Method and system for luminance characterization

• US 8,264,156 B2
• Filed: 11/15/2010
• Issued: 09/11/2012
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: LED Roadway Lighting Ltd.
• Original Assignee: LED Roadway Lighting Ltd.
• Inventors: Cleland, Donald A., Kubek, Laurence E., Wong, Carol A., Kurz, Gerald E.
• Primary Examiner(s): Vu, David Hung
• Application Number:
  US12/946,768
• Publication Number:
  US 20110057570A1
• Time in Patent Office: 666 Days
• Field of Search: 700/295, 700/296, 700/286, 315/240, 315/241.R, 315/320, 315/149, 315/159, 315/156, 315/157, 315/158
• US Class Current: 315/149
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G01J 2001/4247 for testing lamps or other light sources
• CPC Class Codes: H05B 41/2882 the control resulting from an action on the static converter
• CPC Class Codes: H05B 41/2885 Static converters especially adapted therefor; Control thereof H05B41/2882 takes precedence
• CPC Class Codes: H05B 41/30 in which the lamp is fed by pulses, e.g. flash lamp
• CPC Class Codes: H05B 41/40 discontinuously
• CPC Class Codes: H05B 47/195 the transmission using visible or infrared light
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A system for luminance characterization of a luminaire includes a ballast coil and a multi-tap capacitor connected in series with the ballast coil. The multi-tap capacitor has a plurality of tap capacitors integrated into a capacitor housing. A plurality of switches are each coupled to one of the plurality of tap capacitors for selectively coupling the tap capacitors together to produce a multi-tap capacitance corresponding to a configuration of the plurality of switches. A lamp is connected in series with the multi-tap capacitor and the ballast coil. A photometer is located to measure light intensity of the lamp and to produce a lumen output measurement. A memory is used to store a database having a plurality of lumen output measurements, each corresponding to a multi-tap capacitance corresponding to all configurations of the plurality of switches.

Claims

1. A method comprising:

detecting a triggering event;

identifying an operating parameter of a streetlight;

identifying a different operating parameter associated with the triggering event;

controlling one or more of a plurality of switches selectively to generate a control signal corresponding to the different operating parameter, the control signal configured to control the streetlight while the streetlight is enabled;

measuring a characteristic of the streetlight; and

reconfiguring the plurality of switches to compensate for a deviation of the measured characteristic from an expected characteristic associated with the different operating parameter if the deviation exceeds a predetermined threshold.

2. The method of claim 1, further comprising:

adjusting a first brightness level of the streetlight to a second, different brightness level in response to the triggering event while the streetlight is enabled.

3. The method of claim 1, further comprising:

referencing a list of triggering events containing the detected triggering event, each triggering event in the list associated with an individual operating parameter;

identifying the different operating parameter as corresponding to the detected triggering event; and

adjusting the operating parameter of the streetlight to match the different operating parameter.

4. The method of claim 3, further comprising controlling a plurality of capacitive components associated with the plurality of switches to generate the control signal for controlling the streetlight.

5. The method of claim 1, wherein measuring the characteristic of the streetlight includes measuring one of a luminance or power consumption of the streetlight.

20. The method of claim 1, wherein the step of measuring comprises measuring a lumen level of the streetlight by a lumen level sensor, and further comprising:

sensing an operation condition of the lumen level sensor; and

compensating for reading from the lumen level sensor based on the sensed operation condition.

6. A device comprising:

a sensor coupled to a streetlight and configured to detect a triggering event;

a second sensor configured to measure an actual output of the streetlight; and

a controller including a plurality of switches and configured to;

identify a different operating parameter associated with the triggering event; and

selectively control one or more of the plurality of switches to generate a control signal corresponding to the different operating parameter, the control signal configured to control the streetlight while the streetlight is enabled; and

reconfigure the plurality of switches to compensate for a deviation of the measured actual output from an expected actual output associated with the different operating parameter if the deviation exceeds a predetermined threshold.

7. The device of claim 6, further comprising a multi-tap capacitor configured to adjust, in response to the triggering event, a first brightness level of the streetlight to a second, different brightness level while the streetlight is enabled.

8. The device of claim 6, wherein the controller is configured to:

reference a list of triggering events containing the detected triggering event, each triggering event in the list associated with an individual operating parameter;

identify the different operating parameter as corresponding to the detected triggering event; and

adjust the operating parameter of the streetlight to match the different operating parameter.

9. The device of claim 8, wherein the controller is configured to selectively control a plurality of capacitors associated with the plurality of switches to generate the control signal for controlling the streetlight.

10. The device of claim 8, wherein the controller is configured to selectively control one or more of the plurality of switches to adjust the operating parameter of the streetlight from a first output level to a second, different output level.

11. The device of claim 6, wherein the controller is configured to adjust one or more capacitance values associated with the plurality of switches to compensate for the difference.

12. The device of claim 6, wherein the controller is configured to store the operating parameter, the different operating parameter, and switch settings of the plurality of switches associated with the operating parameter and the different operating parameter in a log from which the controller identifies the different operating parameter associated with the triggering event.

13. The device of claim 6, wherein the plurality of switches include a plurality of capacitors connected in parallel.

14. The device of claim 6, wherein the plurality of switches include a predetermined number of capacitors, the predetermined number dependent on a total number of lumen adjustment levels, each lumen adjustment level configured to control the streetlight to operate at a different lumen level.

15. The device of claim 6, further comprising an activity sensor configured to detect an activity level associated with one or more activities occurring in a vicinity of the streetlight,

wherein the controller is configured to adjust the operating parameter of the streetlight based on the detected activity.

21. The device of claim 6, further comprising:

a third sensor for sensing an operation condition of the second sensor, and

wherein the controller is configured to;

compensate for reading from the second sensor based on the operation condition sensed by the third sensor.

16. A system comprising:

a streetlight; and

a controller configured to;

identify a schedule associated with controlling the streetlight, the schedule including a plurality of scheduled events each corresponding to a different scheduled brightness level;

control the streetlight to operate at a first brightness level;

control the streetlight to operate at a first scheduled brightness level different from the first brightness level upon detecting a first scheduled event associated with the first scheduled brightness level;

monitor a lighting parameter associated with the first scheduled brightness level;

control the streetlight to operate at a second brightness level different from the first scheduled brightness level until the lighting parameter reaches a predetermined level;

receive one or more feedback parameters relating to the lumen output of the streetlight; and

refine the brightness level of the streetlight based on a deviation between the one or more feedback parameters and one or more premeasured characteristics of the streetlight if the deviation exceeds a predetermined threshold.

17. The system of claim 16, wherein the controller is configured to reduce a brightness level of the streetlight until the first scheduled event is detected.

18. The system of claim 17, wherein the controller is configured to control one or more capacitance values associated with a plurality of switches to adjust the brightness level of the streetlight.

19. The system of claim 16, wherein:

the lighting parameter includes a lumen output of the streetlight; and

the controller is configured to control the streetlight until the lumen output of the streetlight reaches a desired power level.

22. The system of claim 16, comprising:

a first sensor for measuring the one or more feedback parameters; and

a second sensor for sensing an operation condition of the first sensor, and

the controller being configured to compensate for reading from the first sensor based on the operation condition sensed by the second sensor.