determines at least one illumination adjustment time with reference to the clock of the control subsystem at which to adjust a level of illumination produced by at least one illumination source during a current one of the plurality of daily cycles based at least in part on the determined time of the first event during the first one of the daily cycles and filters out information corresponding to a short term event from the information based on at least one threshold value that specifies a minimum duration; and

adjusts the level of illumination produced by the least one illumination source responsive to the occurrence of the determined at least one illumination adjustment time as indicated by the clock of the control subsystem.

18. The illumination system of claim 17 wherein the control circuit determines a time of dusk based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

19. The illumination system of claim 17 wherein the control circuit determines a time of dawn based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

20. The illumination system of claim 17 wherein the control circuit determines a time of solar midnight based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

21. The illumination system of claim 17 wherein the control circuit determines a time of solar midday based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

22. The illumination system of claim 17 wherein the control circuit further determines a time of a second event during the first one of the daily cycles based at least in part on each of the plurality of levels of illumination sensed in the environment during the first one of the daily cycles by the at least one sensor.

23. The illumination system of claim 22 wherein the control circuit determines a time of dusk based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

24. The illumination system of claim 22 wherein the control circuit determines a time of dawn based at least in part on three or more levels of illumination sensed during the first one of the daily cycles.

25. The illumination system of claim 17 wherein the control circuit determines at least one of a time of dusk or a time of dawn based on a percentage of the plurality of illumination levels associated with the first event in the first one of the daily cycles.

26. The illumination system of claim 17 wherein the control circuit determines at least one of a time of dusk or a time of dawn based on a percentage of the plurality of illumination levels associated with the first event in the first and at least a second one of the daily cycles.

27. The illumination system of claim 17 wherein the control circuit determines at least one of a minimum illumination level, a maximum illumination level, a minimum rate of change in illumination level, a maximum rate of change of illumination level, a change in direction from increasing illumination level to decreasing illumination level or a change in direction from decreasing illumination level to increasing illumination level based on three or more levels of illumination sensed by the at least one sensor during the first one of the daily cycles.

28. The illumination system of claim 17 wherein the control circuit limits a change in at least one of a time of dusk or time of dawn in a current one of the daily cycles from a determined time of dusk or time of dawn from at least one previous one of the daily cycles based at least in part on a defined permitted value.

29. A method of operating an illumination system, the method comprising:

processing, by at least one control subsystem, at least three samples, each of the at least three samples including information indicative of a level of illumination in an environment sensed by at least one sensor at respective ones of at least three times during each of a plurality of daily cycles;

the processing by the at least one control subsystem including;

determining a time of a first event during a first one of the plurality of daily cycles based at least in part on each of the at least three samples including information indicative of the level of illumination sensed by the at least one sensor during the first one of the plurality of daily cycles;

determining at least a first illumination adjustment time at which to adjust a luminous output provided by at least one illumination source during a current one of the plurality of daily cycles, the first illumination adjustment time determined with reference to a clock of the at least one control subsystem and based at least in part on the determined time of the first event during the first one of the plurality of daily cycles; and

adjusting the luminous output provided by the least one illumination source responsive to an occurrence of the determined at least one illumination adjustment time as indicated by the clock of the at least one control subsystem.