Motion detection system and associated methods having at least one LED of second set of LEDs to vary its voltage

• US 8,680,457 B2
• Filed: 01/11/2013
• Issued: 03/25/2014
• Est. Priority Date: 05/07/2012
• Status: Active Grant

• Current Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Original Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Inventors: Maxik, Fredric S., Bretschneider, Eric, Medelius, Pedro, Bartine, David E., Soler, Robert R., Flickinger, Gregory
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US13/739,665
• Publication Number:
  US 20130292550A1
• Time in Patent Office: 438 Days
• Field of Search: 250/221, 250/205, 250/214.R, 250/559.4, 340506-541, 340555-557, 362/205, 362/202, 362/231, 362/268
• US Class Current: 250/221
• CPC Class Codes: F21V 23/0471 the sensor detecting the proximity, the presence or the movement of an object or a person
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating
• CPC Class Codes: G01V 8/20 using multiple transmitters or receivers
• CPC Class Codes: H05B 45/30 Driver circuits
• CPC Class Codes: H05B 47/115 by determining the presence or movement of objects or living beings
• CPC Class Codes: H05B 47/14 by determining electrical parameters of the light source
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A lighting system which includes a light source to emit illuminating light and sense reflected light from an environment. The light source may be included in an array to be selectively enabled and disabled by the controller. The array may include a plurality of light sources, each of which may be sensitive to a wavelength respective to each light source, thus providing the array sensitivity to one or more wavelength. Each of the plurality of light sources in the array may be selectively operable between a sensing operation and an emitting operation. The sensing operation may be defined by the light source sensing the environmental light, and the emitting operation being defined by the light source emitting the illuminating light. The controller may selectively operate the light source between the passive operation and the active operation.

Claims

1. A lighting system for detecting movement comprising:

a first set of light emitting diodes (LEDs);

a second set of LEDs;

a voltage sensor coupled to an LED of the second set of LEDs defining a coupled LED; and

a controller functionally coupled to each of the first and second sets of LEDs;

wherein the controller is configured to continuously operate the first set of LEDs to emit light within a field of view of the first and second sets of LEDs;

wherein the controller is configured to operate the second set of LEDs in alternating active and passive states;

wherein the controller is configured to operate the second set of LEDs to emit light in the active state

wherein the controller is configured to operate the second set of LEDs to not emit light in the passive state and maintain a baseline voltage;

wherein the voltage sensor is configured to monitor the voltage of the coupled LED during the passive state;

wherein the coupled LED is configured to vary the voltage there across upon incidence of light reflected by a target; and

wherein a change of voltage from the baseline voltage in the coupled LED during the passive state indicates the detection of a target within the field of view of the first and second sets of LEDs.

2. A lighting system according to claim 1 wherein the controller is configured to include a threshold voltage;

and wherein the controller is configured to interpret a change in the voltage across the coupled LED beyond the threshold voltage as an indication of the detection of a target within the field of view of the first and second sets of LEDs.

3. A lighting system according to claim 2 wherein the threshold voltage is about a 1 percent difference from the baseline voltage.

4. A lighting system according to claim 2 where in the controller is configured to include a hysteresis range;

wherein the controller is configured to interpret a change in voltage from the baseline voltage beyond the threshold voltage as an indication of the detection of a target within the field of view of the first and second sets of LEDs; and

wherein the controller is configured to indicate the continued detection of a target within the field of view when the change in voltage drops within the threshold voltage but remains within a hysteresis range.

5. A lighting system according to claim 4 wherein the hysteresis range is from about a 0.5 percent difference from the baseline voltage to about a 1 percent difference the baseline voltage.

6. A lighting system according to claim 1 wherein the active state is associated with a duty cycle of the second set of LEDs;

and wherein the duty cycle for the second set of LEDs is about 98%.

7. A lighting system according to claim 1 wherein the controller is configured to adjust the baseline voltage responsive to gradual changes in the voltage detected across the coupled LED.

8. A lighting system according to claim 1 wherein the controller is programmable to determine the length of time a detected target remained within the field of view of the first and second LEDs.

9. A lighting system according to claim 8 further comprising a computing device positioned in communication with the controller;

wherein the computing device is configured to categorize the length of time the target is detected within the field of view of the first and second sets of LEDs; and

wherein the computing device is configured to display each of the categories.

10. A system according to claim 1 further comprising a network interface device positioned in communication with a network;

wherein the controller is configured to transmit data related to the detection of the target within the field of view of the first and second sets of LEDs to a computerized device across the network.

11. A method of detecting an object within the field of view of a lighting system comprising a first set of lighting element, a second set of lighting elements, a controller functionally coupled to each of the first and second sets of LEDs, and a voltage sensor coupled to at least one LED of the second set of LEDs, wherein the LED that the voltage sensor is coupled to is configured to vary its voltage, when in a non-emitting state, proportionally to light that is incident thereupon, the method comprising the steps of:

operating the first set of LEDs to continuously emit light;

operating the second set of LEDs to alternate between an active state and a passive state; and

determining a voltage across the coupled LED;

wherein the second set of LEDs are emitting during the active state;

wherein the controller operates the second set of LEDs to not emit light in the passive state and maintain a baseline voltage; and

wherein a change of voltage from the baseline voltage in the coupled LED during the passive state indicates the detection of a target within the field of view of the first and second sets of LEDs.

12. A method according to claim 11 further comprising the step of determining whether the change of voltage from the baseline voltage is at or above a threshold voltage;

wherein a change of voltage from the baseline voltage at or above a threshold voltage indicates the detection of a target within the field of view of the first and second sets of LEDs.

13. A method according to claim 12 wherein the controller is configured to include a hysteresis range, the method further comprising the steps of:

detecting a drop in the change of voltage below the threshold voltage;

determining whether the change of voltage is within the hysteresis range;

wherein the determination that the change of voltage is within the hysteresis range indicates the continued detection of the target within the field of view.

14. A method according to claim 11 further comprising the step of adjusting the baseline voltage responsive to a gradual change detected across the coupled LED.

15. A lighting system for detecting movement comprising:

a first set of LEDs;

a second set of LEDs comprising an LED;

a voltage sensor coupled to at least one LED of the second set of LEDs;

a controller functionally coupled to each of the first and second sets of LEDs;

wherein the controller is configured to continuously operate the first set of LEDs to emit light within a field of view of the first and second sets of LEDs;

wherein the controller is configured to operate the second set of LEDs in alternating active and passive states;

wherein the controller is configured to operate the second set of LEDs to emit light in the active state

wherein the controller is configured to operate the second set of LEDs to not emit light in the passive state and maintain a baseline voltage;

wherein the voltage sensor is configured to monitor the voltage of the coupled LED during the passive state;

wherein the coupled LED is configured to vary the voltage there across upon incidence of light reflected by a target;

wherein the controller is configured to include a threshold voltage; and

wherein the controller is configured to interpret a change in the voltage across the coupled LED beyond the threshold voltage as an indication of the detection of a target within the field of view of the first and second sets of LEDs.

16. A lighting system according to claim 15 where in the controller is configured to include a hysteresis range;

wherein the controller is configured to interpret a change in voltage from the baseline voltage beyond the threshold voltage as an indication of the detection of a target within the field of view of the first and second sets of LEDs; and

wherein the controller is configured to indicate the continued detection of a target within the field of view when the change in voltage drops within the threshold voltage but remains within a hysteresis range.

17. A lighting system according to claim 15 wherein the active state is associated with a duty cycle of the second set of LEDs;

and wherein the duty cycle for the second set of LEDs is about 98%.

18. A lighting system according to claim 15 wherein the controller is configured to adjust the baseline voltage responsive to gradual changes in the voltage detected across the coupled LED.

19. A lighting system according to claim 15 wherein the controller is programmable to determine the length of time a detected target remained within the field of view of the first and second LEDs.

20. A lighting system according to claim 19 further comprising a computing device positioned in communication with the controller;

wherein the computing device is configured to categorize the length of time the target is detected within the field of view of the first and second sets of LEDs; and

wherein the computing device is configured to display each of the categories.