Radio-frequency lighting control system with occupancy sensing

• US 9,148,937 B2
• Filed: 09/23/2011
• Issued: 09/29/2015
• Est. Priority Date: 09/03/2008
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Electronics Company Incorporated (Lutron Electronics)
• Inventors: Steiner, James P., Schmalz, Andrew Peter, Offenbacher, Andrew Ryan, Schrems, Adam J., Valenta, Brian Raymond
• Primary Examiner(s): A, Minh D
• Assistant Examiner(s): YANG, AMY X
• Application Number:
  US13/242,383
• Publication Number:
  US 20120068611A1
• Time in Patent Office: 1,467 Days
• Field of Search: 315/149, 315/159, 315/291, 315/307, 315/308
• US Class Current: 1/1
• 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 47/19 via wireless transmission
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A load control system controls a lighting load provided in a space and comprises a load control device and one or more occupancy sensors. The load control device controls the load in response to the wireless control signals received from the occupancy sensors. Each occupancy sensor transmits an occupied control signal to the load control device in response to detecting an occupancy condition in the space and a vacant control signal to the load control device in response to detecting a vacancy condition. The load control device adjusts the intensity of the load to a first intensity in response to receiving the occupied control signal from at least one of the occupancy sensors, and adjusts the intensity of the load to a second intensity less than the first intensity (e.g., a non-off intensity) in response to receiving vacant control signals from both of the occupancy sensors.

Claims

1. A load control system for controlling the amount of power delivered from an AC power source to a lighting load provided in a space, the load control system comprising:

a load control device adapted to be coupled in series electrical connection between the AC power source and the lighting load for controlling the amount of power delivered to the lighting load to control the intensity of the lighting load, the load control device operable to receive wireless control signals and to control the intensity of the lighting load in response to the wireless control signals; and

two occupancy sensors, each operable to independently detect an occupancy condition in the space and to transmit an occupied wireless control signal to the load control device in response to detecting the occupancy condition, the occupancy sensors further operable to transmit a vacant wireless control signal to the load control device in response to detecting a vacancy condition in the space;

wherein the load control device adjusts the intensity of the lighting load to a first intensity in response to receiving the occupied wireless control signal from at least one of the occupancy sensors, and adjusts the intensity of the lighting load to a second intensity less than the first intensity in response to receiving vacant control signals from both of the occupancy sensors,

the load control device associating a unique identifier with each occupancy sensor and storing in respective memory locations an occupancy/vacancy status of each occupancy sensor in accordance with its unique identifier, the load control device adjusting the intensity of the lighting load to a second intensity when the occupancy/vacancy statuses of the memory locations for both of the occupancy sensors denote vacancy.

2. The load control system of claim 1, wherein each of the occupancy sensors are characterized by a unique serial number, the unique serial number comprising the unique identifier, the load control device comprising a memory for storage of the serial numbers of the two occupancy sensors, the load control device responsive to wireless control signals including the serial numbers of the two occupancy sensors.

3. The load control system of claim 2, wherein the load control device keeps track of the occupancy sensors from which the load control device received the occupied wireless control signals.

4. The load control system of claim 3, wherein the load control device adjusts the intensity of the lighting load to the second intensity in response to receiving vacant control signals from all of the occupancy sensors from which the load control device received the occupied wireless control signals.

5. The load control system of claim 1, wherein each of the occupancy sensors transmits a third wireless control signal to the load control device in response to detecting a continued occupancy condition in the space, the load control device adjusting the intensity of the lighting load to the second intensity in response to determining that no wireless control signals have been received from one of the occupancy sensors for the length of a predetermined timeout period and receiving a vacant control signal from the other occupancy sensor.

6. The load control system of claim 1, wherein the second intensity is 0%, such that the load control turns the lighting load off in response to receiving vacant control signals from both of the occupancy sensors.

7. The load control system of claim 1, wherein the second intensity is a non-off intensity.

8. A method of controlling the amount of power delivered from an AC power source to a lighting load provided in a space, the method comprising the steps of:

providing two occupancy sensors in the space;

detecting by one of the occupancy sensors an occupancy condition in the space;

transmitting by one of the occupancy sensors an occupied wireless control signal in response to the step of detecting the occupancy condition;

receiving at a load control device the occupied wireless control signal from at least one of the occupancy sensors;

adjusting the intensity of the lighting load to a first intensity using the load control device in response to the step of receiving the occupied wireless control signal from at least one of the occupancy sensors;

detecting by one of the occupancy sensors a vacancy condition in the space;

transmitting by one of the occupancy sensors a vacant wireless control signal in response to the step of detecting a vacancy condition in the space;

receiving at the load control device vacant control signals from both of the occupancy sensors;

associating a unique identifier with each occupancy sensor and storing in respective memory locations an occupancy/vacancy status of each occupancy sensor in accordance with its unique identifier at the load control device, and

adjusting the intensity of the lighting load to a second intensity less than the first intensity using the load control device when the occupancy/vacancy statuses of the memory locations for both of the occupancy sensors denote vacancy.

9. The method of claim 8, wherein the second intensity is 0%, such that the step of adjusting the intensity of the lighting load to a second intensity comprises turning the lighting load off in response to the step of receiving vacant control signals from both of the occupancy sensors.

10. The method of claim 8, wherein the second intensity is a non-off intensity.

11. A load control system for controlling the amount of power delivered from an AC power source to a lighting load provided in a space, the load control system comprising:

a load control device adapted to be coupled in series electrical connection between the AC power source and the lighting load for controlling the amount of power delivered to the lighting load to control the intensity of the lighting load, the load control device operable to receive wireless control signals and to control the intensity of the lighting load in response to the wireless control signals; and

an occupancy sensor operable to detect an occupancy condition in the space and to transmit a first wireless control signal to the load control device in response to detecting the occupancy condition, the load control device operable to adjust the intensity of the lighting load to a first intensity in response to the first wireless control signal, the occupancy sensor further operable to transmit a second wireless control signal to the load control device in response to detecting a continued occupancy condition in the space;

wherein the load control device adjusts the intensity of the lighting load to a second intensity less than the first intensity in response to determining that no wireless control signals have been received from the occupancy sensor for the length of a predetermined timeout period; and

the occupancy sensor further comprising an occupancy timer, on the expiration of the occupancy timer, the occupancy sensor transmitting a vacant wireless control signal to the load control device, the load control device storing an occupancy/vacancy status of the occupancy sensor in a memory location of a memory of the load control device.

12. The load control system of claim 11, wherein the load control device initializes a failsafe timer with the predetermined timeout period and restarts the failsafe timer in response to receiving the second wireless control signals from the occupancy sensor, the load control device operable to adjust the intensity of the lighting load to the second intensity when the failsafe timer expires.

13. The load control system of claim 12, wherein the occupancy sensor is characterized by a unique serial number, the load control device comprising a memory for storage of the serial number of the occupancy sensor, the load control device responsive to wireless control signals including the serial number of the occupancy sensor.

14. The load control system of claim 13, wherein the load control device comprises a first actuator and the occupancy sensor comprises a second actuator, the load control device operable to store the serial number of the occupancy sensor in the memory in response to simultaneous actuations of the first and second actuators.

15. The load control system of claim 14, wherein the load control device adjusts the intensity of the lighting load to the first intensity in response to an actuation of the first actuator, and starts the failsafe timer when the intensity of the lighting load is at the first intensity and the serial number of the occupancy sensor is stored in the memory.

16. The load control system of claim 12, wherein the second wireless control signal comprises an occupied-no-action command, and the first wireless control signal comprises an occupied-take-action command.

17. The load control system of claim 12, wherein the load control device adjusts the intensity of the lighting load to the first intensity and starts the failsafe timer in response to receiving the first wireless control signal.

18. The load control system of claim 11, wherein the second intensity is 0%, such that the load control turns the lighting load off in response to receiving vacant control signals from both of the occupancy sensors.

19. The load control system of claim 11, wherein the second intensity is a non-off intensity.

20. A method of controlling the amount of power delivered from an AC power source to a lighting load provided in a space, the method comprising the steps of:

providing an occupancy sensor in the space;

detecting by the occupancy sensor an occupancy condition in the space;

transmitting by the occupancy sensor a first wireless control signal in response to the step of detecting the occupancy condition;

adjusting the intensity of the lighting load to a first intensity using a load control device in response to the first wireless control signal;

detecting by the occupancy sensor a continued occupancy condition in the space;

transmitting by the occupancy sensor a second wireless control signal in response to the step of detecting a continued occupancy condition in the space;

determining in the load control device that no wireless control signals have been received from the occupancy sensor for the length of a predetermined timeout period;

adjusting the intensity of the lighting load to a second intensity less than the first intensity using the load control device in response to the step of determining that no wireless control signals have been received;

providing the occupancy sensor with an occupancy timer;

transmitting by the occupancy sensor a vacant wireless control signal on the expiration of the occupancy times; and

storing an occupancy/vacancy status of the occupancy sensor in a memory location of a memory of the load control device.

21. The method of claim 20, further comprising the steps of:

initializing a failsafe timer with the predetermined timeout period; and

restarting the failsafe timer in response to receiving the second wireless control signals from the occupancy sensor;

wherein the step of adjusting the intensity of the lighting load to a second intensity further comprises adjusting the intensity of the lighting load to the second intensity when the failsafe timer expires.

22. The method of claim 21, further comprising the step of:

starting the failsafe timer in response to receiving the first wireless control signal.

23. The method of claim 21, further comprising the steps of:

pressing a button;

adjusting the intensity of the lighting load to the first intensity in response to the step of pressing a button; and

starting the failsafe timer in response to the step of pressing a button.

24. The method of claim 20, wherein the second intensity is 0%, such that the step of adjusting the intensity of the lighting load to a second intensity comprises turning the lighting load off in response to the step of receiving vacant control signals from both of the occupancy sensors.

25. The method of claim 20, wherein the second intensity is a non-off intensity.

26. A load control device for controlling the power delivered from an AC power source to a lighting load provided in a space having at least two occupancy sensors, the load control device comprising:

a controllably conductive device adapted to be coupled in series electrical connection between the AC power source and the lighting load for controlling the amount of power delivered to the lighting load to control the intensity of the lighting load;

a wireless receiver for receiving wireless control signals from the occupancy sensors, the wireless control signals comprising an occupied wireless control signal indicating an occupancy condition in the space and a vacant wireless control signal indicating a vacancy condition in the space; and

a controller operatively coupled to the controllably conductive device and the wireless receiver for controlling the amount of power delivered to the lighting load in response to the wireless control signals;

wherein the controller adjusts the intensity of the lighting load to a first intensity in response to receiving the occupied wireless control signal from at least one of the occupancy sensors, and adjusts the intensity of the lighting load to a second intensity less than the first intensity in response to receiving vacant control signals from both of the occupancy sensors,

the controller associating a unique identifier with each occupancy sensor and storing in respective memory locations an occupancy/vacancy status of each occupancy sensor in accordance with its unique identifier, the controller adjusting the intensity of the lighting load to the second intensity load when the occupancy/vacancy statuses of the memory locations for both of the occupancy sensors denote vacancy.

27. The load control device of claim 26, further comprising:

a memory for storage of the unique identifiers, each unique identifier comprising a unique serial number of each of the two occupancy sensors;

wherein each of the wireless control signals from the occupancy sensors includes the unique serial number of the respective occupancy sensor, the controller responsive to wireless control signals including the serial numbers of the two occupancy sensors.

28. The load control device of claim 27, wherein the controller keeps track of the occupancy sensors from which the load control device received the occupied wireless control signals.

29. The load control device of claim 28, wherein the controller adjusts the intensity of the lighting load to the second intensity in response to receiving vacant control signals from all of the occupancy sensors from which the controller received the occupied wireless control signals.

30. The load control device of claim 26, wherein the second intensity is 0%, such that the load control device turns the lighting load off in response to receiving vacant control signals from both of the occupancy sensors.

31. The load control device of claim 26, wherein the second intensity is a non-off intensity.